Can This Man Save Earth From A Disastrous NEO IMPACT?
NASA Designated Planetary Defense Officer—that’s a hefty title and one that Lindley Johnson is accepting with pride. Johnson is the leader of exciting new efforts from NASA, which has formalized its program for detecting and tracking near-Earth objects (NEOs) under the name of the Planetary Defenses Coordination Office. The new office will reportedly be responsible for all of NASA’s projects to find and characterize asteroids and comments that pass near Earth’s orbit. It’ll also be responsible for coordinating a plan if things get a little too close for comfort.
“Asteroid detection, tracking and defense of our planet is something that NASA, its interagency partners, and the global community take very serious,” John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington said in an announcement. “While there are no known impact threats at this time, the 2013 Chelyabinsk super-fireball and the recent Halloween Asteroid’s close approach remind of us why we need to remain vigilant and keep our eyes to the sky.”
Already, PDCO has some hurdles to overcome. Since 1998, more than 13,500 near-Earth objects have been discovered and about 1,500 new ones are identified yearly. Only a handful of those are really worth noting—like the 1,300-foot-wide asteroid that passed us last Halloween. While some of these objects are clear threats, others can be useful, carrying usable water we could someday mine for space exploration.
The federal budget for this year includes $50 million for NEO observation and planetary defense. The plan is twofold: identify the threats and then find a way to “redirect” them. Here is how PDCO defines a “potentially hazardous” asteroid:
A potentially hazardous asteroid (PHA) is an asteroid whose orbit is predicted to bring it within 0.05 Astronomical Units (just under 8 million kilometers, or 5 million miles) of Earth’s orbit; and of a size large enough to reach Earth’s surface – that is, greater than around 30 to 50 meters. (Smaller objects entering Earth’s atmosphere tend to disintegrate.) The potential for an asteroid to make a close approach to Earth does not mean that it will impact Earth. By monitoring PHAs and updating their orbits as new observations are made, observers can improve their predictions of Earth impact risk. Sometimes the term potentially hazardous object, or PHO, is used to describe an asteroid, or comet, that meets these criteria.
So what happens if a threat can’t be redirected?
“Even if intervention is not possible, NASA would provide expert input to FEMA about impact timing, location, and effects to inform emergency response operations,” the agency noted in its announcement. “In turn, FEMA would handle the preparations and response planning related to the consequences of atmospheric entry of impact to U.S. communities.”