Asteroid Bennu Had Water! NASA Probe Makes Tantalizing Find
By Mike Wall, Space.com Senior Writer | December 11, 2018
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 asteroids like 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 Bennu precisely 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.
The abundance of these obstacles means the OSIRIS-REx team must plan out its sample-grabbing activities in great detail and with great care. But that's fine, team members said, because there's still plenty of time to choose and characterize a sampling site; OSIRIS-REx isn't scheduled to snag any Bennu bits until July 2020.
This material will come down to Earth in a special return capsule in September 2023. Scientists around the world can then scrutinize the sample with a variety of laboratory equipment, making observations that address the main mission goals as well as a variety of other questions.
For example, the mission could help researchers better understand the resource potential of Bennu-like asteroids — whether they contain enough accessible water to support in-space mining operations. And OSIRIS-REx's measurements at Bennu will reveal key details about the forces that affect asteroids' paths through space, which should help fine-tune predictions of the trajectories of potentially hazardous space rocks, NASA officials have said.
"We have an awesome asteroid to explore," Lauretta said. "It's a dream come true, and it's an honor and a privilege to be able to lead a program like this for NASA and for the United States and, really, for the world."
spotless38: Iam back after a long break . What a couple of years I had . After what had happened I lost my brother and had to bury him and then I had caught that type A flue and I was a very sick puppy I also needed blood for the loss of it .
Jul 7, 2018 13:30:41 GMT -6
lois: Very Happy to see you Ron. Missed you. Glad you are doing better now. Sorry for your lost. I did not know your brother had passed. hugs lois
Jul 10, 2018 0:52:45 GMT -6
paulette: Ron - hope you've hit a quiet spot. Sorry for your loss.
Aug 3, 2018 10:49:30 GMT -6
lois: I picked up my phone a few days ago and I looked at the name of the caller. Boy was I surprise. It has been a couple of years. So good to hear your voice Ron. Hope you make it a habit again. love and hugs .
Aug 15, 2018 23:21:38 GMT -6
leia77: Spotless, I am glad that you are feeling better and welcome back! I too am back from a long time away...
Aug 31, 2018 2:08:32 GMT -6
jcurio: I am much relieved to see that you have been on here, Spotless! I hope that things are going much better for you now
Sept 19, 2018 16:46:42 GMT -6
jcurio: And Lois, And Lorelei!
Sept 19, 2018 16:47:07 GMT -6
casper: And Meeeeeee!!
Oct 16, 2018 18:41:31 GMT -6
lois: Sorry guys I cannot see the print. On is tiny hand computer
Oct 21, 2018 20:42:09 GMT -6
lois: Casper your page stops at page five in 2016
Nov 15, 2018 23:54:01 GMT -6
lois: How did your Halloween night go this year?
Nov 15, 2018 23:54:58 GMT -6
skywalker: He posted on the Halloween thread this year.
Nov 25, 2018 18:33:36 GMT -6
lois: Oh ok Sky I will check it out. Thanks.
Dec 21, 2018 21:45:31 GMT -6
lois: What topic was it under.
Dec 21, 2018 21:51:07 GMT -6