On China's FAST radio telescope, with planned completion in 2016

A few days ago we saw news of plans by China to build the world's largest radio telescope, one called FAST that would be quite a bit larger than Arecibo but also more sophisticated as well. Details on that here, but the short answer is that it will be able to observe 19 regions simultaneously instead of seven.

Being concerned as much with the PR of space as space itself, this is a particularly welcome piece of news because radio telescopes of this magnitude are the best way to observe asteroids as they fly by the Earth. It is only thanks to Arecibo that we have found out that a great deal of tiny asteroids we thought to be lone bodies are actually binary or even trinary systems, and a new telescope that can contribute to and improve on this will be phenomenal. Here are just a few examples of what we know of some really tiny asteroids thanks to Arecibo, without which we would have little more than pinpoints of light.

Asteroid 2005 YU55 - 400m in diameter, will pass by Earth in November at 0.85 lunar distances:

1999 RQ36 - 560m in diameter, and the target of the Osiris-Rex mission in 2016. It looks like this:

2001 SN263 - a triple system with the main asteroid 2 km in diameter, the other two are 1 km and 400 metres. It was imaged during a close encounter by Arecibo:

1992 UY4: 2 km in diameter, looks like this.

In other words, a radio observatory of this calibre is like having near-flyby quality images every time an asteroid of respectable size passes by. And starting in 2016 we'll have two of them.

Scheduled asteroid observations by Arecibo can be seen here.