This year Christmas Eve will bring a long-awaited gift to astronomers around the world with the launch of the James Webb Telescope. Our parishioner Dr. Misty Bentz, professor of physics and astronomy at Georgia State University, has a special interest in this launch. She is heading one of the telescope’s research projects. I asked her to explain the significance of this telescope and of her project. Here is what she wrote:
The James Webb Space Telescope, NASA’s newest flagship mission, has been more than 30 years in the making. With a final price tag of $11B and after numerous delays, it is scheduled to launch this week on December 25, 2021 at 7:20am EST (watch live at https://www.nasa.gov/nasalive or https://www.youtube.com/nasa).
While it has sometimes been referred to as “the next Hubble”, JWST is a very different kind of tool. Hubble mostly studies visible light, but the gold-coated mirrors of JWST are optimized to detect infrared light that our eyes cannot see. When combined with a mirror that will collect 7 times more light than Hubble, JWST will be able to detect the extremely faint light from the very first stars and galaxies that formed in our universe after the Big Bang. As Scott Pelley put it on 60 Minutes, “Webb can see back in time all the way to the ‘let there be light’ moment.” (https://www.cbsnews.com/news/james-webb-space-telescope-60-minutes-2021-12-12/) But JWST can also do much more. It will be able to peer inside the dusty cocoons in our own galaxy where new stars and planet systems are forming. It will help us study planets in our own solar system as well as planets around other stars, while helping inform our understanding of the potential for life to arise. And it will tell us more about the trillions of galaxies between us and the edge of the universe. JWST will be a step forward in answering some of the most ancient questions we have: Where did we come from? How did we get here? And are we alone?
In preparation for launch, over 100 international teams of astronomers competed in 2017 to carry out the very first science with JWST. Only 13 teams were selected, and I am leading one of those teams (https://www.nasa.gov/feature/goddard/2018/how-to-weigh-a-black-hole-using-nasa-s-webb-space-telescope/). Our project will push the capabilities of one of JWST’s scientific instruments to its limits, thus informing all astronomers of the practical, rather than theoretical, limits of the instrument. We will probe the physical conditions and the motions of gas and stars deep in the crowded, dusty center of a galaxy, with the ultimate goal of studying the supermassive black hole lurking there. Two of the surprising things we learned after Hubble was launched in 1990 are that (1) black holes live in the centers of all galaxies, and (2) they grow with and shape their galaxies. So in order to understand how galaxies are born, grow, and change over time, and ultimately why they are the way they are today, we need to understand black holes, and our program is a tiny step towards that goal.
With launch finally happening this week (or shortly after if the weather causes any problems), we will still have to wait a bit before our observations begin. JWST will spend its first 6 months traveling to its final orbit one million miles away from Earth (4 times farther away than the Moon!), unfolding its mirrors and sunshield, undergoing technical checks, and calibrating its instruments. If all goes well (and an army of astronomers are right now holding their breath and crossing their fingers and toes and wearing their lucky socks), then science operations will begin and I, along with everyone else on those first 13 teams, will have a busy and productive summer ahead.
Our expectations for JWST have been developed and built and honed over the last 32 years. But once science operations begin, we will enter an era in which surprising and unexpected discoveries will be made. Every time scientists have used a new tool to study the universe, we have learned something surprising. And while we don’t yet know what surprises JWST will bring, we do know that they will change our understanding of ourselves and our place in the universe forever.