The sun has become increasingly active since 2008, a new NASA study shows. Solar activity is known to fluctuate in cycles of 11 years, but there are longer-term variations that can last decades. Case ...

A group of gold commemorative Sacagawea coins, seven of which traveled into orbit aboard a NASA space shuttle, recently sold for more than $3 million.

The Trump administration's central human resources office acted illegally when it directed the mass firings of probationary workers as part of President Donald Trump's efforts to downsize the federal ...