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Drone Footage of Arecibo Observatory Collapse

nsf.gov

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Re: Drone Footage of Arecibo Observatory Collapse

#71
post #55
post #34

Earlier quoted context omitted.

Seems like they knew exactly where it was going to fail.

And they must have known it was imminent, it seems unlikely they had a drone over it 24/7 given the available hover time.

On the bottom of the linked page there's a press release from last month: one cable failed in August, then another a few weeks later at 60% of expected of load, and they decided on Nov19 it's unsafe to fix it and it should be decommissionned.

https://www.nsf.gov/news/news_summ.jsp?cntn_id=301674&org=NS...

Re: Drone Footage of Arecibo Observatory Collapse

#72
post #69

Earlier quoted context omitted.

"now" is doing a lot of work here... If I'm not mistaken, we have about a millennium or a hundred make arrangements.

Overall it's quite a bright time for (radio) astronomy. The number of telescopes and sensing ability only increases with time. Just this year alone, a large clone of Arecibo, FAST, just became fully operational. Other telescopes like the SKA are still in construction. In the future decades, we'll likely build even more and even larger telescopes.

FAST is not a clone. It is a very big and powerful dish, but Arecibo could do things that FAST cannot (radar astronomy). Just like particle accelerators, no two telescopes are ever identical in capabilities/missions.

FASTs other difference is location: China. The community of people who would work at Arecibo is probably very different than the community that will work at FAST.

Re: Drone Footage of Arecibo Observatory Collapse

#74

So now, humans are going to be the intergalactic assholes of the universe who go and change their phone number without leaving a forwarding number. When our message sent from Arecibo is finally received, their response will go to a disconnected number. https://www.youtube.com/watch?v=2BVbyCZXc5s

Humans have an incredible way of elevating their universal importance to hold the conviction that an alien species capable of receiving such a message and actionably responding would have any desire to do so, let alone that the loss of one observatory would leave the species thinking that they were being ghosted and that humans are assholes. We're really nothing more than flatlanders at this point and we need to work on our humility toward the situation.

Re: Drone Footage of Arecibo Observatory Collapse

#76
post #30

The instrument platform was listed at 900 tons. The maximum takeoff weight of a Boeing 787 is just over 500,000 pounds, or 250 tons ... is it fair to say the instrument platform was the equivalent of three fully loaded 787s, plus two M1A1 tanks piled on for good measure? That's a lot of weight for those cables to support.

I always think it's funny when people use large planes as a reference for heavy weights, since they're designed to be as light as possible for the volume.

I don't think the instrument platform was exactly designed to be heavy!

Re: Drone Footage of Arecibo Observatory Collapse

#77
post #55
post #34

Earlier quoted context omitted.

Seems like they knew exactly where it was going to fail.

And they must have known it was imminent, it seems unlikely they had a drone over it 24/7 given the available hover time.

For a use case like this, I'd imagine that tethered multicopters could be a very nice fit. If you can just plug the base station into a power outlet, suddenly 24/7 doesn't seem that crazy.

PS: Apparently I'm not alone with this idea, search engine comes up with hits. https://elistair.com/ even have a tether kit you can plug into some DJI models (and others) instead of the conventional battery pack. Out of Lyon, France, nice!

Re: Drone Footage of Arecibo Observatory Collapse

#78

Earlier quoted context omitted.

I work at UW astronomy. It’s mostly symbolic. The main capability loss is that Arecibo was able to transmit, which is unique at its size. As an example, that was useful to rescue the ISEE-3 explorer when it passed through a comet trail in the 1980s. Only Arecibo was powerful enough to blast a radio message through the comet trail. (PDF reference: https://ipnpr.jpl.nasa.gov/progress_report/42-84/84T.PDF ) Arecibo was…

There was still way more requests for observing time and the total amount of time available in the last cycles. Also there is a lot of value to have long-term datasets that are recorded with the same instruments as it removes a lot of systematics. Nanograph is being badly bitten by that, as they use pulsar timing data over 10 or 12 years. (And were likely only 1 or 2 years away from results, which may now be delayed…

Doesn't the instrument itself change over those long time periods?

Re: Drone Footage of Arecibo Observatory Collapse

#80

Wow. As tragic as the collapse is, at least it has been filmed (i thought it had not when I saw the announcement tweet with its far-away photo). If nothing else it's about as spectacular as I had expected. Had I been in the area I'd have been tempted to set up my camera somewhere close (remember that the risk of collapse was known to be high).

346 people dying in 737 MAX crashes is tragic. This is a 50-year-old telescope; the word I'd use is "unfortunate."
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