Vocabulary > Space

NGC 6302

Butterfly Emerges from Stellar Demise in Planetary Nebula NGC 6302

This celestial object looks like a delicate butterfly. But it is far from serene.

What resemble dainty butterfly wings are actually roiling
cauldrons of gas heated to more than 36,000 degrees Fahrenheit.
The gas is tearing across space at more than 600,000 miles an hour
-- fast enough to travel from Earth to the moon in 24 minutes!

A dying star that was once about five times the mass of the Sun is at the center of this fury.
It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation
that is making the cast-off material glow.
This object is an example of a planetary nebula,
so-named because many of them have a round appearance
resembling that of a planet when viewed through a small telescope.

The Wide Field Camera 3 (WFC3), a new camera aboard NASA’s Hubble Space Telescope,
snapped this image of the planetary nebula, catalogued as NGC 6302,
but more popularly called the Bug Nebula or the Butterfly Nebula.
WFC3 was installed by NASA astronauts in May 2009,
during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.

NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius.
The glowing gas is the star’s outer layers, expelled over about 2,200 years.
The "butterfly" stretches for more than two light-years,
which is about half the distance from the Sun to the nearest star, Alpha Centauri.

The central star itself cannot be seen, because it is hidden within a doughnut-shaped ring of dust,
which appears as a dark band pinching the nebula in the center.
The thick dust belt constricts the star’s outflow,
creating the classic "bipolar" or hourglass shape displayed by some planetary nebulae.

The star’s surface temperature is estimated to be about 400,000 degrees Fahrenheit,
making it one of the hottest known stars in our galaxy.
Spectroscopic observations made with ground-based telescopes
show that the gas is roughly 36,000 degrees Fahrenheit,
which is unusually hot compared to a typical planetary nebulae.

The WFC3 image reveals a complex history of ejections from the star.
The star first evolved into a huge red-giant star, with a diameter of about 1,000 times that of our Sun.
It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed,
perhaps as low as 20,000 miles an hour, creating the doughnut-shaped ring.
Other gas was ejected perpendicular to the ring at higher speeds,
producing the elongated "wings" of the butterfly-shaped structure.
Later, as the central star heated up, a much faster stellar wind,
a stream of charged particles travelling at more than 2 million miles an hour,
plowed through the existing wing-shaped structure, further modifying its shape.

The image also shows numerous finger-like projections pointing back to the star,
which may mark denser blobs in the outflow that have resisted the pressure from the stellar wind.

The nebula's outer edges are largely due to light emitted by nitrogen, which marks the coolest gas visible in the picture.
WFC3 is equipped with a wide variety of filters that isolate light emitted by various chemical elements,
allowing astronomers to infer properties of the nebular gas, such as its temperature, density, and composition.

The white-colored regions are areas where light is emitted by sulfur.
These are regions where fast-moving gas overtakes
and collides with slow-moving gas that left the star at an earlier time,
producing shock waves in the gas (the bright white edges on the sides facing the central star).
The white blob with the crisp edge at upper right is an example of one of those shock waves.

NGC 6302 was imaged on July 27, 2009 with Hubble’s Wide Field Camera 3 in ultraviolet and visible light.
Filters that isolate emissions from oxygen, helium, hydrogen, nitrogen, and sulfur
from the planetary nebula were used to create this composite image.

These Hubble observations of the planetary nebula NGC 6302
are part of the Hubble Servicing Mission 4 Early Release Observations.


Credit: NASA, ESA, and the Hubble SM4 ERO Team

Images from Refurbished Hubble        2009
http://www.nasa.gov/images/content/384540main_ero_ngc6302_label.jpg
http://www.nasa.gov/mission_pages/hubble/multimedia/ero/index.html
http://www.nasa.gov/images/content/384572main_ero_ngc6302_full_full.jpg

NGC 6217
Barred Spiral Galaxy NGC 6217

This image of barred spiral galaxy NGC 6217
is the first image of a celestial object taken with the newly repaired
Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope.
The camera was restored to operation during the STS-125 servicing mission in May to upgrade Hubble.

The barred spiral galaxy NGC 6217 was photographed on June 13 and July 8, 2009,
as part of the initial testing and calibration of Hubble's ACS.

The galaxy lies 6 million light-years away in the north circumpolar constellation Ursa Major.

Credit: NASA, ESA, and the Hubble SM4 ERO Team

Images from Refurbished Hubble        2009
http://www.nasa.gov/images/content/384940main_ero_teaser_ngc6217_full_full.jpg
http://www.nasa.gov/mission_pages/hubble/multimedia/ero/index.html

Andromède, panier percé

vendredi 14 octobre 2005 - 16:05    Libération.fr

Des étoiles lumineuses et vieillissantes et un arc en spirale au centre de la galaxie, c'est Andromède vue avec les yeux infra-rouges de Spitzer,
un télescope spatial de la Nasa dont les images ont été montrées jeudi. La plus étudiée des galaxies laisse apercevoir plusieurs éléments jamais observés.

Sur la vue obtenue par Spitzer, l'anneau d'Andromède semble coupé en deux morceaux –en haut à gauche et en bas à droite.
Ces entailles asymétriques ont pu être provoquées par des interactions avec les galaxies voisines.
«Parfois, des petites galaxies satellites peuvent pénétrer dans des plus grandes»,
explique Karl Gordon (Université d'Arizona, Tucson), responsable de l'observation.
n bas à droite, «une petite galaxie a percé un trou dans le disque d'Andromède, comme un caillou perce la surface d'un étang.»
En outre, on peut voir dans la moitié gauche de la galaxie un anneau d'étoiles en formation.

Située approximativement à 2,5 millions d'années-lumière,
Andromède est la galaxie en spirale la plus proche, et la seule visible à l'œil nu.
À la différence de la Voie Lactée, que nous regardons de l'intérieur, Andromède est étudiée de l'extérieur.
http://www.libe.com/page.php?Article=313053&Template=GALERIE&Objet=47659

© REUTERS/NASA/JPL-Caltech/Univ. of Arizona

The Horsehead Nebula, embedded in the vast and complex Orion Nebula,

is seen in this representative-color image from the Canada-France-Hawaii Telescope in Hawaii.

The dark molecular cloud, roughly 1,500 light years distant, is visible only because its obscuring dust

is silhouetted against another, brighter nebula. The prominent horse head portion of the nebula

is really just part of a larger cloud of dust which can be seen extending toward the bottom of the picture.

Nasa / http://www.nasa.gov/multimedia/imagegallery/image_feature_89.html

Credit and Copyright: Jean-Charles Cuillandre (CFHT), Hawaiian Starlight, CFHT

Ten thousand years ago, before the dawn of recorded human history,

a new light must suddenly have appeared in the night sky and faded after a few weeks.

Today we know this light was an exploding star and record the colorful expanding cloud as the Veil Nebula.

Pictured above is the west end of the Veil Nebula known technically as NGC 6960,

but less formally as the Witch's Broom Nebula.

The rampaging gas gains its colors by impacting and exciting existing nearby gas.

Astronomy Picture of the Day

Credit & Copyright: T. A. Rector (U. Alaska), NOAO, AURA, NSF

life
http://www.guardian.co.uk/science/2010/nov/14/exoplanets-astronomy-robin-mckie

alien life
http://www.guardian.co.uk/science/alien-life
http://www.nytimes.com/2011/03/27/opinion/27jayawardhana.html

aliens
http://www.nytimes.com/2012/01/30/science/space/seti-research-is-revived-life-out-there.html
http://www.guardian.co.uk/science/2011/aug/18/aliens-destroy-humanity-protect-civilisations
http://www.guardian.co.uk/science/2011/jan/10/earth-close-encounter-aliens-extraterrestrials

