Submitted by ClienteFrecuente t3_10zvwxa in askscience
I’ve read water on Earth came from an asteroid. What are the current theories about water on Mars?
Submitted by ClienteFrecuente t3_10zvwxa in askscience
I’ve read water on Earth came from an asteroid. What are the current theories about water on Mars?
atomfullerene t1_j8bjh12 wrote
Not an asteroid. One possibility (I'm not sure if it's currently in favor) is that asteroids and comets delivered much of Earth's water. We are talking not one or two, but very large numbers of them.
Another possibility is that most of Earth's water was emitted by volcanoes (which do emit water vapor).
And of course, a mix of the two is also possible.
Either route could potentially explain Mars' water.