That bright star just might be a planet! How can you tell?

By Will Kalif

Everyone is familiar with the song, “Twinkle, Twinkle, Little Star.”

It is a rhyming song that has a lot of truth in it. Stars are extremely small pinpoints of light, and turbulence in the atmosphere can have an effect on them – causing them to twinkle.

But some stars never twinkle. And this is because they are actually planets. And planets are not pinpoints of light. They have a small amount of width to them. This width makes them immune to turbulence in the atmosphere.

So, on a dark night go outside and look up at the twinkling stars. Then scan toward the south to find two very bright stars that are not twinkling. These two stars are Jupiter and Saturn. August and September are great months for spotting them. Both are very bright and very prominent.

If you have a pair of binoculars this would be a great time to get them out and get a closer look!

And if you would like to get a closer look at them come down to a South Mountain Astronomy Club Star Party and take a look through our telescope. We would be happy to have you. And we have volunteers on hand that can help you identify constellations and learn more about the night sky.

The two brightest stars in the picture above over Picket Post Arizona are Jupiter and Saturn and both are near the constellation of Sagittarius (The Teapot). The glow in the picture comes from the city of Tucson.

Photo credit: Will Kalif of The