UFO
http://www.nytimes.com/2010/11/26/us/26ufo.html
http://www.guardian.co.uk/science/story/0,,2071275,00.html
http://www.guardian.co.uk/science/story/0,,1880308,00.html

extraterrestrial        ET
http://www.nytimes.com/2012/01/30/science/space/seti-research-is-revived-life-out-there.html
http://www.guardian.co.uk/science/blog/2009/aug/17/alien-life-exobiology-extraterrerstrial

extraterrestrial life
http://www.guardian.co.uk/science/video/2010/oct/15/richard-dawkins-extraterrestrial-life

harbour water and life

light

at 240 million light years away

give off

time

energy

matter

Time        Vol. LX No. 23

December 8, 1952
http://www.time.com/time/covers/0,16641,1101521208,00.html

space
http://www.guardian.co.uk/space/article/0,,1925757,00.html

The Guardian > Series > A month in space
http://www.guardian.co.uk/science/series/space-monthly

deep space

outer space

spaceport
http://observer.guardian.co.uk/international/story/0,6903,1456156,00.html

commercial spaceflight

Spaceship Co.
http://www.usatoday.com/tech/science/space/2007-04-15-spaceduo_N.htm

spaceship

Virgin Galactic's SpaceShipTwo
http://www.guardian.co.uk/technology/2009/dec/07/spaceshiptwo-virgin-commercial-space-travel
http://www.guardian.co.uk/world/gallery/2009/dec/07/virgin-richard-branson-global-flyer
http://www.guardian.co.uk/science/2009/dec/04/richard-branson-space-travel

unmanned spaceship

supply ship

craft

spacecraft
http://www.usatoday.com/tech/science/space/2008-05-25-mars-lander_N.htm

space plane > US X-37B
http://www.guardian.co.uk/science/2010/dec/01/space-vehicle-earth

space facility
http://www.guardian.co.uk/science/2008/nov/26/esa-space-facility-harwell-earth-observation

spacesuit

space program
http://www.nytimes.com/2010/02/09/opinion/09tue1.html

space policy
http://www.nytimes.com/2010/06/29/science/space/29orbit.html

space travel

space traveler

space exploration
http://www.guardian.co.uk/science/spaceexploration

http://www.guardian.co.uk/space/article/0,,1832818,00.html
http://www.guardian.co.uk/space/interactive/0,,1392183,00.html
http://www.guardian.co.uk/life/feature/story/0,13026,1501759,00.html
http://www.guardian.co.uk/spacedocumentary/0,2759,179472,00.html
http://www.time.com/time/archive/collections/0,21428,c_space_exploration,00.shtml 

space capsule / NASA's Stardust spacecraft
http://stardustnext.jpl.nasa.gov/index.html
http://www.usatoday.com/tech/science/space/2006-01-15-stardust_x.htm
http://www.nytimes.com/2006/01/15/science/space/15cnd-stardust.html

space fan

onlookers

space obsessives

space race

space elevator
http://observer.guardian.co.uk/world/story/0,,1863755,00.html

Spaceship One        The Guardian

22.6.2004
Related > http://www.guardian.co.uk/flash/0,,1243994,00.html

Scaled composites        The Economist        16.6.2004
http://www.economist.com/agenda/displayStory.cfm?story_id=2765230

space tourism / private space flight / space travel business
http://www.usatoday.com/tech/science/space/2006-05-14-spaceports_x.htm
http://www.guardian.co.uk/space/article/0,14493,1244539,00.html
http://www.guardian.co.uk/flash/0,5860,1243994,00.html
http://www.guardian.co.uk/space/article/0,14493,1244169,00.html
http://www.economist.com/agenda/displayStory.cfm?story_id=2765230
http://www.guardian.co.uk/space/article/0,14493,1235926,00.html

SpaceShip One
http://www.guardian.co.uk/flash/0,,1243994,00.html
http://www.guardian.co.uk/space/article/0,,1319616,00.html

Virgin Galactic
one of several private companies trying to kick-start the space tourism industry        2008-2007
http://www.virgingalactic.com/
http://www.reuters.com/article/scienceNews/idUSSP12834820080221
http://www.usatoday.com/tech/science/space/2007-05-07-space-tourist_N.htm

Sacles Composites
http://www.scaled.com/projects/tierone/
http://business.guardian.co.uk/story/0,,2136112,00.html

spacecraft    (sing / plur)

 robot spacecraft
http://www.guardian.co.uk/science/story/0,3605,1581631,00.html

space walk / spacewalk
http://www.usatoday.com/tech/science/space/2007-02-04-spacewalk_x.htm
http://www.usatoday.com/tech/science/space/2006-07-06-discovery-shuttle_x.htm

spacewalker

take a space walk

space probe
http://www.usatoday.com/tech/science/space/2006-01-19-new-horizons-launch_x.htm
http://www.guardian.co.uk/spacedocumentary/story/0,2763,1081437,00.html
http://www.guardian.co.uk/spacedocumentary/story/0,2763,1112915,00.html

space junk
http://www.usatoday.com/tech/science/space/2006-01-19-space-junk_x.htm

space trash
http://www.usatoday.com/tech/science/space/2007-03-15-spacejunk_N.htm

fly

flyby
http://www.usatoday.com/tech/science/space/2006-01-11-stardust-return_x.htm

flight

maiden flight

height

mother ship / mothership
http://www.guardian.co.uk/spacedocumentary/story/0,2763,1110453,00.html

launch

launch

vulture-free launch
http://www.usatoday.com/tech/science/space/2006-06-07-nasa-vulture-plan_x.htm

countdown to launch

count down

during launch

at the Cape Canaveral Air Force Station

postpone / scrub
http://www.usatoday.com/tech/science/space/2006-07-02-shuttle-launch_x.htm

reach

land / touch down
http://www.usatoday.com/tech/science/space/2006-07-17-discovery-landing_x.htm

landing

crash

crashland
http://www.guardian.co.uk/life/science/story/0,12996,1330678,00.html

parachute

touch down on

speed

the probe's high-speed entry into the atmosphere

the craft's parachutes

the planet's surface

journey

250-million-mile journey to Mars

module

solar arrays

time

universe / cosmos
http://www.guardian.co.uk/science/2008/sep/07/particlephysics.darkmatter
http://www.guardian.co.uk/science/2008/apr/26/universe.physics
http://www.nytimes.com/aponline/us/AP-Odd-Universe.html

Stephen Hawking
http://www.guardian.co.uk/science/hawking
http://www.guardian.co.uk/science/2012/jan/08/stephen-hawking-70-cambridge-speech

Stephen Hawking > universe
http://www.guardian.co.uk/science/2010/sep/02/stephen-hawking-big-bang-creator

timeline of the universe
http://www.guardian.co.uk/science/2008/apr/26/universe.physics

expansion of the universee
http://www.nytimes.com/2011/10/05/science/space/05nobel.html

dark matter
http://www.guardian.co.uk/science/2009/dec/17/dark-matter-detected
http://www.nytimes.com/2008/11/25/science/25dark.html
http://www.guardian.co.uk/science/2008/sep/07/particlephysics.darkmatter
http://www.guardian.co.uk/science/2008/apr/24/physics.sciencenews

dark energy
http://topics.nytimes.com/top/news/science/topics/dark_energy_astronomy/index.html
http://www.nytimes.com/2011/10/05/science/space/05nobel.html
http://www.nytimes.com/2011/01/04/science/space/04telescope.html 
http://www.guardian.co.uk/science/blog/audio/2009/oct/05/science-weekly-podcast-astronomy
http://www.guardian.co.uk/spacedocumentary/story/0,2763,1110244,00.html

Big Bang
http://education.guardian.co.uk/higher/research/story/0,,1886516,00.html
http://www.usatoday.com/tech/science/space/2006-03-16-big-bang-expansion_x.htm

dark ages

cosmic microwave background radiation

the original blaze of creation

big crunch

cosmos

cosmology

cosmic

expand

gravity

zero gravity

weightlessness

planet
http://topics.nytimes.com/top/news/science/topics/planets/index.html
http://www.planetary.org/
http://pds.jpl.nasa.gov/planets/

Earth-size planets
Kepler 20e, the closer and hotter planet, is also the smaller
— about 6,900 miles across, or slightly smaller than Venus —
and it resides about 5 million miles from its star.
The more distant planet, Kepler 20f, also broiling at around 800 degrees,
is 10 million miles out from its star. It is 8,200 miles in diameter, about the size of Earth.
The two planets are presumed to be rocky orbs
that formed in the outskirts of their planetary system and then migrated inward.
http://www.nytimes.com/2011/12/21/science/space/nasas-kepler-spacecraft-discovers-2-earth-size-planets.html
http://www.guardian.co.uk/science/2011/dec/20/planets-earth-like-exoplanet-solar-system

planet > LkCa 15 b
http://www.guardian.co.uk/science/2011/oct/20/youngest-planet-ever-found-lkca15b

HIP13044b – the first planet ever detected in the Milky Way that was born outside our galaxy        2010
http://www.guardian.co.uk/science/2010/nov/18/wandering-star-planet-galaxy

planet > Hat-P-1

exoplanets – worlds outside our solar system
http://www.guardian.co.uk/science/2010/nov/14/exoplanets-astronomy-robin-mckie

exoplanet > Kepler 22-b o
http://www.guardian.co.uk/science/2011/dec/05/exoplanet-kepler-22-b-nasa-earth

exoplanet > Gliese 581g
http://www.nytimes.com/2010/09/30/science/space/30planet.html

exoplanet > Wasp-12b
http://www.guardian.co.uk/science/2010/may/26/star-planet-yellow-dwarf

parent star
http://www.guardian.co.uk/science/2010/may/26/star-planet-yellow-dwarf

planet-like objects / "ice dwarfs"
http://www.guardian.co.uk/science/story/0,,1873087,00.html

planethood

a new planet-hunting technique called gravitational microlensing
http://www.guardian.co.uk/science/story/0,,1695046,00.html

Earth-like planet / world
http://www.guardian.co.uk/science/2011/dec/18/science-discoveries-review-2011
http://www.nytimes.com/2011/01/31/science/space/31planet.html
http://www.guardian.co.uk/science/2010/oct/28/galaxy-planets-mass-earth-life

Earth-like planet / OGLE-2005-BLG-390Lb
http://www.guardian.co.uk/science/story/0,,1695046,00.html

harbour life

at the outer edges of the planetary system
http://www.usatoday.com/tech/science/space/2006-01-17-new-horizons_x.htm

extrasolar planets
http://www.guardian.co.uk/science/blog/audio/2009/oct/05/science-weekly-podcast-astronomy
http://www.nytimes.com/2008/11/14/science/space/14planet.html

An artist's rendering shows NASA's Stardust spacecraft closing in on Comet Wild 2.

