Because of #Chile’s near-ideal conditions for astronomy, it has become home to almost 40 percent of the world’s ground-based astronomy observing capacity. Including current projects under construction , within the next decade that number will increase to 60 percent. This makes any threat to the natural celestial purity of this remote region of Chile a threat to the present and future of ground-based astronomy as a whole https://www.scientificamerican.com/article/europes-extremely-large-telescope-faces-a-new-dire-threat

I edited a couple of my own photos into a size comparison of ESO's Very Large Telescope(s) and Extremely Large Telescope. The top is the VLT photographed from the ELT (in the middle of the day) and the bottom photo is the ELT photographed from the VLT (at sunset). Same distance (20 km), same camera, same lens, so the scale of the two photos should be identical.

The source photos (and more) can be found here: https://drhotdog.smugmug.com/Astronomy-and-Observatories/Paranal-2024/Landscapes-with-telescopes

Edit: I removed the ELT scale bar because of a couple of issues. First, because the photo of the ELT was taken from a lower altitude part of the ELT building is hidden behind the near side of the flattened mountaintop. Second, the ELT dome doors have not yet been installed so the current structure is, I think, less than 80 metres tall.

I've started to sift through all the photos I took in Chile, picking out and reprocessing the good ones, and uploading them to web galleries here: https://drhotdog.smugmug.com/Astronomy-and-Observatories/Paranal-2024

Web galleries? Yes, I know, it's very 2010 of me. It's also the only way to share photos in quantity without having all the detail squeezed out of them by heavy re-compression.

Here's an example pic of the VISTA telescope at sunset, as seen from the VLT Platform. The VISTA telescope was built to perform an all sky imaging survey in the near infrared, but with that complete the infrared camera is being replaced with a visible wavelength spectroscopic survey instrument, 4MOST (https://www.4most.eu/).

I'm back home in Sydney now, but I reckon I can manage a few more posts about the trip to Paranal Observatory.

Here's a photo of the MAVIS delegation on the Very Large Telescope platform, taken by Juan Beltran Peña.

Photos from our last night at Paranal. It's been amazing.

These are two of the four lasers in question, mounted on the side of VLT Unit Telescope 4. They are the black objects labelled LGSU1 and LGSU4. LGSU2 and LGSU3 are mounted in the corresponding positions on the far side of the telescope. Each of the four laser guide star units emits 22 Watts of continuous wave optical power at 589 nm.

Below the lasers you can see the 8.2 metre diameter primary mirror almost side on, and in the centre of the structure above you can see the small Deformable Secondary Mirror.

There are two exciting things about today.

1. There is now help-yourself ice cream in the Paranal Observatory canteen.

2. The maintenance on the 4 Laser Guide Star Facility has been completed, so we will all be going up to the Platform after dinner to get photos of the sky lasers from close range. This is just in time, as tonight is our last night here.

The humidity got up to 18% this evening, practically steamy by Atacama standards. That would explain the clouds. It made for a nice sunset, though.

Clouds? Clouds above us?!? That's not supposed to happen here.

M̶a̶r̶s̶ B̶a̶s̶e̶ A̶l̶p̶h̶a̶ Paranal Observatory base camp, as seen from the Star Track.

I went back outside after the Moon had set. No lasers, unfortunately, but with no moonlight my camera could see the stars properly.

Photographing the sky lasers again. This time they were only using one instead of all four, and there's more moonlight too, but I was fairly pleased with how this came out.

I'm may try for some more deep sky shots in about an hour when the Moon has set.

This place is absolutely amazing. I have so many cool photos and so many things to say, but for now I'll just post this one.

It's a photo I took just now of the Very Large Telescope UT4 firing its lasers into the Milky Way.