Joel Achenbach

Lisa Kaltenegger’s “Alien Earths” describes intriguing and potentially habitable worlds that have only recently been discovered around distant stars.

NASA announced that it is overhauling its highly anticipated but troubled mission to bring pieces of Mars back to Earth as part of its hunt for ancient life.

The telescope’s uncertain status is part of an acute budgetary problem at NASA that is pitting flat funding against big ambitions.

Americans took in the awe-inspiring view of the last coast-to-coast total solar eclipse until 2045.

On Monday, the moon will begin gradually covering the sun and — if the clouds don’t spoil everything — people will behold the spectacle of a total solar eclipse.

Can I make eclipse glasses at home? Can I view the eclipse through a camera? Our solar safety tips will help protect your eyes during the April 8 eclipse.

These are anxious times for eclipse aficionados, many of whom are worried that clouds could obscure the grand spectacle.

It is only during totality that the eclipse reveals a simple if profound fact: The sun lives among the stars.

The melting of polar ice due to global warming is affecting Earth’s rotation and could have an impact on precision timekeeping, a new study says.

Contaminated fuel is one of several possible factors that might have caused the cargo ship Dali to lose power before it smashed into the Francis Scott Key Bridge.