Welcome to Ask an Astronomer at Cornell University!

Hello, curious astronomers! Welcome to Ask an Astronomer at Cornell, where you can submit any question you may have about the cosmos, and receive an answer from our own Astronomy graduate student team.

Ask an Astronomer is run by volunteers in the Astronomy Department at Cornell University. There are several astronomers involved in maintaining this site and answering the questions sent in. Please take the time to browse our site and first try to search our site and other sites (with your favorite search engine) to find an answer to your question. For those tricky questions with unsatisfying answers, don’t hesitate to submit your question to our website!

Ask an Astronomer was set up in 1997 by Dave Kornreich when he was a graduate student here at Cornell. He told us that he started it because he thought it would be fun – which it is! Somehow it got picked up by Yahoo and got very popular. It has been run in various iterations since it began, always by volunteer graduate students with a passion for sharing their knowledge and excitement about space.

The website had a recent overhaul in 2023, and is still a work in progress; if you’ve visited us before and the website looks a little different, it’s because we’re always trying to make updates and improvements to bring you the most up-to-date answers to your pressing astronomy questions!

Answers on this site with a “legacy” tab were answered before 2023, and have been ported over from a previous iteration of the website. With that being said, we try to make sure the answers are all current and accurate.

Enjoy our website and stay curious!