The gold ring around your finger may symbolize “till death do us part” for you, but for scientists, it poses a problem.
That shiny band probably cost a small fortune at the jewelry store, but gold is actually abundant on the Earth’s surface (which helps explain why it’s the ideal form of money). The difficulty is, when scientists apply what they know about how the solar system formed, it’s hard to explain how all that gold (and other precious metals that bond easily to iron, like palladium and platinum) got into the Earth’s crust, where bling-loving humans could get at it. A new study in Science sets forth an explanation: In the Earth’s younger days, impacts by huge objects—perhaps even one as big as Pluto—may have brought it here.
To explain this theory, let’s start with the most dramatic impact in our planet’s history: the one that formed the moon and re-melted the solidifying Earth in the process.
Moon rocks brought back during the Apollo missions led to the now widely accepted theory that the moon formed when a Mars-size object crashed into early Earth. Energy from the impact would have spurred the still forming Earth to develop its mostly iron core. When this happened, iron-loving metals should have followed molten iron down from the planet’s mantle and into the core. But we know that gold and other iron-lovers are found in modest abundances in Earth’s mantle. [National Geographic]
Out in the asteroid belt beyond Mars, two asteroids rendezvous-ed in the darkness, with explosive results. Atomic bomb level explosive.
These two asteroids, one probably 400 feet wide and the other, smaller asteroid around 10 to 15 feet across, collided sometime in early 2009. This is the first time we humans have observed an asteroid impact right after it has occurred, and the first time a resulting x-shape has been seen. Researchers aren’t sure what caused the novel shape, and they were surprised by how long the dust tail has lasted. The analysis of the finding, originally announced earlier this year, is published in Nature this week.
This is a false-color image showing the object, called P/2010 A2, in visible light. The long tail of debris is obvious; this is probably dust being blown back by the solar wind, similar to the way a comet’s tail is blown back. What apparently has happened is that two small, previously-undiscovered asteroids collided, impacting with a speed of at least 5 km/sec (and possibly faster). The energy in such a collision is like setting off a nuclear bomb, or actually many nuclear bombs! The asteroids shattered, and much of the debris expanded outward as pulverized dust.
Looking at the image, the bright spot to the left is most likely what’s left of one of the two asteroids, a chunk of rock estimated to be a mere 140 meters (450 feet) across. In the press release they’re not clear about the curved line emanating to the right of the nucleus. It may be — and I’m spitballing here — dust blown back from a stream of chunks, since the tail is broad and appears to originate from that swept curve, and not from the nucleus itself. The other filament perpendicular to the curve is from yet another piece of debris.
Our own moon, the thinking goes, formed when a huge rock slammed into the Earth billions of years ago. Is the same true of one of Mars’ dual moons?
The Martian moon Phobos hides an unknown history. One idea has been that the 12-mile by 17-mile rock came from the nearby asteroid belt, and Mars’ gravity captured it. However, new evidence from the European Space Agency’s explorer Mars Express suggests that the stuff of Phobos is more Mars-like than asteroid-like, and therefore its origin goes back to a violent collision that knocked material from Mars into its own orbit. That material would have eventually coalesced into Phobos.
Zoom, zoom: Today two asteroids make close flybys of the Earth, passing inside the orbit of the moon. We’re in no danger, NASA says, but these close passes are a reminder that the United States and the world need to figure out how we’re going to catch an asteroid that could be on a collision course with our planet.
The larger asteroid, called 2010 RX30, passed by this morning. The smaller, 2010 RF12, is due for a pass at 5:12 p.m. Eastern time today. RF12, which is estimated to be between 20 and 46 feet in diameter, will come within about 50,000 miles of the Earth.
This is higher than communications satellites in geosynchronous orbit 22,369 miles (36,000 km) above Earth. On average, the moon is about roughly 238,600 miles (384,000 km) from Earth, so 2010 RF12 will pass by at nearly 0.2 of that lunar distance. [MSNBC]
Astronomers have confirmed it: Neptune has a stalker. They have spotted, for the first time, an asteroid follower that keeps a fairly constant distance behind the planet in its orbit around the sun. And there may be many more.
