NASA says the threat is real: an asteroid can impact Earth and the United States, perhaps destroying an entire state …or more. NASA Administrator Jim Bridenstine addressed the threat and the importance of using the science of planetary defense to protect Earth yesterday at the International Academy of Astronautics’ 2019 Planetary Defense Conference held in College Park, Maryland.
“We have to make sure that people understand that this is not about Hollywood, it’s not about movies,” Bridenstine said, referencing the so-called “giggle factor” that he believes causes the public to write off the severity of the risk from an asteroid impact. “This is about ultimately protecting the only planet we know right now to host life, and that is the planet Earth.”
In March, NASA disclosed that a space rock several meters in size exploded 16 miles above the Bering Sea with 10 times the energy of the Hiroshima atomic bomb in December. NASA says such an impact or explosion happening again isn’t a matter of if, but when.
Image: Landsat/Copernicus/Google Earth/Department of State Geographer
It is believed such an impact brought about an end to the dinosaur era on Earth. “We have to use our systems, use our capabilities to ultimately get a lot more data, and we have to do it faster,” Bridenstine said. “We know for a fact that the dinosaurs did not have a space program. But we do, and we need to use it.”
This week, NASA and FEMA are practicing a scenario involving such an impact. NASA and FEMA have partnered with international groups such as NASA’s Planetary Defense Coordination Office (PDCO), the European Space Agency’s Space Situational Awareness-NEO Segment , and the International Asteroid Warning Network (IAWN). Using the 2019 Planetary Defense Conference as a backdrop, experts are working through exercises dealing with a near-earth-object, also known as NEO. NASA Jet Propulsion Laboratory’s Center for NEO Studies (CNEOS) developed the fictional incident that will be war-gamed this week. In their sample scenario, astronomers discover a NEO that is potentially hazardous to earth, determining that it poses a 1:100 chance of impact with Earth in 2027. Because a 1:100 chance has been established as the threshold for action, emergency management officials and scientists are working through scenarios of what they’d do.
“These exercises have really helped us in the planetary defense community to understand what our colleagues on the disaster management side need to know,” NASA’s Planetary Defense Officer Lindley Johnson said in a statement. “This exercise will help us develop more effective communications with each other and with our governments.”
These different scenarios have been explored since the Obama Administration. In 2016, then-FEMA Administrator Craig Fugate said, “It is critical to exercise these kinds of low-probability but high-consequence disaster scenarios. By working through our emergency response plans now, we will be better prepared if and when we need to respond to such an event.”
This year’s drill even has its own website, emblazoned with “This is only a drill” on it. One of the assets being used in this drill is an ominous map which has numerous red dots indicating potential places of impact; when viewed together, the red dots make a line stretching from Los Angeles to New York. The red dots in the risk corridor are Monte Carlo points, which are all essentially equally likely. While there are gaps between the points shown here, the risk corridor is really a continuum, with the impact probability proportional to the average density of the points. Note that the points become more widely spaced towards the ends of the corridor because the asteroid enters at shallower and shallower elevation angles. In a real impact, this may be the best science can offer today at where such an asteroid impact could occur.
