To deflect an asteroid, paint it white. That’s the idea that made MIT graduate student Sung Wook Paek the winner of the 2012 Move An Asteroid Competition, a contest set up by the United Nations’ Space Generation Advisory Council that sought innovative ways to deflect asteroids. Paek’s plan is to hurl pellets of white paint at an asteroid in order to make it more reflective, meaning that more photons, or particles of light, would bounce off it, rather than being absorbed. Over time, the force of those photonic collisions, combined with the initial force of the paintballs, would be enough, Paek thinks, to move the asteroid off its path toward Earth.
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.
From Phil Plait, DISCOVER’s Bad Astronomer:
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].