Touching Down on Asteroid Bennu


Oct. 21, 2020

Particles ejected from Bennu

Bennu, a well-preserved, ancient asteroid, is currently more than 200 million miles (321 million kilometers) from Earth and offers scientists a window into the early solar system as it was first taking shape billions of years ago and flinging ingredients that could have helped seed life on Earth.

On Tuesday, Oct. 20, 2020, NASA’s OSIRIS-REx sample collection mission performed a successful “Touch-And-Go” (TAG) maneuver.

At 1:50 p.m. EDT, OSIRIS-REx fired its thrusters to nudge itself out of orbit around Bennu. It extended the shoulder, then elbow, then wrist of its 11-foot (3.35-meter) sampling arm, known as the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), and transited across Bennu while descending about a half-mile (805 meters) toward the surface. After a four-hour descent, at an altitude of approximately 410 feet (125 meters), the spacecraft executed the “Checkpoint” burn, the first of two maneuvers to allow it to precisely target the sample collection site, known as “Nightingale.”

All spacecraft telemetry data indicates the TAG event executed as expected. However, it will take about a week for the OSIRIS-REx team to confirm how much sample the spacecraft collected.

This view of asteroid Bennu ejecting particles from its surface on January 19, 2019 was created by combining two images taken on board OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image.

Image Credit: NASA/Goddard/University of Arizona/Lockheed MartinLast Updated: Oct. 21, 2020Editor: Yvette Smith

35 thoughts on “Touching Down on Asteroid Bennu

  1. The NASA OSIRIS-REx mission is scheduled to return to earth in 2023. The sample retrieved by the Touch-and-go sample collection system will then be examined by scientists who will discover it is identical to some examples that have already crashed on earth. Nonetheless, this is a tremendous technological event. Where to next?

    • Except that (hopefully) there will be absolutely no doubt about whether the sample is pristine.

      I wasn’t aware of this mission; now I’ll try to find out what provisions they’ve made to prevent changes in the sample as it moves back into the “warm zone” of the system.

      • “Dirty” Coal ? Keep it in space !!

        I’m very disappointed by the PR, I was expecting some actual info and details, not : landed, scooped and coming back. See you in 3y.


        • Oh well, it seems that they did not manage to shut the doors properly. The sample cargo is spilling into space. Even if they don’t drop it all into space on the way back, it’s hard to see how it will make it though re-entry.

          400 million mile trip, 800 million bucks and 7 years wasted.

          Another win for NASA.

      • “The carbon-rich material holds the preserved building blocks of our solar system and could help scientists better understand how the planets were formed and how life originated on Earth.”
        So it is the coal 🙂

    • Interesting. Looking carefully, you can see at least a couple rocks visibly “move” after the touchdown. So hopefully it did collect a usable-size sample.

    • I think I saw that rock on e-bay the other week! LOL

      It’s kind of weird knowing that “debris” is just barely clinging together due to its own gravity.

  2. Is it out of the question that the ‘flung ingredients’ arrived here via the Solar Wind.
    Surely all the stuff that’s here exists in the sun. The lighter ones would have evaporated away first/fastest, condensed on a bald lump of iron/rock to nicely explain why The Crust is made of the ‘lighter elements’
    Might explain the water ice on Mercury, Elle Luna and Mars? Maybe even here?

    Any water in the Solar Wind that missed Earth & the planets would slow, cool, condense and freeze when it got beyond Pluto, to neatly explain comets, rocky snowballs as they (supposedly) are.

    Is it *really* true that El Sol evaporates away One Billion Tonnes of ‘stuff’ every second – seems a lot to me

    What about the 100 tonnes per day of assorted grit/sand/micro wotsitoids that fall onto Earth every day – could not whoever ‘flung’ those know the secret to life the universe and everything?

    Personally, I wouldn’t trust NASA to do an oil change on my car – what with their Trapped Heat, Ocean Acidation, CFC Ozone Hole explanation and, failed heat-tiles & O-rings.Muppets.


    • People Eating Tasty Animals of Newark, I hear you in reference to the new NASA. However, one truly great visit is to Cape Canaveral and the NASA exhibits, especially the Saturn 5 and the Space Shuttle. This visit is one I will never forget, and for sure it was the original NASA.

      • Especially the Saturn 5’s and the shuttle’s cavernous maw of their rockets.
        Reading about their pounds of thrust is meaningless without the context of their freaking size.

    • Nope. The composition of the -1 part in a million in solar wind that isn’t hydrogen or helium doesn’t match the abundance of Earth’s crustal emements at all. The earth’s crust came from fractionating elements as the Earth cooled from a molten ball. The sun and the Earth came from the same collapsing disk of dust and gas but that doesn’t mean that the top layers of the sun (where the solar wind comes from) has the same elemental and isotopic ratios as the crust of the Earth.

    • Maybe you missed the part where they did a touch and go on an asteroid 200 MILLION miles away from here. Not exactly a trick some rednecks could pull of from the garage. Just because parts of NASA have gotten lost in political wrangling doesn’t mean we shouldn’t be proud of the accomplishment. I am continuously amazed at the level of accomplishment that is done, pretty routinely. We live in amazing times. Bravo NASA.

    • The only thing that has ever been in the solar wind has been a tiny bit of helium, hydrogen and lots of sub atomic particles. The idea that the solar wind has ever contained water and metals is just plain nutso.

      The fact that the earth and other planets have lighter crusts is easily explained by the fact that they were molten during the early days.

