I’ve read that Arecibo was especially useful in tracking already discovered asteroids. So their trajectories could be projected further into the future. The lead times for practical planetary defense are measured in decades, not years.
But I see that Lindley Johnson, of NASA’s Planetary Defense Coordination Office demurs: “As far as planetary defense and NEO [near-Earth object] observations are concerned, it’s only a slight negative impact. It doesn’t affect our discovery rate of near-Earth objects at all, it only has some impact on the opportunities we have to characterize these objects.” After Arecibo, NASA isn't sure what comes next for planetary radar | Space
“In planetary defense, Arecibo has unparalleled capabilities to characterize the detailed shapes of near-Earth asteroids,” Bruck Syal [a planetary defense researcher at the Lawrence Livermore National Laboratory] says. Knowing a threatening asteroid’s shape, in turn, helps to predict how it might react to deflection attempts using nuclear explosives or kinetic impactors. Arecibo could also nail down the position of near-Earth asteroids very precisely so that their orbital paths could be more accurately predicted. “That’s essential for driving down the uncertainty on whether an asteroid might impact Earth in the future or not,” Bruck Syal says.
Admittedly, it was an old observatory, one that the NSF tried to take off its hands starting in 2006. Funding it isn’t exactly no-brainer and I frankly wonder whether the next big radar observatory should be designed around requirements, not location.
Seems NSF figured that the cost/benefit of a new installation — and it would have had to be fully new, this was not fixable — was beyond what they could justify.
But even more so, it also concluded that the other observatory instruments and activities on-site (the Big Dish was not the only thing, only the, well, biggest) would no longer be supported either, at least it did not include funding for them. That stung the local academics and authorities: a mere “STEM education center” they could have put in any more conveniently located town for less.
There is a new report out on what caused the failure:
Long-term zinc creep-induced failure in the 57-year-old telescope’s cable spelter sockets was the root cause of the telescope’s collapse, the report says. Sockets filled with zinc held in place a set of cables suspending the telescope’s main platform over the reflector dish. Gradually the zinc lost its hold on the cables and allowed several of them to pull out, leading to the collapse of the platform into the reflector.
The failure sequence began with Hurricane Maria, over three years prior to the collapse, according to the report. Indications of cable pullout were minimal before the hurricane. Large and progressive cable pullouts could be seen during post-hurricane visual inspections, observation of which should have prompted remedial action. Safety factor calculations made following the first cable failure did not recognize the accelerated time-dependent materials failure process governing the eventual zinc pull out…
A possible explanation for the accelerated zinc-creep is long-term low-current electroplasticity, induced by the electromagnetic waves from the Arecibo Telescope.
Failure and Collapse of the Arecibo Observatory Telescope Assessed by New Report
