James Webb “Movie Trailer”
Oh man what is this thing? Is it a trailer for that one movie about post-apocalyptic Earth?
(Ha, get it, cause they’re all movies about post-apocalyptic Earth…)
No, unfortunately, this is only about a million times cooler… Because this is the “movie trailer” for the James Webb Space Telescope (JWST)!
To astronomers, JWST is the Next Big Thing. (I have actually heard an astronomer say that it’s “as exciting as the next episode of ‘Doctor Who.’” Yes, astronomers actually do fangirl that hard, who knew?)
You see, JWST is the planned successor to the Hubble Space Telescope (HST). You know Hubble, the telescope that brought pictures like this to the world:
and in doing so, accidentally started the unfortunate Internet trend known as “star porn.”
(But more on that later.)
So why do we need JWST if Hubble is already da bomb? Well, it’s bigger, more sensitive, and at a farther distance from Earth—and it’s looking at invisible things.
HST is aimed primarily at the optical part of the electromagnetic spectrum. That’s the visual part of the spectrum—the colors that we humans can actually see. And that’s cool and all… but optical light can only tell us so much about the things we observe. Other wavelengths, like radio and ultraviolet and infrared, can tell us a heck of a lot more.
JWST will be optimized for the infrared (IR) portion of the spectrum. This means that it mostly observes wavelengths of light that are longer than the ones we see. Why does that matter? Well, for one thing, the farther you get from Earth, the more the Doppler effect “shifts” light to longer wavelengths. (Doppler effect? What the chicken nuggets is that? Click here to find out)
So almost all of the optical light from far away gets shifted to the IR, which means JWST can see farther away—and farther back in time (whaaaat, crazy! How does that work? Check out this site on lookback time for more info)—than optical telescopes.
tl;dr: If you want to get an astronomer to squeal like an excited fangirl, talk about JWST. The end.
Credit: JWST collaboration (NASA/ESA/CSA)
Video details: A “movie trailer” for JWST, from the JWST website. http://www.jwst.nasa.gov
Image details: A UV-optical composite image of merging star clusters in 30 Doradus, taken by the HST WFC3. Credit and link above.