After travelling about 2 billion miles in just under five years,

Stardust is set to come within 186 miles of the comet on Friday, January 2, 2004.

Using a "cometary catcher's mitt" filled with a special material called aerogel,

Stardust will collect particles from Wild 2

and bring them back to Earth in January 2006.

Photo Credit: NASA/JPL

Related
http://www.usatoday.com/tech/science/space/2006-01-11-stardust-return_x.htm
http://stardustnext.jpl.nasa.gov/index.html

comet
http://stardustnext.jpl.nasa.gov/index.html
http://www.nytimes.com/2010/11/23/us/23marsden.html
http://www.usatoday.com/tech/science/space/2006-01-11-stardust-return_x.htm
http://www.guardian.co.uk/spacedocumentary/story/0,2763,1115284,00.html

comet dust
http://stardustnext.jpl.nasa.gov/index.html
http://www.usatoday.com/tech/science/space/2006-02-20-stardust-particles_x.htm

star

stargazing
http://www.guardian.co.uk/commentisfree/2012/jan/19/in-praise-of-stargazing

stardust
http://www.nytimes.com/2010/02/07/science/space/07burbidge.html

shooting star

supergiant star

wandering star
http://www.guardian.co.uk/science/2010/nov/18/wandering-star-planet-galaxy

swirls

eddies

clouds

swirls of interstellar dust

in the void of interstellar space

galaxy
http://www.usatoday.com/tech/science/space/2007-09-24-hidden-galaxies_N.htm

the giant elliptical galaxy Centaurus A, a relatively close neighbour of our galaxy, the Milky Way
http://www.guardian.co.uk/science/2011/jun/16/hubble-photograph-centaurus-a

Hyperactive Galaxies in the Early Universe
http://www.nasa.gov/mission_pages/hubble/news/hyperactive_galaxies.html

cluster of galaxies
http://www.nytimes.com/slideshow/2009/09/09/science/0909HUBBLE_3.html

Milky Way
http://www.nasa.gov/mission_pages/hubble/news/hyperactive_galaxies.html
http://www.guardian.co.uk/science/2010/nov/18/wandering-star-planet-galaxy
http://www.guardian.co.uk/science/2008/may/14/usa
http://www.usatoday.com/tech/science/space/2006-01-09-milkyway-lumpy_x.htm

on the outer edge of the Milky Way

on the fringes of the Milky Way
http://www.guardian.co.uk/science/story/0,,1873087,00.html

at the boundary of Earth and space
http://www.usatoday.com/tech/science/space/2006-10-26-hubble-fate_x.htm

quasar
http://www.usatoday.com/tech/science/space/2007-09-24-hidden-galaxies_N.htm

constellation
http://www.nytimes.com/slideshow/2009/09/09/science/0909HUBBLE_2.html

constellation of Libra

nebula
http://www.nytimes.com/slideshow/2009/09/09/science/0909HUBBLE_index.html
http://www.nasa.gov/multimedia/imagegallery/image_feature_974.html
http://www.nasa.gov/multimedia/imagegallery/image_feature_89.html

Eyewitness

Centaurus constellation, 463m light years from Earth

The Guardian        pp. 20.21

Wednesday February 14 2007
http://digital.guardian.co.uk/guardian/2007/02/14/pdfs/gdn_070214_ber_20_15807114.pdf

Eyewitness

Centaurus constellation,

463m light years from Earth

The Guardian        p. 21        Wednesday February 14 2007
http://digital.guardian.co.uk/guardian/2007/02/14/pdfs/gdn_070214_ber_20_15807114.pdf

rocket
http://www.nytimes.com/2011/09/15/science/space/15nasa.html
http://www.usatoday.com/tech/science/space/2007-10-10-iss-russia-blastoff_N.htm

rocket scientist > Robert Collins Truax        1917-2010
http://www.nytimes.com/2010/09/30/us/30truax.html

expendable booster

velocity

launchpad / launch pad
http://www.usatoday.com/tech/science/space/2006-05-18-shuttle-launch-pad_x.htm

payload

 aeronautics company

launching

blast off / blast-off / blastoff
http://www.guardian.co.uk/space/article/0,,1812638,00.html
http://www.usatoday.com/tech/science/space/2006-01-19-new-horizons-launch_x.htm

blast off from

lift off / liftoff
http://www.usatoday.com/tech/science/space/2007-10-10-iss-russia-blastoff_N.htm

take off / take-off

man spaceflight

satellite

dead satellite
http://www.nytimes.com/2011/09/23/science/space/23satellite.html

The Soviet Union launches Sputnik, the first man-made satellite        Oct. 4, 1957
http://www.nytimes.com/2010/04/14/science/space/14stever.html

Global Positioning System        GPS
http://en.wikipedia.org/wiki/GPS

Supernova acceleration probe        Snap

National Aeronautics and Space Administration        NASA        USA
http://www.nasa.gov/home/index.html
http://www.guardian.co.uk/space/article/0,,2039820,00.html
http://www.usatoday.com/tech/science/space/2006-09-27-nasa-aviation-cuts_x.htm

Nasa scientist

NASA's mission control in Houston / Mission Control Center at Johnson Space Center
http://www.nasa.gov/centers/johnson/home/index.html

'Houston, we have a problem'
http://www.guardian.co.uk/science/2008/oct/25/nasa-space-astronaut-houston-therapy

Apollo 13 > 'Houston, we have a problem'
http://www.phrases.org.uk/meanings/188425.html
http://houstonstrategies.blogspot.com/2005/03/houston-we-have-problem.html
http://history.nasa.gov/SP-350/ch-13-1.html

NASA > libraries of space images
http://solarsystem.nasa.gov/multimedia/nasagalleries.cfm

NASA > Great Images in Nasa        GRIN
http://grin.hq.nasa.gov/index.html

NASA > Images
http://www.nasa.gov/multimedia/imagegallery/index.html

Esa
http://www.esrin.esa.it/export/esaCP/index.html

elliptical orbit

11m radio dish

on-board spectograph

physicist

Albert Einstein
http://www.guardian.co.uk/fromthearchive/story/0,12269,1462418,00.html

theory

quantum mechanics

infrared light

nova
http://www.guardian.co.uk/fromthearchive/story/0,12269,1686371,00.html

supernovae / supernova / exploding star
http://www.guardian.co.uk/science/supernovae
http://www.guardian.co.uk/science/2011/dec/14/supernova-explosion-glimpse-life-created
http://www.guardian.co.uk/science/2011/sep/08/supernova-explosion-visible-from-uk
http://www.guardian.co.uk/science/gallery/2008/may/22/spaceexploration?picture=334311691
http://www.reuters.com/article/newsOne/idUSN2141465920080521
http://www.guardian.co.uk/science/2008/may/14/usa
http://www.usatoday.com/tech/science/space/2007-05-07-supernova_N.htm
http://www.nasa.gov/mission_pages/chandra/news/chandra_bright_supernova.html
http://www.usatoday.com/tech/science/space/2006-02-23-supernova_x.htm

SN2011fe supernova in Pinwheel galaxy
http://www.guardian.co.uk/science/2011/dec/14/supernova-explosion-glimpse-life-created

giant supernova RCW 86
http://www.guardian.co.uk/science/2011/oct/25/massive-supernova-mystery-rcw86-nasa

baby supernova
http://www.reuters.com/article/domesticNews/idUSN1452084320080514

burst of gamma-ray radiation

cosmic explosion

the birth of a supernova

quasar > active black hole
http://www.usatoday.com/tech/science/space/2007-10-10-cosmic-origins_N.htm

black hole > dense gravitational region that sucks in everything around it
http://www.nytimes.com/2011/12/06/science/space/astronomers-find-biggest-black-holes-yet.html
http://www.usatoday.com/tech/science/space/2007-10-10-cosmic-origins_N.htm
http://www.usatoday.com/tech/science/space/2007-09-22-blackholes_N.htm
http://www.usatoday.com/tech/science/space/2007-05-21-black-hole-weight_N.htm

force

mutual gravitational pull

gravity

dark energy

Neptune

Neptune's orbit

The planet Mercury
is the smallest of the inner planets (4,880 km/3,032 mi in diameter),
and the closest to the Sun (58 million km/36 million mi - or 3.2 light minutes).
http://www.boston.com/bigpicture/2009/06/mercury_and_messenger.html

