Asteroid Bennu getting first visitor in billions of years

Asteroid Bennu getting first visitor in billions of years
This artist's rendering made available by NASA in July 2016 shows the mapping of the near-Earth asteroid Bennu by the OSIRIS-REx spacecraft. The spacecraft will spend a year surveying Bennu before collecting a sample that will be returned to Earth for analysis. (NASA/Goddard/University of Arizona via AP)

An asteroid that may hold the key to life is getting its first visitor in billions of years.

Asteroid Bennu, a black roundish rock taller than the Empire State Building, is the intended target of a NASA spacecraft set to blast off Thursday night. Not only will the robotic probe named Osiris-Rex fly to this ancient asteroid, it will scout it out for two years before scooping up some gravel and dust, and deliver the samples back to Earth.

All told, the mission will take seven years, from launch to sample return.

Flying to another world is no simple matter. Neither is vacuuming samples off an asteroid. "We're going out into the unknown," said principal scientist Dante Lauretta of the University of Arizona at Tucson.

Five tidbits about Bennu, chosen for NASA's first such mission from more than 500,000 known asteroids in our solar system:

BENNU THE BIRD

Bennu (BEHN'-oo) was discovered in 1999 and got its name for this mission 14 years later. A North Carolina schoolboy had the winning entry in an international student naming contest held by the University of Arizona, the Planetary Society and others; he likened the boxy spacecraft, with its twin and 10-foot mechanical arm, to the heron of Egyptian mythology, Bennu. The spacecraft shares that Egyptian motif, bearing the mythological god's name Osiris. Osiris-Rex also doubles as a NASA acronym.

BIG SPACE BALL

Bennu is shaped like a ball, with a fat middle. Scientists believe the equatorial girth is loose rubble or gravel, the ideal size for collecting a sample. The asteroid rotates every four hours—yes, a day is just over four hours at Bennu. This rotation is slow enough for a spacecraft to reach out and suck in samples, using nitrogen gas to stir up the surface. "We are basically a space vacuum cleaner," Lauretta said Wednesday. Also think hummingbird, as the spacecraft hovers over Bennu during the big grab. Bennu is believed to be 1,600 feet across. Asteroids smaller than 650 feet in diameter were eliminated as candidates; they spin so fast that their surface material can be hurled out into space.

Asteroid Bennu getting first visitor in billions of years
A United Launch Alliance Atlas V rocket, carrying NASA's OSIRIS-REx spacecraft, sits at its launchpad at Cape Canaveral Air Force Station in Florida on Wednesday, Sept. 7, 2016. The mission, scheduled to launch on Sept. 8, is the first U.S. attempt to reach an asteroid return a sample to Earth for study. (NASA/Joel Kowsky via AP)

CLOSE BY COSMIC STANDARDS

Bennu's orbit around the sun is only a little bigger than Earth's; it circles the sun about every 14 months and, in fact, swings by Earth every six years. That cuts down on the travel time for Osiris-Rex and, via its proximity to the sun, keeps its solar wings energized. The asteroid's orbit is slightly off-kilter to Earth's, however, which will require an adjustment to the spacecraft's path. When Osiris-Rex swings by Earth a year after launch for a gravity assist, it will end up in the same tilted orbital plane as Bennu.

NO EARTH-ENDER

Bennu is potentially hazardous, but no Earth-ender. There's a slight chance it could strike the home planet 150 years or so from now—just one-tenth of 1 percent, according to Lauretta. It would be a major natural disaster, carving out a huge crater, but not a knockout punch for Earth or life as we know it, he stressed. This mission should help scientists better understand the changing paths of asteroids.

CARBON, PLEASE

Bennu is the color of coal. That's a sign the asteroid is rich in carbon dating back to the origin of the solar system 4.5 billion ago. If so, Bennu is a time capsule that could help explain how life sprouted on Earth and, possibly, elsewhere in the neighborhood. "We've done the best job we can" to characterize the with telescopes, Lauretta said. Once a sample is brought back "then we'll be able to answer the question definitively."

___

Online:

NASA: www.nasa.gov/osiris-rex


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NASA chasing down asteroid to scoop up, bring back samples

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Sep 07, 2016
Just wondering how they intend to "Suck up" dust off the asteroid in the vacuum of space.

Sep 07, 2016
two hoses. one supplies the gas (nitrogen?) to blow particles off. the other hose sucks the gas back up with the lose particles..

Sep 07, 2016
Just wondering how they intend to "Suck up" dust off the asteroid in the vacuum of space.

According to http://forum.kerb...=2478484
The sampling system uses a jet on nitrogen gas to blow surface regolith into an air filter-like collector on the end of a robotic arm.  It touches the surface for only 5 seconds then stows the collection head inside the (Stardust-like) sample return capsule (SRC) by severing the head.

Sep 07, 2016
Wonder if this asteroid, which they believe is rich in carbon, may be a left over from the alleged collision supposedly giving Earth its carbon?

http://phys.org/n...hup.html

Sep 08, 2016
I wonder how much Bennu will alter the asteroid's orbit. I don't know how to do the calculations, but it seems like it could a measurable change in orbit.

Sep 11, 2016
Seems to me that when Bennu "touches the surface for only 5 seconds" it's likely to crash into that surface as a result. And I also wonder exactly how they determined it will touch for only 5 seconds, given the lack of details regarding the surface and how spherical it actually is. One little 1 m boulder on that surface in its supposed 5 second path will do the trick. Bennu will have to be pretty smart to avoid that potential boulder, mound, sand dune or other obstacles, given the delay of communications across space.

Sep 11, 2016
Seems to me that when Bennu "touches the surface for only 5 seconds" it's likely to crash into that surface as a result. And I also wonder exactly how they determined it will touch for only 5 seconds, given the lack of details regarding the surface and how spherical it actually is. One little 1 m boulder on that surface in its supposed 5 second path will do the trick. Bennu will have to be pretty smart to avoid that potential boulder, mound, sand dune or other obstacles, given the delay of communications across space.
You like to pretend you know what you're talking about don't you? I know that whatever occurs to guys like you in the 5 seconds you spend thinking about it, has also occurred to the teams of scientists and engineers who have been working on it for months.

And so when they describe what they intend to do with it I accept what they say, and giggle when I read crap like your post.

But hey - keep pretending if it gives you a thrill.

Sep 11, 2016
Just wondering how they intend to "Suck up" dust off the asteroid in the vacuum of space
See, when you ask questions like this instead of taking a few seconds to Google it yourself and learn something, it gives guys like tomcat the opportunity to Google it and post a half-assed explanation like he knew it all along instead of posting an excerpt or a link which is after all the only way we learn anything useful here.

So what did we accomplish? Besides some quality snark that is-
Wonder if this asteroid, which they believe is rich in carbon, may be a left over from the alleged collision supposedly giving Earth its carbon?
-Ditto. It's on the internet.

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