NASA Calculations Show Asteroid Bennu Has a Chance of Slamming Into Earth

Asteroid Bennu Mosaic OSIRIS-REx

This mosaic of Bennu was created using observations made by NASA’s OSIRIS-REx spacecraft that was in close proximity to the asteroid for over two years. Credit: NASA/Goddard/University of Arizona

Along with collecting a sample from the Bennu’s surface, the spacecraft provided precision data to better predict the near-Earth object’s orbit around the Sun.

In a study released today (August 11, 2021), NASA researchers used precision-tracking data from the agency’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft to better understand movements of the potentially hazardous asteroid Bennu through the year 2300, significantly reducing uncertainties related to its future orbit, and improving scientists’ ability to determine the total impact probability and predict orbits of other asteroids.

The study, titled “Ephemeris and hazard assessment for near-Earth asteroid (101955) Bennu based on OSIRIS-REx data,” was published in the journal Icarus.

“NASA’s Planetary Defense mission is to find and monitor asteroids and comets that can come near Earth and may pose a hazard to our planet,” said Kelly Fast, program manager for the Near-Earth Object Observations Program at NASA Headquarters in Washington. “We carry out this endeavor through continuing astronomical surveys that collect data to discover previously unknown objects and refine our orbital models for them. The OSIRIS-REx mission has provided an extraordinary opportunity to refine and test these models, helping us better predict where Bennu will be when it makes its close approach to Earth more than a century from now.”

In 2135, asteroid Bennu will make a close approach with Earth. Although the near-Earth object will not pose a danger to our planet at that time, scientists must understand Bennu’s exact trajectory during that encounter in order to predict how Earth’s gravity will alter the asteroid’s path around the Sun – and affect the hazard of Earth impact.

Using NASA’s Deep Space Network and state-of-the-art computer models, scientists were able to significantly shrink uncertainties in Bennu’s orbit, determining its total impact probability through the year 2300 is about 1 in 1,750 (or 0.057%). The researchers were also able to identify September 24, 2182, as the most significant single date in terms of a potential impact, with an impact probability of 1 in 2,700 (or about 0.037%).

Asteroid Bennu Impact Hazard Animation

Credit: NASA’s Goddard Space Flight Center

Although the chances of it hitting Earth are very low, Bennu remains one of the two most hazardous known asteroids in our solar system, along with another asteroid called 1950 DA.

Before leaving Bennu May 10, 2021, OSIRIS-REx spent more than two years in close proximity to the asteroid, gathering information about its size (it is about one-third of a mile, or 500 meters, wide), shape, mass, and composition, while monitoring its spin and orbital trajectory. The spacecraft also scooped up a sample of rock and dust from the asteroid’s surface, which it will deliver to Earth on September 24, 2023, for further scientific investigation.

“The OSIRIS-REx data give us so much more precise information, we can test the limits of our models and calculate the future trajectory of Bennu to a very high degree of certainty through 2135,” said study lead Davide Farnocchia, of the Center for Near Earth Object Studies (CNEOS), which is managed by NASA’s Jet Propulsion Laboratory in Southern California. “We’ve never modeled an asteroid’s trajectory to this precision before.”

Gravitational keyholes

The precision measurements on Bennu help to better determine how the asteroid’s orbit will evolve over time and whether it will pass through a “gravitational keyhole” during its 2135 close approach. These keyholes are areas in space that would set Bennu on a path toward a future impact with Earth if the asteroid were to pass through them at certain times, due to the effect of Earth’s gravitational pull.

To calculate exactly where the asteroid will be during its 2135 close approach – and whether it might pass through a gravitational keyhole – Farnocchia and his team evaluated various types of small forces that may affect the asteroid as it orbits the Sun. Even the smallest force can significantly deflect its orbital path over time, causing it to pass through or completely miss a keyhole.

Among those forces, the Sun’s heat plays a crucial role. As an asteroid travels around the Sun, sunlight heats up its dayside. Because the asteroid spins, the heated surface will rotate away and cool down when it enters the nightside. As it cools, the surface releases infrared energy, which generates a small amount of thrust on the asteroid – a phenomenon called the Yarkovsky effect. Over short timeframes, this thrust is minuscule, but over long periods, the effect on the asteroid’s position builds up and can play a significant role in changing an asteroid’s path.

“The Yarkovsky effect will act on all asteroids of all sizes, and while it has been measured for a small fraction of the asteroid population from afar, OSIRIS-REx gave us the first opportunity to measure it in detail as Bennu traveled around the Sun,” said Steve Chesley, senior research scientist at JPL and study co-investigator. “The effect on Bennu is equivalent to the weight of three grapes constantly acting on the asteroid – tiny, yes, but significant when determining Bennu’s future impact chances over the decades and centuries to come.”

The team considered many other perturbing forces as well, including the gravity of the Sun, the planets, their moons, and more than 300 other asteroids, the drag caused by interplanetary dust, the pressure of the solar wind, and Bennu’s particle-ejection events. The researchers even evaluated the force OSIRIS-REx exerted when performing its Touch-And-Go (TAG) sample collection event on October 20, 2020, to see if it might have slightly altered Bennu’s orbit, ultimately confirming previous estimates that the TAG event had a negligible effect.