The Guardian        p. 1        9.6.2004

Venus

http://www.guardian.co.uk/science/venus

http://www.guardian.co.uk/science/story/0,,1751894,00.html

transit of Venus across the Sun        2012

http://www.guardian.co.uk/science/2012/mar/25/venus-transit-sun

science fiction

alien
http://www.guardian.co.uk/science/2008/jul/26/spaceexploration
http://observer.guardian.co.uk/uk_news/story/0,6903,1557919,00.html

an alien world
http://www.guardian.co.uk/space/article/0,14493,1391031,00.html

extraterrestrial intelligence
http://www.seti.org/

UFO
http://www.guardian.co.uk/science/2008/jul/26/spaceexploration

Is there anybody out there?
http://www.guardian.co.uk/science/story/0,,1880308,00.html

Star Trek > "Beam me up, Scotty"

Studies of Universe’s Expansion Win Physics Nobel

October 4, 2011
The New York Times
By DENNIS OVERBYE

Three astronomers won the Nobel prize on Tuesday for discovering that the universe is apparently being blown apart by a mysterious force that cosmologists now call dark energy. They are Saul Perlmutter of the Lawrence Berkeley National Laboratory in Berkeley, Calif., Brian P. Schmidt of the Australian National University in Weston Creek, Australia, and Adam G. Riess of the Space Telescope Science Institute and Johns Hopkins University in Baltimore.

They were the leaders of two competing teams of astronomers who were trying to use the exploding stars known as Type 1a supernovae as cosmic lighthouses to measure the expansion of the universe. They were hoping to measure how fast the universe, which has been expanding since its fiery birth in the Big Bang 14 billion years ago, was slowing down, and thus to find out if its ultimate fate was to fall back together in what is called a Big Crunch or not. Instead, they reported in 1998, it was inexplicably speeding up, a conclusion that nobody would have accepted if not for the fact that both groups wound up with the same answer.

At the time, “We were a little scared,” Dr. Schmidt said. Subsequent cosmological measurements have confirmed that roughly 70 percent of the universe by mass or energy consists of this antigravitational dark energy.

The most likely explanation for this bizarre behavior is a fudge factor Albert Einstein introduced into his equations in 1917 to stabilize he universe against collapse and then abandoned as his greatest blunder. “Every test we have made has come out perfectly in line with Einstein’s original cosmological constant in 1917,” Dr. Schmidt said.

Quantum theory predicts that empty space should exert a repulsive force, like dark energy, but one that is 10 to the 120th power times stronger than what the astronomers have measured, leaving some physicists mumbling about multiple universes.

Lawrence M. Krauss, a cosmologist at Arizona State University said, “The discovery that the universe is dominated by the energy of empty space has changed everything in cosmology. Nothing could, literally, not be more exciting, because now we know nothing is almost everything!”

In the years since then the three astronomers have shared a number of awards.

Dr. Perlmutter, who led the Supernova Cosmology Project out of Berkeley, will get half of the prize of 10 million Swedish kronor ($1.4 million). The other half will go to Dr. Schmidt, leader of the rival High-Z Supernova Search Team, and Dr. Riess, who was the lead author of the 1998 paper in The Astronomical Journal, in which the dark energy result was first published. They will get their prizes in Stockholm on Dec. 10.

This article has been revised to reflect the following correction:

Correction: October 4, 2011

An earlier version of this article incorrectly stated the publication in which Adam G. Riess's 1998 paper on dark energy appeared. It was The Astronomical Journal, not Science. The article also stated incorrectly the amount of the prize. It is 10 million Swedish kronor ($1.4 million).

    Studies of Universe’s Expansion Win Physics Nobel, NYT, 4.10.2011,
    http://www.nytimes.com/2011/10/05/science/space/05nobel.html

A Sultry World Is Found Circling a Distant Star

December 17, 2009
The New York Times
By DENNIS OVERBYE

Call it Sauna World.

Astronomers said Wednesday that they had discovered a planet composed mostly of water.

You would not want to live there. In addition to the heat — 400 degrees Fahrenheit on the ocean surface — the planet is probably cloaked in a crushingly dank and dark fog of superheated steam and other gases. But its discovery has encouraged a growing feeling among astronomers that they are on the verge of a breakthrough and getting closer to finding a planet something could live on.

“This probably is not habitable, but it didn’t miss the habitable zone by that much,” said David Charbonneau of the Harvard-Smithsonian Center for Astrophysics, who led the team that discovered the new planet and will reports its findings on Thursday in the journal Nature.

Geoffrey W. Marcy, a planet hunter from the University of California, Berkeley, wrote in an accompanying article in Nature that the new work provided “the most watertight evidence so far for a planet that is something like our own Earth, outside our solar system.”

Only 2.7 times the size of Earth and 6.6 times as massive, the new planet takes 38 hours to circle a dim red star, GJ 1214, in the constellation Ophiuchus — about 40 light-years from here. It is one of the lightest and smallest so-called extrasolar planets yet found, part of a growing class that are less than 10 times the mass of the Earth.

Dr. Charbonneau’s announcement capped a week in which the list of known planets, including these “super-Earths,” grew significantly.

An international team of astronomers using telescopes in Australia and Hawaii reported in one paper that they had found three planets, including a super-Earth, orbiting 61 Virginis, a star in the constellation Virgo that is almost a clone of the Sun. In a separate paper, they reported finding a planet somewhat larger than Jupiter at the star 23 Librae. It was the first time, they said, that a super-Earth had been found belonging to a star like the Sun; the other home stars have been dwarfs.

And in yet another paper, a subset of the same group reported finding a super-Earth and probably two bigger planets circling HD 1461, a star in Cetus.

Paul Butler of the Carnegie Institution of Washington, who was involved in all three papers, said astronomers thought that from one-third to one-half of all Sun-like stars harbor such super-Earths orbiting at scorching distances much closer than Mercury is to the Sun.

In the 15 years since the first extrasolar planet was found, more than 400 have been detected. The field is getting more intense as dedicated planet-hunting instruments like the Kepler satellite from the National Aeronautics and Space Administration, due to report a new batch next month, get into the game.

Alan P. Boss, a planetary theorist at the Carnegie Institution of Washington, said of the planet hunters, “Give them a couple more years and they’re going to knock your socks off.”

Dr. Charbonneau’s planet, only 1.3 million miles from its home star, is distinguished by its relative coolness. It bakes rather than roasts, a consequence of the dimness of GJ 1214, which puts out one three-hundredth the Sun’s energy. He and his colleagues had set out to search for planets around such stars, noting that they are more numerous and that it is easier to discern planets around them.

“There is no question,” Dr. Charbonneau wrote in an e-mail message, “that small stars provide us with the fastest track to looking for life outside the solar system.”

His planet-hunting equipment is a bank of eight telescopes called MEarth, pronounced “mirth,” on Mount Hopkins in Arizona. They are only 16 inches in diameter, no bigger than those that grace the backyard of many amateur astronomers. They monitor the light of 2,000 nearby stars, looking for the regular blips caused when a planets passes by, or transits.

In May, Zachory Berta, a first-year graduate student of Dr. Charbonneau’s, called the group’s attention to a series of blips in the Ophiuchus star that seemed to be happening every 1.6 days. If he was right, Mr. Berta said, the next transit would occur at 6 a.m. on May 13.

Dr. Charbonneau was in Washington later that day preparing for a State Department dinner when he got a group e-mail message that began: “We have a winner. Congrats Zach!”

From the drop in starlight, the astronomers could calculate the diameter of the Ophiuchus planet, known now as GJ 1214b. Then they used a sensitive spectrograph on a 3.6-meter telescope in Chile to measure its gravitational tug on the star, thus deriving the planet’s mass. Dr. Charbonneau and his colleagues, using those two numbers, could calculate the density of the planet.

It was only the second time the density of a super-Earth had been measured, offering a rare chance for comparative planetology. The first — CoRoT 7b, discovered last year by the European Corot satellite — turned out to be about as dense as the Earth, suggesting that it is mostly rock.

The new planet is slightly heavier but significantly larger than the earlier one, and it is only about one-third Earth’s density.

“What we probably have here is a water world,” said Dr. Charbonneau, explaining that there are three basic ingredients abundant enough to go into the recipe for a planet.

They are light gases like hydrogen and helium, rocks like iron and silicates and so-called volatile materials like water.

The best recipe for the new planet would be a world that is predominantly water, with small amounts of rock in a core tens of thousands of miles underwater, surrounded by a suffocating atmosphere. By comparison, Earth is 0.06 percent water.

