Redshift and Hubble's Law - NASA
The amount of departure, and the type, depends on the value of the total mass of the universe. In this way a plot of recession velocity (or redshift) vs. distance, which is a straight line at small distances, can tell us about the total amount of matter in the universe and may provide crucial information about the mysterious dark matter.
How do we measure the distances to things in space? - NASA
Redshift and Hubble's Law - measuring distances to objects far, far away; Return to the StarChild Main ...
They're light years away, man, and that's pretty far (lightspeed's …
They're light years away, man, and that's pretty far (lightspeed's the limit, the big speed limit) But there's plenty we can learn from the light of a star (split it with a prism, there's little lines in it) By looking at the spectrum at the light that's glowing (wavelengths of emission, measured with precision) Its Doppler Shift will tell us if it's coming or going Doo doo doo doo doo-ooo ...
StarChild: A Learning Center for Young Astronomers
When a star is approaching and it's coming our way Its spectrum seems bluer, won't you hear what I say And when a star's retreating way out of range And the scientist measures its frequency change 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 …
What is the shape of the universe? - NASA
StarChild Question of the Month for July 2001 Question: What is the shape of the universe? Answer: One of the most profound insights of General Relativity was the conclusion that mass caused space to curve, and objects travelling in that curved space have their paths deflected, exactly as if a force had acted on them.
Cepheids - NASA
Cepheids. 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 of light-years.
StarChild: A Learning Center for Young Astronomers - NASA
2018年5月14日 · This site is intended for students in grades K through 8. StarChild is a learning center for young astronomers ages 5-13 to learn about the solar system, the Milky Way galaxy, and the universe beyond.
How do we know that dark matter exists? - NASA
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 galaxies in the cluster (the bright spots in the visible image).
NGC 253, a starburst galaxy - NASA
NGC 253, a starburst galaxy. On the left, you see an image of the spiral galaxy NGC 253, taken with a ground-based telescope.
Parallax - NASA
Parallax. Astronomers derive distances to the nearest stars (closer than about 100 light-years) by a method called stellar parallax.