Twelve years ago, Dante Lauretta, a budding meteorite scientist at the University of Arizona in Tucson, was close to a breakthrough. His team was examining carbon-rich meteorites and had detected whiffs of triphosphate—the “TP” in adenosine triphosphate, or ATP, the molecule that powers life. But they couldn’t nail it because of terrestrial contamination. One sample, for instance, came from a meteorite that had crashed into an Australian manure ditch. Lauretta needed something pristine.
On 8 September, Lauretta will be a space flight away from getting his wish, with the launch of the $1 billion Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx). Although it won’t be the first spacecraft to bring asteroid dust back to Earth—Japan’s Hayabusa 1 returned several thousand grains of dust in 2010—the scoop of grit it delivers in 2023 could reveal new insights into the unaltered building blocks of the solar system and the types of amino acids and other organic molecules that asteroid impacts delivered to an early Earth.
The samples will come from Bennu, a half-kilometer-wide asteroid that’s as black and dense as coal. It’s a “B-type” asteroid, one of the parent bodies suspected to be responsible for the carbon-rich meteorites that Lauretta studied. Its orbit at times brings it nearly as close to Earth as the moon, so astronomers have studied it well. Nevertheless, mystery remains. There’s a small chance, for instance, that a hint of blue in its reflection could point to a past episode of heating that might have destroyed the anticipated organic molecules.
Upon arrival in August 2018, the spacecraft will survey Bennu from 240 meters above the surface. It will study the Yarkovsky effect, in which photons emitted from the sun-heated surface of a small, rotating asteroid generate a minuscule force that can alter its orbit. Because the effect varies greatly depending on subtle differences in shape and reflectivity, scientists want an opportunity to study it up close. The effect can also be used to trace asteroid orbits back in time, in order to identify the events that created them. Team scientists hope to confirm suspicions that Bennu was born hundreds of millions of years ago in collisions within the asteroid belt.
http://www.sciencemag.org/news/2016/08/nasa-sample-asteroid-clues-life-earth
On 8 September, Lauretta will be a space flight away from getting his wish, with the launch of the $1 billion Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx). Although it won’t be the first spacecraft to bring asteroid dust back to Earth—Japan’s Hayabusa 1 returned several thousand grains of dust in 2010—the scoop of grit it delivers in 2023 could reveal new insights into the unaltered building blocks of the solar system and the types of amino acids and other organic molecules that asteroid impacts delivered to an early Earth.
The samples will come from Bennu, a half-kilometer-wide asteroid that’s as black and dense as coal. It’s a “B-type” asteroid, one of the parent bodies suspected to be responsible for the carbon-rich meteorites that Lauretta studied. Its orbit at times brings it nearly as close to Earth as the moon, so astronomers have studied it well. Nevertheless, mystery remains. There’s a small chance, for instance, that a hint of blue in its reflection could point to a past episode of heating that might have destroyed the anticipated organic molecules.
Upon arrival in August 2018, the spacecraft will survey Bennu from 240 meters above the surface. It will study the Yarkovsky effect, in which photons emitted from the sun-heated surface of a small, rotating asteroid generate a minuscule force that can alter its orbit. Because the effect varies greatly depending on subtle differences in shape and reflectivity, scientists want an opportunity to study it up close. The effect can also be used to trace asteroid orbits back in time, in order to identify the events that created them. Team scientists hope to confirm suspicions that Bennu was born hundreds of millions of years ago in collisions within the asteroid belt.
http://www.sciencemag.org/news/2016/08/nasa-sample-asteroid-clues-life-earth
