The Energy Department says a small nuclear reactor under development at a national lab has reached a crucial milestone that could allow it to produce electricity in the next few years

Astronauts aboard the International Space Station have briefly taken shelter during a repair to fix a new leak

A federal judge in Washington has blocked a plan to loosen rules for fishing red snapper in the Atlantic, halting what was expected to be the longest recreational snapper season in years

The U.S. Department of Agriculture has confirmed that the New World screwworm fly has arrived in south Texas

A new study finds that smoke from larger wildfires is reversing more than a decade of American improvements in smog

There were no treatments or vaccines to protect people during the recent hantavirus outbreak on a cruise ship

The Canadian government has endorsed a plan to move the last remaining captive whales from a shuttered theme park and zoo in Ontario to aquariums in the U.S. and Spain

NASA's Maven spacecraft around Mars has been declared dead after six months of radio silence

SpaceX says it plans to raise up to $75 billion when it goes public this month, setting the stage for the largest-ever stock market debut and putting Elon Musk on course to becoming the world’s first trillionaire