Heavy and Light Just Right
Using NASA Herschel Space Observatory, astronomers have discovered that comet Hartley 2 possesses a ratio of heavy water to light, or normal, water that matches what found in Earth oceans.
The Same Here as There
New measurements from NASA Herschel Space Observatory have discovered water with the same chemical signature as our oceans in a comet called Hartley 2 pictured at right. The image at bottom right is an artist concept of a comet.