Jupiter ESO Infrared (APOD 2008 Nov 06)

[apodman]

http://antwrp.gsfc.nasa.gov/apod/ap081106.html

The APOD description said:

using multiple guide stars and deformable mirrors to sense and correct for the distortions produced by turbulence in Earth's atmosphere

I didn't know it was possible to deform mirrors quickly enough to correct for turbulence, but I clicked on the MAD link and (sure enough) found the following:

Adaptive Optics systems work by means of a computer-controlled deformable mirror (DM) that counteracts the image distortion induced by atmospheric turbulence. It is based on real-time optical corrections computed from image data obtained by a 'wavefront sensor' (a special camera) at very high speed, many hundreds of times each second.

Wow! Then I noticed they've had this instrument working since March 2007, and that its forerunners have been working since 1989. I must have been looking the other way. Anyway, I'm impressed.

[Indigo_Sunrise]

Hiya apodman,
I agree - adaptive optics is amazing technology!
And as you said, I also didn't realize it was first built/utilized back in 1989. We've come a long way!
From that 'MAD' link, did you notice a gallery of images? I saw they had press releases, but couldn't find any gallery or collection of AO images on ESO's site. (Yes, I know: 'google is your friend'. I'm off on a search.....)


Pretty cool image! 8)

[bystander]

... From that 'MAD' link, did you notice a gallery of images? I saw they had press releases, but couldn't find any gallery or collection of AO images on ESO's site. ...

http://www.eso.org/gallery/v/ESOPIA

[Chris Peterson]

I didn't know it was possible to deform mirrors quickly enough to correct for turbulence...

Indeed, adaptive optics have been around for a few decades. Most of the major professional telescopes around the world utilize adaptive optics. There was a company in Colorado Springs about ten years ago developing a system for amateur and low-budget pro use, that had a segmented primary mirror with fast actuators on each segment. There was also a company more than ten years ago making an inexpensive second-order adaptive correction device for amateurs, useful for planets (it required a bright target). Many imagers these days are using tip/tilt correctors, which are a very simple form of adaptive optics.

What all these systems have in common is that they use a single reference for feedback- either a star near the target, or an artificial star created with a laser. The problem is that the area of sky that can be corrected is very small- typically less than an arcminute. So the adaptive optics work great for getting high resolution of small targets, but not for correcting wide fields. (Ground-based telescopes like the Kecks substantially outperform the Hubble on small targets.) The system used for this Jupiter image seems to have taken things to the next level, using multiple reference stars in order to construct a model of the wide field atmospheric distortion, allowing for compensation when imaging extended sources. Very promising technology (probably limited to IR for now, as atmospheric distortions are smaller at longer wavelengths).

[Moonshadow]

Does anyone have any idea what the small white bump on Jupiter's limb is (~ 7 o' clock)?

[iamlucky13]

Does anyone have any idea what the small white bump on Jupiter's limb is (~ 7 o' clock)?

Maybe a tall cloud system?

A few more tidbits about adaptive optics...typically they aren't put on the primary mirror a telescope...way too big to big practical. Rather they're one of the secondary mirrors or lenses. Also, the Air Force's Airborne Laser, a giant chemical laser carried by a 747 for shooting down ballistic missiles, will use adaptive optics to keep the laser beam focused through the 200-300 kilometers of atmosphere, or else it would be too diffuse to do any damage.

[apodman]

Here are some links I liked about adaptive optics (the first two with diagrams). Of course I had heard the phrase thrown around, but I never looked into it because my imagination was limited and therefore I didn't expect much.

http://www.aoainc.com/technologies/adap ... orial.html

http://cfao.ucolick.org/ao/how.php

http://www.eso.org/projects/aot/what_AO/