[dalke]

But we are doing that.

Hubble was started and launched before adaptive optics. That's revolutionized ground-based telescopes. The newest generation of extremely large telescopes, like the Giant Magellan Telescope, will have better angular resolution of Hubble, in visible light.

Of course, the relevant comparison should be to the James Webb Space Telescope, but it's estimated cost of $9 billion is rather a lot higher than the $800 million for the GMT.

I'm emphatically not saying that we shouldn't have space telescopes. There's no way to have a ground-based X-ray telescope, as an obvious example.

I'm only pointing out that the evidence is that land-based telescopes are not, broadly speaking, "too limited" to do new science.

[mturmon]

Smart comment. Adaptive optics have rearranged the fundamental drivers for visible-light astronomy.

And a lot of physics experts who were working on high-resolution space-based telescopes, telescopes that are in many cases are now replaceable by ground telescopes, have paid a heavy price for this fact. Technology can be a tough field sometimes.

If you want to see what is likely to be built in the next decade, you can start at:

http://sites.nationalacademies.org/bpa/BPA_049810

Go to the last report on the web page ("2020 Vision") and go to page 17 of the PDF. It's all there.

[dalke]

Thanks!

"What's likely" is, sadly, optimistic. I see that LISA's isn't likely to be built by the 2020s.

Reviewing the list of other space telescopes, WFIRST is now WFIRST-AFTA, with a change to use a second-hand NAO telescope.

NuSTAR and IRIS are two launched Small Explorer missions since 2010. (Oddly, they used an artist's concept of WISE to highlight the concept. Odd, because WISE was launched in 2009, so a 2010 publication should not have needed a concept image.) I haven't figured out what the new missions are/might be, but I didn't look too hard.

The International X-Ray Observatory has had a "reboot", to ATHENA (Advanced Telescope for High Energy Astrophysics). NASA withdrew from IXO.

[sliverstorm]

Awesome! I've dreamed of adaptive optics (not specifically, just how it might be achieved), I didn't realize they already existed. Thanks for the information.