Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: syhprum on 27/01/2011 11:04:30

Title: Will E-ELT find Earth twins in the goldilocs zone
Post by: syhprum on 27/01/2011 11:04:30
E-ELT is a proposed 42m telescope due to be constructed in Brazil (I remember as a boy wondering if the Hale 200" would ever be completed)
An excellent article here lists the technical problems and observing strategy here.

http://www.eso.org/sci/facilities/eelt/science/doc/drm_report.pdf
Title: Will E-ELT find Earth twins in the goldilocs zone
Post by: imatfaal on 27/01/2011 14:49:27
does that Acronym stand for European Excessively Large Telescope? ...Enviably Large, Enormously large, Elephantine Lens...

I must admit I have never understood the physics of why we cannot use a myriad of small mirrors bolted together.  I have three aluminium discs on my desk that are manufactured to an incredibly low error tolerance and yet they are mass produced and fairly cheap (HDD platers - now used as coasters). 

I will read that ESO prgramme with interest - thanks
Title: Will E-ELT find Earth twins in the goldilocs zone
Post by: CliffordK on 27/01/2011 16:27:50
Whew...
A big "summary" for a big telescope.

I suppose I must ask if there is a large benefit of having 100 off-axis mirrors pointed towards a single photo receptor versus having an array of a hundred telescopes each with their own photoreceptors, and able to be focused either together, or independently.

A distributed array wouldn't have to be located at the same site either.
Title: Will E-ELT find Earth twins in the goldilocs zone
Post by: Soul Surfer on 27/01/2011 22:55:38
The advantage of the large single mirror is sensitivity multiple telescopes can offer advantages of resolution although separation distance are limited compared with radio telescopes because of phase stability requirements.
Title: Will E-ELT find Earth twins in the goldilocs zone
Post by: Bored chemist on 28/01/2011 07:17:46
Quote from: imatfaal on 27/01/2011 14:49:27
does that Acronym stand for European Excessively Large Telescope? ...Enviably Large, Enormously large, Elephantine Lens...

I must admit I have never understood the physics of why we cannot use a myriad of small mirrors bolted together.  I have three aluminium discs on my desk that are manufactured to an incredibly low error tolerance and yet they are mass produced and fairly cheap (HDD platers - now used as coasters). 

I will read that ESO prgramme with interest - thanks

Imagine bolting lots of them together. The thickness of the composite disk would be the same, but the weight and length would be bigger. It would be too floppy.