Put the science in stargazing

By Meghan Meier

Looking at the sky is like gazing through a kaleidoscope. As day becomes night, constellations, planets and other celestial phenomena forge patterns as they cross the sky. But stargazing is very much a science, which requires a level of understanding of how both your geographical location and the seasons affect your ability to find deep space objects. For advice on what to think about when stargazing this spring and summer, we spoke with GMU observatory coordinator Tiffany Lewis and associate professor Edward Murphy from the University of Virginia to get the inside scoop.

What is the difference between seasonal skies?

Lewis: The Earth orbits the sun once each year. There is always one side of Earth facing the sun, which we interpret as day, and one side of Earth facing away from the sun, which is what we call night. As the Earth moves around the sun, night is facing different parts of the sky. Thus, we see different stars and constellations according to the seasons.

What celestial objects can be seen during spring and summer?

Lewis: In the winter and early spring, we look a lot at the constellation Orion because it is high in the sky after sunset. In the spring, Gemini will be of interest shortly after sunset, and in summer, we will be looking at Cygnus and Lyra after sunset.

Murphy: By spring you will see the Big Dipper high in the sky right after sunset, and once you have the Big Dipper, you can use it to find the North Star, you can use it to find the Little Dipper, and then you can use the arch of the handle to come down and find the herdsman. Then you can go down from that to find Virgo … the thing to find on most summer nights straight overhead is the Summer Triangle.

Is light pollution a problem?

Murphy: Light pollution is just light shining up in the sky and not on the ground where it is needed … if you look at street lamps and you look at the lamps in front of your home and you look at a lot of business lighting, those lights are sending an awful lot of light sideways and light up into the sky.

How does the hemisphere we’re in affect what people can see?

Murphy: It does make a huge difference. For those of us in Virginia there is whole set of constellations around the South Pole that we never get to see. A famous example of course is the Southern Cross, which is one of the most beautiful sights in the sky … it is very distinctive, very easy to see in the southern hemisphere, and we never get to see it in Virginia because it never rises above our horizon.