Redshift and Hubble's Law For very far objects (beyond about 1 billion light-years) none of the above methods work. Scientists must move from direct observation to using observations in …

Well that's a redshift, redshift If the star is moving away By reading Doppler Shifts of all we see in the skies (clusters of galaxies, near and far) We get the big picture and a big surprise …

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 just run out there with a ruler! To measure distances in the …

StarChild Question of the Month for July 2003 Question: How do we know that dark matter exists? Answer: Dark matter is the name scientists have given to the particles which we believe exist …

Well that's a redshift, redshift If the star is moving away By reading Doppler Shifts of all we see in the skies (clusters of galaxies, near and far) We get the big picture and a big surprise …

Astronomers derive distances to the nearest stars (closer than about 100 light-years) by a method called stellar parallax. This method that relies on no assumptions other than the geometry of …

The universe is a vast expanse of space which contains all of the matter and energy in existence. The universe contains all of the galaxies, stars, and planets. The exact size of the universe is …

Cepheids, also called Cepheid Variables, are stars which brigthen and dim periodically. This behavior allows them to be used as cosmic yardsticks out to distances of a few tens of millions …

Question: 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 …

For more than ten years astronomers studied the expansion of the universe by measuring the redshift and brightness of distant supernovae. By 1998, enough information had been …