Liquid Water

In February, exoplanet hunters announced the discovery of seven rocky planets orbiting a star called TRAPPIST-1 only forty light-years away. Compared to our sun, TRAPPIST-1 is tiny, and all its planets orbit closer than Mercury orbits Sol. But three of them are still in the Goldilocks zone that could be "just right" for life, and all seven planets could theoretically hold liquid water. While Ethan Siegel introduces the neighboring star system with spectacular illustrations from NASA and ESO, Greg Laden notes that the practice of saying these images are artistic interpretations "has largely…
"Mars once was wet and fertile. It's now bone dry. Something bad happened on Mars. I want to know what happened on Mars so that we may prevent it from happening here on Earth." -Neil deGrasse Tyson Oh, it's true alright, something bad did once happen on Mars. And although there isn't any real danger of that happening to Earth, a little conversation I had earlier this week made me think that it's time to tell all of you a story about our red neighbor, and why it is the way it is today. You see, when we think about Mars, we think about the smallish, red, desolate world that fascinates us today…