On Feb. 15th an asteroid about half the size of a football field will fly past Earth closer than many man-made satellites. Since regular sky surveys began in the 1990s, astronomers have never seen an object so big come so close to our planet.
Entries in Asteroid (58)
In the event that a giant asteroid is headed toward Earth, you'd better hope that it's blindingly white. A brightly colored asteroid would reflect sunlight — and over time, this bouncing of photons off its surface could create enough of a force to push the asteroid off its course.
How might one encourage such a deflection? The answer, according to an MIT graduate student: with a volley or two of space-launched paintballs.
Read more at MIT News: http://web.mit.edu/newsoffice/2012/deflecting-an-asteroid-with-paintballs-102...
With optical telescopes, it's difficult to make out the surface features of asteroid Toutatis. Radar gives us a different picture. On Dec. 12 and 13, 2012, scientists pointed NASA's Goldstone Solar System Radar precisely on the asteroid while it was over four million miles/6.9 million kilometers away. Using the bounced radar signals scientists assembled these "images" showing the surface features of Toutatis, an asteroid measuring about 3 miles long (4.8 km). The orbit of Toutatis is well understood. An analysis indicates there is zero possibility of an Earth impact over the entire interval over which its motion can be accurately computed, which is about the next four centuries.
Japan's space agency, JAXA, is preparing for a mission to an asteroid where it hopes to find clues to the origins of life on Earth. In 2010 a similar mission successfuly brought asteroid samples back to Earth for examination but this next attempt, set for 2014, is aiming even higher. Rob Muir has more.
NASA's Dawn space probe has found hydrogen within the giant asteroid Vesta's surface. The element may have at one time been part of water ice before boiling off and leaving behind hydrated minerals.