Asteroid Bennu Had Water! NASA Probe Makes Tantalizing Find.

Pedro_P

This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24 kilometers).
Credit: NASA/Goddard/University of Arizona
▼ It looks like NASA chose the right space rock for its asteroid-sampling mission.
The agency's OSIRIS-REx probe, which just  arrived at Bennu last week, has already found hydrated minerals on the 1,640-foot-wide (500 meters) near-Earth asteroid, mission team members announced yesterday (Dec. 10).
The discovery suggests that liquid water was once plentiful in the interior of Bennu's parent body, which scientists think was a roughly 62-mile-wide (100 kilometers) rock in the main asteroid belt between Mars and Jupiter. (Bennu is likely a pile of rubble that coalesced after a massive impact shattered that larger object hundreds of millions of years ago.)
OSIRIS-REx's main goal involves helping scientists better understand the solar system's early days and the role that asteroidslike Bennu may have played in delivering water and the chemical building blocks of life to Earth. So, the water find is big news for the mission team.
"We targeted Bennuprecisely because we thought it had water-bearing minerals and, by analogy with the carbonaceous chondrite meteorites that we've been studying, organic material," OSIRIS-REx principal investigator Dante Lauretta, of the University of Arizona, said today during a news conference at the annual fall meeting of the American Geophysical Union in Washington, D.C.
"That still remains to be seen — we have not detected the organics — but it definitely looks like we've gone to the right place," Lauretta added.
The $800 million OSIRIS-REx mission(whose name is short for "Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer") launched in September 2016 and began its Bennu-approach phase in mid-August of this year.
Measurements made over the past four months by the spacecraft's two onboard spectrometers revealed the presence of molecules containing hydroxyls — bonded-together oxygen and hydrogen atoms — on Bennu, Lauretta and fellow team members announced today. Mission scientists think these hydroxyls are widespread across the asteroid, locked into clay minerals.
Scientists also announced today that OSIRIS-REx's observations pretty much confirm Bennu shape models devised a half-decade ago by researchers using radar data gathered by the Arecibo and Goldstone dishes here on Earth. That's good news, Lauretta said, because the mission team drew up its plans based on those earlier shape models.
In addition, NASA today released OSIRIS-REx's best look at Bennu to date. The dazzling photo, taken on Dec. 2 just before the spacecraft's official asteroid arrival, shows Bennu in unprecedented detail and highlights the rugged nature of its surface. (Arrival is different than orbit, by the way; OSIRIS-REx won't begin circling Bennu until Dec. 31.)
Bennu is littered with boulders, to an extent that Lauretta and his colleagues deemed surprising. The biggest of these jutting rocks is about 165 feet tall by 180 feet wide (50 by 55 m), mission team members said. (▪ ▪ ▪)

► Please, read the full note/article here: Source