NASA upgrades software for monitoring potentially dangerous asteroids
NASA has installed a major upgrade to the software it uses for monitoring, tracking, and predicting the future orbits of potentially dangerous asteroids.
Sentry [the original software used for the past 20 years] was very effective at calculating orbital paths based on how an asteroid is affected by the gravitational pull of the Sun and planets, but there were a few factors that it couldn’t account for. In the long run, these uncertainties can snowball into many possible orbits that may or may not impact Earth.
The Yarkovsky effect, for instance, is where the Sun unevenly heats the surface of an asteroid as it spins, creating thermal forces between the “day” and “night” sides of the rock that can produce thrust. Other times, asteroids that swing past Earth very closely could be nudged into different orbits by the planet’s gravity, changing the paths of their eventual return.
The first Sentry system couldn’t incorporate either of these two factors, meaning that for special case asteroids like Bennu or Apophis, astronomers would have to manually analyze their orbits, which is a complex and time-consuming process.
But Sentry-II is designed to account for things like these. This latest version uses a different algorithm that models thousands of random points within the uncertainty space of an asteroid’s orbit, then figures out which ones have a chance of striking Earth in future. This, the team says, could help find scenarios that have very low probability of impact.
What this upgrade means is that as new asteroids are discovered the software will be able to very quickly calculate with better accuracy any potential impacts in the coming centuries. The results won’t be perfect, but less manual work will be necessary, meaning fewer dangerous asteroids will fall through the cracks.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
NASA has installed a major upgrade to the software it uses for monitoring, tracking, and predicting the future orbits of potentially dangerous asteroids.
Sentry [the original software used for the past 20 years] was very effective at calculating orbital paths based on how an asteroid is affected by the gravitational pull of the Sun and planets, but there were a few factors that it couldn’t account for. In the long run, these uncertainties can snowball into many possible orbits that may or may not impact Earth.
The Yarkovsky effect, for instance, is where the Sun unevenly heats the surface of an asteroid as it spins, creating thermal forces between the “day” and “night” sides of the rock that can produce thrust. Other times, asteroids that swing past Earth very closely could be nudged into different orbits by the planet’s gravity, changing the paths of their eventual return.
The first Sentry system couldn’t incorporate either of these two factors, meaning that for special case asteroids like Bennu or Apophis, astronomers would have to manually analyze their orbits, which is a complex and time-consuming process.
But Sentry-II is designed to account for things like these. This latest version uses a different algorithm that models thousands of random points within the uncertainty space of an asteroid’s orbit, then figures out which ones have a chance of striking Earth in future. This, the team says, could help find scenarios that have very low probability of impact.
What this upgrade means is that as new asteroids are discovered the software will be able to very quickly calculate with better accuracy any potential impacts in the coming centuries. The results won’t be perfect, but less manual work will be necessary, meaning fewer dangerous asteroids will fall through the cracks.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
One of the possibilities opened up is using one small asteroid to impact a larger one that’s in a dangerous orbit. Changing a kiloton unit takes far less human supplied energy than that of a megaton unit. Many of the closing velocities of different asteroids are in the 10+ km/sec range.
The key is first finding the potential impactor. Then finding much smaller units that can be nudged to intercept the potential impactor. 10 m/sec change is several hundred km/day of difference in orbit.
Monitoring how close they come to each other is important-a grazing strike demands recalculation.