Astronomy Day: A Time to Celebrate the Universe

When the World Celebrates Stargazing

doing astronomy from the international space station
Astronomy Day reminds us that there's a big universe of stars and galaxies to study. Even astronauts aboard the International Space Station turn their gaze to the skies during their brief orbital "nights". NASA

Every year, people in the United States who are interested in astronomy—whether they are professional, amateur, enthusiasts, or are just plain curious about the sky—gather together to celebrate Astronomy Day. It's also part of Astronomy Week in the United Kingdom. Two dates are selected each year to fall near or close to the first quarter moon in April and September. This gives skygazers a chance to see the Moon plus a starry sky after it sets. For 2017, Astronomy Day falls on April 29 and September 30th and there are events planned to commemorate our skygazing heritage throughout the world. 

Why Celebrate Astronomy?

Why have an Astronomy Day? People are always interested in astronomy—it's one of the more interesting sciences you can study. It's also the easiest one you can learn to do. What other activity lets you observe a star at night and then spend a little time learning about what makes it tick: its temperature, distance, size, mass, and age? Astronomy does all that, and more. It can teach you about the origins of our own Sun and stars as well as the history of the universe. And, it shows you how and where stars are born, how they live and how they die in the many different types of galaxies spread out as far as we can see (and beyond). There are interesting sub-disciplines to astronomy, where scientists who are chemists, biologists, geologists, and physicists all make important contributions. 

Astronomy is one of humanity's oldest sciences. There's plenty of evidence for our ancestors' interest in the sky. Tens of thousands of years ago, artists painted pictures of star patterns on rock walls in France, and carved bones with the phases of the Moon. People counted on the calendar of the sky to keep track of the seasons for planting and harvesting and measure the passage of time. Over the centuries, those practical uses of the sky also piqued the interest of scientists and today, the science of astronomy is the result. 

Of course, you don't need to know any of that to simply enjoy stargazing. Observing the sky is a great delight all by itself. It doesn't take much effort to get started: simply walk outside and look up at the night sky. That's the beginning of a life-long interest in the stars. Once you do that, you start to notice interesting objects, and you might wonder what they are.

Sharing Big and Little Astronomy

Astronomers (both professional and amateur) dedicate their lives to observing and explaining objects and events in the sky. Astronomy Day provides a good way to connect astronomers with the general public. In fact, the theme of Astronomy Day is "Bringing Astronomy to the People", and for several decades, it has done just that. Planetariums and observatories (such as Griffith Observatory in Los Angeles and Gemini Observatory in Hawai'i), the Adler Planetarium in Chicago, astronomy clubs, astronomy publications and many others get together to bring a love of the sky to everybody. 

Astronomy Day celebrations in recent years have taken on a new character, as people's access to the sky has been all but wiped out in some places due to the effects of light pollution. People living in cities have very little view of the sky. They might be able to see a planet and a few of the brighter stars, but views of the Milky Way and other fainter objects are washed away in the glow of millions of lights. For them, Astronomy Day is a chance to learn about what they're missing out on, to go to a facility where they might be able to take a look at the sky, or see a simulation in a planetarium. 

Want to Celebrate with Others?

Chances are your local planetarium, observatory, or science center is also celebrating Astronomy Day. Look up their schedules online, or give them a call to see what they have planned. In many places, they haul out the telescopes for some sidewalk stargazing. Some astronomy clubs also get into the spirit, opening up their clubhouses and telescopes for public viewing. You can see a list of events and get more information about staging your own celebration courtesy of the Astronomical League's web site