Biologists have found new evidence of why mice, people and other vertebrate animals carry thousands of varieties of genes to make immune-system proteins named MHCs -- even though some of those genes make vertebrate animals susceptible to infections and to autoimmune diseases.

Although the tyrannosaur made news, other fossils sold at auction may also have been looted.

Paleontologists have a simple reason to believe the fossils came illegally from Mongolia.

The dinosaur tentatively sold at auction is known as Tarborsaurus to most scientists.

Opportunity was perched at the rim of Mars' Endeavour Crater when it took the picture.

Researchers are trying to understand the origins of the beautiful planetary nebula Sharpless 2-71.

Decades of rigorous research, testing and development performed in the Entry Systems and Technology Division at NASA's Ames Research Center, Moffett Field, Calif., has garnered Ames' thermal protection engineers the respect of not just other government agencies, but also commercial entities. The successful re-entry in late May or early June ...

We’ve all heard earthquakes described in terms of their magnitude number. But what does this scale really mean? This video illustrates the variation of energy released in easy-to-understand terms.