
Cosmic Citizens
Caleb A. Scharf is a researcher and writer. He is the senior scientist for astrobiology at NASA's Ames Research Center in Silicon Valley.

Cosmic Citizens

The Panspermia Paradox

We All Carry Stardust Memories

A River Runs Through...Gale Crater

Tweets In Space Are Go - TODAY!

Black Hole Roundup

A Martian Stares Back

Single Suns Adorn Most Alien Skies (Probably)

Watch Out Mars! 1080 HD Video of Curiosity Descent

More Tales of Life

Black Holes to the Rescue

Curiosity Targets Gale Crater

Skiing To Mars: The Original Rovers

Black Holes: Incredibly Loud and Extremely Distant

Defining Life: Scientists Squirm, Chickens Carry On

Calling All Sentient Lifeforms

Exo-cornucopia

The Hole

Black Holes are Everywhere

The Venus Movies

Venus was Just the Beginning: The Science of Planetary Transits

From Andromeda With Love

A Dragon in the Sky: Space X

Dust to Dust: A Disintegrating Exoplanet?