The asteroid, estimated to be about 11 m (36 ft) in diameter, was first detected on Wednesday. At its closest, the space rock — named 2012 BX34 — passed within about 60,000 km of Earth — less than a fifth of the distance to the Moon. Astronomers stressed that there had been no cause for concern. “It’s one of the closest approaches recorded,” said Gareth Williams, associate director of the US-based Minor Planet Center.

“It makes it in to the top 20 closest approaches, but it’s sufficiently far away …” he told the BBC. The asteroid’s path made it the closest space-rock to pass by the Earth since object 2011 MD in June 2011.

Here’s more from Space.com:

The Earth has always had a temporary second moon, new study has claimed. When astronomers caught sight of a mysterious titanium white object circling around the Earth in 2006, they assumed it was a spent rocket. But it was actually a small asteroid captured by the Earth’s gravitational field that rotated around the Earth until June 2007.

In the new study, astrophysicists at Cornell claim that this little moon was not an anomaly as these asteroids come and go so often it means our planet always has a temporary second moon.

According to Cornell University’s Mikael Granvik, Jeremie Vaubaillon and Robert Jedicke, they have calculated the population of “irregular natural satellites that are temporarily captured” by Earth.

In their study, researchers say that while these moons are small, the scientific implications of this discovery are phenomenal. Instead of having to send crews to asteroids astronomers can wait until they come closer to Earth to intercept and learn more about the origins of our solar system.

Back in 2006, the Catalina Sky Survey in Arizona noticed that a mysterious body had begun orbiting the Earth. This object had a spectrum that was remarkably similar to the titanium white paint used on Saturn V rocket stages and, indeed, a number of rocket stages are known to orbit the Sun close to Earth.

But this was not an object of ours. Instead, 2006 RH120, as it became known, turned out to be a tiny asteroid just a few metres across–a natural satellite like the Moon. It was captured by Earth’s gravity in September 2006 and orbited us until June 2007 when it wandered off into the Solar System in search of a more interesting neighbour.

2006 RH120 was the first reliably documented example of a temporary moon …

Read More: MIT’s Technology Review

We have a visitor — a large asteroid called 2005 YU55 that is expected to come within approximately 201,700 miles of Earth on Tuesday, according to NASA. That’s slightly less than the distance from Earth to the moon.

Asteroids often pass this close, but most are tiny. Countless thousands of pieces come plunging into the atmosphere, but they burn up without doing any harm. If they’re as large as grains of sand, we may, if we’re lucky, see them in the night sky as shooting stars.

But 2005 YU55 is at least 1,300 feet wide — larger than an aircraft carrier, according to radar measurements. The last time an asteroid this big passed by was in 1976, and the next one scientists know of won’t be until 2028, NASA says. (There have been some rude surprises in between, but not involving anything remotely as large.)
Don Yeomans, manager of NASA’s Near-Earth Object Program Office at Jet Propulsion Laboratory, in Pasadena, Calif., said this fly-by is an opportunity to learn more about c-type — that is, carbon-based — asteroids, to find “clues as to what it was like when our solar system was forming.”

More: ABC News

An asteroid 300 metres in diameter is stalking the Earth. Hiding in the pre-dawn twilight, it has marched in lockstep with our planet for years, all but invisible to our telescopes.

The rock is Earth’s first confirmed Trojan, which can orbit the sun in either of two gravitational wells along the same orbital path as our planet. From the sun’s point of view, these wells lie 60 degrees ahead of and behind the Earth, at Lagrange points where gravitational forces between the sun and the Earth balance out.

Trojans are common — Jupiter alone boasts about 5000, and Neptune and Mars each have their own smaller collections. But finding Earth’s has proven difficult, because the Lagrange points lie towards the sun in the sky. Astronomers must look for the objects just before the sun rises or after it sets, and until now the glare of this sunlight has obscured the feeble light reflected from any rocks that might be hiding there.

