Air and Space: NASA’s Most Important Mission, Long Delayed, Is Finally on Track

By Tony Reichhardt

    Most people believe that the probability of a truly dangerous asteroid hitting Earth is very small - and for a good reason. Over the past few decades, ground telescopes have identified over 95 percent of the asteroids in our atmosphere that are over a kilometer wide, and none of them are on course to hit Earth. Next year, a new spacecraft called DART will do a test drive to see if it can change an asteroid's course, should one be headed in our direction. However, this doesn't mean that we can rest easy.

    There are an estimated 25,000 smaller objects in orbit that are around 140 meters or larger. These could strike with enough impact to wipe out southern California. An asteroid half that size landed in Arizona 50,000 years ago and left the famous crater. In 2005, NASA was ordered to find at least 90% of objects this size, and the deadline was supposed to be 2020. But the project currently sits at just 40% finished and estimates show that it will take another 30 years to complete if it continues at this pace.

    One reason is that people don't seem to care about a threat so rare. Another is that NASA is having trouble figuring out which department should complete the task. While scientific asteroid missions have gotten plenty of funding, it's been harder to get the same for the so-called "planetary defense". A 2014 project was turned down by NASA. Fortunately, another project by the acronym NEO surveyor spacecraft has gotten funding and is on track for launch in 2026. Its infrared cameras should complete the project in the next ten years and pick up plenty of other small objects along the way.