Origin of Dinosaur-Killing Asteroid Is Still a Mystery
The source of the asteroid that killed off the dinosaurs 65 million years ago remains a mystery, a new study finds.
Some researchers had thought the deadly asteroid was a piece of a larger space rock called Baptistina. Baptistina broke apart after a massive in-space collision about 160 million years ago, the theory went, spawning a swarm of mountain-size chunks of rock. One of those eventually slammed into Earth, killing off the dinosaurs and many other species.
Scientists are confident that a 6-mile-wide (10-kilometer asteroid) is indeed what wiped out the dinosaurs. But new observations from NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope suggest the space rock didn’t come from Baptistina.
The timing just isn’t right, according to the new study.
“As a result of the WISE science team’s investigation, the demise of the dinosaurs remains in the cold case files,” said Lindley Johnson, program executive for the Near Earth Object Observation Program at NASA headquarters in Washington, in a statement.
Questioning The Theory
Baptistina first came under suspicion in some astronomers’ minds after a 2007 study. In that work, researchers used visible-light data from ground-based telescopes to estimate the size and reflectivity of the Baptistina “family” — the pieces of the broken-apart space rock.
With these estimates in hand, researchers determined that the big space rock likely broke apart about 160 million years ago. That would have given plenty of time for the Baptistina family asteroids to disperse to different and potentially dangerous orbits by the time of the dino-killing impact.