A group of experts from US and European space agencies attended a week-long exercise led by NASA in which they faced a hypothetical scenario: An asteroid 35 million miles away was approaching the planet and could hit within six months.
With each passing day of the exercise, the participants learned more about the asteroid’s size, trajectory, and chance of impact. Then they had to cooperate and use their technological knowledge to see if anything could be done to stop the space rock.
Nasa said in a press release, “These exercises ultimately help the planetary-defense community communicate with each other and with our governments to ensure we are all coordinated should a potential impact threat be identified in the future,” Lindley Johnson, NASA’s planetary defense officer
The fictitious asteroid in the simulation was called 2021PDC. In NASA’s scenario, it was first “spotted” on April 19, at which time it was thought to have a 5% of hitting our planet on October 20, six months after its discovery date.
But Day 2 of the exercise fast-forwarded to May 2, when new impact-trajectory calculations showed that 2021PDC would almost certainly hit either Europe or northern Africa. The participants in the simulation considered various missions in which spacecraft could try to destroy the asteroid or deflect it off its path.
According to the participant of NASA, “If confronted with the 2021PDC hypothetical scenario in real life, we would not be able us to launch any spacecraft on such short notice with current capabilities,”
“Deploying a nuclear disruption mission could significantly reduce the risk of impact damage,” they found. Still, the simulation stipulated that 2021PDC could be anywhere from 114 feet to half a mile in size, so the chance that a nuke could make a dent was uncertain.
Day 3 of the exercise skipped ahead to June 30, and Earth’s future looked grim: 2021PDC’s impact trajectory showed it headed for eastern Europe. By Day 4, which fast-forwarded to a week before the asteroid impact, there was a 99% chance the asteroid would hit near the border between Germany, the Czech Republic, and Austria. The explosion would bring as much energy as a large nuclear bomb.
All that could be done was evacuate the affected regions ahead of time.
To address that problem, NASA announced two years ago that it would launch a new space telescope dedicated to watching for hazardous asteroids. That telescope, named the Near-Earth Object Surveillance Mission, along with the European Space Agency’s newly launched Test-Bed Telescope and the Flyeye Telescope that’s being built in Italy, should eventually bolster the number of NEOs we can track.
NASA has investigated the options scientists would have if they were to find a dangerous asteroid on a collision course with Earth. These include detonating an explosive device near the space rock, as the exercise participants suggested, or firing lasers that could heat up and vaporize the asteroid enough to change its path.
Another possibility is sending a spacecraft up to slam into an oncoming asteroid, thereby knocking it off its trajectory. This is the strategy NASA is most serious about: Later this year, the agency is scheduled to launch a test of such a technology. The Double Asteroid Redirection Test (DART) will send a spacecraft to the asteroid Dimorphos and purposefully hit it in the fall of 2022.
NASA hopes that the collision will change Dimorphos’s orbit. While that asteroid isn’t a threat to Earth, the mission could prove that redirecting an asteroid is possible with enough lead time.
Source: Business Insider