Now Martin Connors of Athabasca University in Alberta, Canada, and colleagues have used a heat sensor to see past the gloaming. Using data from NASA’s Wide-field Infrared Survey Explorer (WISE) satellite, they identified a 300-metre-wide Trojan now dubbed 2010 TK7.

Read More in the New Scientist

Rather than looking for aliens who use interstellar radio signals to say “hi,” an alternative search strategy is simply to spy on any mega-engineering projects that an advanced civilization might be undertaking. Veteran SETI astronomer Jill Tarter calls this strategy “SETT” — the Search for Extraterrestrial Technology.

A new science paper by Duncan Forgan at the University of Edinburgh in Scotland and Martin Elvis at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., suggests we look for evidence of a very ambitious macro-engineering project: the wholesale mining of an asteroid belt. The asteroid material may be mined to build space colonies, solar power satellites or maybe even an entire “ringworld,” as imagined by sci-fi writer Larry Niven.

What’s more, precious metals are in high demand for technologies such as computers, high-speed networks and mobile phones. So-called “green technologies” of the future, such as hydrogen fuel cells, will also place a demand on rare resources.

The unconsolidated debris from the birth of planets, asteroids provide a smorgasbord of elements and minerals for harvesting. Meteorite samples suggest that large quantities of gold, platinum, iron, nickel, magnesium and silicon, among other elements, are abundant on asteroids.

For more information, see original article.

At about 3am on 8 October last year, an asteroid the size of a small house smashed into the Earth’s atmosphere over an isolated part of Indonesia. The asteroid disintegrated in the atmosphere causing a 50 kiloton explosion, about four times the size of the atomic bomb used to destroy Hiroshima. The blast was picked up by several infrasound stations used by the Comprehensive Nuclear-Test-Ban Treaty Organization to monitor nuclear tests.

No-one was injured in blast but the incident highlights the threat that planet faces from near Earth asteroids. Astronomers expect a strike like this once every 2-12 years. And the US congress has given NASA the task of sweeping the skies to identify anything heading our way. So far NASA has looked for objects of a kilometre or more in size and determined that none of these is on track to hit Earth in the foreseeable future.

But what of smaller objects? Various estimates show that an impact with an asteroid just 50 metres across would cause some 30,000 deaths (compared with 50 million deaths from an impact with a 1 kilometre-sized object).

This raises two important questions. The first is how best can astronomers monitor the skies for these smaller objects. The second is what to do should we find something heading our way.

Today, John Tonry from the University of Hawaii gives us his view. He believes the goal of finding 90 per cent of city-destroying asteroids in time to deflect them is extremely challenging. He says a more realistic target is to evacuate the area under threat. And for that we’ll need just three week’s notice.

Given these constraints, he reckons he can do the job with an array of eight 25cm aperture telescopes with a wide field of view that simultaneously scan the visible sky twice a night. He calls this early warning system the Asteroid Terrestrial-impact Last Alert System or ATLAS…

[continues at Technology Review]

The Hubble Space Telescope has captured the aftermath of just what happens when two asteroids collide at 11,000 mph (17,702 km/h), prompting an explosion “as powerful as the detonation of a small atomic bomb”.

P/2010 A2. Photo: NASA

The result is a “peculiar” object – dubbed P/2010 A2 – which boasts a comet-like debris trail behind a mysterious X-shaped formation.

The asteroid belt pile-up happened in early 2009, according to NASA, but it wasn’t until January this year that the Lincoln Near-Earth Research (LINEAR) Program Sky Survey spotted the tail.

Hubble’s Wide Field Camera 3 observations indicate a surviving 400-foot-wide (122m-wide) object, which was hit by a smaller body, “perhaps 10 to 15 feet wide” (3 to 4m). The latter was vapourised in the blast, and its remains and material thrown off from the former were swept into a tail by solar radiation.

