Medical researchers want to keep astronauts' hearts healthy in space, so they looked to the sporting world to find the best excercise. Hear about why rowing is best.

Forests can't be left alone to take care of themselves, says Sally Collins of the U.S. Forest Service.

Astronomers believe that galaxies have spiral arms - in part - because galaxies rotate, or spin around, a central axis.

How many stars in the Milky Way? The estimate for the number of stars in the Milky Way is about 100 billion stars - plus or minus 50 billion.

Hurricanes may start to interact at even a thousand kilometers apart.

Astronomers estimate that the luminosity of the Milky Way’s “core” is equal to about 10 million suns. Read more about interstellar dust here.

Light from Earth becomes too faint to see with the eye alone at around 14 billion kilometers (about 9 billion miles) from our home planet.

Bruce Rittmann talked about creating microbial fuel cells that use organic waste to create energy. Read more in using bacteria to make energy from waste.

The Indian Ocean tsunami of 2004 claimed the lives of tens of thousands of people, who didn't have time to evacuate to higher ground. Now scientists are developing a technology that they say can predict a tsunami before a tsunami even starts.

NASA has announced plans to return to the moon and establish a human presence there. Read more about the inflatable lunar habitat being developed.