      • Why is the idea that solar wind ever contained “metals” nutso? “Metals” as defined in astronomy is everything heavier than Helium. Stars are usually formed out of 2nd or 3rd generation dust, not pristine hydrogen and helium – even then there would have been some tiny traces of lithium. The Sun likely has trace amounts of metals in it and some of these atoms are likely to get blown off with hydrogen and helium – not much mind you but probably some tiny amount.

        I am truly curious why there would be no detectable metals in the Solar Wind.

        I got this from Wikipedia: ” The composition of the solar wind plasma also includes a mixture of materials found in the solar plasma: trace amounts of heavy ions and atomic nuclei C, N, O, Ne, Mg, Si, S, and Fe. There are also rarer traces of some other nuclei and isotopes such as P, Ti, Cr, Ni, Fe 54 and 56, and Ni 58,60,62″

        This is what I would expect to happen although I am certainly no expert on this.

  3. Bennu is waaayyy cooool!

    Asteroid Bennu was once part of a space rock with flowing water

    The asteroid Bennu is a strange little place, but data from NASA’s OSIRIS-REx mission is starting to unravel its mysteries. The spacecraft, which has been orbiting Bennu since December 2018, is gearing up to take a sample from the asteroid’s surface later this month. In preparation, it has gathered a smorgasbord of information, including hints that Bennu’s parent asteroid may have had flowing water.

    Bennu is a type of asteroid called a rubble pile, formed when something smashed into a larger asteroid billions of years ago and the bits coalesced into many smaller asteroids. By studying Bennu, which is about 500 metres wide, we can learn more about this parent asteroid, which was probably a few hundred kilometres across.

    When OSIRIS-REx reached Bennu, it spotted something strange: some of the boulders had bright veins up to 150 centimetres long and 14 centimetres thick. These veins are too large to have formed on Bennu itself, says Hannah Kaplan at NASA’s Goddard Space Flight Center in Maryland, so they were probably portions of larger cracks on Bennu’s parent that were up to several kilometres long.

    “They suggest that there was fluid flowing on fairly large scales on Bennu’s parent asteroid,” says Kaplan. That is because the veins are made of carbonates, a type of compound that generally forms due to interactions between water and rock, she says.

    Read more:

    • The reason we don’t currently have better, safer nuclear power plants has little to do with technology or money; it is public perception. The Green Mob have been particularly effective in convincing the general public that nuclear power is inherently unsafe regardless of design. And because most people don’t understand it, it’s not difficult to get them to fear it. Only fear of catching Covid-19 right now is more intense than fear over nuclear power. Irrational fear is the bane of human existence and one of the biggest things holding us back as a species.

      • Watched ‘Forbidden Planet’ last night.

        Before chips, especially memory and computational chips.
        The alleged Krell built massive energy generators and storage devices apparently managed by analog switches and meters.

        Technology has advanced tremendously since the late 1950s.
        Unlike nuclear regulatory departments, employees and open acceptance of technology improvement.

  4. Bennu comes too close to Earth for comfort, despite being only 490 meters across.

    Our next encounter with it might be to blow it up or push it into a different orbit.

  5. Bennu is the Roomba collection bin of the solar system. All the specks and pebbles will be interesting. I do hope any ice is preserved.

  6. Mining in space, that is where the riches are. All we have to do is go and get it and bring it back. Difficult but they are working on it. Hopefully.

    • Oh great! And then the environmental mob can become hysterical about “Gravity Pollution”.

      They will make claims that every 1 kilo brought back is amplified by some weird environmental effect causing the world’s gravity to increase thus leading to massive amounts of back pain.

      If you just send them more money they will study the effect more, build better models, and tell you what you need to give up in order to set things right.

  7. Bennu seems to have remarkably few craters. An estimate of the age of a surface is obtained from the number and size of craters seen. It is surmised that in the earliest days, projectiles were large and frequent and created large and many craters. Bennu seems to have very few craters, and these are very small, I could only see five distinct craters in the several phots I have seen. And these are small. Given the 500 m width of Bennu, the largest crater seems to be no more than 50 m. Quite a few very small craters. This indicates that Bennu may be no more than a few thousand years old, if that. Even if it is a ‘rubble pile’ there should be many large craters in the pile, if it is hundreds of millions of years old.

  8. The asteroid belt contains the remains of a planet that exploded. Mars was its moon.
    From the late, great Dr. Tom Van Flandern:

    Evidence that Mars is a former moon (MJS: And that it was subjected to a massive, nearby explosion)
    1. Mars is much less massive than any planet not itself suspected of being a former moon
    2. Orbit of Mars is more elliptical than for any larger-mass planet
    3. Spin is slower than larger planets, except where a massive moon has intervened
    4. Large offset of center of figure from center of mass
    5. Shape not in equilibrium with spin
    6. Southern hemisphere is saturated with craters, the northern has sparse cratering
    7. The “crustal dichotomy” boundary is nearly a great circle
    8. North hemisphere has a smooth, 1-km-thick crust; south crust is over 20-km thick
    9. Crustal thickness in south decreases gradually toward hemisphere edges
    10. Lobate scarps occur near hemisphere divide, compressed perpendicular to boundary
    11. Huge volcanoes arose where uplift pressure from mass redistribution is maximal (MJS: Biggest volcanoes in solar system on one of smallest planets? Van Flandern surmised they were set off by the cataclysm)
    12. A sudden geographic pole shift of order 90° occurred
    13. Much of the original atmosphere has been lost
    14. A sudden, massive flood with no obvious source occurred
    15. Xe129, a fission product of massive explosions, has an excess abundance on Mars

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