Astronomers are keen to find out just how much dust such high-speed encounters eject into interplanetary space, and while they reckon that “modest-sized asteroids smash into each other about once a year”, they’re difficult to spot…

[continues in the Register]

NASA/JPL plot of asteroids' paths

These ones probably won’t hit, but they show that so-called Near Earth Objects could collide with our planet at any time with precious little warning. From ABC News:

Today is not a good day for the anxious among us. Two small asteroids — two in twelve hours — are passing the earth, both coming within the moon’s orbit, one of them whipping by about 49,000 miles away.

In a spirit of calm, we ought to point out that NASA says close calls like these happen, on average, almost daily. The difference is that usually we never know. These two objects were both spotted Sunday by the Catalina Sky Survey at the University of Arizona.

The specifics:

–Asteroid 2010 RX30 is estimated to be 32 to 65 feet in size (10-20 meters) and passed within 154,000 miles of Earth at 5:51 a.m. EDT this morning. (The moon, by comparison, is 2,200 miles in diameter and respectfully stays about 240,000 miles away.)

–Asteroid 2010 RF12, about 20-45 feet in maximum width (6-14 meters), is passing within approximately 49,088 miles of us at 5:12 p.m. EDT. That’s a fifth as far away as the moon.

A decade ago, this was the stuff of movies — think “Armageddon” and “Deep Impact” — but one of the more memorable lines from back then was that the planet would be whacked by something “the size of Texas.” Asteroids the size of today’s passersby enter the earth’s atmosphere about once a decade, mostly harmlessly.

Of course, every now and then — remember the theory about the death of the dinosaurs — something hits us that is not harmless…

[continues at ABC News]

This isn’t an urgent call to arms, but it’s certainly a future date to consider. In the year 2182 — 172 years time — there’s the possibility that we might be hit by an asteroid with potential to cause some significant global turmoil.

This long-distance forecast could help mankind determine whether asteroid deflection techniques are warranted, especially when given nearly two centuries of lead time.

The not-so-romantically named (101955) 1999 RQ36 — discovered in 1999 — measures approximately 510 meters in diameter and is classified as an Apollo asteroid. Apollo asteroids pose a threat to our planet as they routinely cross Earth’s orbit.

With a one-in-a-thousand chance of 1999 RQ36 hitting Earth — with half of this probability indicating a 2182 impact — the threat might not sound too acute.

But compare this with the panic that ensued with the discovery of 99942 Apophis in 2004. Initially, it was thought there was a 1-in-233 chance of Apophis hitting us in 2029. This estimate was alarming; it was the first time an asteroid had been promoted to “Level 4″ on the Torino Scale — a near-Earth object (NEO) impact hazard categorization method.

Read More: Discovery News

A near-Earth object becomes visible in infrared (Image: NASA/JPL-Caltech/UCLA)

David Shiga writes on New Scientist:

An infrared space telescope has spotted several very dark asteroids that have been lurking unseen near Earth’s orbit. Their obscurity and tilted orbits have kept them hidden from surveys designed to detect things that might hit our planet.

Called the Wide-Field Infrared Survey Explorer (WISE), the new NASA telescope launched on 14 December on a mission to map the entire sky at infrared wavelengths. It began its survey in mid-January.

In its first six weeks of observations, it has discovered 16 previously unknown asteroids with orbits close to Earth’s. Of these, 55 per cent reflect less than one-tenth of the sunlight that falls on them, which makes them difficult to spot with visible-light telescopes. One of these objects is as dark as fresh asphalt, reflecting less than 5 per cent of the light it receives.

Many of these dark asteroids have orbits that are steeply tilted relative to the plane in which all the planets and most asteroids orbit. This means telescopes surveying for asteroids may be missing many other objects with tilted orbits, because they spend most of their time looking in this plane.

Read More: New Scientist

A puzzling object that seemed to be a comet flying inside the solar system’s asteroid belt is no comet at all, but the remains of a violent collision between two fossil rocks that populate the belt, astronomers say.

