By Monica Young

For hours under August skies, I have been known to sprawl out on the grass, listening to crickets sing and counting the meteors flashing by. On more than one crystal winter night, I bundled up my 4-year-old, and we set out to look for the Orion Nebula. Even when I exit the grocery store, I often glance up to say a quick hello to Jupiter or Orion.
But why? What use is stargazing and night-dreaming? Why count meteors or learn the constellations? It’s not as if it hasn’t already been done a hundred times before, a more practical-minded person might argue.
In a way, the question seems moot if you have to ask it. Astronomy provides solace to the soul! Yet there’s a point to the asking.
Such questions are even more common in the arts, which must defend their existence on a regular basis. And from those questions, we learn that teaching music in schools helps improve students’ concentration, and that a doctor with a painting habit may be more apt to think outside the box in her diagnoses. There are real-world benefits that accompany art’s intangible qualities.
So, even if the question is moot, let’s answer it anyway: what use is astronomy today?

Telling Time
The ancients used the Sun, Moon, and stars to count the seasons, and even today, astronomers determine the calendar down to the leap second. Alan MacRobert, a senior editor at Sky & Telescope, gives an excellent rundown of astronomy’s involvement in time-telling systems in “Time In the Sky and the Amateur Astronomer.”
But for the average citizen, it’s even simpler than that — stars help mark the passage of time if we pay attention to them. Orion steps into winter evenings just as surely as Altair, Deneb, and Vega attend summer nights. Solstices and equinoxes herald changes in seasons. And on a daily basis, the Moon changes form and position — a feat that remains quite mysterious to my 20-month-old son. Perhaps he marks the slow passage of months by when he can glimpse the crescent Moon in the evening hours. I know I do.

Sailing the High Seas
Celestial navigation may bring Moby Dick to mind, but the technique refuses to be relegated to ancient history just yet. The U.S. Naval Academy discontinued its CELNAV course in 2006 thanks to the accuracy and ease of the Global Positioning System (GPS). But in 2015 the Navy reversed their decision and brought it back. 

Navy SextantA U.S. Navy officer uses a sextant at sea. Credit: Mass Communication Specialist 2nd Class Scott Raegen / U.S. Navy

As regular S&T blogger David Dickinson wrote in his recent post, “U.S. Navy Resumes Celestial Navigation Training,” sailors depend on GPS just as much as civilians do (which is to say, a lot!), but that system is vulnerable. Not just to cyber threats, which the Navy considers a possibility, but also to solar storms or space junk collisions. 
So, naval officers in training are once again standing on ship bows, using sextants to measure the position of stars off of the horizon. And should disaster ever befall GPS, these astronomy-trained cadets will be ready to take the helm.

A Gateway Science
Perhaps astronomy’s most practical use is as an entryway to math, as well as the general sciences. It’s fun to think about what might happen if you were to reach your arm into a black hole — so what better way to teach a student general relativity, or at least some basic geometry? Perhaps the idea of measuring the age of the universe would provide the right motivation for students bored or struggling with algebra. And statistics might become more appealing when applied to the question of how common Earth-like planets are in our galaxy.
Astro 101 courses have a habit of sneaking in a good helping of math, and even a dash of chemistry or geology. And, according to a recent Nature study, the Apollo Moon landings motivated a large fraction of today’s scientists, biologists just as much as physicists. Even students who go on to major in business, those who probably soon forget the meaning of RA and Dec, may hold on to their spatial reasoning skills — and a love of the night sky.
And that’s really the point, isn’t it? There are more applications of astronomy than what I’ve written here. But practical purpose is only a fraction of the reason we look up to the sky at night.

headshot1Dr. Monica Young earned her Ph.D. researching the behavior of supermassive black holes in distant galaxies. In 2012, she joined the talented team at Sky & Telescope, where as Web Editor, she edits, writes, and commissions web news stories and magazine feature articles.