Asteroid 2008 LC18 can’t help itself. It’s caught in a balancing game between the gravitational tug of the sun and Neptune, and effects from its whirling course. The conflicting tugs cause the asteroid not to orbit Neptune or crash into it, but instead to follow the planet from a little distance behind (about 60 degrees on its path).
Neptune has five of the these pits–called Lagrangian points (see diagram below the fold)–but the spots ahead and behind the planet, researchers say, are best for asteroid-trapping, since the hold is particularly stable in these places. Researchers have previously spotted several asteroids in front of the planet (again by about 60 degrees), but this is the first time they’ve found one following it. The findings appeared online yesterday in Science.
Beware death from above! So blared science headlines yesterday. Citing a study in the Journal Icarus that said a huge asteroid perhaps could have a 1 in 1,000 shot of striking earth late in the next century, stories broke such as,
They’re correct in that there’s a giant asteroid out there called 1999 RQ36, and there’s a small chance it might hit us in a just less than couple hundred years. There’s just one problem: It isn’t news, though you wouldn’t have gotten that from the articles. The study everyone is referring to came out last year—it was in Icarus last October.
On Saturday, the European Space Agency’s Rosetta probe took the world’s closest pictures of the 80- by 50-mile-wide asteroid known as 21 Lutetia. Though the Lutetia visit is just a stop on the way to Rosetta’s real destination–a 2014 visit to the comet 67P/Churyumov-Gerasimenko–Saturday’s pictures document the closest visit to this big asteroid, the largest we’ve ever visited with a spacecraft.
We’ve known about Lutetia for quite a while: since 1852, according to Sky and Telescope. In November of that year, Hermann Goldschmidt spotted the space rock from his Paris balcony. The asteroid is now around 280 million miles from the Sun. From only 2,000 miles away, Rosetta got a much closer look at Lutetia, whipping around it at about 10 miles per second (30,000 miles per hour) as its OSIRIS camera snapped pictures recording details down to a few dozen meters.
“The fly-by has been a spectacular success with Rosetta performing fautlessly,” ESA said in a statement. “Just 24 hours ago, Lutetia was a distant stranger. Now, thanks to Rosetta, it has become a close friend.” [AFP]
Yes, the Hayabusa mission’s sample container captured some tiny dust particles. No, we still don’t know whether those particles are the first bits of an asteroid ever returned to Earth by a spacecraft.
Scientists from Japan’s space agency, JAXA, have slowly and cautiously been prying open Hayabusa’s container. They have released photos that show particles trapped in there, none of which are larger than a millimeter, but at least 10 of which are visible to the naked eye. However, it may take months to know whether those came from the Itokawa asteroid that Hayabusa visited, or somewhere else.
Hayabusa project manager Junichiro Kawaguchi said scientists believed materials from Earth were among the particles found in the pod. “But it’s important that it wasn’t empty… I’m glad that there is the possibility” that some are from the asteroid, Kawaguchi told a press briefing [AFP].
When Japan’s Hayabusa space probe returned home from a seven-year odyssey this month, we got to see the amazing video as it broke up in a brilliant flash in the atmosphere and deposited its sample container (hopefully containing asteroid material) in Australia. Three high school students from Massachusetts, however, got a much better view. They experienced it first hand, and helped make that video for the world to see, thanks to a little white lie told by their teacher.
Ron Dantowitz of Brookline, Massachusetts, gave the three a challenge: If you had to track an object entering the atmosphere at 27,000 miles per hour, how would you know where to look, how would you keep the camera trained on the careening object, and what could you learn about the temperatures the object encountered? After they worked on the project for half a year, Dantowitz let loose his secret—this was no hypothetical scenario. He and the three students got to fly on the DC-8 over Australia and help NASA film Hayabusa’s return.
“We had flown several practices, but when we took off for the real thing, I felt a surge of adrenaline,” says [James] Breitmeyer. “I was on the edge of my seat, anxious for our plane to arrive at the right place at the right time.”
