Two Grand Canyon-size valleys on the far side of the moon formed within 10 minutes, scientists say

Two Grand Canyon-size features on the far side of the moon were likely formed in about 10 minutes after an unknown object slammed into the moon 3.8 billion years ago.

​ Two Grand Canyon-size features on the far side of the moon were likely formed in about 10 minutes after an unknown object slammed into the moon 3.8 billion years ago. Read More Breaking News, Latest News and Videos | CNN