An asteroid or asteroids will hit Earth. It’s not a matter of ‘if’, but a matter of ‘when’ and… ‘how big?’. That point was driven home in Michael B. Lund’s article in The Conversation (made known to us through space.com). But, he also made it clear that scientists are on the case; with a very big telescope.
The Large Synoptic Survey Telescope (LSST) is being built in Chile for the purpose of tracking 90 percent of asteroids called near-Earth objects (NEO’s). Those are the ones that could hit us. And, the LSST is specifically on the lookout for NEO’s that are considered potentially hazardous asteroids (PHA’s); meaning they’re over 14o meters in diameter and would devastate any area of Earth that they might hit.
How many of those PHA’s are really out there threatening to potentially hit Earth at some point? Scientists estimate about 25,000. And, right now, they think that 75 percent of those 25,000 PHA’s have not yet been found. Gulp. Okay. Let’s breathe and talk about what’s being done… because it’s pretty cool.
The LSST will look at the same part of the sky, and in one-hour intervals, search for “objects that have changed position. Anything that moves in just one hour has to be so close that it is within our solar system.” Experts at University of Washington and JPL expect the LSST to find 60 percent of the PHA’s they’re looking for on its own. The slack will be picked up by other astrological surveys like Pan-STARRS and the Catalina Sky Survey.