|
Vocabulary > Space > Asteroids, Comets, Meteorites
The Guardian
p. 9 7.3.2007
It's called Apophis. It's 390m wide. And it
could hit Earth in 31 years time
Scientists call for plans to change asteroid's path Developing technology could
take decades
Alok Jha
The Guardian Wednesday December
7, 2005
http://www.guardian.co.uk/space/article/0,14493,1660485,00.html
An artist's
impression of an asteroid passing Earth.
Photograph: Getty Images
The Guardian 29.9.2004
near-Earth objects NEOs
Near-Earth objects > asteroids and comets
— mineral-rich bodies bathed in a
continuous flood of sunlight
http://www.nytimes.com/2010/10/26/opinion/26schweickart.html
http://www.guardian.co.uk/space/article/0,14493,1660485,00.html
http://www.guardian.co.uk/life/feature/story/0,13026,1458536,00.html
http://neo.jpl.nasa.gov/news/news_archives0206.html
Near-Earth asteroids
http://www.guardian.co.uk/science/2011/jun/27/asteroid-poses-no-threat-earth
http://www.nasa.gov/topics/solarsystem/features/neo20110624.html
http://www.usatoday.com/tech/science/space/2007-02-12-asteroid_x.htm
close encounter
http://www.guardian.co.uk/science/2011/jun/27/asteroid-poses-no-threat-earth
asteroid
http://www.guardian.co.uk/science/2012/mar/25/asteroid-headed-for-earth-laser
http://www.guardian.co.uk/science/2012/apr/24/tech-tycoons-asteroid-mining-venture
http://www.nytimes.com/aponline/2011/11/08/science/AP-US-SCI-Asteroid-Flyby.html
http://www.nytimes.com/2010/10/26/opinion/26schweickart.html
http://www.timesonline.co.uk/tol/news/uk/science/article3082960.ece
http://www.usatoday.com/tech/science/space/2007-02-12-asteroid_x.htm
Asteroid mining: how it might work –
interactive April 24, 2012
http://www.guardian.co.uk/science/interactive/2012/apr/24/asteroid-mining-how-work-interactive
asteroid's path
a 390-metre wide asteroid
reach the Earth's
atmosphere
break up
Earth-bound asteroid
http://www.guardian.co.uk/space/article/0,14493,1660485,00.html
http://www.guardian.co.uk/space/article/0,14493,1315681,00.html
http://www.guardian.co.uk/space/article/0,14493,1262516,00.html
killer asteroid
http://www.guardian.co.uk/science/story/0,,1950258,00.html
near-miss
http://www.nytimes.com/2010/10/26/opinion/26schweickart.html
http://www.guardian.co.uk/space/article/0,,1811563,00.html
deflect the
asteroid
http://www.guardian.co.uk/space/article/0,14493,1660485,00.html
smack into Earth
http://www.usatoday.com/tech/science/space/2007-02-12-asteroid_x.htm
collision with Earth
http://www.guardian.co.uk/space/article/0,,2028153,00.html
hit
'nuclear winter'
http://www.usatoday.com/tech/science/space/2007-02-12-asteroid_x.htm
close call
meteor
http://www.usatoday.com/tech/science/space/2008-11-23-meteor-canada_N.htm
meteorite
http://www.guardian.co.uk/science/audio/2011/jan/10/science-weekly-podcast-meteors-ted-nield
http://www.usatoday.com/tech/science/space/2007-01-11-meteorite-bathroom_x.htm
comet
http://www.nytimes.com/2011/02/14/science/space/14comet.html
http://www.nytimes.com/2005/07/05/science/05comet.html
Biggest Asteroid in 35 Years Swings Close to Earth
November 8,
2011
The New York Times
By THE ASSOCIATED PRESS
LOS ANGELES
(AP) — An asteroid as big as an aircraft carrier zipped by Earth on Tuesday in
the closest encounter by such a massive space rock in more than three decades.
Scientists ruled out any chance of a collision but turned their telescopes
skyward to learn more about the object known as 2005 YU55.
Its closest approach to Earth was pegged at a distance of 202,000 miles at 6:28
p.m. EST. That's just inside the moon's orbit; the average distance between
Earth and the moon is 239,000 miles.
The last time a large cosmic interloper came that close to Earth was in 1976,
and experts say it won't happen again until 2028.