Dr. Charbonneau said the weight of the new planet’s presumptive atmosphere that kept the water liquid rather than just boiling into space. If all such super-Earths have this type of atmosphere, he and his colleagues write in their paper, none of them is likely to harbor life. Astronomers would have to redouble their efforts to seek even smaller planets to find habitable environments.

Dr. Charbonneau acknowledged that a different recipe, with more rock and a very puffy atmosphere, would also fit the data. That is unlikely, he and other planet experts say, but the sauna world theory may be soon tested.

The planet is close enough to be studied directly by telescopes on or near Earth. Indeed, Dr. Charbonneau said his team had already applied for observing time on the Hubble Space Telescope.

“Our own TV signals,” he said, “have already passed this star.”

    A Sultry World Is Found Circling a Distant Star, NYT, 17.12.2009, http://www.nytimes.com/2009/12/17/science/space/17planet.html

A Whisper, Perhaps, From the Universe’s Dark Side

November 25, 2008
The New York Times
By DENNIS OVERBYE

Is this the dark side speaking?

A concatenation of puzzling results from an alphabet soup of satellites and experiments has led a growing number of astronomers and physicists to suspect that they are getting signals from a shadow universe of dark matter that makes up a quarter of creation but has eluded direct detection until now.

Maybe.

“Nobody really knows what’s going on,” said Gordon Kane, a theorist at the University of Michigan. Physicists caution that there could still be a relatively simple astronomical explanation for the recent observations.

But the nature of this dark matter is one of the burning issues of science. Identifying it would point the way to a deeper understanding of the laws of nature and the Einsteinian dream of a unified theory of physics.

The last few weeks have seen a blizzard of papers trying to explain the observations in terms of things like “minimal dark matter” or “exciting dark matter,” or “hidden valley” theory, and to suggest how to look for them in particle accelerators like the Large Hadron Collider, set to begin operation again outside Geneva next summer.

“It could be deliriously exciting, an incredibly cool story,” said Nima Arkani-Hamed of the Institute for Advanced Study in Princeton, N.J., who has been churning out papers with his colleagues. “Anomalies in the sky tell you what to look for in the collider.”

On Thursday, a team of astrophysicists working on one of the experiments reported in the journal Nature that a cosmic ray detector onboard a balloon flying around the South Pole had recorded an excess number of high-energy electrons and their antimatter opposites, positrons, sailing through local space.

The particles, they conceded, could have been created by a previously undiscovered pulsar, the magnetized spinning remnant of a supernova explosion, blasting nearby space with electric and magnetic fields. But, they say, a better and more enticing explanation for the excess is that the particles are being spit out of the fireballs created by dark matter particles colliding and annihilating one another in space.

“We cannot disprove that the signal could come from an astrophysical object. We also cannot eliminate a dark matter annihilation explanation based upon current data,” said John P. Wefel of Louisiana State University, the leader of the team, adding, “Whichever way it goes, for us it is exciting.”

The results came on the heels of a report earlier this fall from Pamela, a satellite built by Italian, German, Russian and Swedish scientists to study cosmic rays. Pamela scientists reported in talks and a paper posted on the Internet that the satellite had recorded an excess of high-energy positrons. This, they said, “may constitute the first indirect evidence of dark matter particle annihilations,” or a nearby pulsar.

Antimatter is rare in the universe, and so looking for it is a good way of hunting for exotic phenomena like dark matter.

Another indication that something funny is happening on the dark side of the universe is evident in maps of the cosmic background radiation left over from the Big Bang. Those maps, produced most recently this year by the Wilkinson Microwave Anisotropy Probe satellite, show a haze of what seem to be charged particles hovering around the Milky Way galaxy, according to an analysis by Douglas Finkbeiner of the Harvard-Smithsonian Center for Astrophysics.

Adding to the mix and mystery, the European Space Agency’s Integral satellite detected gamma rays emanating from the center of the Milky Way, suggesting the presence of positrons there, but with much lower energies than Pamela and Dr. Wefel’s experiments have seen.

What all this adds up to, or indeed whether it all adds up to anything at all, depends on which observations you trust and your theoretical presumptions about particle physics and the nature of dark matter. Moreover, efforts to calculate the background level of high-energy particles in the galaxy are beset with messy uncertainties. “The dark matter signal is easy to calculate,” Dr. Kane said. “The background is much harder.”

Dark matter has teased and obsessed astronomers since the 1930s, when the Caltech astronomer Fritz Zwicky deduced that some invisible “missing mass” was required to supply the gravitational glue to hold clusters of galaxies together. The idea became respectable in the 1970s when Vera C. Rubin of the Carnegie Institution of Washington and her collaborators found from studying the motions of stars that most galaxies seemed to be surrounded by halos of dark matter.

The stakes for dark matter go beyond cosmology. The most favored candidates for its identity come from a theory called supersymmetry, which unifies three of the four known forces of nature mathematically and posits the existence of a realm of as-yet-undiscovered particles. They would be so-called wimps — weakly interacting massive particles — which feel gravity and little else, and could drift through the Earth like wind through a screen door. Such particles left over from the Big Bang could form a shadow universe clumping together into dark clouds that then attract ordinary matter.

The discovery of a supersymmetric particle would also be a boost for string theory, the controversial “theory of everything,” and would explicate the nature of a quarter of the universe. But until now, the dark matter particles have mostly eluded direct detection in the laboratory, the exception being a controversial underground experiment called Dama/Libra, for Dark Matter/Large Sodium Iodide Bulk for Rare Processes, under the Italian Alps, where scientists claimed in April to have seen a seasonal effect of a “dark matter wind” as the Earth goes around its orbit.

The sky could be a different story. Dark matter particles floating in the halos around galaxies would occasionally collide and annihilate one another in tiny fireballs of radiation and lighter particles, theorists say.

Dr. Wefel and his colleagues have been chasing sparks in the sky since 2000, when they flew an instrument known as ATIC, for Advanced Thin Ionization Calorimeter, around Antarctica on a balloon at an altitude of 23 miles, looking for high-energy particles known as cosmic rays raining from space.

In all they have made three flights, requiring them to spend the winter at the National Science Foundation’s McMurdo Station, which Dr. Wefel described as very pleasant. “It’s not bad until a storm moves in. You put your hand out till you can’t see it. Then you go out and start shoveling snow,” he explained.

The Nature paper includes data from the first two balloon flights. It shows a bump, over theoretical calculations of cosmic ray intensities, at energies of 500 billion to 800 billion electron volts, a measure of both energy and mass in physics. One way to explain that energy bump would be by the disintegration or annihilation of a very massive dark particle. A proton by comparison is about one billion electron volts.

Dr. Wefel noted, however, that according to most models, a pulsar could generate particles with even more energy, up to trillions of volts, whereas the bump in the ATIC data seems to fall off at around 800 billion electron volts. The ATIC results, he said, dovetail nicely with those from Pamela, which recorded a rising number of positrons relative to electrons, but only up to energies of about 200 billion electron volts.

Reached in China, where he was attending a workshop, Neal Weiner of New York University, who is working with Dr. Arkani-Hamed on dark matter models, said he was plotting ATIC data gleaned from the Web and Pamela data on the same graph to see how they fit, which was apparently very well.

But Piergiorgio Picozza, a professor at the University of Rome and the Pamela spokesman, said in an e-mail message that it was too soon to say the experiments agreed. That will depend on more data now being analyzed to learn whether Pamela continues to see more positrons as the energy rises.

Moreover, as Dr. Kane pointed out, Pamela carries a magnet that allows it to distinguish electrons from positrons — being oppositely charged, they bend in opposite directions going through the magnetic field. But the ATIC instrument did not include a magnet and so cannot be sure that it was seeing any positrons at all: no antimatter, no exotic dark matter, at least at those high energies.

But if he is right, Dr. Wefel said that the ATIC data favored something even more exotic than supersymmetry, namely a particle that is lost in the fifth dimension. String theory predicts that there are at least six dimensions beyond our simple grasp, wrapped up so tightly we cannot see them or park in them. A particle in one of these dimensions would not appear to us directly.

You could think of it as a hamster running around on a wheel in its cage. We cannot see the hamster or the cage, but we can sort of feel the impact of the hamster running; according to Einsteinian relativity, its momentum in the extra dimension would register as mass in our own space-time.

Such particles are called Kaluza-Klein particles, after Theodor Kaluza and Oscar Klein, theorists who suggested such an extra-dimensional framework in the 1920s to unify Einstein’s general theory of relativity and electromagnetism.

Dr. Wefel’s particle would have a mass of around 620 billion electron volts. “That’s the one that seems to fit the best,” he said in an interview. The emergence of a sharp edge in the data, he said, “would be a smoking gun” for such a strange particle.

