Saturday, April 2, 2011

30 meter space telescope

Parts 1 and 2 at The Unwanted Blog. This would be a giant leap beyond the capabilities of the ATLAST telescopes, each far more powerful than Hubble. Large space telescopes, even a 16 meter class telescope (considerably more modest, ready to launch on one Ares V) could work with a 100 meter ground telescope like the OWL. As a team, these would be able to image and get spectra for thousands of planets to at least 100 LY.


Bayourat Rocketry said...

Instead of one giant space telescope. Wouldn't it be more feasible to do a space based telescope array?

R2K said...

In some ways, yes. An array of smaller telescopes can do some things better, such as better resolution. Some of the Terrestrial Planet Finder ideas were like this. But there is no replacement for a large telescope when it comes to raw light gathering ability. A space telescope combines this (30 meters is significantly larger than any single active telescope right now, as big as the next generation of giants will be in a few years) with the ability to take very long (24 hour or more) exposures. I suspect that a 30 meter telescope could image any galaxy in the observable universe if it is in a clear line of sight. The Hubble can see to about magnitude 30 with a deep exposure. JWST will do somewhat better than this, perhaps magnitude 34. A 30 meter space telescope will add to this by several magnitudes again. Most of the distant universe will be within clear view of a giant space telescope. But there will still be limitations on resolution (diffraction limited) and ability to see small things like stars.

Just as space and land based telescopes both have pros and cons, so do arrays and monolithic telescopes. All are needed to leverage the benefits of each.

This type of telescope probably represents the state of the art around the time people of my generation retire. Sadly it wont come much sooner.