Detecting Life Beyond Earth
How could a scientist here on Earth know whether a planet outside our solar system, beyond the reach of spacecraft, harbored life? Harvard astrophysicist Lisa Kaltenegger describes the clues she would look for—spectroscopic “golden fingerprints” that would reveal the chemical make-up of the planet’s atmosphere.
In this video and quiz, see how scientists sniff out signs of life on distant planets, then try it yourself.
The Drake Equation, named after its creator, radio astronomer Frank Drake, tackles a perplexing question: Does intelligent life, capable of communicating with us, exist beyond Earth? It makes the question easier to address by framing it as a numbers game. In this interactive version, learn about the factors in the equation and play around with the numbers yourself.
NASA Finds Life at ‘Extremes’
Hundreds of feet under the Alaska tundra, NASA astrobiologist Dr. Richard Hoover ignores the eerie silence of the icy tunnel around him, even ignores the bones of woolly mammoths and steppe bison jutting here and there from the jagged walls, frozen where they died tens of thousands of years ago… about the time Homo sapiens began to assert dominance over the prehistoric planet.
Astronomers have their radio telescopes tuned to receive signals from alien worlds. But is anybody out there?
Search for Life