But Dr. Arkani-Hamed said that Kaluza-Klein particles would not annihilate one another at a fast enough rate to explain the strength of the ATIC signal, nor other anomalies like the microwave haze. He and his colleagues, including Dr. Weiner, Dr. Finkbeiner and Tracy Slatyer, also of Harvard, drawing on work by Matthew Strassler of Rutgers, have tried to connect all the dots with a new brand of dark matter, in which there are not only dark particles but also a “dark force” between them.

That theory was called “a delightful castle in the sky” by Dr. Kane, who said he was glad it kept Dr. Arkani-Hamed and his colleagues busy and diverted them from competing with him. Dr. Kane and his colleagues favor a 200 billion-electron-volt supersymmetric particle known as a wino as the dark matter culprit, in which case the Pamela bump would not extend to higher energies.

Dr. Wefel said he had not kept up with all the theorizing. “I’m just waiting for one of these modelers to say here is the data, here is the model,” he said. “Fit it out. I’m not sure I’ve seen it yet.”

Dr. Picozza said that it was the job of theorists to come up with models and that they were proliferating.

“At the end of the story only one will be accepted from the scientific community, but now it is too early,” he said in an e-mail message.

Sorting all this out will take time, but not forever.

Pamela is expected to come out with new results next year, and the first results from the Fermi Gamma-ray Space Telescope, launched last summer, should also be out soon. Not to mention the Large Hadron Collider, which will eventually smash together protons of seven million electron volts. It is supposed to be running next summer.

“With so many experiments, we will soon know so much more about all of this,” Dr. Weiner said. “In a year or two, we’ll either not be talking about this idea at all, or it will be all we’re talking about.”

    A Whisper, Perhaps, From the Universe’s Dark Side, NYT, 25.11.2008, http://www.nytimes.com/2008/11/25/science/25dark.html

Now in Sight: Far-Off Planets

November 14, 2008
The New York Times
By DENNIS OVERBYE

A little more of the universe has been pried out of the shadows. Two groups of astronomers have taken the first pictures of what they say — and other astronomers agree — are most likely planets going around other stars.

The achievement, the result of years of effort on improved observational techniques and better data analysis, presages more such discoveries, the experts said, and will open the door to new investigations and discoveries of what planets are and how they came to be formed.

“It’s the tip of the iceberg,” said Christian Marois of the Herzberg Institute of Astrophysics in Victoria, British Columbia. “Now that we know they are there, there is going to be an explosion.”

Dr. Marois is the leader of a team that recorded three planets circling a star known as HR 8799 that is 130 light-years away in the constellation Pegasus. The other team, led by Paul Kalas of the University of California, Berkeley, found a planet orbiting the star Fomalhaut, only 25 light-years from Earth, in the constellation Piscis Austrinus.

In an interview by e-mail, Dr. Kalas said that when he finally confirmed his discovery last May, “I nearly had a heart attack.”

In scratchy telescope pictures released Thursday in Science Express, the online version of the journal Science, the planets appear as fuzzy dots that move slightly around their star from exposure to exposure. Astronomers who have seen the new images agreed that these looked like the real thing.

“I think Kepler himself would recognize these as planets orbiting a star following his laws of orbital motion,” Mark S. Marley of the Ames Research Center in Mountain View, Calif., wrote in an e-mail message elaborating on HR 8799.

More than 300 so-called extrasolar planets have been found circling distant stars, making their discovery the hottest and fastest-growing field in astronomy. But the observations have been made mostly indirectly, by dips in starlight as planets cross in front of their home star or by wobbles they induce going by it.

Astronomers being astronomers, they want to actually see these worlds, but a few recent claims of direct observations have been clouded by debates about whether the bodies were really planets or failed stars.

“Every extrasolar planet detected so far has been a wobble on a graph,” said Bruce Macintosh, an astrophysicist from Lawrence Livermore National Laboratory in California and a member of Dr. Marois’s team. “These are the first pictures of an entire system.”

The new planetary systems are anchored by young bright stars more massive than our own Sun and swaddled in large disks of dust, the raw material of worlds.

The three planets orbiting HR 8799 are roughly 10, 9 and 6 times the mass of Jupiter, and orbit their star in periods of 450, 180 and 100 years respectively, all counterclockwise.

The Fomalhaut planet is about three times as massive as Jupiter, according to Dr. Kalas’s calculations, and is on the inner edge of a huge band of dust, taking roughly 872 years to complete a revolution of its star.

Both systems appear to be scaled-up versions of our own solar system, with giant planets in the outer reaches, leaving plenty of room for smaller planets to lurk undetected in the warmer inner regions. Dust rings lie even farther out, like the Kuiper belt of icy debris extending beyond the orbit of Neptune.

“This is a window into what our own solar system might have looked like when it was 60 million years old,” Dr. Marois said.

Sara Seager, a planetary theorist at the Massachusetts Institute of Technology, said it was significant that the planets in both cases seemed to be associated with disks of dust, particularly Fomalhaut, one of the brightest and closest stars known to be host to a massive disk.

“Fomalhaut is like a Hollywood star to astronomers, so we have some personal excitement here,” Dr. Seager said. “It feels like finding out that one of your four closest friends just won the lottery big time”

Alan Boss, a planetary theorist at the Carnegie Institution of Washington, said the triple-planet system in Pegasus was particularly promising, “as we expect planets to form in systems in general, whereas spurious background interlopers will generally appear as single ‘planets.’ ” But he and others cautioned that much more study of these objects was necessary and that the masses imputed to them were still highly uncertain.

Being able to see planets directly opens the door to spectroscopic observations that can help determine the composition, temperature and other physical characteristics of planets and allow for comparisons with one another and with their parent stars. Dr. Macintosh said he hoped to train a spectroscope on his new planets as early as Monday.

The new images are the fruits of a long campaign by astronomers to see more and more of the unseeable. In particular, it is a triumph for the emerging technology of adaptive optics, in which telescope mirrors are jiggled and warped slightly many times a second to compensate for the atmospheric turbulence that blurs star images.

The problem in seeing other planets is picking them out of the glare of their parent stars, which are millions of times brighter, at least in visible light. As a result, planet hunters usually look for infrared, or heat radiation, which is emitted copiously by planets still shedding heat from the process of formation.

For their observations, Dr. Marois and his colleagues used the 8-meter in diameter Gemini North and the 10-meter Keck telescopes on Mauna Kea in Hawaii, both of which had been fitted with adaptive optics. Then they processed the images with a special computer program, which Dr. Marois described as “a software coronagraph,” for processing the images.

The team first spied a pair of dots about four billion and six billion miles out from HR 8799 in October last year. Following up, they discovered a third planet closer in, at about two billion miles. Then they discovered an old observation from 2004, which also showed the planets and how far they had moved around the star in three years.

“Seeing the orbit is one of the coolest things,” Dr. Macintosh said.

Dr. Kalas did his work with the Hubble Space Telescope, which is immune to turbulence because it is in space. He used a coronagraph to block light from the actual star.

He said he had been driven to look for a planet around Fomalhaut after Hubble photographs in October 2004 showed that a dust ring around the star had a suspiciously sharp inner edge, often a clue that the ring is being sculpted by the gravity of some body orbiting nearby.

A second set of Hubble observations, in July 2006, revealed a dot moving counterclockwise around the star. “I basically held my breath for three days until I could confirm the existence of Fomalhaut in all of my data,” Dr. Kalas recalled.

Fomalhaut is also a young star, about 200 million years old, and its dust ring extends 11 billion to 20 billion miles from its planet, Dr. Kalas said. In order not to disturb or roil the dust ring, Fomalhaut’s planet must be less than three Jupiter masses, well within regulation planet size, Dr. Kalas and his collaborators calculated.

A more detailed analysis, with another team member, Eugene Chiang of the University of California, Berkeley, as lead author will appear in the Astrophysical Journal, Dr. Kalas said.

In an e-mail message, Dr. Kalas pointed out that Fomalhaut was the closest exoplanet yet discovered, “close enough to contemplate sending spacecraft there.”

    Now in Sight: Far-Off Planets, NYT, 14.11.2008, http://www.nytimes.com/2008/11/14/science/space/14planet.html

Virgin Galactic plans more spaceships

Thu Feb 21, 2008
5:16am EST
Reuters
By Melanie Lee

SINGAPORE (Reuters) - Virgin Galactic, billionaire Richard Branson's space travel venture, plans to order five more spaceships and aims to turn a profit in five years from its commercial launch in 2010, an official told Reuters on Thursday.

Prospective space travelers have so far placed deposits totaling more than $31 million for tickets that cost $200,000 each and would give them five minutes in space, said Alex Tai, the firm's group director.

"In the short term, we have firm orders for five spaceships and options for seven ... We believe there is a very strong market," Tai said in an interview at the Singapore Airshow.

About 80,000 people from 120 countries have shown interest in these commercial space flights that are likely to start in 2010. Seriously interested travelers are asked to deposit at least $20,000, according to Virgin Galactic's Web site (http://www.virgingalactic.com).

