The thing was iconic... even if not everyone watching/playing Goldeneye knew it was a real radio telescope, it was nevertheless one of those science megaprojects that featured prominently in the popular zeitgeist and got more than one young kid excited about what's out there in the stars. But infrastructure ages, and 60 years isn't a bad run. What comes next? Clearly there's going to be a capabilities gap for a while…
A radio astronomer here, and writing opinion for all that's worth.
I visited Arecibo once and stayed for a short project for 3 months. It was awesome, and they have a fabulous small astronomy team doing some really interesting science.
My mentor and long-term collaborator has used this telescope since the 70s, and she will be devastated. This dish has produced so many unexpected discoveries, solid science of highest calibre, and has stayed at the edge of science over 50+ years. It's sad to see such a sudden end.
There are three variants of radio-telescope design:
1. monolith dish (Arecibo or Green Bank) 2. Network of dishes (Very Large Array, or VLA, in New Mexico) 3. Network of individual dipoles (LOFAR in the Netherlands)
One needs to combine all three in some ways to target different classes of astronomical problems. For example, if you want to understand the source structure, separate its left limb from the right, then you need smaller dishes separated by a large distance (like Very Large Array -- VLA). If you are looking at low frequencies of radio light, then you need dipole arrays like LOFAR. On the other hand if you are looking for giant burst of short-term energy, you are collecting light from a distant object. The more you collect, the better it is. So, single dish (or many dishes combined) works very well. Large single dish (Arecibo like) telescopes are also critical to characterize arrays like VLA or LOFAR. So, they are very useful still.
Arecibo's success gave rise to improved design of a single mammoth dish telescopes in China (FAST). So, the design stays relevant and of importance. A new telescope called Square Kilometer Array (of size one square kilometer in effective area) would in principle replace a mammoth dish like Arecibo and tackle very diverse set of problems.
However, Arecibo is like an old Volvo car that kept on going strong. You never want to junk such a old beauty even if you have a swanky Tesla standing outside your door, would you?
Cheers!