We have always been fascinated with the heavens above- wondering what’s out there, beyond the bright stars in the empty blackness of space.
Advances in technology, especially over the last 75 years, have allowed us to examine previously unknown reaches of space- black skies now becoming nebula and galaxies. All a result of gathering more light-here’s Laura Penny, an astronomy professor at the College of Charleston with a great explanation.
“If you want to think about collecting more water in a short amount of time- you’d want as wide a bucket as possible. It’s the same thing with light. The wider the telescope, the more light you can take in.”
Taking in more distant light results in those images, taken by this telescope at the C of C Observatory- the only one in the Lowcountry. Its mirror is 2 feet wide, and takes in over 1.4 million times more light than a human pupil, which only measures close to a fifth on an inch in diameter.
This is important because as beautiful as seeing distant galaxies is, this telescope is being used for a different purpose as well- finding exoplanets outside of our solar system.
To understand how this works- let’s take a trip back two years ago to August 2017. The solar eclipse was a once in a lifetime event- marked by darkness as the moon moved in front of the sun.
What is darkness but a decrease in light or brightness?
This same idea is being used to observe distant planets by observing the decrease in brightness over time as the planet moves, or transits, in front of its parent star during its orbit.
Astronomers can figure out a lot by looking at that drop in light!
“How long it takes to repeat tells you how long it took the objects to go around each other, the amount of light that gets blocked is determined by how large and the temperature of the object blocking the light, so we can get an enormous amount of information from a transit.”Laura Penny, CofC Astronomy Professor
This method is the main way exoplanets are being found through other telescopes in space such as Kepler and TESS- expanding our horizons in deep space by looking for changes in light where our eyes cannot.
Storm Team 2 Meteorologist David Dickson