"It's silly to divide the $200,000 by that 5 minutes. It really is a life-time experience," Tai said.

Virgin, which aims to be the first to take paying passengers into space on a regular basis, will invest $250 million in the space program, Tai said.

He declined to give the cost of each craft or the maker, though some parts will come from Pratt & Whitney, the jet engine unit of United Technologies Corp

Asked when the company would become profitable, Tai said: "I imagine it will be inside the first five years."

Virgin's SpaceShipTwo, unveiled last month and to be tested later this year, will be able to carry 8 people into sub-orbital space. Virgin aims to start with one flight a week before ramping it up to 14 flights a week, Tai said.

For $200,000, Virgin will prepare space travelers over three days for their 2-hour flight beyond Earth's atmosphere that will culminate in five minutes in space. The three-day program will include simulating a zero-gravity environment, showing travelers what it means to accelerate and decelerate quickly, as well as what the Earth looks like from space, Tai said. The spaceship will initially be launched from Mojave, California, but will eventually take off from a space port in New Mexico.

Virgin Galactic is one of several high-profile contenders in the new commercial space race.

Others include Astrium, the space arm of European aerospace firm EADS, Blue Origin, started by Amazon.com Inc founder Jeff Bezos, Space Exploration Technologies Corp (SpaceX), created by PayPal founder Elon Musk, and Bigelow Aerospace, a venture aimed at creating space hotels, started by hotelier Robert Bigelow.

The leader in the budding sector is Virginia-based Space Adventures, which started the space tourism phenomenon in 2001 when it put U.S. businessman Dennis Tito on a Russian Soyuz craft for a reported $20 million.

(Additional reporting by Koh Gui Qing, editing by Neil Chatterjee, Valerie Lee)

    Virgin Galactic plans more spaceships, R, 21.2.2008, http://www.reuters.com/article/scienceNews/idUSSP12834820080221

Smaller Version of the Solar System Is Discovered

February 15, 2008
The New York Times
By DENNIS OVERBYE

Astronomers said Wednesday that they had found a miniature version of our own solar system 5,000 light-years across the galaxy — the first planetary system that really looks like our own, with outer giant planets and room for smaller inner planets.

“It looks like a scale model of our solar system,” said Scott Gaudi, an assistant professor of astronomy at Ohio State University. Dr. Gaudi led an international team of 69 professional and amateur astronomers who announced the discovery in a news conference with reporters.

Their results are being published Friday in the journal Science. The discovery, they said, means that our solar system may be more typical of planetary systems across the universe than had been thought.

In the newly discovered system, a planet about two-thirds of the mass of Jupiter and another about 90 percent of the mass of Saturn are orbiting a reddish star at about half the distances that Jupiter and Saturn circle our own Sun. The star is about half the mass of the Sun.

Neither of the two giant planets is a likely abode for life as we know it. But, Dr. Gaudi said, warm rocky planets — suitable for life — could exist undetected in the inner parts of the system.

“This could be a true solar system analogue,” he said.

Sara Seager, a theorist at the Massachusetts Institute of Technology who was not part of the team, said that “right now in exoplanets we are on an inexorable path to finding other Earths.” Dr. Seager praised the discovery as “a big step in finding out if our planetary system is alone.”

Since 1995, around 250 planets outside the solar system, or exoplanets, have been discovered. But few of them are in systems that even faintly resemble our own. In many cases, giant Jupiter-like planets are whizzing around in orbits smaller than that of Mercury. But are these typical of the universe?

Almost all of those planets were discovered by the so-called wobble method, in which astronomers measure the gravitational tug of planets on their parent star as they whir around it. This technique is most sensitive to massive planets close to their stars.

The new discovery was made by a different technique that favors planets more distant from their star. It is based on a trick of Einsteinian gravity called microlensing. If, in the ceaseless shifting of the stars, two of them should become almost perfectly aligned with Earth, the gravity of the nearer star can bend and magnify the light from the more distant one, causing it to get much brighter for a few days.

If the alignment is perfect, any big planets attending the nearer star will get into the act, adding their own little boosts to the more distant starlight.

That is exactly what started happening on March 28, 2006, when a star 5,000 light-years away in the constellation Scorpius began to pass in front of one 21,000 light-years more distant, causing it to flash. That was picked up by the Optical Gravitational Lensing Experiment, or Ogle, a worldwide collaboration of observers who keep watch for such events.

Ogle in turn immediately issued a worldwide call for continuous observations of what is now officially known as OGLE-2006-BLG-109. The next 10 days, as Andrew P. Gould, a professor of mathematical and physical sciences at Ohio State said, were “extremely frenetic.”

Among those who provided crucial data and appeared as lead authors of the paper in Science were a pair of amateur astronomers from Auckland, New Zealand, Jennie McCormick and Grant Christie, both members of a group called the Microlensing Follow-Up Network, or MicroFUN.

Somewhat to the experimenters’ surprise, by clever manipulation they were able to dig out of the data not just the masses of the interloper star and its two planets, but also rough approximations of their orbits, confirming the similarity to our own system. David P. Bennett, an assistant professor of astrophysics at the University of Notre Dame, said, “This event has taught us that we were able to learn more about these planets than we thought possible.”

As a result, microlensing is poised to become a major new tool in the planet hunter’s arsenal, “a new flavor of the month,” Dr. Seager said.

Only six planets, including the new ones, have been discovered by microlensing so far, and the Scorpius event being reported Friday is the first in which the alignment of the stars was close enough for astronomers to detect more than one planet at once. Their success at doing just that on their first try bodes well for the future, astronomers say.

Alan Boss, a theorist at the Carnegie Institution of Washington, said, “The fact that these are hard to detect by microlensing means there must be a good number of them — solar system analogues are not rare.”

    Smaller Version of the Solar System Is Discovered, NYT, 15.2.2008, http://www.nytimes.com/2008/02/15/science/space/15planets.html?hp

Pictures Reveal Mercury’s Tumultuous Past

January 31, 2008
The New York Times
By WARREN E. LEARY

WASHINGTON — The Messenger spacecraft that zipped past Mercury two weeks ago found more evidence of the innermost planet’s turbulent past, including ridges that run hundreds of miles and a unique feature made up of more than 100 troughs radiating in all directions, scientists said Wednesday.

A preliminary look at data from the flyby, including 1,213 images, shows a small, cratered planet that superficially looks like Earth’s moon but is very different in reality, they said.

The robot spacecraft, the first to visit the planet in more than three decades, passed 124 miles above Mercury’s surface on Jan. 14 before continuing on a path that is to bring it back three more times in the next three years before settling into orbit.

During the encounter, the Messenger’s seven scientific instruments scanned the planet, its magnetic field and its wispy atmosphere in great detail.

“Our little craft has returned a gold mine of exciting data,” said Dr. Sean C. Solomon of the Carnegie Institution of Washington, the mission’s lead investigator.

“We were continually surprised,” Dr. Solomon said at a NASA news conference. “It was not the planet we expected. It was not the moon.”

Mercury remains a very dynamic planet and is a key to understanding the evolution of the inner solar system and its four rocky planets, including Earth, he said.

NASA’s Mariner 10 spacecraft, which made three flybys of Mercury in 1974 and 1975, mapped about 45 percent of the planet’s surface. The Messenger craft took pictures of another 30 percent during its first visit and should complete the portrait when it returns on its next flyby in October, scientists said.

After that visit and another in September 2009 to slow the craft, the Messenger is to settle into orbit around Mercury on March 18, 2011, for at least a year of studies.

Among the features spotted by the Messenger — short for the $446 million mission’s formal name, Mercury Surface, Space Environment, Geochemistry and Ranging — is one informally called “the spider.” It appears to be an impact crater 25 miles in diameter from which more than 100 flat-bottomed troughs shoot out in all directions, said Louise Prockter, an imaging instrument scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., which built and operates the spacecraft.

“It’s a real mystery, a very unexpected find,” Ms. Prockter said, unlike anything ever observed in the solar system. It is unclear if the impact crater caused the shattered-looking feature or came later, after the troughs formed for another reason, she said.

    Pictures Reveal Mercury’s Tumultuous Past, NYT, 31.1.2008, http://www.nytimes.com/2008/01/31/science/31mercury.html

9 Billion-Year-Old ‘Dark Energy’ Reported

November 17, 2006
The New York Times
By DENNIS OVERBYE

A strange thing happened to the universe five billion years ago. As if God had turned on an antigravity machine, the expansion of the cosmos speeded up, and galaxies began moving away from one another at an ever faster pace.

Now a group of astronomers using the Hubble Space Telescope have discovered that billions of years before this mysterious antigravity overcame cosmic gravity and sent the galaxies scooting apart like muscle cars departing a tollbooth, it was already present in space, affecting the evolution of the cosmos.

