Stars move slowly across the sky over very long periods. The closer a star is, the more easily we can see its movement. Stellar parallax is a shift in a star's apparent position due to Earth's orbit.

Let’s try a demonstration that we all enjoyed in elementary school. Close one eye, hold out your thumb at arm’s length, and align it with an object on the other side of the room. Without moving your ...

Astronomers quickly become used to dealing with huge numbers. For example, in any one lecture, I might declare that the sun emits some 400 billion trillion watts of power each second, that our Milky ...

Regular readers of my Stargazers columns have surely become accustomed to seeing some pretty big numbers. For example, in any one column, I might explain that our Milky Way galaxy is home to hundreds ...

One of the questions I am sometimes asked is, "How do astronomers know how far away a star or a distant galaxy happens to be from Earth?" In our sky this week, there are three stars that have been ...

Exit strategy Artist’s impression of New Horizons as it flew past Pluto in 2015. (Courtesy: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute) NASA’s New Horizons ...

The article details the historical significance of observing double stars, highlighting their use as visual acuity tests in ancient Arabic texts and their role in advancing our understanding of ...

Don't miss the big stories. Like us on Facebook. Astronomers quickly become used to dealing with huge numbers. For example, in any one lecture, I might declare that the sun emits some 400 billion ...