"And those, as your humble hack discovered when walking home a couple of months back, can be awesome as seen in the tweet below depicting my cosmic encounter."
Still would have scared the hell out of me though!
A space rock the size of a sports utility vehicle zoomed within 2,950km of Earth over the weekend. It's good news because, as NASA explained, the 15 August flyby of 2020 QG was the closest pass humanity has ever detected and therefore speaks to our enormous cleverness. "It's quite an accomplishment to find these tiny close-in …
"A space rock the size of a sports utility vehicle "
How do they KNOW is was a space rock. I reckon it's just as likely to be an SUV on its way to pick up the kids from Moon School because the poor little darlings can't be asked to walk home on their own.
Bloody SUVs get everywhere these days.
Car accidents kill 3200 per day worldwide but hardly ever make the news. Every time someone gets killed because a driver was not paying attention to his Tesla on autopilot it makes the news. Teslas on autopilot must miss things well over 32000 times per day but that almost never appears on the news.
News outlets focus on the unusual so make a poor basis for making decisions about what is safe or unsafe.
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A space rock [...] zoomed within 2,950km of Earth
That's inside the orbit of many satellites, way inside the orbit of geostationary satellites and less than 1000km from the orbit of the ISS.
Apart from the picture was it detected by the radar or other sensors of one of those satellites?
I wouldn't call it "busy". Work out the volume of a sphere of that radius and consider the fraction filled by satellites and the volume of the cylinder swept out by the rock.
Even Earth appears (fortunately) to be quite hard to hit and it has measurable gravitational field. (Pedant's alert: Yes, I know that you can measure the gravitational field of a small lump of metal and have been able to since Cavendish's time, but you get my drift.)
I woud like to know how it happened. Some on the Intertubez think it may have been aliens . . .
As hurricanes get more frequent and more violent, the Caribbean may not be the best location for a high-maintenance object like that. Unless they can somehow hurricane-proof it. And earthquake-proof. Hmm. Maybe just move it altogether?
> Maybe just move it altogether?
Where? I'm guessing it needs a valley of the right size and shape (to keep structure costs low), an environment without the slightest electromagnetic pollution (so no TV/radio/phone reception whatsoever, and no settlement with WiFi and microwave ovens nearby) and it needs to be outside of the main air traffic corridors (plane radio traffic, also the danger of frying a plane overhead when using the dish as a radar...).
That excludes most if not all of the continental USA. As for other tropical islands, they would have the exact same problems concerning hurricanes and stuff.
I guess the best place is where it currently is, most of the investment has been made, and after all, it stood there and worked just fine for quite a while before getting damaged. They just need to find it in them to fix it (instead of letting it deteriorate beyond the point where repair still makes any sense).
Given its age (completed in 1963) and size, I doubt they will be moving it. Also, there are a number of newer radio telescopes and radio telescope arrays which are probably a higher priority for future funding. Arecibo is going to struggle to get sufficient funding to repair the current damage and meet operating needs.
I think the biggest (pun not intended) problem is that Arecibo isn't the biggest dish anymore, and the moneybags clearly balk at the idea of spending money for second best.
In the current USA-China male genitalia measuring contest it's way better to say "oh, we don't consider needing one of those" than to have the smaller one...
Arecebo is built on a sinkhole - there are many with similar dimensions across the world. Its location is more to do with its near equatorial location (and thats where the hurricanes are)
The main thing is that newer techniques for receivers have superseded its original effectiveness. It is still useful - just not the most powerful any more. for flexibility, it is usually better to have many receivers spread out over a wide area (ideally the circumference of the planet). There is a large one in Australia now
> newer techniques for receivers have superseded its original effectiveness
That might be true, but Arecibo remains quite unique since it's also a radar astronomy dish, able among others to spot asteroids and check their orbits (what the OP of this thread referred to). AFAIK there is only one other dish able to be used as a radar (GSSR), and it's 4 times smaller.
What? There are thousands of radio telescopes all over the world; why would that one be that much different? It may not have the latest gadgets but radio(radar) it is. I drove by one of the largest arrays on the way to LA once. They have them on tracks that change position depending on the mission. They were huge!
> There are thousands of radio telescopes all over the world
You seem to have completely missed the point here. Radio telescopes are common indeed, but they are all passive devices, they just listen to incoming radio signals.
The specificity of Arecibo and GSSR is that they can be used as a radar emitter, capable of sending a radar signal out and receiving the echo reflected by some body (planet, asteroid), allowing you to pinpoint its exact distance and speed. Check the Wikipedia article about it: https://en.wikipedia.org/wiki/Radar_astronomy
Being that it passed only 2,950km from Earth, if the asteroid is in its own elliptical orbit that orbit has now been affected by Earth's gravity well. This means, quite possibly, that in some near or distant future that "near miss" maybe won't be quite such a miss after all.
If all your ducks are (unwelcomingly) in a row, that is.
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