Volume 30

  • Cosmic Distances, Stellar Brightness, and The Hubble Constant

    FAS Astronomers Blog, Volume 30, Number 3. The Hubble Constant The Universe is expanding. The farther a galaxy is from us, the faster it is moving away from us. We measure this expansion using something called the Hubble constant, which is the rate with which galaxies are receding from us as a function of their…

  • Project Mercury

    FAS Astronomers Blog, Volume 30, Number 2. Sixty years ago this month (February 20, 1962), Astronaut John Glenn became the first American to orbit the Earth. He did so as part of NASA’s Project Mercury. This is the story. On October 4, 1957, a small round ball called Sputnik was launched into orbit by the…

  • Dark Energy

    FAS Astronomers Blog, Volume 30, Number 1. In a previous article, I explored the Standard Model of Particle Physics and discussed what ordinary matter is made of. It can be a bit confusing because of the different ways to look at it. Matter is made up of atoms, which are composed of protons, neutrons, and…