Tombstone and Yeti go the distance in a no-hold-barred slug-fest.

Minotaur and Bombshell go head-to-head.

Beta and Tombstone go the distance.

Chomp and Yeti go head-to-head in a no-holds-barred match to the death.

Tombstone brings the rukus and leaves a cloud of smoke in its wake.

Beta upsets Nightmare after suffering debilitating damage.

Chomp scores a one-in-a-million shot against the reigning champ.

Minotaur decapitates Warhead.

Hypershock feels the heat, and gets burned.

Beta drops the hammer on Overhaul.

HyperShock swats the competition.

Mega Tento and Stinger go head-to-head in this epic bug-eat-bug battle.

The apex predator of Battlebots, Tombstone, punishes its opponent, Escape Velocity.

Razorback and Ghost Raptor go head-to-head in a battle for redemption.

Warhead and Complete Control square off in this heated match.

Red Devil grapples with Witch Doctor, leaving the competition in a cloud of smoke.

Tombstone and Yeti go the distance in a no-hold-barred slug-fest.

Razorback and Icewave exchange blows in the hard-hitting series premiere of BATTLEBOTS.

Next-generation robots duke-it-out to become the BATTLEBOT champion.

Author Nick Sagan hasn't seen his godfather, Frank Drake, in over 30 years. We capture their reunion - and find out how Drake became friends with Nick's famous father, Carl Sagan, in this exclusive clip.

Since launching in 2009, the Kepler program has detected hundreds of previously unknown planets. How many of them are Earth-like, and what does that mean for the probability of intelligent life beyond our solar system?

Since the 1960s, NASA has been keeping an eye on man-made objects in space. Here, engineers are replicating the devastating impact of space debris. 'Alien Encounters' airs Tuesdays at 10/9c.

What would receiving a message from an alien civilization tell us about human evolution, and about surviving the most serious problems facing our planet?

Author Nick Sagan hasn't seen his godfather, Frank Drake, in over 30 years. We capture their reunion - and find out how Drake became friends with Nick's famous father, Carl Sagan, in this exclusive clip.

It's possible that life on earth began off-planet and spread here.

An alien spacecraft might not rely solely on sunlight to power its trajectory. Find out what other energy technology aliens could use to travel through the universe.

It's likely that an advanced civilization would combine the advantages of a machine with the advantages of biological systems.

Will ETs look like us? Will they resemble giant insects? Scientists debate how various environments could have created life forms beyond our wildest imagination.

If the chirality of aliens is different than ours, it couldn't interact with us, and therefore would be non threatening.

It's 1967, the Cold War is on and there's a glowing orange light hovering over a U.S. Air Force base.

John Smith and his cousin Billy have a mysterious encounter while driving on a remote highway in the Yukon. Was it a UFO?

Reports of a downed aircraft bring a volunteer firefighter to a remote wooded area.