Today’s Wonder of the Day was inspired by Joey from Mineral Wells. Joey Wonders, “WHY DO STARS TWINKLE?” Thanks for WONDERing with us, Joey!
Whether it's the Star Wars movies or The Martian, movies that take place on another planet or even a galaxy far, far away capture the imagination like nothing else can. Do you like to watch movies about outer space?
Many kids love to daydream about what life might be like on another planet or in another galaxy. Do aliens exist? Is there another planet out there somewhere even more spectacular than Earth?
It's easy to let your imagination run wild when you gaze at the stars in the night sky. How far away are some of those stars? Is there intelligent life out there somewhere trying to make contact with Earthlings?
As you look for planets, like Mercury and Venus, and try to identify different constellations, some of the points of light appear to flicker. Are the stars twinkling? Or are your eyes playing tricks on you?
Don't worry! It's not an optical illusion. When you're stargazing, stars often do appear to be twinkling, and it's Earth's atmosphere that's to blame. Scientists call this twinkling phenomenon astronomical scintillation.
Earth's atmosphere can be quite turbulent at times. As it stretches high into the air, it varies in both density and temperature. To reach your eyes, light from distant stars must pass through Earth's ever-changing atmosphere.
As the light travels through the atmosphere, it gets refracted in different directions constantly. Your eyes may latch onto a pinpoint of light from a particular star and then, a fraction of a second later, it may appear to be in a different place. Our eyes interpret this as twinkling.
All heavenly bodies experience astronomical scintillation to some degree. However, it's usually only stars that really appear to twinkle.
Planets, for example, rarely appear to twinkle. This is because they are much closer to Earth and thus appear larger. The greater amount of light reflected by planets isn't affected by the atmosphere as noticeably as the light from distant stars.
While twinkling starlight may seem romantic to some, it's very frustrating for astronomers. To overcome the effects of Earth's atmosphere, astronomers prefer to rely upon space-based telescopes, such as the Hubble telescope, whenever possible.
When they must use land-based telescopes for observations, astronomers prefer telescopes that feature advanced adaptive optics. These telescopes use many tiny mirrors that can adjust rapidly to changing atmospheric conditions to minimize astronomic scintillation.