Carl Sagan Day Date in the current year: November 9, 2026

Carl Sagan was born on November 9, 1934, in New York City. He recalled visiting the 1939 New York World’s Fair as the moment he became interested in science and science fiction. He also credited trips to the American Museum of Natural History and reading Astounding Stories of Super-Science with helping him develop this interest. After graduating from high school at age 16, Sagan attended the University of Chicago, where he earned his bachelor’s, master’s, and doctoral degrees.

After earning his PhD, Sagan worked as an assistant professor at Harvard but later moved to Cornell when Harvard denied him tenure. Throughout his scientific career, Sagan published over 600 papers and articles. Most of his research focused on planetary science, particularly the atmospheres, climates, and surface conditions of the planets in our solar system. Sagan also played an active role in NASA’s Mariner, Viking, and Voyager programs.

Sagan was also one of the most influential science communicators of the 20th century. He wrote several popular science books and earned the Pulitzer Prize for General Nonfiction for The Dragons of Eden: Speculations on the Evolution of Human Intelligence. He is also known for writing and presenting the documentary television series Cosmos: A Personal Voyage, which first aired on PBS in 1980. The series won two Emmy Awards and has been seen by more than half a billion people since its release.

A lifelong science fiction fan, Sagan wrote the hard science fiction novel Contact, which was adapted into the 1997 film of the same name, directed by Robert Zemeckis and starring Jodie Foster. Due to Sagan’s death on December 20, 1996, the film was released posthumously.

In 2009, the Center for Inquiry (CFI) in Fort Lauderdale, Florida, along with the Florida Atheists and Secular Humanists (FLASH) and a number of other groups, launched Carl Sagan Day. It is celebrated on Sagan’s birthday to honor his contributions to modern science and science communication.

There are many ways to celebrate the holiday. Some involve apple pie because of Sagan’s famous saying: “If you wish to make an apple pie from scratch, you must first invent the universe.” This means that everything we make or create depends on things that already exist, and tracing these dependencies far enough takes us back to the origin of the universe. In that sense, nothing can be made entirely from scratch without first having a universe in which it can exist.

So you can celebrate Carl Sagan Day by making an apple pie from scratch, organizing a baking contest, or hosting a space-themed party with apple pie. However, if you’re not a fan of apple pie or baking, there are many other ways to celebrate. For example, you can rewatch Contact or your favorite Cosmos episodes, visit a planetarium, organize a stargazing party, or read one of Sagan’s books.