Scientists at NASA's Deep Space Network in the California desert have tracked
the quarter-mile-wide asteroid since last week as it approached from the
direction of the sun at 29,000 mph.
Astronomers and amateur skygazers around the world kept watch, too.
The Clay Center Observatory in Brookline, Mass., planned an all-night viewing
party so children and parents could peer through research-grade telescopes and
listen to lectures. The asteroid can't be detected with the naked eye.
For those without a telescope, the observatory streamed video of the flyby live
on Ustream, attracting several thousand viewers. The asteroid appeared as a
white dot against a backdrop of stars.
"It's a fantastic opportunity to educate the public that there are things out in
space that we need to be aware of," including this latest flyby, said
observatory director Ron Dantowitz.
Dantowitz added: "It will miss the Earth. We try to mention that in every
breath."
If an asteroid that size would hit the planet, Purdue University professor Jay
Melosh calculated the consequences. The impact would carve a crater four miles
across and 1,700 feet deep. And if it slammed into the ocean, it would trigger
70-foot-high tsunami waves.
Since its discovery six years ago, scientists have been monitoring the
spherical, coal-colored asteroid as it slowly spins through space and were
confident it posed no danger.
Asteroids are leftovers from the formation of the solar system some 4.5 billion
years ago. Scientists believe their growth was stunted by Jupiter's
gravitational pull and never had the chance to become full-fledged planets.
Pieces of asteroids periodically break off and make fiery plunges through the
atmosphere as meteorites.
Don Yeomans, who heads NASA's Near Earth Object Program, said 2005 YU55 is the
type of asteroid that humans may want to visit because it contains carbon-based
materials and possibly frozen water.
With the space shuttle program retired, the Obama administration wants
astronauts to land on an asteroid as a stepping stone to Mars.
"This would be an ideal object," Yeomans said.
___
Online:
NASA's Near-Earth Object Program:
http://neo.jpl.nasa.gov
Ustream:
http://www.ustream.tv/channel/clay-center-observatory
___
Follow Alicia Chang's coverage at
http://www.twitter.com/SciWriAlicia
Biggest Asteroid in 35 Years Swings Close to Earth, NYT,
8.11.2011,
http://www.nytimes.com/aponline/2011/11/08/science/AP-US-SCI-Asteroid-Flyby.html
NASA’s
Second Close Encounter With a Comet
February
13, 2011
The New York Times
By KENNETH CHANG
The last
time NASA visited the Tempel 1 comet, it was with fireworks, on July 4, 2005. On
that day, the Deep Impact spacecraft slammed an 820-pound projectile into Tempel
1, excavating a plume of ice and dust.
On Monday night — Valentine’s Day — NASA will return to Tempel 1 but will not
bombard it. This time, a different spacecraft, Stardust, will zip past at more
than 24,000 miles per hour, taking 72 high-resolution pictures of the comet’s
surface.
Stardust will make its closest approach, within 125 miles, at 11:37 p.m. Eastern
time.
Tim Larson, the mission’s project manager, said NASA was not deliberately
scheduling its missions to coincide with holidays. “That’s just how the orbital
mechanics worked out on these,” he said, “although it makes for great P.R.”
Tempel 1 will be the first comet to be seen at close range twice, and scientists
will make a then-and-now comparison — one that they expect will reveal a change
in topography and tell them more about the inner workings of comets.
“Here’s a chance where we can see what has changed, how much has changed,” said
Joseph Veverka, a professor of astronomy at Cornell and the mission’s principal
investigator, “so we’ll start unraveling the history of a comet’s surface."
For example, photographs taken by Deep Impact in 2005 showed areas that looked
old and others that seemed much younger. But the snapshots did not tell the ages
of any of them. “We have no idea whether we’re talking about things that have
been there for a hundred years, a thousand years, a million years,” Dr. Veverka
said.
In the five and a half years since Deep Impact’s visit, Tempel 1 — whose orbit
brings it as close to the Sun as Mars and as far away as Jupiter — has completed
a full orbit.
Stardust was launched in 1999 and arrived five years later at its primary
destination, a comet named Wild 2, where it collected particles of dust.
Stardust then looped back to Earth and released a canister containing the comet
dust, which parachuted back to the ground.
The spacecraft, still operating well, continued onward, and NASA decided to use
it for a return visit to Tempel 1. (Deep Impact, meanwhile, also extended its
scientific journey, visiting another comet last November.)
