Scientists have issued a stark warning after NASA admitted it does not know where thousands of potentially dangerous asteroids are located.
The space agency says there could be around 15,000 “city killer” asteroids still unaccounted for. These space rocks are at least 140 metres wide and are large enough to cause serious regional damage if they hit Earth.
NASA has been tracking near-Earth objects for years. While experts say they know the location of most large, planet-destroying asteroids, it is the mid-sized ones that worry them most.
Dr Kelly Fast, who leads planetary defence efforts at NASA, said these are the objects that keep her up at night. Speaking at the American Association for the Advancement of Science conference in Phoenix, she said smaller rocks hit Earth often and the very large ones are mostly tracked. But the “in-between” asteroids remain a major concern.
She explained that scientists estimate there are about 25,000 of these mid-sized asteroids, yet only around 40 percent have been identified so far. Finding the rest will take time, even with advanced telescopes.
Another expert, Nancy Chabot from Johns Hopkins University, warned that Earth currently has no ready defence system if one of these objects were heading our way.
In 2022, NASA carried out the Double Asteroid Redirection Test (DART) mission, which successfully changed the path of an asteroid by crashing a spacecraft into it. The test proved that deflection is possible in theory.
However, Chabot admitted there is no similar mission prepared to launch quickly if a real threat appeared tomorrow. She said more investment is needed to prepare for this kind of danger before it becomes a real emergency.