Captured in images by the Hubble Space Telescope, the crash of the asteroids provides scientists with their first opportunity to see clear evidence of the violent activity that has constantly churned the asteroid belt since its formation, probably when the planets themselves were forming about 4.5 billion years ago.

The object was first sighted in early January by astronomers at the Air Force LINEAR project telescope in New Mexico, who reported it as a comet that must have flown into the asteroid belt from the solar system’s outer reaches, as all comets do. It was the fifth presumed comet to be reported in the unlikely region, they said, and they gave it the code name P/2010 A2.

The main asteroid belt lies between the orbits of Mars and Jupiter, and the strange object was spotted there again later in the month by astronomers at the Kitt Peak National Observatory in Tucson.

David Jewitt, a leading expert on comets and asteroids at UCLA, was intrigued by the reports of a possible comet inside the asteroid belt where millions of rocky objects fly in orbit around the sun, constantly colliding and grinding each other down.

He quickly obtained time for the Hubble Space Telescope’s wide field camera to home in on the object, and the images showed a stony nucleus just beyond an X-shaped halo of rocky filaments and a long, streaming tail of dust and gravel.

Read More: SF Chronicle

Hubble has discovered a mysterious X-shaped object traveling at 11,000mph. NASA says that P/2010-A2 may be a comet, product of the collision between two asteroids. Or a Klingon Bird of Prey. Either way, UCLA investigator David Jewitt is excited:

This is quite different from the smooth dust envelopes of normal comets. The filaments are made of dust and gravel, presumably recently thrown out of the nucleus. Some are swept back by radiation pressure from sunlight to create straight dust streaks. Embedded in the filaments are co-moving blobs of dust that likely originated from tiny unseen parent bodies.

OK, David, we will believe you until Jerry Bruckheimer finish his next movie, in which a “comet” suddenly stops, turns to Earth, and starts firing anti-matter rays against our underpants.

The weirdest thing, however, is not only the prettyful X-shaped debris pattern, but the fact that its 460-foot-wide nucleus is outside the dust halo and separated from the trail. This behavior is something which has never been seen before in a comet or any other solar-system-swooshing object.

Read Jesus Diaz’s article at Gizmodo

Space scientists in Russia are preparing to boldly go where no man has gone before, except for the actor Bruce Willis.

The head of the Russian space agency said today that it was considering a Hollywood-style mission to send a spacecraft to bump a large asteroid from a possible collision course with Earth.

Anatoly Perminov told the Russian radio station Golos Rossii: “People’s lives are at stake. We should pay several hundred million dollars and build a system that would allow us to prevent a collision, rather than sit and wait for it to happen and kill hundreds of thousands of people.”

The mission would be aimed at an asteroid called Apophis, he said, which is expected to pass close to the Earth in 2029 and again in 2036. “Calculations show that it’s possible to create a special-purpose spacecraft within the time we have, which would help avoid the collision. The threat of collision can be averted.”

The Hollywood action films Deep Impact and Armageddon both featured space missions scrambling to avert catastrophic collisions, the latter led by Willis.

But the creation of a system to deflect asteroids has long been the subject of scientific debate. Some experts have proposed sending a probe to circle around a dangerous asteroid and gradually change its trajectory. Others suggested sending a spacecraft to collide with it and alter its momentum, or using nuclear weapons.

Perminov said details of the project still needed to be worked out. But he said the agency would invite Nasa, the European Space Agency and others to participate.

When Apophis was discovered in 2004, astronomers made headlines when they said there was a one in 37 chance that the 350-metre-wide rock would collide with Earth in 2029. Further studies ruled out such an impact, but there remains a one in 250,000 chance it could strike in 2036.

Read More in the Guardian

Contrary to preconceived notions, the atmosphere and the oceans were perhaps not formed from vapors emitted during intense volcanism at the dawning of our planet. Francis Albarède of the Laboratoire des Sciences de la Terre (CNRS / ENS Lyon / Université Claude Bernard) suggests that water was not part of the Earth’s initial inventory but stems from the turbulence caused in the outer Solar System by giant planets. Ice-covered asteroids thus reached the Earth around one hundred million years after the birth of the planets.