“The force exerted on Bennu’s surface during the TAG event were tiny even in comparison to the effects of other small forces considered,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “TAG did not alter Bennu’s likelihood of impacting Earth.”

Tiny risk, huge gain

Although a 0.057% impact probability through the year 2300 and an impact probability of 0.037% on September 24, 2182, are low, this study highlights the crucial role that OSIRIS-REx operations played in precisely characterizing Bennu’s orbit.

“The orbital data from this mission helped us better appreciate Bennu’s impact chances over the next couple of centuries and our overall understanding of potentially hazardous asteroids – an incredible result,” said Dante Lauretta, OSIRIS-REx principal investigator and professor at the University of Arizona. “The spacecraft is now returning home, carrying a precious sample from this fascinating ancient object that will help us better understand not only the history of the solar system but also the role of sunlight in altering Bennu’s orbit since we will measure the asteroid’s thermal properties at unprecedented scales in laboratories on Earth.”

Reference: “Ephemeris and hazard assessment for near-Earth asteroid (101955) Bennu based on OSIRIS-REx data” by Davide Farnocchia, Steven R. Chesley, Yu Takahashi, Benjamin Rozitis, David Vokrouhlický, Brian P. Rush, Nickolaos Mastrodemos, Brian M. Kennedy, Ryan S. Park, Julie Bellerose, Daniel P. Lubey, Dianna Velez, Alex B. Davis, Joshua P. Emery, Jason M. Leonard, Jeroen Geeraert, Peter G. Antreasian and Dante S. Lauretta, 10 August 2021, Icarus.
DOI: 10.1016/j.icarus.2021.114594

More about OSIRIS-REx

Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Lauretta is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace in Tempe, Arizona are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the agency’s Science Mission Directorate in Washington.

32 Comments on "NASA Calculations Show Asteroid Bennu Has a Chance of Slamming Into Earth"

  1. NASA’s chance of calling anything on the spot accurate is more a crap shoot than anything science related. Hell your local weather reader with all their sophisticated this & that barely get anything right. 2135? Luckily all the foot in mouth clowns will be long passed before that date arrives saving them long lived embarassesment.

    • You nailed it, Dan. Yep, this is just more scaremongering bullsh*t along with Covid and climate change that’s designed to place us all fear.

      I’m not buying ANY of it.

      • Of a different opinion | October 9, 2021 at 7:29 pm | Reply

        So, you’re this upset about something happening long after you’re gone, and you link this to other topics you’re also ill informed about such as the pandemic and climate change.

        You sound frightened out of your wits by anything you perceive as questioning your position as the center of the universe.

  2. M. P. Muraleedharan | August 12, 2021 at 12:02 am | Reply

    NASA considered almost all of the possibilities into consideration which all will deviate the path of Bennu.I do apprehend that one parameter is omitted. That is: the journey of Earth towards the center of the galaxy. It is known that Earth is travelling towards the center at a speed of seven kms per second. If Bennu is also not in that journey alongwith, the proximity of the same to Earth may be nearer or farther.

    • Of yet another different opinion | October 9, 2021 at 7:34 pm | Reply

      >> NASA considered almost all of the possibilities

      You really think this, without any actual evidence, that NASA scientists haven’t taken everything of that nature into consideration? The same professionals that have calculated every orbit of every space vehicle such as the one this article is about, that was able to arrive at this a speck of a rock traveling a zillion miles away, then to land on it, take samples and afterward rendezvous back with Earth?

      Thank Zeus you’re here to correct them!

  3. Compelling scientific arguments here from the obviously bright minds not left behind. The likelihood of impact based on the current orbital data is given as less than 1%. Before crowing about predictions and competency perhaps READ the article and what’s actually in NASA’s calculations (and what’s missing), and avoid embarrassing yourselves. If the likelihood is less than 1%, and NASA is incompetent as stated, why is it you conclude the “error” is that the methods and data are flawed having access to none of it? The percentage ALREADY tells you this event is highly, highly unlikely and you misattribute the article’s written content to NASA, unaware of what the numbers actually say. I also have to laugh at the fact that the predicted date is far enough in the future that we will all be dead anyway. Science education in America is in crisis.

  4. Dianne Richardson | August 12, 2021 at 7:07 am | Reply

    I didn’t know that earth was traveling toward the center of our Galaxy. Is that along with our entire solar system or independently?

  5. 2135?? The rate we are depleting the world’s resources, humanity probably won’t be around to worry about an impact in 2135… we’ll be lucky to get out of this century alive. And if you’re a “science denyer”, why bother commenting that you don’t believe any of the science on a SCIENCE SITE?? D.A.!

  6. I find it hilarious that anyone who considers climate change and covid “scaremongering”, would have the nerve to admit it in the comments of an article about the science of predicting the paths of near earth objects. Is it at all possible that we just stick to science here??