“We got to the rendezvous area 30 minutes ahead of time,” says Dantowitz. “So we practiced the rendezvous to make sure everyone knew which stars to line the cameras up with to capture Hayabusa’s re-entry. By the time we finished the trial run, we had only 2 or 3 minutes to go” [NASA Science News].
You try coming home on time after traveling four billion miles.
Three years after its initially scheduled return date, Japan’s Hayabusa spacecraft returned to Earth yesterday and dropped its collection canister in the Australian outback. The team from JAXA, Japan’s space agency, hopes that the container holds samples from Hayabusa’ 2005 landing on an asteroid called Itokawa. They won’t know for sure for a couple weeks, but Hayabusa has already made history by landing on an asteroid and returning to Earth.
(Check out DISCOVER blogger Phil Plait’s post featuring video footage of Hayabusa’s return in which the probe breaks up into a spectacular flash.)
The headline on JAXA’s website currently reads, “Welcome back HAYABUSA to Earth after overcoming various difficulties!” That’s putting it mildly:
Hayabusa was originally due to return to Earth in 2007 but a series of technical glitches — including a deterioration of its ion engines, broken control wheels, and the malfunctioning of electricity-storing batteries — forced it to miss its window to maneuver into the Earth’s orbit until this year [AP].
South Korea’s attempt to jump into the space race met with disaster today. A little more than two minutes after takeoff today, the nation’s Naro rocket exploded. It had been carrying a satellite, and South Korea was vying to become the tenth country to put a satellite in orbit with rockets assembled at home.
South Korea has invested more than 500 billion won (400 million dollars) and much national pride in the 140-ton Naro-1. The liquid-fuelled first stage of the rocket was made in Russia, while the second stage was built domestically, as was the satellite [AFP].
In Japan, meanwhile, happier news: Last month its space agency, JAXA, launched a batch of new missions into space that included its solar sail project, called Ikaros. Today it unfurled the sail, seen above in the blinding light of the sun.
After separating from Akatsuki [a separate probe going on to Venus], Ikaros began unfolding four panels that, when fully unfurled, should look like a square kite measuring 66 feet (20 meters) along its diagonal. Pictures sent back by a camera mounted on the spacecraft’s hub show the extension of four booms holding the panels, plus the unfurling of sail material. This is the “primary deployment” of the sail. During the secondary stage of deployment, the sail is stretched out to its full extent [MSNBC].
There are millions of asteroids in the asteroid belt between Mars and Jupiter, but yesterday attention focused on just one. According to a couple of studies in Nature, a large asteroid called 24 Themis is rife with water ice and organic molecules, and the researchers say that it could be more evidence that the water so precious to life on Earth came to our planet on board such rocks.
Two research teams took infrared images of 24 Themis, which is about 120 miles in diameter and was discovered in 1853. This asteroid has an extensive but thin frosty coating. It is likely replenished by an extensive reservoir of frozen water deep inside rock once thought to be dry and desolate [AP].
The team, led by Humberto Campins, says finding so much ice on the surface was a surprise; at the asteroid’s distance from the sun—3.2 astronomical units (AU), or just more than three times further than the Earth—exposed ice has a “relatively short lifetime,” the scientists write. As a result, the idea of a below-surface reservoir seems likely. (Icy comets aren’t nearly so close to the sun on average; Halley’s comet can come within .6 AU of the sun, but then retreats to a farthest distance of more than 35 AU.)
Battered, drained of fuel, and travel-weary, Japan’s asteroid-sampler is almost home. The Hayabusa, which the Japanese Aerospace Exploration Agency (JAXA) launched in 2003, is scheduled to drop its sample canister in the Australian outback in June. But, the project leaders warn, there’s still a chance than the beleaguered sojourner won’t make it. And even if it does successfully return to Earth, it’s possible that the sample capsule may not contain extraterrestrial rock.
Hayabusa spent three months exploring the Itokawa asteroid in late 2005, even making an unplanned landing on the asteroid’s surface. The probe spent up to a half-hour on Itokawa, making it the first spacecraft to lift off from an asteroid [Space.com]. The craft also took 1,600 pictures and more than 100,000 infrared images.
