The interstellar medium is the stuff between the stars. Made up mostly of hydrogen and helium gas, it contains all the material needed to make stars and planets. It is shaped by stellar winds, dying stars, galactic magnetic fields, and supernova explosions.
The sun generates about 400 billion billion megawatts of power and it has done so for five billion years. Nuclear fusion - combining lighter atoms to make heavier one - is what makes it possible.
Astronomers have discovered young spiral arms in the center of the giant elliptical galaxy Centaurus A. The spiral arms formed shortly after a collision with another galaxy several hundred million years ago.
X-ray astronomy studies interstellar gas heated to millions of degrees around extreme environments like black holes, neutron stars, and colliding galaxies.
Very Long Baseline Interferometry, or VLBI, links together widely separated radio telescopes to allow astronomers to see the universe in more detail than ever.
Explanation of sidereal time, or star time. New Year's celebrations on Mercury. How Venus spins backwards and is the slowest rotating planet in the solar system.
Chris Crockett got his Ph.D. in astronomy from UCLA in 2011 and worked at Lowell Observatory and the U.S. Naval Observatory. He then realized he enjoyed talking about astronomy a lot more than actually doing it. After being awarded a Mass Media Fellowship in 2013 by the American Association for the Advancement of Science, he spent a summer writing for Scientific American, then went on to become the staff astronomy writer at Science News from 2014 - 2017. These days, he freelances, focusing on stories about astronomy, planetary science, and physics. His work has appeared in Science News, Scientific American, Smithsonian Magazine, Knowable, Sky & Telescope, and the American Physical Society's online magazine Physics.