Since the Kepler telescope went online, astronomers have found there may be an estimate 40 billion planets like Earth in the Milky Way galaxy alone. What does it take for a planet to be considered Earth-like?
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

Selects: Mangroves: Nature's Best Tree?
44:31

How the Kowloon Walled City Worked
41:27

Short Stuff: In-Flight Entertainment
12:23