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Astronomy Picture of the Day - Gravel Ejected from Asteroid Bennu
APOD.NASA.gov ^ | 16 Sep, 2020 | Image Credit: NASA's GSFC, U. Arizona, OSIRIS-REx Lockheed Martin

Posted on 09/16/2020 5:54:43 PM PDT by MtnClimber

Explanation: Why does asteroid Bennu eject gravel into space? No one is sure. The discovery, occurring during several episodes by NASA's visiting OSIRIS-REx spacecraft, was unexpected. Leading ejection hypotheses include impacts by Sun-orbiting meteoroids, sudden thermal fractures of internal structures, and the sudden release of a water vapor jet. The featured two-image composite shows an ejection event that occurred in early 2019, with sun-reflecting ejecta seen on the right. Data and simulations show that large gravel typically falls right back to the rotating 500-meter asteroid, while smaller rocks skip around the surface, and the smallest rocks completely escape the low gravity of the Earth approaching, diamond-shaped asteroid. Jets and surface ejection events were thought to be predominantly the domain of comets, responsible for their tails, comas, and later meteor showers on Earth. Robotic OSIRIS-REx arrived at 101955 Bennu in late 2018, and is planned to touchdown to collect a surface sample in October 2020. If all goes well, this sample will then be returned to Earth for a detailed analysis during 2023. Bennu was chosen as the destination for OSIRIS-REx in part because its surface shows potential to reveal organic compounds from the early days of our Solar System, compounds that could have been the building blocks for life on Earth.

(Excerpt) Read more at apod.nasa.gov ...


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; asteroid; asteroids; astronomy; catastrophism; nasa; science
To be added or removed from the Astronomy Picture of the Day ping list please send me a request via "Private Reply" (Mail).

For more detail go to the link and click on the image for a high definition image. You can then zoom by moving the magnifying glass over an area and then clicking. The side bars will move the zoomed area over the photograph.

1 posted on 09/16/2020 5:54:43 PM PDT by MtnClimber
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To: MtnClimber

2 posted on 09/16/2020 5:55:21 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: 21stCenturion; 21twelve; .30Carbine; 4everontheRight; AFB-XYZ; America_Right; Art in Idaho; ...

Pinging the APOD list.


3 posted on 09/16/2020 5:56:15 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: MtnClimber
Leading ejection hypotheses include impacts by Sun-orbiting meteoroids, sudden thermal fractures of internal structures, and the sudden release of a water vapor jet.

My guess is Reptilian miners blasting for Unobtainium.

4 posted on 09/16/2020 6:11:04 PM PDT by Pontiac (The welfare state must fail because it is contrary to human nature and diminishes the human spirs)
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To: MtnClimber

Most interesting gravel I’ve ever seen... I guess.


5 posted on 09/16/2020 6:17:50 PM PDT by Bullish (CNN is what happens when 8th graders run a cable network.)
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To: Pontiac

My guess is dandruff...


6 posted on 09/16/2020 7:38:05 PM PDT by null and void (The Left weaponizes everything in the service of tyranny.)
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To: MtnClimber

There is air in space. We have been lied to by he spacesuit manufacturers!


7 posted on 09/16/2020 9:44:49 PM PDT by minnesota_bound (homeless guy. He just has more money....He the master will plant more cotton for the democrat party)
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To: MtnClimber

Big space dogs digging big holes.


8 posted on 09/16/2020 10:29:35 PM PDT by rfp1234 (Caveat Emperor)
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To: Pontiac

Yes, it has to be that - I marvel at the comic book/cgi devotees in matters such as this.


9 posted on 09/16/2020 10:38:45 PM PDT by Sioux-san
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To: MtnClimber

Space farts? Asteroid/hemorrhoid farts? “In space, no one can hear you fart”. Ripley, lone survivor of the Nostrodamus!


10 posted on 09/17/2020 1:17:28 AM PDT by MadMax, the Grinning Reaper
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To: 75thOVI; Abathar; agrace; aimhigh; Alice in Wonderland; AnalogReigns; AndrewC; aragorn; ...
Why does asteroid Bennu eject gravel into space? No one is sure. The discovery, occurring during several episodes by NASA's visiting OSIRIS-REx spacecraft, was unexpected. Leading ejection hypotheses include impacts by Sun-orbiting meteoroids, sudden thermal fractures of internal structures, and the sudden release of a water vapor jet. The featured two-image composite shows an ejection event that occurred in early 2019, with sun-reflecting ejecta seen on the right. Data and simulations show that large gravel typically falls right back to the rotating 500-meter asteroid, while smaller rocks skip around the surface, and the smallest rocks completely escape the low gravity of the Earth approaching, diamond-shaped asteroid.
Thanks MtnClimber.



11 posted on 09/17/2020 8:52:54 AM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: MtnClimber

How do they determine that the ejecta is gravel, as opposed to ice chunks?


12 posted on 09/17/2020 11:37:11 AM PDT by JimRed (TERM LIMITS, NOW! Build the Wall Faster! TRUTH is the new HATE SPEECH.)
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To: JimRed

Probably the color, but possibly spectrum analysis. The OSIRIS-REx spacecraft will touch down next month and attempt to return to earth with a sample.


13 posted on 09/17/2020 12:01:40 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: null and void
My guess is dandruff...

Ah yes, the ever-present Space Ghost dandruff.

People always wondered why he wore the cowl. Dandruff, uncontrollable dandruff.

14 posted on 09/17/2020 2:46:58 PM PDT by Pontiac (The welfare state must fail because it is contrary to human nature and diminishes the human spirs)
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To: MtnClimber

Space slugs.


15 posted on 09/17/2020 3:00:33 PM PDT by mewzilla (Break out the mustard seeds.)
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To: rfp1234

16 posted on 09/17/2020 3:25:56 PM PDT by Redcitizen (Nobody needs a 10 round magazine. You need a 30 round magazine. Yeah)
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