Does the possibility of a huge asteroid hitting Earth in the future keep you from sleeping? You can rest assured, NASA is exploring all possible ways to avoid this type of situation, or so it seems. We have already told you about the DART spacecraft, whose mission is to assess whether it is possible to change the trajectory of a threatening celestial body. Now it is the turn to update the system in charge of track asteroids close to our planet and assess their risk of impact.
For more than 20 years, the US space agency has used Sentry, a system that has made it possible to identify a large number of asteroids near the globe we inhabit. If the software detected that an asteroid was on a collision course with Earth, it analyzed its potential risk and added it to an Impact Risk Table. However, the tool had some shortcomings that could cause an asteroid to we are overlooked.
Sentry-II, the latest from NASA to detect asteroids
But this problem is a thing of the past, Sentry-II has been designed to overcome the limitations of the first version of the system and thus expand its range of threat detection, achieving a more robust solution. NASA explains that the new algorithm can quickly calculate impact probabilities as low as a few in 10 million in all NEA (Near Earth Object) orbits, including some “special cases” not captured by the original Sentry.
“The fact that the Sentry couldn’t automatically handle the Yarkovsky effect was a limitation,” says Davide Farnocchia, a NASA JPL navigation engineer who also helped develop Sentry-II. “Every time we came across a special case, like the asteroids Apophis, Bennu or 1950 DA, we had to do complex manual analysis and that they required a lot of time. With Sentry-II, we no longer have to do that, “he adds in an agency news release.
Asteroids are extremely predictable celestial bodies that obey the laws of physics and follow known orbital paths around the sun. This allows for very precise calculations of your future position relative to the earth, but there are some uncertainties in your position. These are evaluated by ground monitoring systems.
The original Sentry observed a series of points within the region of uncertainty. Each point represented a “virtual asteroid” and, based on assumptions, it projected its trajectory to determine if some of them could impact on Earth. Now the Sentry-II algorithm uses thousands of random points within the uncertainty space not limited by assumptions and asks what are the possible orbits within the region of uncertainty that could hit the Earth.
More information | NASA