An asteroid impact is a threat that humanity should not underestimate. For this reason, NASA, several federal agencies, and international organizations are taking part in a tabletop exercise on preparedness during the Planetary Defense Conference happening this week in Washington.
NASA administrator Jim Bridenstine gave the opening keynote talk, encouraging people to take the risk from impacts seriously. Bridenstine used the example of the recent Chelyabinsk Event, when a 20-meter (66-foot) near-Earth object (NEO) entered the atmosphere and exploded over Chelyabinsk Oblast. This created an impressive shockwave that damaged over 7,200 buildings, which in turn led to the hospitalization of 1,491 people.
“I wish I could tell you these events are exceptionally unique … but they’re not,” Bridenstein said during his keynote. “We have to make sure that people understand that this is not about Hollywood, it's not about the movies. This is about ultimately protecting the only planet we know, right now, to host life and that is the planet Earth.”
The NASA chief also talked about the scientific and technical challenges we are yet to meet when it comes to the potential dangers. Last year, a multi-agency report called "The National Near-Earth Object Preparedness Strategy and Action Plan” detailed what was required of NASA when it comes to NEOs.
“We’re only about a third of the way there and the law that has been passed says that NASA is required to be able to detect, track, and characterize not just one-third but 90 percent of them,” Bridenstine explained, “which means we have to use our systems, use our capabilities, to ultimately get a lot more data, and we have to do it faster. We want more international partners that can join us in this effort. We want more systems on the face of the Earth that can detect and track these objects.”
But to characterize objects as small as the Chelyabinsk superbolide, we need a space observatory. NASA has studied such a mission: the Near Earth Object Camera (NEOCam). It was a finalist in the most recent competition for the Discovery-class planetary science missions, but it was not selected in the end. A large portion of NASA's current budget for planetary defense has been spent on the Double Asteroid Redirection Test (DART), which will launch in 2021. This means soon there should be funding available for NEOCam, dramatically expanding the known space rocks around our planet.
It has been estimated that roughly 50 percent of all NEOs larger than 140 meters (460 feet) but smaller than 1 kilometer (0.6 miles) have been discovered so far. If one of these were to impact, it could bring devastation on a continent-wide scale.
[H/T: Space News]