The FAS Astronomers Blog

  • A History of the Earth (Geologic Time)

    FAS Astronomers Blog, Volume 31, Number 10. The history of the Earth is described by geologists using something call Geologic Time. This is a timeline from the beginning of the Earth to the present day broken down into a hierarchy of four main groupings: Eons, Eras, Periods, and Epochs. Epochs are broken down further into…

  • The Making Of The Atomic Bomb

    FAS Astronomers Blog, Volume 31, Number 9. Physics drives the cosmos. Okay, there is a lot of chemistry going on as well. But astrophysics is the big topic, not astrochemistry. Physics played an important role in something that happened down here on the Earth during July and August just under eighty years ago. For the…

  • Owen Gingerich

    FAS Astronomers Blog, Volume 31, Number 8. Astronomer Owen Gingerich passed away on May 28, 2023 at the age of 93. With his passing, we lost one of the top scholars devoted to the history of astronomy and someone who almost kept Pluto as a planet.

  • The Solar System

    FAS Astronomers Blog, Volume 31, Number 7. We live in a solar system. So, just what is it? It is a star and all the objects and material that are gravitationally bound to the star. Until recently, the only example we knew of was our local group of planets orbiting the Sun. In 1995, Michel…

  • The Multiverse

    FAS Astronomers Blog, Volume 31, Number 6. This is part 5 of a 5-part series on the Universe (The Visible Universe, The Dark Universe, The Expanding Universe, The Microscopic Universe, and The Multiverse). Define the Universe and give five examples. Many years ago, this would be a joke, but today maybe not. Recently, astronomers have…

  • The Microscopic Universe

    FAS Astronomers Blog, Volume 31, Number 5. This is part 4 of a 5-part series on the Universe (The Visible Universe, The Dark Universe, The Expanding Universe, The Microscopic Universe, and The Multiverse). The universe is huge and filled with light. We can see out 46 billion light-years in any direction. It is full of…

  • The Expanding Universe

    FAS Astronomers Blog, Volume 31, Number 4. This is part 3 of a 5-part series on the Universe (The Visible Universe, The Dark Universe, The Expanding Universe, The Microscopic Universe, and The Multiverse). For a long time, people thought that the universe was static and everlasting. It was here. It had always been here. And…

  • The Dark Universe

    FAS Astronomers Blog, Volume 31, Number 3. This is part 2 of a 5-part series on the Universe (The Visible Universe, The Dark Universe, The Expanding Universe, The Microscopic Universe, and The Multiverse). There is much we can see in the visible universe. On the other hand, the universe is also dark and mysterious. And…

  • The Visible Universe

    FAS Astronomers Blog, Volume 31, Number 2. This is part 1 of a 5-part series on the Universe (The Visible Universe, The Dark Universe, The Microscopic Universe, The Expanding Universe, and The Multiverse). When we look up at the night sky, we can see clouds. Yes, for most of us interested in astronomy, this is…