More stunning pics from our favorite space telescope, this time of Saggitarius C along with some “as-yet unidentified features” in our very own milky way :-
https://webbtelescope.org/contents/media/images/2023/148/01HF7NQKFCWPXHB5MT68G7Z2ED
Embeddable image. I don’t know why Webb’s site makes this such a pain in the ass sometimes.
Cheers.
(Hi-res version available from my link^ as usual.)
NASA has just released a beautiful image of Neptune captured by the JWTs Near-Infrared Camera to show Uranus’ seasonal north polar cap and some details of its ring system - all of which are nearly face-on.
The blue “stars” are five of its moons.
That’s cery cool. The only picture I’ve got of Neptune is a blue dot.
And check out all those galaxies photobombing it.
That is indeed very cool. Amazing how looking in the infrared allows us to see the rings so well.
Nitpick - It’s Uranus, not Neptune
Argh what a stupid error. I was looking right at the article!
We should really contact those messy light-polluting galaxies about dimming their light so we can take more pristine Milky Way photos.
Krikket can help
I hope @Fiendish_Astronaut is not in charge of navigating his space ship.
One of the discoveries which I didn’t understand; perhaps someone could clarify:
Besides throwing out seeds of potential new crises in astronomy, the telescope also cemented an old one: the Hubble tension.
Put simply, the universe is expanding, but depending on where cosmologists look, it’s doing so at different rates. In the past, the two best experiments to measure the expansion rate were the European Space Agency’s Planck satellite (which gave a most likely expansion rate of 67 kilometers per second per megaparsec) and the Hubble Space telescope, which studied pulsating stars called Cepheids and found a higher value of 73 km/s/Mpc.
Cosmologists thought this tension might be down to uncertainty caused by Hubble not distinguishing between Cepheids and background stars, but the JWST snuffed out that hope with a result of 74 km/s/Mpc.
Since then, cosmology has lurched deeper into a “crisis” that could reveal new physics or even break the standard model. What might resolve it? More measurements by the JWST, of course.
67 vs 73 vs 74 km/s/Mpc just suggests to me measurement errors–that the instrumentation isn’t good enough yet, so why the comments about crisis…?
The divergences in measurement are well beyond the margin of error. That’s why JWST made the ‘crisis’ worse - more accurate measurements made the error bars smaller and enhanced the gap between the various measurements.
It’s not a ‘crisis’, and I wish they wouldn’t use that terminology. It’s more of an opportunity to advance understanding. We are discovering that our simple model of expansion seems to have issues.
It’s a crisis in that, as the measurements diverge further, we become more and more sure that our best understanding of the universe is wrong in some pretty substantial way.
Dr. Becky’s youtube channel has several videos explaining the issue, and responding to various newly released studies on the issue, including the Webb results regarding Cepheids.
Getting back to pretty pictures…
New photo of Uranus, looking at it from a polar view, with all its rings, fourteen of its moons, and several galaxies photobombing it.
+1
call it 70km/s/Mpc (+/- 5%) and you are good
.
(and once again, the great Al128, unbethanked by humanity, managed to defuse a crisis in science)
Fifteen or so years ago that’s what cosmologists were telling each other but as the measurements grew more precise the error bars separated until there is no longer any overlap at all. One way or another, they’re doing it wrong.
Here is a 14-minute video from a month ago where Dr. Becky explains the crisis. The first couple minutes she puts up a graph showing the inexorable separation of the two measurements.
Ouch!
nevermind …
the science crisis is still on