To test the operational readiness of planetary defense systems, researchers sometimes use the close approach of a real asteroid as a simulated encounter with a potentially dangerous new asteroid. The lessons learned from these exercise simulations could help limit, or even prevent, global devastation should such a situation occur in the future. Scientists used the infamous asteroid 99942 Apophis for this purpose.
Named after the ancient Egyptian god of chaos and darkness, Apophis was discovered in 2004. It was quickly identified as one of the most dangerous asteroids likely to impact Earth. In fact, the near-Earth object was thought to pose a slight risk of impacting Earth in 2068, but radar observations ruled it out. As astronomers followed Apophis better, they ruled out the possibility of asteroid risk for at least 100 more years.
More than 100 astronomers from around the world participated in such an exercise last year, in which a known and potentially dangerous large asteroid was essentially removed from the planetary defense monitoring database to see if it would be at again detected by the system. Not only was Apophis “rediscovered” during the exercise, but its chances of hitting our planet were continually reassessed as it was tracked and the possibility of an impact ruled out.
The exercise was coordinated by the International Asteroid Warning Network (IAWN) and NASA’s Planetary Coordination Office (PDCO). He confirmed that the international planetary defense community can act quickly to identify and assess the danger posed by the discovery of a new near-Earth asteroid. The researchers documented the study in an article titled “Apophis Planetary Defense Campaign,” published in The Planetary Science Journal.
The best of Express Premium
The researchers knew that Apophis would approach Earth in early December 2020. But the Minor Planet Center (MPC), an internationally recognized clearinghouse for position measurements of small celestial bodies, claimed it was of an unknown asteroid by preventing further sightings of Apophis. in line with previous observations. This was done to make the exercise more realistic and meant that the astronomical surveys had no previous records from Apophis.
On December 4, 2020, the asteroid began to brighten. This allowed the Catalina Sky Survey in Arizona to make the first detection, which then reported it to the Minor Planetary Center. Since previous recordings were blocked, Apophis was recorded as a brand new detection. The Hawaii-based Asteroid Earth Impact Last Warning System (ATLAS) and Panoramic Telescope and Rapid Response System. (Pan-STARRS) quickly followed with their reports.
As the asteroid drifted into the field of view of NASA’s NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer) mission, the MPC linked its observations to those made by ground-based telescopes to show the movement of the asteroid in the sky. He then announced the “discovery of a new asteroid” on December 23.
“Even though we knew that in reality Apophis had no impact on Earth in 2029, from square one – with only a few days of astrometric data from survey telescopes – there were great uncertainties. in the object’s orbit that theoretically allowed for an impact that year,” said Davide Farnocchia, navigation engineer at NASA’s Jet Propulsion Laboratory (JPL), in a press release.
As Apophis approached Earth in March 2021, JPL astronomers used NASA’s 70-meter Goldstone Solar System Radar in California to image and accurately measure the asteroid’s speed and distance. Astronomers combined these observations with measurements from other observatories to rule out a 2029 impact for the purposes of the exercise.
#Notorious #asteroid #Apophis #test #planetary #defense #system