This new space telescope should show us what the universe looked like as a baby
Imagine knowing nothing about your childhood, nothing about where you came from, and spending years hunting for the answers. Then someone hands you a just-discovered trove of photographs of yourself as an infant. You’d finally be able to scrutinize every detail, searching for clues about yourself and how you came to be the way you are.
That’s just what it will be like for astronomers once a long-anticipated, $10 billion telescope finally blasts off into space in the coming days. If all goes well, it will soon show them what the universe looked like as a newborn, nearly 14 billion years ago.
NASA’s James Webb Space Telescope, the most powerful space telescope ever, is waiting at a launch site in French Guiana. It should be able to detect infrared light from galaxies that are so far away that the light from them has been traveling through space for almost the entire history of the universe.
A telescope, or a time machine?
Using telescopes, astronomers have been able to see far more distant galaxies, which means they’ve been able to see farther back into the universe’s history. So far, the most distant galaxy ever discovered, GN-z11, was spotted by the Hubble Space Telescope.
To the untrained eye, it looks like a red blob, but “it’s basically like looking back in time about 13.3, 13.4 billion years ago,” says Charlotte Mason, associate professor at the Cosmic Dawn Center of the Niels Bohr Institute and the University of Copenhagen. “That’s just 300, 400 million years after the Big Bang.”
Hubble is limited in how far back in time it can look, so finding this galaxy was kind of a lucky break. Astronomers only spotted it because decades of using Hubble have let them scour much of the sky, and this particular early galaxy is surprisingly bright.
The James Webb Space Telescope should be able to provide more information about lots of additional galaxies this old and even older, which will help researchers understand how galaxies formed and changed into the familiar shapes and structures seen today.
The James Webb Space Telescope has technology that should let it see back to 100 million to 200 million years after the Big Bang.
“So really, the period when we think the very first galaxies formed,” says Mason.
This telescope, which took decades to design and build, also has instruments that will let scientists probe the chemical make-up of the galaxies.
A churning mix of excitement and anxious dread has taken hold of astronomers around the world as they wait for the launch of the most powerful telescope ever, planned for the morning of Christmas Eve.
The James Webb Space Telescope has been in the works for decades, and its gold-plated, 21-foot mirror will see much farther out into space than the venerable Hubble Space Telescope. Its launch has been delayed so many times over the years that, for many, it seems almost unbelievable that it’s finally about to happen.
The three-story-tall telescope, with its heat shield the size of a tennis court, is all folded up and crammed inside a rocket. It will have to unfold itself and travel about a million miles away from Earth, cooling down to temperatures around minus 370 degrees Fahrenheit.
Before all that can happen, it has to get safely off the planet. Astronomers can’t help but imagine this $10 billion telescope getting obliterated in an instant by an unlikely, but still possible, rocket explosion. But Faherty, who will be using the telescope for her research, thinks her anxiety will actually lessen on launch day.