Thursday, July 14, 2022

Webb Images in Context


At some level, if you're not an astronomer this stuff all blurs together.  Let's put the new images from the Webb space telescope into some context.  First up, here's a page with straight-up comparisons between Webb and Hubble images.  Scroll down to the one that says "Deep Field" (or "Galaxy Cluster SMACS" – it seems to vary with edits) and click on that, then give it a little while to load.  There's a zoom feature and a slider, and if your computer's OS allows, you can screen-zoom in even more.  Go fiddle around with it for a half-hour or so.  I've probably burned a couple of hours at it, so don't feel bad if your evening suddenly gets short, it'll be worth it.

Next up, here's the Wikipedia page on deep field images.  Briefly, a deep field image is one where you point a telescope at what appears to be a blank spot of blackness between known stars and galaxies, and then accumulate photons for hours, days, or longer.  Then you look at what stacked up and say "oh my goodness."  There's something mesmerizing about deep field images.  The sense of awe feels a lot like like playing in the more exotic corners of math.  Anyway, the Hubble's deepest and the one new Webb image both reach back to about 700 million years after the big bang.  Ultimately, the hope is to get back to the 100-ish million years-after mark, before which there probably won't be anything to see*.  We think.  But we really don't know, and we won't know until we look, and that prospect is damn exciting.

After that, looking for biosignatures in exoplanet atmospheres and a few dozen other amazing tricks should have us all on the edge of our seats for several decades.  And all for less that a quarter of the current bid price on Twitter, which is a whole 'nother level of imponderability.

Let's close out with a graphic summary, shamelessly dragged over from that deep field Wikipedia page:


* Except for microwave background and we already have a lot on that.

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