All the Water on Planet Earth

September 12, 2016

all-water-on-planet-earth

Explanation: How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth’s surface, these oceans are shallow compared to the Earth’s radius. The featured illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth’s Moon, but slightly larger than Saturn’s moon Rhea which, like many moons in our outer Solar System, is mostly water ice. How even this much water came to be on the Earth and whether any significant amount is trapped far beneath Earth‘s surface remain topics of research.

Astonishing, from NASA’s Astronomy Picture of the Day.

Suppose, now, we asked for–imagined–a picture of all the living water on planet earth.

 

Advertisements

About Doug Bennett

Doug Bennett is Emeritus President and Professor of Politics at Earlham College. He has a wife, Ellen, and two sons, Tommy (born 1984) and Robbie (born 2003).
This entry was posted in Image, Uncategorized and tagged . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s