Prof. Meghan Gray explains some of the physics behind building a liquid mirror telescope, such as the ILMT in India.

cross-posted from: https://lemmy.world/post/14585017

> Voyager 1 contact restored

Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun.

TIL Venus is a mostly featureless white ball in the visible spectrum.

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cross-posted from: https://sh.itjust.works/post/17700325

> >In a 26 March update, ESA announced that after the very first two mirrors were warmed by just 34 degrees, Euclid’s sight was restored, with the telescope’s optics achieving a 15% gain in sensitivity. The process only took a few minutes, with the mirror being warmed from -147 to -113 degrees. The procedure was so successful that it has given operators the confidence to repeat it every couple of months, if necessary, without much impact on Euclid’s six-year survey. > > > >“We expect ice to cloud the VIS instrument’s vision again in the future,” explained Reiko Nakajima, Euclid VIS instrument scientist. “But it will be simple to repeat this selective decontamination procedure every six to twelve months and with very little cost to science observations or the rest of the mission.”

Hey everyone, just an update to my last post from Sunday night.

The eclipse went off without a hitch -- thankfully, I am not personally capable of interfering with celestial events -- and I have to say, nothing could have ever possibly prepared me for the experience. No photo has ever actually captured what I saw Monday afternoon. I don't think any of them have come close.

Picture of my own attached for total lack of effect.

As I looked down at my camera screen and watched the last light of the crescent Sun disappear from my view, I felt totality occur. The umbra of the Moon swept over me while I looked down, and the world got noticeably chilly. The wind died down. The world was silent for a hiccup. I immediately and excitedly looked up, and I think my brain broke.

Hovering in the sky over Potato World was an black, alien orb, surrounded by a thin ring of brilliant white and pink shimmering fire. It was something straight out of a science fiction movie, and not necessarily a good one, either. It looked so incredibly fake.

It looked downright cartoony.

And it hit me like a ton of bricks. I wept as I stared at it, completely unable to maintain composure. I gawked at how bright the solar corona actually was -- I had completely expected to have to strain to see it. I marveled as I realized I was seeing, with my own two, naked eyes, solar prominences arching over the limb of the Moon. And I just sobbed through the whole experience.

My fiancee, whose interest in this had seemed to be primarily a mix between modest curiosity in a significant natural and cultural event and support for my interest, also cried at seeing it, while her son sat on the ground with his mouth hanging open.

It was both the longest and the shortest 3 minutes of my life. When it was over, I just stood in the field in a daze, periodically pressing my camera's shutter button. In just a few minutes following the end of totality, the field, in which hundreds of people had gathered, was nearly empty. Only a handful of us remained, and most of the others had heavier equipment than my DSLR and tripod.

At the end of the day, I didn't quite get the pictures I wanted. I had hoped to get bracketed exposures during totality, and I had assumed that my camera's settings for that when using the LCD display as digital viewfinder would be the same as when using the optical viewfinder, and they weren't. But I'm not too fussed about it. The pictures still turned out significantly better than I could have hoped for.

I'll be posting the rest of my photos -- including some pictures of Potato World itself -- to my PixelFed account, which can be found here, if anyone's interested: https://pixey.org/i/web/profile/384533916920271164

I'm sitting in a dark hotel room on the eve of my first - and possibly only - total solar eclipse, with my partner and step-son, and I am positively awash with emotions.

I have been waiting for this day for 30 years, since my first partial eclipse in May of 1994. That was an underwhelming experience for many reasons, but not the least of them was that I had nothing and no one to view the eclipse with.

Three decades, two astronomy degrees, 5 years operating a planetarium, and 5 years as a guide at the local observatory later, and I'm fully prepared. Today, I have more viewing glasses than i have fingers, two cameras with filters, I have my family, and I am smack dab in the middle of the path of totality.

And the forecast calls for clear skies.

I can't believe it. I can't believe that this is actually happening for me. That everything looks like it's going to work out.

The only disappointment is that I discovered that Potato World exists - it's the New Brunswick potato museum (and it's next door to my hotel) - but it's closed!

So I bought 2 sets because it looked like one set was briefly lost in the mail and this past week I got an email from Amazon that said one set I bought were “fakes.”

• Both sets have printing that matches legitimate manufactures.
• The “legitimate” set have all black filters (not the metalized filters I am used to like Thousand Oaks Optical) the “fakes” have the metalized filters.
• Both sets of glasses have the same transmittance as the Thousand Oaks filter material I use on my telescope and cameras.
• The build quality of the “legitimate” glasses is quite a bit worse than the “fakes” with the two layers of paper being misaligned

So, what I suspect is that I actually received a crappy set of “real” glasses and a well made set of counterfeits, this seems in line with the press release made by the American Astronomical Scociety.^[0]

> Some of these newly identified counterfeits are indistinguishable from genuine Qiwei products and appear to be safe. Others look like Qiwei’s eclipse glasses, but when you put them on, you realize they are no darker than ordinary sunglasses. So, these products are not just counterfeit, but also fake –– they’re sold as eclipse glasses, but they are not safe for solar viewing.

So, did anyone get unlucky enough to get some ‘real-fake’ glasses? An did anyone get a set of legitimate glasses with the non-metalized filter?

^[0] https://aas.org/press/american-astronomical-society-warns-counterfeit-fake-eclipse-glasses