Scientists have updated the risk posed to this potentially dangerous near-Earth object by using data gathered by NASA's OSIRIS REx during its years of zipping about Bennu.AdvertisementOSIRIS-REx, a spacecraft carrying samples from Bennu's surface, is currently on its way to Earth. The NASA spacecraft examined the massive rubble pile from all angles, measuring its size and composition as well as its orbital trajectory. Scientists can draw inferences from Bennu's study of this primitive carbonaceous asteroids, which allows them to make inferences about the history of our solar system during its formation.This $800 million mission is not just about looking for organic molecules and signs of water or heavy elements. Bennu currently ranks second on the list for potentially dangerous asteroids. This highlights the importance of learning more about it, especially the orbital dynamics that will determine its future movements.Icarus published a new study that does exactly this. It provides a detailed trajectory for Bennu up to 2300. You misanthropes may be happy to know that Bennu still has a small chance of striking our planet in the next century. However, the odds of a collision in 2300 are still very low. They're currently estimated at 1 in 1,750 or 0.057%.OSIRIS-REx data, NASAs Deep Space Network and computer models were used to help scientists constrain uncertainty in Bennus orbit by 20. This was possible because OSIRIS-REx measured Bennus' position relative to Earth to a scale of just a few meters.Davide Farnocchia was the lead author of today's paper. He is also a researcher at NASAs Jet Propulsion Laboratory, Southern California. Dante Lauretta is a co-author of this study and OSIRIS–REx principal investigator at Arizona. He said that the incredible precision enabled the team to identify the orbital parameters of asteroids and help predict their future.The new model was able to eliminate 24 out of 26 keyholes that could have been present for Bennu on September 11, 2135. This is when the asteroid is expected to safely pass Earth. One can think of gravititational keyholes as fictional gateways that allow characters to travel through alternate timelines. Fans of the Loki series will know exactly what Im talking about. Keyholes are real and dangerous. They allow asteroids to be taken onto orbital trajectories that could pose a threat to Earth.AdvertisementFarnocchia stated that there is no chance of an impact in 2135. However, Bennu will be very close to Earthabout half the distance between Earth and the Moon. This will alter the trajectory of the asteroids. Scientists must consider gravitational keyholes to determine the change in trajectory.NASA calls them keyholes. These are areas in space that could set Bennu up for a future collision with Earth. Farnocchia repeatedly reminded reporters during the press conference that there is no reason to be concerned.AdvertisementAll the variables at play are responsible for creating uncertainty. Sir Isaac Newton spoke of a universe with clock-like precision. However, the solar system's clock has an inordinate number of moving parts. These perturbing influences include the Sun's gravity, the planets and all their moons.Farnocchia and colleagues attempted to include as many variables possible in the new study to predict Bennus' future trajectory. This included the 343 known asteroids. Farnocchia and his colleagues even considered a possible nudge from OSIRIS-REx, which grabbed a sample surface material on October 20, 2020. However, it turned out not to be a factor. They also included bits of debris naturally falling from Bennu.AdvertisementYou should also consider the Yarkovsky Effect. This is when an object absorbs radiation emitted by the Sun. The radiation then vaporizes. This alters the object's momentum and causes it to drift from the path prescribed by gravity. Although the effect is small, it can have a significant impact over long time periods. OSIRIS-REx gathered invaluable informationinformation thats hard if not impossible to collect from the groundthat was used to calculate the Yarkovsky effect as Bennu travelled around the Sun, including the objects size, mass, shape, rotation, surface properties, and other factors, as Farnocchia explained. He explained that this information helped us model Bennu's future motion.The OSIRIS-REx samples could help us understand how the Yarkovsky effect might continue to alter Bennus' trajectory. Analyzing the surface samples may reveal changes over time to the asteroid, such as surface weathering. This would help us understand one of the most important parameters in determining orbital trajectory.AdvertisementAlthough the new research is more solid than any previous estimates of Bennus' future, there are still areas for improvement. Farnocchia stated that the researchers want to account for the gravitational effect of all asteroids in our solar system. Identifying the mass of these asteroids is a significant next step. It would be helpful to have better measurements of Bennus density and mass, which are still unknown. Bennu is composed of loose rocks and dust. It likely has empty cavities and uneven distributions of materials below the surface.Now we wait until September 24, 2023 when OSIRIX -REx will return to Earth with its samples. Lauretta stated that the mission is in excellent shape at the moment, which is clearly good news. This fascinating and possibly alarming asteroid still has much to be learned.
