The James Webb Space Telescope will find the first galaxies that formed in the early universe and see stars forming planetary systems.

The James Webb Space Telescope will find the first galaxies that formed in the early universe and see stars forming planetary systems. This is SUCH a strange but wonderful day (at the start of a strange and wonderful week)- Today is the day that the first images are coming back from the telescope. I have literally been hearing about The James Webb Space Telescope for the majority of my life, since I was graduating high school and first getting interested in astronomy, and to see that we are now truly in the James Webb Space Telescope era is mind-boggling! Not gonna lie, I think a cynical part of me thought something would go wrong and we wouldn’t get here… and not only seeing the images, but having such immense pride for the humans who made this possible, is just so emotional.

To answer a few quick questions I’ve seen around:

What is the image of?

A galaxy field called SMACS 0723, located 4.6 billion light years away. What’s more, because of the orientation of the foreground galaxies we get to see some really zany gravitational lensing of light from galaxies much further away in this field- about 13 billion years, to be precise! So these are all very young galaxies, all formed just a few hundred thousand years after the Big Bang. Incredible! And wow, never seen galaxies like those lensed ones before- very Salvador Dali, if I may say so. 😀

The ones that appear to have white light are the ones creating the lensing 5-ish billion light years away, and the reddish ones are the lensed ones. (At least, I’m pretty sure that’s how it works as a general rule of thumb.) Here is Hubble’s view of the same field by comparison, courtesy of /u/NX1.

Also note, James Webb Space Telescope is an infrared telescope (ie, light more red than red) because its first science priority was to detect the earliest galaxies (it’s been under development so long exoplanets frankly weren’t the huge thing they are now), and by the time the light from the earliest galaxies reaches us, it has been “redshifted” to these wavelengths. So before you couldn’t see these lensed galaxies with Hubble, and to see them let alone in such detail is astounding!

Pretty! Is there scientific value to it?

Yes! The thing to realize is even with these very first images, because James Webb Space Telescope is able to see in detail no telescope has had before there’s a ton of low hanging fruit. In the case of this image, one of the big outstanding questions is a feature called the UV luminosity function, which tells you the star formation rate in those early galaxies. If you literally just count up the number of galaxies you see in those first James Webb Space Telescope images, you’ll already know more about the star formation rate in the early universe than we do now! Further, when you study the gravitational lensing pattern, you can learn about those foreground galaxies– things like their mass, and how the dark matter is distributed around them. OMG this is gonna be so neat!

I need more Space images in my life! What’s next?

There is a press conference tomorrow at 10:30am! At the press conference there will be several more images revealed, from the Carina Nebula to Stephan’s Quintet (links go to the Hubble images to get you psyched). There will also be some data revealed, such as the first exoplanet spectrum taken by James Webb Space Telescope- note, exoplanet spectra have been done before scientifically, but the signal to noise of James Webb Space Telescope allows this to be done to greater accuracy than before. (No, this is not going to have a signature from life- it’s a gas giant exoplanet, and it’s safe to say if it had a signature from life Biden would have revealed that today.)

Pretty pictures aside, can I access the actual science data?

The James Webb Space Telescope archive will be launched with all the commissioning data for these images on Wednesday, July 13 at 12 EDT, with the first Early Release Science programs’ data going up on Thursday. Specifically for the latter, there are “early release science” programs which are going to be prioritized over the first three months (list here) where those data are going to be immediately available to the public, so everyone can get a jump start on some of the science. (Also, the next cycle of James Webb Space Telescope proposals is in January, so this is going to be really crucial for people applying for that.) My understanding is there are many people in the sub-field of early galaxies who literally have a paper draft ready to go and intend to get the preprints out ASAP (like, within hours), just because there will be so much low hanging fruit for that field in those very first images! Like, I’ll be shocked if they’re not out by the end of the week, and the place to see those first science papers are on the ArXiv

You can learn more about the James Webb Space Telescope archive here.

How did they decide what to observe anyway?

As is the case for all NASA telescopes, anyone in the world can apply for James Webb Space Telescope time! You just need to write a proposal justifying why your idea is better than anyone else’s, and well enough that a panel of astronomers agrees. In practice, it’s really competitive, and about 4.5x more hours were requested than there are literal hours for James Webb Space Telescope to observe (actually way better than Hubble which has been closer to 10x- Hubble can only observe on the night half of the Earth’s orbit, but JWST has a sun shade so you get almost nonstop observing). The resulting proposals that won out are all a part of “Cycle 1” which begins this week, and you can read all about them here. (Cycle 1 includes the Early Release Science projects I discussed above.)

As an aside, while I am not personally involved in it (I’m an accountant or a bad lawyer) I’m super excited. Anyway, a toast to James Webb Space Telescope- and if anyone who works on it is reading this, we are all so proud of you! I can’t wait to see where this new adventure takes us!