To study the history of life on Earth and look for it beyond our planet, scientists in the field of astrobiology look for signs called “biosignatures.” NASA Goddard researcher Heather Graham discusses some of the oldest evidence of life on Earth and what scientists are searching for when they look for biosignatures in ancient rocks. By looking at what life on Earth was like millions and even billions of years ago, astrobiologists can make predictions about what signs of life could be hiding in the rest of the solar system and beyond.

How did life originate and evolve here on Earth? What form could life take elsewhere – and where else could life survive beyond our planet? These are questions that scientists called astrobiologists tackle every day. By using space telescopes, doing laboratory experiments and studying extreme environments on Earth, astrobiologists hope to uncover new insights about what it means to be “life” and get more clues to the ultimate question: Are we alone in the universe? Mary Voytek, head of NASA’s astrobiology program, discusses in this episode.

Besides learning how to live in space, astronauts training for Artemis missions to the Moon will need to become experts in geology, so they know what to look for when they're scoping out rocks and other features. Kelsey Young of NASA's Goddard Space Flight Center describes her experience of teaching astronauts through analog sites, places on Earth that resemble parts of the Moon.

Neil Armstrong and Buzz Aldrin landed far from where they had anticipated because, 50 years ago, we didn't have a complete understanding of the Moon's gravity. Recent maps of the Moon's gravity have taught us a lot about its overall shape, and have been invaluable for lunar exploration. Maria Zuber, principal investigator of NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, reflects on the twin spacecraft and their implications for future investigations.​

Just like earthquakes help scientists figure out what's going on inside our home planet, moonquakes have taught scientists a lot about the interior of the Moon. NASA's Gravity Recovery And Interior Laboratory (GRAIL) mission has also given us a clearer picture of the Moon beneath its surface. Seismic activity on the Moon is one area of scientific interest as NASA makes plans to send the first woman and the next man to the Moon by 2024.

Early in its history, the Moon was molten, with “fire fountains” erupting from its surface. Astronauts have found tiny beads of glass on the Moon that preserve this history. How did the Moon cool down and become the quiet, cratered world we know today? NASA’s Chief Scientist Jim Green chats with NASA’s Deputy Chief Scientist Dave Draper about the Moon’s volcanic past and what we have learned from Apollo lunar samples.

From lunar samples brought back in the Apollo program, scientists have figured out that the Moon once had a shield around it called a magnetosphere, just like the Earth has today. As NASA prepares to send humans to the Moon, and eventually on to Mars, scientists are exploring the Moon's magnetic past.

It's been 50 years since humans walked on the moon. Now NASA is planning to return, this time to stay. What will future lunar missions look like? Why do we go back at all?

Why do we see only one face of the Moon? What would happen to Earth if the Moon didn't exist? We dive into questions you asked on social media.

Learn how Moon rocks can reveal all kinds of information about our nearest neighbor, as NASA prepares to send astronauts to the Moon and on to Mars.