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, …
Teachers' Center Activity: Densities - NASA
Planetary Densities Density is defined as the ratio of the mass of an object to the volume of space the object takes up. Mathematically, we would say D = M/V. Density will determine if you sink or float …
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. …
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, …
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 …
Where do comets come from? - NASA
The Kuiper Belt is a disk-shaped region past the orbit of Neptune roughly 30 to 100 AU from the Sun. The Belt contains many icy bodies which can become comets. Occasionally the orbit of a Kuiper Belt …
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 …
StarChild: Cosmology - NASA
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 gathered to lead …