What happens to a comet after it's exciting entrance into our orbit?
Solar winds create a bubble that cover our entire solar system! Scientists call this the sun's heliosphere.
The sun may be far away, but its solar flares still present a deadly risk for astronauts going to the moon.
When you look up into the night sky you can see hundreds of stars without even using a telescope. How did all of these stars form?
How fast does light travel? What could you do to find out? One natural thing to try is to have someone send some light your way and see how long it takes to reach you. How about if you got a friend to shine a flashlight at you from a distant hill, exactly at midnight? With your stopwatch you start counting the seconds until you see the light. Learn more on this Moment of Science.
For a long time people have been fascinated by comets passing by the earth. How close are they? Learn more on this Moment of Science.
Does earth have a second moon? Find out on this Moment of Science.
Although the earth has been hit by asteroids in the past, and will surely be hit again someday, much of the gloom-and-doom you hear about in the media is based on very little data.