What did Hubble discover in the 1920s quizlet?
Hubble, who, in the 1920’s, found galaxies beyond the Milky Way and discovered that the universe is expanding.
Can optical telescopes penetrate interstellar dust?
The center of our Milky Way galaxy is hidden from the prying eyes of optical telescopes by clouds of obscuring dust and gas. But in this stunning vista, the Spitzer Space Telescope’s infrared cameras penetrate much of the dust, revealing the stars of the crowded galactic center region.
How does NASA know how the Milky Way looks?
Astronomers using data from NASA’s Wide-field Infrared Survey Explorer, or WISE, are helping to trace the shape of our Milky Way galaxy’s spiral arms. This illustration shows where WISE data revealed clusters of young stars shrouded in dust, called embedded clusters, which are known to reside in spiral arms.
Why does dust Redden starlight?
Why does dust redden starlight? It scatters optical and shorter-wavelength light. The reflection nebula is a cloud of dust. When light from a star encounters this cloud, the short wavelength blue light “bounces back” from the cloud towards us, and the longer wavelength red light passes through.
How does NASA get pictures of the Milky Way?
Several different telescopes, both on the ground and in space, have taken images of the disk of the Milky Way by taking a series of pictures in different directions – a bit like taking a panoramic picture with your camera or phone.
How many black holes are in the Milky Way?
Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone.
Which is the smallest galaxy in the universe?
A candidate for the smallest galaxies that can form are the ultrafaint galaxies. The star formation of ultrafaints appears to have been shut off during the epoch of reionization, when radiation from the first stars ionized all the free hydrogen in the universe.
Which is the biggest galaxy in the universe?
IC 1101