    • The earth moves away from the sun in a spiral orbit. Cooling is approaching the earth. Warm the planet:
      1) Sunspots directed towards the Earth;
      2) Associated gas flares for oil production;
      3) Fires, when all the forests on the planet are burning.
      Combining these 3 components, you can organize both global warming and global cooling.
      Cool the planet:
      1) The sun, on which there are no spots (then there are many clouds above the Earth);
      2) the shadow of the moon;
      3) the shadow of the Earth’s artificial satellites.

    • I have the same hopes, Marcy, but some of those weird uncles have been on disability and abusing pain killers for so long that their minds are close to completely gone.

      Most of it has nothing to do with the topic and all about how life didn’t work out for them and so they’re bent on tearing it down for everyone else.

  7. Michael Lukas X | August 12, 2021 at 10:23 am | Reply

    When scientists are able to explain in mathematical detail how 2 planes were able to make 3 skyscrapers collapse at free fall speed, hours and miles apart from each other,then maybe we should give them a minute of our time. Until then I believe we all can agree they should STFU.
    Michael Lukas X

  8. Average American Halfwit | August 12, 2021 at 10:49 am | Reply

    I no understand science therefore nasa bad, conspiracy theory good.

  9. … just few months ago, there was article in which it was explained that there will be no impact in near future. So! How is this possible now…

  10. It was first recognized in the late 2007 that our solar system movement was a negatively rate vector . Now the recognition of Black Holds have placed our solar system in a movement toward the galactic source of the spiral center of the Milky Way .

  11. Murphy Pendleton | August 12, 2021 at 2:10 pm | Reply


    Article: There is a 0.057% chance the asteroid might hit the planet in over 100 years.

  12. Hopefully will be able to mine it a lot just before blasting it with nukes as it’s moving away from us on an outward tragegtory the gurus can simulate & calculate with computers a million times faster in a 100 years. Amazing the simulations that can be done now with ANSYS dot COM finite element program

  13. I mean it’s math. Math I don’t understand or know how to implement but unless anyone here has a degree in physics or statistics or in some sort of math.
    I’m going to stick with the rocket scientists.
    Plus what does it even matter, everyone here and their children will be dead before this thing maybe hits earth.

  14. I’d also like to add to the conspirators that NASA has become less affiliated with the feds than any other program. So… your conspiracy theories don’t make sense.
    You really think people actually go to a decade of schooling and continue to and dedicate their lives to deceiving Americans? Get out of here.
    Most scientists don’t even have the salary you think they do.
    All of their money goes to their projects and research.

  15. I’ll be quite dead by 2182 so ” what me worry” not a chance

  16. Has NASA ever been honest with the public (no) so what makes these clowns think after all the lies and photoshop junk and cover-ups they do anyone e en trusts them give me a break

  17. If it is coming in at an angle and trajectory behind us, the chance of a salvage would be the best chance we’ve got depending on what materials it is made of. The calculations to slow it down enough to remain on a speed with us and trajectory long enough to harvest.

  18. Remember when we were told not to wear masks? Remember when we were told that covid wasnt spread during riots but was spread during biker rallies? Yea think ill hold off judgement on this one. Getting tired of all the bs.

  19. I kind of hope it does slam into earth. Humanity has lost its perspective of LIFE and Love periode. In order to rid ourselves of all this high tech horse crap we need to start over for those willing to survive and start life overin a wold of godliness and love for one another like our ancestors did 300 years ago. Hard work and giving thanks to our creator.

  20. RICHARD S GIESER | August 12, 2021 at 9:11 pm | Reply

    Not to worry, global cooling/global warming/climate change/liberal political policies, will do us all in long before that time.

  21. I sure hope so

  22. I do not believe any human species still exist by 2135, thanks for stupidity of the worlds leaders as they will bring end of life on this planet before that date so our offsprings will not suffers.

  23. Dr. Alexander Montgomery V, PhD. Astrophysics & Virology | August 13, 2021 at 1:56 am | Reply

    All of you are correct in one thing: we all will be dead by the time it even gets near us (even with NASA”s sloppy data calculations, none of which anyone here has seen).

    This is a scientific website….if you don’t believe in science or the pursuit of scientific discovery….STFU and go read your Trump Truthful NRA newsletter. And go to your Trump rally, football games, Walmart and catch an illness that comes from a fictional fake virus….but when you’re suffocating and feel like an elephant is sitting on your chest…. don’t call the paramedics or ambulance, don’t go to the hospital fearing for your miserable life…those doctors and nurses are treating people who want to live, who did they social responsibility and got vaccinated. Just try to stay calm, take a deep breath if you can suck in enough air and just feel the cold hand of death wrap around your feeble brain….and remember it is all fake…the virus isn’t real…it is just heartburn or you got the “vapors”. Don’t worry the real truth will set you free….in hell. Never knew the devil like the dumb ones so much. So STFU and do us all a favor and die quickly. The rest of us have a world to save…cause Mother Earth is trying to rid this place of the worse virus ever known….humanity.

  24. Well said Alex. But a bit confusing for Donald and the Q folks.

  25. Or to restate the obvious: every object in the universe may hit the earth. All that differs between Bennu and any other object is the probability.

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