The Webb Delivers

NASA has released the first images taken by the James Webb telescope and they're gorgeous. The Webb telescope can see back in time 13.6 billion years to what the universe looked like just a few million years after it was born. This is 200 million years further than the Hubble telescope can see but as this Time article states that's a huge difference when we go back that far:

Webb is as much a time machine as it is an observing machine. The farther into space a telescope can peer, the farther back in time it’s looking, since images from distant objects—even traveling at the speed of light—take a very long time to reach us.

The image we see of a galaxy 13.6 billion light years away is thus not an image of how it looks today—but how it looked 13.6 billion years ago, during the universe’s infancy. The Hubble space telescope can see a maximum of 13.4 billion light years distant, and while the mere 200 million light-year advantage the Webb offers doesn’t seem like much, it’s in fact huge.

A great deal happened in that particular 200 million years and telescopes have been blind to it until now.

“The difference between what Hubble and Webb [see] is not like comparing someone who’s 70 years old to somebody who’s 71 years old,” said Scott Friedman, an astronomer with the Webb team, in a conversation with TIME last year. “It’s like comparing a baby who’s one day old to a baby who’s one year old, and that’s a huge difference.”

Webb's resolution is also greater than Hubble's. You can see the difference by comparing the following two images. The top pic was taken by Hubble and shows a portion of space about the size of a postage stamp held at arm's length against the sky. The bottom image is of a section of space the size of a grain of sand held at arm's length against the sky.

Most of the points of light in that pic are actually galaxies like our Milky Way. To give an idea of the scale, our Milky Way is 100,000 light years across (one light year is almost 6 trillion miles), and there are dozens of similar galaxies in just this small portion of the sky.

This is a picture of a cluster of five galaxies taken by the Webb:

These pictures are exciting (go to the link for more), but they're only the beginning of what astronomers hope Webb will deliver.