One more puzzle that scientists may be able to solve with the second look at
Tempel 1 involves depressions that look like the type of craters caused by
impacts. The depressions, though, could have been caused by explosions that were
a result of underground ice that converted to gas.
The scientists will now be able to compare the depressions with something they
know is definitely a crater — the scar left by Deep Impact. “Simple question,”
Dr. Veverka said, “direct answer.”
NASA’s Second Close Encounter With a Comet, NYT,
13.2.2011,
http://www.nytimes.com/2011/02/14/science/space/14comet.html
June 7, 1923
On This Day
From The Times archive
What a labourer thought was gunfire was a rare meteorite
THE Natural History Museum at South Kensington has received a very rare and
interesting gift in the shape of a meteorite, which fell just before 1pm on
March 9 between Saffron Walden and Ashdon, in Essex.
The man who saw the meteorite fall was a labourer, who states that he heard a
“sissing” noise and supposed that an aeroplane was overhead. Looking up a second
or two after he saw what he thought was a projectile fall about ten to fifteen
yards from him, causing the earth to spout up like water.
He was much alarmed, because he considered that something had been discharged
from a gun. Three days later, in company with another man, he took the meteorite
up from where it had fallen. He says that there was a small hole where it had
entered the ground, and this hole increased in width as he dug deeper. The stone
was found at a depth of two feet.
The specimen weighs about 3lb, and is what is known as a white chondrite
meteoric stone. It is about 5in long by 4in wide and has a thickness of about
3in in its thickest part.
The surface of the stone shows with remarkable distinctness, the lines of flow
of fused materials radiated from the centre of the surface and proves that it
was partially fused owing to the high velocity at which it entered the earth’s
atmosphere.
The rarity of the occurrence of a meteor seen to be falling is evident by the
fact that only about fifteen falls have been recorded in the British Islands.
From The Times Archives > On This Day - June 7, 1923, The Times, 7.6.2005,
http://www.newsint-archive.co.uk/pages/main.asp
May 24, 1910
Halley's comet, seen from a Whit-week train
From the Guardian archive
Tuesday May 24, 1910
Guardian
Halley's comet, writes a correspondent, was very clearly visible last night as I
travelled from Crewe to Manchester.
Looking out at the left-hand side of the carriage all the way from Crewe to
within a mile or two of Stockport, when the haze swallowed it up, we could see
the pale light of it, almost level with the eye below Leo and to the right of
Castor and Pollux.
The tail was scarcely visible. A crowded carriage of returning holiday-makers
found it a good butt for the a last round of holiday jests.
"Tail fourteen million miles long, has it; shouldn't like to walk it."
"How do they measure it - with a foot rule?"
"Algebra," snapped a man in the corner, and the rest were silent. It was
surprising how many seemed to know where to look for it.
Last night the long-looked-for comet was visible at last to us in the north. In
Manchester itself the haze which the smoke-stacks of industry gather over the
city hid it from view, but out in the country parts of Lancashire and Cheshire
the sky was beautiful and clear, and the brilliance of a moon reaching its full
was not enough to blot it from sight.
From the rising of the stars it hung there (so those who saw it tell us), just
clear of the mists on the fields, pallid and strangely blurred beside the
shining definiteness of Castor and Pollux to the right of it and the great
constellation of Leo sprawling over its head.
Its unfamiliarity made it easy for the eye to light upon it, but it was very dim
and distant, and there was nothing but a faint luminosity about the edge to
suggest to the naked eye the tail through which our planet had gone swimming in
the past week.
But because its fires glow pale and faint to us here we are not to think that
two thousand years (so far we can trace back its appearances in history) have
burnt it out. In America and other parts of the globe it has shone with all its
former brilliance, accompanied by the same strange bout of terrestrial ecstasy
and panic as it had in days gone by.
When the time comes no doubt each country will fit its appearance to their
special catastrophes, and in history books centuries after this Frenchmen will
read that its coming was heralded by the flooding of their capital, and
Englishmen will say that it killed a king.
And last night returning Whit-week travellers peered at it from railway carriage
windows and joked about the length of its tail.
From the Guardian archive > May 24, 1910 > Halley's comet,
seen from a Whit-week
train, G, Republished 24.5.2006,
http://www.guardian.co.uk/fromthearchive/story/0,,1781490,00.html
|