The Earth’s water could therefore be extraterrestrial, have arrived late in its accretion history, and its presence could have facilitated plate tectonics even before life appeared. The conclusions of the study carried out by Albarède feature in an article published on the 29 October 2009 in the journal Nature.

Space agencies have got the message: wherever there is life there has to be water. Around 4.5 billion years ago, the Earth was bequeathed with sufficient water for oceans to form and for life to find favorable niches in the seas and on the continents resulting from plate tectonics. In comparison, the Moon and Mercury are dry, mortally cold deserts, Mars dried up very quickly and the surface of Venus is a burning inferno…

[continues in Science Daily]

Although no one noticed at the time, the Earth was almost hit by an asteroid last Friday.

The previously undiscovered asteroid came within 8,700miles of Earth but astronomers noticed it only 15 hours before it made its closest approach.

Its orbit brought it 30 times nearer than the Moon, which is 250,000 miles away.

But before you head for the nuclear bunkers you will be relieved to learn the tumbling rock was only 23ft across. Similar sized objects pass by this close to Earth about twice a year and impact on the planet about once every five years.

Astronomers believe the object, called 2009 VA, would have almost completely burned up while entering Earth’s atmosphere, causing a brilliant fireball in the sky but no major damage to the surface.

The asteroid was discovered by the Catalina Sky Survey on November 6, 2009. It was then identified by the Minor Planet Centre in Cambridge, Massachusetts as a near Earth object.

Nasa’s Near Earth Object Programme plotted the orbit of the object and determined that although it would fly extremely close to our planet it wouldn’t hit us.

It was the third-closest known (non-impacting) Earth approach on record for a cataloged asteroid.

[continues in the Daily Mail]

]]> http://www.disinfo.com/2009/11/asteroid-passes-just-8700-miles-from-earth-with-only-15-hours-warning/feed/ 6 http://www.disinfo.com/2009/10/scientists-close-in-on-mystery-of-arctic-asteroid-strikes/ http://www.disinfo.com/2009/10/scientists-close-in-on-mystery-of-arctic-asteroid-strikes/#comments Tue, 13 Oct 2009 14:29:44 +0000 majestic http://www.disinfo.com/?p=12020 Alexis Madrigal reports in Wired:

Two polar scientists hot on the trail of an arctic mystery have a new tool for exploration: a hovercraft, specially outfitted for week-long trips over the ice with scientific instruments and solar panels.

Their quarry is a nearly 22,000 square-mile patch of disturbed Arctic sea floor that could be evidence of a massive asteroid strike. John Hall, a now-retired geoscientist, discovered the anomaly during his late-’60s graduate work aboard Fletcher’s Ice Island, a huge berg U.S. scientists inhabited for several decades.

Since then, no scientific vessel has been back over the area to collect more data. The massive icebreakers that have crunched through the Arctic since the 1990s can’t reach the spot, said Yngve Kristofferson, a scientist and explorer at the University of Bergen in Norway.

]]> Alexis Madrigal reports in Wired:

Two polar scientists hot on the trail of an arctic mystery have a new tool for exploration: a hovercraft, specially outfitted for week-long trips over the ice with scientific instruments and solar panels.

Their quarry is a nearly 22,000 square-mile patch of disturbed Arctic sea floor that could be evidence of a massive asteroid strike. John Hall, a now-retired geoscientist, discovered the anomaly during his late-’60s graduate work aboard Fletcher’s Ice Island, a huge berg U.S. scientists inhabited for several decades.

Since then, no scientific vessel has been back over the area to collect more data. The massive icebreakers that have crunched through the Arctic since the 1990s can’t reach the spot, said Yngve Kristofferson, a scientist and explorer at the University of Bergen in Norway.

]]> http://www.disinfo.com/2009/10/scientists-close-in-on-mystery-of-arctic-asteroid-strikes/feed/ 0