Around the World in 95 Minutes: What It Takes to Be a Celestial Telescope

by Marianna Sorensen

Spring 2017 Intern

Imagine if it were your job to literally go around the world every 95 minutes. Wouldn’t you want to retire after 27 years? Well the Hubble Space Telescope, the “world’s first large, space-based optical telescope,” has reached that point. NASA is beginning its final tests on its replacement, the James Webb Space Telescope (JWST).

JWST, costing nine billion dollars, is going into its final round of ground tests before it’s set to launch in October of 2018. One part that needs to be completed is a shield to protect it from the sun’s heat. Because JWST is designed to look at infrared wavelengths, it has to be kept really cold. Once JWST is deployed, this sun shield will have to go through a series of steps to unfold to its full size, a process which takes two weeks. Scientists and engineers have spent almost 20 years in its design and building, so those on the team are very excited to finish it.

NASA has additional tests to run on JWST before sending it up to space. One test they have completed recently checks whether JWST can withstand vibration and acoustics necessary for traveling into space. Scientists and engineers put JWST in a test chamber and exposed it to noise loud enough to cause comparable vibrations.

What makes JWST different than Hubble is its infrared vision. Because the first stars and galaxies are always moving farther away from us, their light is moving toward redder wavelengths. This means JWST, because it’s a near- and mid-infrared telescope, will be able to show us the early stars—a site that we have never seen before.

JWST will also search for extraterrestrial life on exoplanets by providing information about their atmospheres. It will also study the “transit method” of those exoplanets, or how they are traveling around their stars. And, using coronagraphs, it will get direct, colored images of exoplanets, which will provide scientists with data related to seasons, vegetations, rotation and weather.

Is there life in galaxies far, far away? JWST may just help us find out.

Did You Know?

Hubble is so accurate that it could shine a laser beam through a dime from two hundred miles away. And when Hubble is outside of Earth’s atmosphere, it can see astronomical objects so well, that NASA compares it to being able to see fireflies in Tokyo all the way from Maryland.