BAN #363: Pittsburgh dims, Volcano from spaaaace

04 October 2021   Issue #363

October 04, 2021

[The planetary nebula M 2-9, winds from a dying star. Credit: NASA / ESA / Hubble Legacy Archive / Judy Schmidt]

Astro Tidbit

A brief synopsis of some interesting astronomy/science news

Well, this is very welcome news: The Pittsburgh (PA) City Council has passed a new ordinance pertaining to all the city parks and facilities enacting dark sky rules!

Oh my. That’s a big deal. Pittsburgh has 35,000 street lights which will eventually be replaced with ones that don’t create as much light pollution, and 8,000 more will be installed. This ordinance is the first of its kind in the country. [UPDATE (22:15 UTC): When I wrote that line I wasquoting the article linked above, and I was wondering why this was different than Tucson, which has had outdoor lighting codes to preserve dark skies since at least 2006 (here’s the 2012 code for example). I made a mental note to look into it and then got ditracted, so my apologies for not following up on that. Bottom line is I’m not sure what makes this one different enough to be called the first, so instead I’ll say many other places have dark-sky-friendly codes in place, and Pittsburgh’s is a big/important one due to the size of the city.]

I’ve written about light pollution many times before. This is wasted light, sent up into the sky instead of down to the ground where it’s needed. Unshielded street lights are one source, as are a lot of buildings (car sales lots are the worst). We do need to have light at night, but wasted light ruins the night sky. That’s bad for astronomers of course, but it’s also bad for everyone. Light pollution can affect people’s sleeping habits and have profound impacts on wildlife.

Plus it’s just wasted. Wasted light, wasted electricity. Over time, going to dark-sky-friendly lighting can and will save money, and use less air polluting power, too.

I’ll keep my eye on this new ordinance, and I hope that once it’s enacted other cities take a look as well. If you’ve ever been to a truly dark site, the change in the sky is dramatic. It’s not just more stars, it’s thousands more stars, and the Milky Way stretching across the heavens like its name implies. Once you’ve stood under such a vista even once, you’ll know why so many people like me raise our voices on this subject.

Take a few minutes to watch this TED talk by scientist Diane Turnshek who was instrumental in getting this Pittsburgh ordinance through. She does a fantastic job showing you why the night sky is important.

Pic o’ the Letter

A cool or lovely or mind-bending astronomical image/video with a short description so you can grok it

Last week I talked about the Cumbre Vieja eruption on the island of La Palma. Ironically, I embedded a video in it showing the eruption and lava fountain, but when the newsletter was sent out the eruption had subsided! As it happens it started up again shortly thereafter, so if you missed it try again. The live feed video I embedded is no longer working, but you can find lots more on YouTube if you’d like.

But speaking of that, the European Space Agency Earth-observing satellite Sentinel-2 took an amazing image of the eruption on September 30th, and I have to share it:

[The lava flow from the eruption of the Cumbre Vieja volcano, taken on September 30, 2021 by the Sentinel-2 satellite. Credit: ESA, CC BY-SA 3.0 IGO]

Whoa. This is a cool shot; it shows roughly natural color (red/green/blue) but also used “shortwave infrared” which is wavelengths from roughly 1 – 2 microns (the reddest light our eyes can see is about 0.75 microns). Hot lava emits a lot of infrared light, so it shows up as being very bright in these images, and the color they chose to display it really does look like glowing molten rock. Cool.

Note the scalebar on the lower left that’s 500 meters long. Yikes.

The original eruption was on September 19, but since then two more vents have opened and lava is pouring out of them. On top of that the Hawai’ian volcano Kilauea is active again; the vent in the caldera of Halema’u’ma’u is filling once again and a lava pool is visible in images and videos. I went to Hawai’i for Science Getaways and it was stubbornly quiet for the first two, but on the third trip we were treated to an amazing display of terrifying and powerful geology.

[Me a few kilometers back from an eruption on Kilauea in 2016. Credit: Phil Plait]

The Earth is a pretty amazing planet, but every now and again it reminds us quite jarringly that it’s also not quite done cooking yet.

Blog Jam

What I’ve recently written on the blog, ICYMI

[A Hubble Space Telescope image of Jupiter taken in August 2020. From Wednesday’s article. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team.]

Wednesday 29 September, 2021: In Jupiter's Great Red Spot, a wind is rising

Et alia

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