“We see it doing its thing, starting to fight against ordinary gravity,” Adam Riess of the Space Telescope Science Institute said about the antigravity force, known as dark energy. He is the leader of a team of “dark energy prospectors,” as he calls them, who peered back nine billion years with the Hubble and were able to discern the nascent effects of antigravity. The group reported their observations at a news conference yesterday and in a paper to be published in The Astrophysical Journal.

The results, Dr. Riess and others said, provide clues and place new limits on the nature of dark energy, a mystery that has thrown physics and cosmology into turmoil over the last decade.

“It gives us the ability to look at changes in dark energy,” he said in an interview. “Previously, we knew nothing about that. That’s really exciting.”

The data suggest that, in fact, dark energy has changed little, if at all, over the course of cosmic history. Though hardly conclusive, that finding lends more support to what has become the conventional theory, that the source of cosmic antigravity is the cosmological constant, a sort of fudge factor that Einstein inserted into his cosmological equations in 1917 to represent a cosmic repulsion embedded in space.

Although Einstein later abandoned the cosmological constant, calling it a blunder, it would not go away. It is the one theorized form of dark energy that does not change with time.

Sean Carroll, a cosmologist at the California Institute of Technology who was not on the team, said: “Had they found the evolution was not constant, that would have been an incredibly earthshaking discovery. They looked where no one had been able to look before.”

The paper by Dr. Riess and his colleagues represents a sort of progress report from the dark side, where astrophysicists have found themselves more and more as they try to understand what is happening to the universe.

This encounter with the invisible began eight years ago, when two competing teams of astronomers were using exploding stars known as Type 1a supernovas as cosmic distance markers to determine the fate of the universe.

Ever since the Big Bang 14 billion years ago, the galaxies and the rest of the universe have been flying apart like a handful of pebbles tossed in the air. Astronomers reasoned that gravity would be slowing the expansion, and the teams were trying to find out by how much and, thus, determine whether all would collapse one day into a “big crunch” or expand forever.

Instead, to their surprise, the two teams, one led by Saul Perlmutter of the University of California, Berkeley, and the other by Brian Schmidt of the Mount Stromlo and Siding Spring Observatories in Australia, found that the universe was speeding up instead of slowing down.

But the ground-based telescopes that the two teams used could track supernovas to distances of just seven billion light-years, corresponding to half the age of the universe, and the effect could have been mimicked by dust or a slight change in the nature of the supernova explosions.

Since then, Dr. Riess, who was a member of Dr. Schmidt’s team, and his colleagues have used the Hubble telescope to prospect for supernovas and dark energy farther out in space or back in time.

The new results are based on observations of 23 supernovas that are more than eight billion years in the past, before dark energy came to dominate the cosmos. The spectra of those distant supernovas, Dr. Riess reported, appear to be identical to those closer and more recent examples. By combining the supernova results with data from other experiments like the NASA Wilkinson Microwave Anisotropy Probe, Dr. Riess and his colleagues could begin to address the evolution of dark energy.

“That’s one of the $64,000 questions,” he said. “Is dark energy changing?”

So far, he said, the results are consistent with the cosmological constant, but other answers are also possible. The possibility that it is the cosmological constant is a mixed blessing. Physicists concede that they do not understand it.

Dr. Carroll of Caltech said, “Dark energy makes us nervous.”

Einstein invented his constant to explain why the universe does not collapse. After he abandoned it, the theory was resuscitated by quantum mechanics, which showed that empty space should be bubbling with staggering amounts of repulsive energy. The possibility that it really exists in the tiny amounts measured by the astronomers has flummoxed physicists and string theorists.

Because it is a property of empty space, the overall force of Einstein’s constant grows in proportion as the universe expands, until it overwhelms everything. Other theories of dark energy like strange force fields called quintessence or modifications to Einstein’s theory of gravity can change in more complicated ways, rising, falling or reversing effects.

Astronomers characterize the versions of dark energy by their so-called equation of state, the ratio of pressure to density, denoted by the letter w. For the cosmological constant, w is minus one.

Dr. Riess and his group used their data to make the first crude measurement of this quantity as it stood nine billion years ago. The answer, he said, was minus one — the magic number — plus or minus about 50 percent. By comparison for more recent times, with many more supernovas observable and thus more data, the value is minus one with an uncertainty of about 10 percent.

“If at one point in history it’s not minus one,” Dr. Riess said, “then we have killed the very best explanation.”

Getting to the precision needed to kill or confirm Einstein’s constant, however, will be very difficult, he conceded. One of the biggest sources of uncertainty is the fact that the Type 1a explosions are not completely uniform, introducing scatter into the observations.

The Hubble is the sole telescope that can pursue supernova explosions deeply enough to chart the early days of dark energy. The recent announcement that the National Aeronautics and Space Administration will send astronauts to maintain and refurbish the Hubble once again, enabling it to keep performing well into the next decade, is a lift for Dr. Riess’s project. A new camera could extend observations to 11 billion or 12 billion years back.

    9 Billion-Year-Old ‘Dark Energy’ Reported, NYT, 17.11.2006, http://www.nytimes.com/2006/11/17/science/space/17dark.html

April 27, 1962

On This Day

From The Times archive

The first British satellite was launched by an American rocket to measure

the intensity of the Sun's radiation and cosmic rays

BRITAIN’S first satellite, the UK 1 was successfully launched into orbit from Cape Canaveral, Florida, today by an American Delta rocket. Two hours after it was launched scientists at Cape Canaveral confirmed that telemetry was being received from the spacecraft which was apparently in orbit.

It will, however, be some time before it can be definitely confirmed that the UK 1 has achieved the planned elliptical orbit which will take it as far north as Gretna Green and as far south as New Zealand at altitudes ranging from 200 to 600 miles.

The scientific purpose of UK 1 is to study the properties and behaviour of the ionosphere, the radio reflecting layer, which begins about 35 miles above the earth.

The satellite, which, it is hoped, will send back information to earth for a year, was to be tracked by stations around the world, including the Department of Scientific and Industrial Research’s installations at Winkfield, Berkshire; Sembawang, Singapore; and Port Stanley in the Falkland Islands.

In the ionosphere, where the atmosphere is tenuous, incoming high-energy radiations from the sun collide with molecules of air and atoms, leaving positively charged atoms or ions. The ionosphere filters out dangerous sun radiation and at the same time acts as a mirror to radio waves making international communication possible.

    On This Day - April 27, 1962, Times, 27.4.1962, http://www.newsint-archive.co.uk/pages/main.asp

June 30 1927

The eclipse watched from the sky

From The Guardian archive

June 30 1927
The Guardian

The sun was hidden in cloud when the aeroplane ascended from Chester Aerodrome. We had come from Croydon yesterday afternoon, in the big Imperial Airways 14-seater, and after a short night at Chester we were in the cabin again at half-past five.

We were as assorted a lot of earthians as Mr Wells could have selected for an air story — amateur astronomers, journalists, photographers, two ladies keen on flying, an artist, and a military man. Tired, one of the party slept through the eclipse.

Through smoked glass one watched the moon clearly shutting out the flame of day. It was only when the sun was a crescent that the marvel of what we were seeing began to grip the mind. Before that one only knew that it was a marvel, but now one's consciousness was pervaded by it.

Then there was nothing of the sun, only the wispy silver curls shorn from his locks. We were immediately in the valley of the shadow. It did not seem to me to rush up, but one was suddenly aware of it.

I glanced round the cabin. What did a human being look like in that resurrection pause? I could see heads silhouetted against the windows and could discern [an] old man's ashen face. But the face of the young man beside him was ashen too. And so we flew, a winged chariot of ghosts between earth and a goblin sun.

The earth had almost disappeared in greyness. I could not see any edge to the grey shadow that was there. The double engines roared outside and we were denied, of course, the silence that the earth owes to the terrific apparitions of the cosmos, but at the time one had forgotten the noise.

The sun crescent appeared now in the east, and our aeroplane, firing a salute from its exhaust as it dropped quickly to 2,000 feet, began its flight back to Chester. The sun in the quar ter-phase emerging had become quite strong and glimmered at the sea.

Some of the million watchers were thronged at Southport. We flew low along the sands to the cheering of great parties of school children, and so back to Aerodrome and down in the rain. And in the hangar there the men and women from three aeroplanes, forgetting their Englishness, at once began to talk eagerly together of the marvels they had seen, like the people in the New Testament.

What the Astronomers Say: The Astronomer Royal: A very clear and striking eclipse. Our observations went off very well indeed. Dr. Andrew Crommelin (Colwyn Bay): The most hopeless eclipse I have ever taken part in.

    From The Guardian archive > June 30 1927 > The eclipse watched from the sky, G,
    republished 30.6.2007, p. 36, http://digital.guardian.co.uk/guardian/2007/06/30/pages/ber36.shtml

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