In this "Ask an Astronomer" episode (03:05), Dr. Carolyn Brinkworth fills us in on what the color of the sky has to do with finding life on distant planets.
No, not cockroaches and ants. These bugs are tiny, single-celled bacteria you can’t see. They blanket your skin. They also fill your stomach, intestines, lungs and mouth.
Don’t worry about being less than human, though. Bacterial cells are very small. All of these bugs make up only between 1 and 3 percent of your body weight.
An in-depth online geology textbook written for kids. Learn about the world beneath you. Geology is the study of the Earth's surface and substructure. Geologists look at the processes that form terrian, and the processes that destroy terrian.