Breaking Records

It occurred to me it’s been a while since I’ve shared a behind-the-scenes look at my work at Kitt Peak National Observatory. Now that the DESI spectrograph is on the Mayall Telescope and the NEID spectrograph is on the WIYN Telescope, we’ve fallen into a fairly regular routine where, most nights, I check in with the observing team at 4pm via video chat, then go to the control room where I’ll eat dinner, open the telescope and start observing through the night. We wrap up as the sun starts lightening the sky in the morning. Targets for the night are predetermined before observing begins for the night. Once observing begins, much of my job is watching that the telescope doesn’t try to move to a position where it physically can’t and I’m the first line of defense in case the telescope or instrument malfunctions. I also watch the weather to make sure rain, wind, or snow don’t damage the telescope.

A slice through the 3D map of galaxies from the first few months of the Dark Energy Spectroscopic Instrument (DESI). The Earth is at the center, with the furthest galaxies plotted at distances of 10 billion light years. Each point represents one galaxy. This version of the DESI map shows a subset of 400,000 of the 35 million galaxies that will be in the final map. Image courtesy NOIRLab.

Before the COVID-19 pandemic, we expected that both the telescope operator and lead observer for the night would be working in the same room, possibly with some support scientists. As it turns out, I wrote a post recently describing how these plans had to change so we could operate safely in these times. As things currently stand, I work in a control room alone and coordinate with the rest of the team via video conference. You can read that post here: https://www.desi.lbl.gov/2021/11/17/social-distancing-while-mapping-the-universe/

All this steady plugging away, observing the sky night after night with DESI is paying off. It was just announced that after just seven months of operation, DESI has already surpassed 7.5 million galaxies mapped, which means it has already generated the largest 3D map of the universe to date. And we’ve only completed about 10 percent of the survey. When we’re done, we expect to have mapped over 35 million galaxies. The picture with the post is a slice of the map so far. The map is presented such that Earth is at the center. Each point on the map is a galaxy. I encourage you to take a look at the press release about the DESI results so far. It’s at: https://noirlab.edu/public/news/noirlab2203/

One of my favorite images at the press release is an interactive image where you can look the map above and compare it to all the data from the Sloan Digital Sky Survey in New Mexico. Sloan has been an on-going, ground-breaking project in its own right. I was fortunate enough to be on hand when that telescope was dedicated and the survey began. At the time, I worked as an engineer for a 1-meter telescope just a few yards away from the Sloan at Apache Point Observatory. I think it’s fair to say that DESI would not have been able to achieve what it has so far if Sloan hadn’t paved the way.

As it turns out, DESI’s value isn’t limited to creating a big map of the universe. Yes, that’s important and hopefully it’ll give astronomers clues about how the universe is expanding and how that may be related to this thing called dark energy. However, DESI is also creating a giant database of all these spectra that researchers will be able to use for years to come to understand more about the different types of galaxies and quasars we’re observing along the way.

On a good night up here, everything seems quiet and routine, which doesn’t give me a lot to share here, but it is producing lots of data and expanding our knowledge of the universe. Of course, routine nights also give me a chance to ponder the universe and continue to inspire me. As always, you can find links to my books and stories at http://www.davidleesummers.com

2 comments on “Breaking Records

  1. 7.5 million galaxies mapped. That’s amazing. I’ve taken at least one college course in astronomy, physics, calculus, biology, and chemistry. But in all of them I run into numbers that are way, way, way more than I can even begin to comprehend.

    Five fingers on one hand. I think I got that. Ten fingers on two hands? I don’t think I can really grasp that. Sure, I can talk about it, write about it, etc., but I don’t think my brain can really think of 10 individual fingers at the same time.

    7.5 million galaxies? When our galaxy has, what, somewhere between about 100,000,000,000 and 400,000,000,000 stars? So that many galaxies could mean how many stars?

    I think I’m going to take a break and count the fingers on one hand.

    (Seriously, I do think the whole thing is amazing. It must be cool for you to be a part of that.)

    • Thank you. Yes, these are not easy numbers to comprehend at all. The visualization here at the post helps a little, especially when you realize even that’s not the whole 7.5 million galaxies mapped so far. Definitely proud of my small role in this work.

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