As it cools, the surface releases infrared energy, which generates a small amount of thrust on the asteroid, a phenomenon called the Yarkovsky effect. Because the asteroid spins, the heated surface will rotate away and cool down when it enters the nightside. As an asteroid travels around the sun, sunlight heats up its dayside. Even the smallest force can significantly deflect its orbital path over time, causing it to pass through or completely miss a keyhole.Īmong those forces, the sun’s heat plays a crucial role. 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. 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. Bennu will pass through a gravitational keyhole during its 2135 close approach. In recent year, scientists have sometimes spoken about close-passing asteroids in terms of a gravitational keyhole. This mosaic image of asteroid Bennu is composed of 12 Pol圜am images collected on December 2, 2018, by the OSIRIS-REx spacecraft from a range of 15 miles (24 km). We’ve never modeled an asteroid’s trajectory to this precision before. 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. The spacecraft will deliver its precious sample of rock and dust from the asteroid’s surface to Earth on September 24, 2023.
It gathered information about the asteroid’s size (it is about 1/3 of a mile, or 500 meters, wide), shape, mass, and composition, and its spin and orbital trajectory. The impact probability remains really small. I’m not any more concerned about Bennu than I was before. 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%).ĭavide Farnocchia, a scientist at the NASA Jet Propulsion Laboratory in California and lead author of the paper, told the New York Times: The researchers were also able to identify Sept. 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%). 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. In 2135, asteroid Bennu will make a close approach with Earth. The journal Icarus published the new study, Ephemeris and hazard assessment for near-Earth asteroid (101955) Bennu based on OSIRIS-REx data. Those predictions were published in a study, also released on August 11.
A NASA statement said that, along with collecting a sample from Bennu’s surface, the spacecraft provided precision data to better predict the near-Earth object’s orbit around the sun. It’s a bit wider than the Empire State Building in New York City is tall. The spacecraft learned, among other things, that Bennu is very dark, and very ancient. The OSIRIS-REx spacecraft rendezvoused with Bennu in late 2018 and touched down on the asteroid’s surface in late 2020, successfully collecting a sample. NASA was concerned enough about Bennu that it sent a spacecraft to the asteroid. Still, Bennu and another asteroid known as (29075) 1950 DA remain the two most hazardous asteroids to Earth, as far as scientists know at this time. I don’t think we need to do anything about Bennu. Planetary scientist Lindley Johnson of NASA’s Planetary Defense Coordination Office said at Wednesday’s press briefing: The estimates suggest a slightly greater chance than previously, but scientists say they are not worried. The greatest chance in the next 300 years will come on September 24, 2182. At a news conference on August 11, 2021, NASA scientists said there is a 1-in-1,750 chance that asteroid Bennu could collide with Earth between now and the year 2300.
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