Estimated to have appeared around 200m years after the events of the big bang, the first stars of the universe suddenly came into being, shedding light in the darkness. These stars produced the essential building blocks for entire galaxies (银河系), for planets, and for the creation of life...
Recent findings lend strong support to the theory that a black hole lies at the center of the Milky Way and of many of the 100 billion other galaxies estimated to exist in the universe. 选项: A、that a black hole lies at the center of the Milky Way and of B、that a black hole lies...
Estimated to have appeared around 200m years after the events of the big bang, the first stars of the universe suddenly came into being, shedding light in the darkness. These stars produced the essential building blocks for entire galaxies (银河系), for planets, and for the creation of life...
Based on high precision measurements of the distances to nearby galaxies with the Hubble telescope, we have determined the radii of the zero velocity spheres for the local group, R-0 = 0.96 +/- 0.03Mpc, and for the group of galaxies around M 81/M 82, 0.89 +/- 0.05Mpc. These yield ...
Recent findings lend strong support to the theory that a black hole lies at the center of the Milky Way and of many of the 100 billion other galaxies estimated to exist in the universe. 选项: A、that a black hole lies at the center of the Milky Way and of B、that a black hole lies...