Redshift and Hubble's Law - NASA
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 conjunction …
How do we measure the distances to things in space? - NASA
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 universe, we will …
StarChild: A Learning Center for Young Astronomers
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 (redshifts going, …
StarChild: A Learning Center for Young Astronomers
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 (redshifts going, …
How do we know that dark matter exists? - NASA
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 in the …
StarChild: The Universe - NASA
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 unknown. …
Parallax - NASA
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 Earth's …
What is a brown dwarf? - NASA
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 planet when …
StarChild: Quasars
Quasars give off huge amounts of energy. They can be a trillion times brighter than the Sun! Astronomers think that quasars are located in galaxies which have black holes at their centers. The …
What is meant by "false color"? - NASA
StarChild Question of the Month for April 2000 Question: What is meant by "false color"? Answer: The term "false color" is used to describe what astronomers (and others) often do to images to make …