One week ago today, in response to heavy criticism for killing the Constellation program begun under his predecessor, President Obama presented his revised vision for NASA: To build a new heavy lift spacecraft that will go beyond low Earth orbit and land on an asteroid by around 2025. This goal is far more ambitious than going back to the moon. Space experts say such a voyage could take several months longer than a journey to the moon and entail far greater dangers. “It is really the hardest thing we can do,” NASA Administrator Charles Bolden said [AP].
NASA doesn’t know which of the nearby asteroids it might pick for a visit, but the main candidates are around 5 million miles from Earth. The moon, by contrast, is a little less than a quarter-million miles away. The asteroids are about a quarter-mile across; the moon is more than 2,000 miles in diameter. And a trip to an asteroid could take 200 days, as opposed to the Apollo 11 lunar round-trip, which required little more than a week. That means NASA may have to devise new radiation shields and life-support systems for the asteroid-bound astronauts.
Will we ever get a solid answer on what killed the dinosaurs? According to a new “K-T Boundary Dream Team” comprising of 41 international experts, including geophysicists and paleontologists, yes, the question has been settled: An asteroid is indeed to blame.
For years, scientists have argued over different theories of what killed the dinos–including one hypothesis that has gained ground recently, which suggests that massive volcanic activity in India’s Deccan Traps wiped them out 65 million years ago. However, the latest expert panel stuck to the asteroid theory, saying a massive impact wiped out the dinos and more than half of the Earth’s other species. The panel’s review was published in the journal Science.
After studying all the available data on the Cretaceous-Tertiary (K-T) mass extinction, the panel concluded that the catastrophic event was caused by a 6-mile-wide asteroid that struck Earth at an angle of 90 degrees and a speed of about 12.4 miles per second – about 20 times faster than a speeding bullet [Guardian]. The asteroid hit Chicxulub, Mexico, with a force one billion times more powerful than the atomic bomb at Hiroshima [Science Daily News].
The impact of the crash would have triggered large scale fires, landslides, earthquakes that measured 10 on the Richter scale, and subsequent tsunamis, scientists said. Debris loosened by the impact would have shrouded the planet, clouding the skies, causing a global darkness, and “killing off many species that couldn’t adapt to this hellish environment” [Science Daily News], according to study coauthor Joanna Morgan.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
The gold ring around your finger may symbolize “till death do us part” for you, but for scientists, it poses a problem.
Our own moon, the thinking goes, formed when a huge rock slammed into the Earth billions of years ago. Is the same true of one of Mars’ dual moons?
Zoom, zoom: Today two 
Beware death from above! So blared science headlines yesterday. Citing a study in the Journal Icarus that said a huge asteroid perhaps could have a 1 in 1,000 shot of striking earth late in the next century, stories broke such as,
On Saturday, the European Space Agency’s 
Yes, the Hayabusa mission’s sample container captured some tiny dust particles. No, we still don’t know whether those particles are the first bits of an asteroid ever returned to Earth by a spacecraft.
You try coming home on time after traveling four billion miles.
South Korea’s attempt to jump into the space race met with disaster today. A little more than two minutes after takeoff today, the nation’s Naro rocket exploded. It had been carrying a satellite, and South Korea was vying to become the tenth country to put a satellite in orbit with rockets assembled at home.
There are millions of asteroids in the asteroid belt between Mars and Jupiter, but yesterday attention focused on just one. According to a 
Battered, drained of fuel, and travel-weary, Japan’s asteroid-sampler is almost home. The Hayabusa, which the Japanese Aerospace Exploration Agency (JAXA) launched in 2003, is scheduled to drop its sample canister in the Australian outback in June. But, the project leaders warn, there’s still a chance than the beleaguered sojourner won’t make it. And even if it does successfully return to Earth, it’s possible that the sample capsule may not contain extraterrestrial rock.
If you wanted dangerous, you got it.
Will we ever get a solid answer on what killed the 
