Latest Issue of Science News


Comets don't all start out on the fringe

New model suggests comets also come from the inner Oort Cloud

WASHINGTON — A new study of fringe comets could let the outer solar system lose some weight.

Simulations of the most distant objects in the solar system suggest that, counter to long-standing thinking, the comets that swing past Earth can originate in the inner region of the Oort Cloud, not just from its outer fringes. The new model could resolve a discrepancy: The amount of solid mass estimated to have been in the protoplanetary disk falls short of the amount needed to build the Oort Cloud in the first place, said Nathan Kaib of the University of Washington. Kaib presented his calculations on January 5 at the winter meeting of the American Astronomical Society.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

This article is available only to subscribing members. Join SSP today or Log in.