Living things that have only one cell and are so small they can only be seen with a microscope. BLACK HOLE An invisible object in outer space formed when a massive star collapses from …

How do we measure the distances to things in space? [November 2001] Where do comets come from? [December 2001] Do stars last forever? [January 2002] Why did Herschel name his …

This composite image (Chandra X-ray image on the left and DSS optical image on the right) of the galaxy cluster Abell 2029 shows a huge hot gas cloud (as seen in X-rays) envelopes the …

There are two things to think about here. Let's take the easy one first and ask "why is the daytime sky blue here on Earth?" That is a question we can answer. The daytime sky is blue because …

Susan Jocelyn Bell was born in Belfast, Northern Ireland on July 15, 1943. Her father was an architect and an avid reader.

What is a brown dwarf? Answer: In order to understand what is a brown dwarf, we need to understand the difference between a star and a planet. It is not easy to tell a star from a planet …

The story of Isaac Newton discovering the laws of gravity by watching apples falling from a tree is probably just a myth.

How do we measure the distances to things in space? Answer: It is not an easy thing to measure the distances to objects in the universe since these objects are usually very far away. We can't …

Put your finger on the planet you think is the smallest. This planet's name is Mercury. Mercury is the closest planet to the Sun. Mercury is a fast-moving planet. Mercury moves around the Sun …

In 1632, he published a book that stated, among other things, that the heliocentric theory of Copernicus was correct. Galileo was once again called before the Inquisition and this time was …