NASA's Next-Generation Asteroid Impact Monitoring System Goes Online
Sunday December 12, 2021. 05:34 PM , from Slashdot
'To date, nearly 28,000 near-Earth asteroids have been found by survey telescopes that continually scan the night sky, adding new discoveries at a rate of about 3,000 per year...' according to an article from NASA:
'The first version of Sentry was a very capable system that was in operation for almost 20 years,' said Javier Roa Vicens, who led the development of Sentry-II while working at JPL as a navigation engineer and recently moved to SpaceX. 'It was based on some very smart mathematics: In under an hour, you could reliably get the impact probability for a newly discovered asteroid over the next 100 years — an incredible feat.'
But RockDoctor (Slashdot reader #15,477), summarizes some new changes:
For nearly 20 years, newly discovered asteroids had orbital predictions processed by a system called 'Sentry', resulting in quick estimates on the impact risk they represent with Earth. Generally this has worked well, but several things in the future required updates, and a new system adds a number of useful features too.
The coming wave of big survey telescopes which will check the whole sky every few days is going to greatly increase the number of discoveries. That requires streamlining of the overall system to improve processing speed. The new system can also automatically incorporate factors which previously required manual intervention to calculate, particularly the effect of asteroid rotation creating non-gravitational forces on a new discovery's future orbit. Objects like asteroid Bennu (recently subject of a sampling mission) had significant uncertainty on their future path because of these effects. That doesn't mean that Bennu can possibly hit us in the next few centuries, but it became harder to say over the next few millennia. As NASA puts it:
Popular culture often depicts asteroids as chaotic objects that zoom haphazardly around our solar system, changing course unpredictably and threatening our planet without a moment's notice. This is not the reality. Asteroids are extremely predictable celestial bodies that obey the laws of physics and follow knowable orbital paths around the Sun.
But sometimes, those paths can come very close to Earth's future position and, because of small uncertainties in the asteroids' positions, a future Earth impact cannot be completely ruled out. So, astronomers use sophisticated impact monitoring software to automatically calculate the impact risk....
[T]he researchers have made the impact monitoring system more robust, enabling NASA to confidently assess all potential impacts with odds as low as a few chances in 10 million.
The article includes videos explaining the future uncertainties on the orbits of potentially hazardous asteroids Bennu and Apophis.
Read more of this story at Slashdot.
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