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It's planned as a general purpose observatory. Bigger mirror than any ever used would allow sharper, better images.

by pas 7y ago

madaxe_again 7y ago
The ELT will be complete five years before the TMT, and has a forty meter aperture.
- wumms 7y ago
  First light: ELT 2025 (39.3m, 978m²) TMT 2027 (30m, 655m²) (Future first-light dates are provisional and likely to change. https://en.wikipedia.org/wiki/Extremely_Large_Telescope https://en.wikipedia.org/wiki/Extremely_Large_Telescope) Nice mirror size comparison: https://en.wikipedia.org/wiki/Extremely_Large_Telescope#/media/File:Comparison_optical_telescope_primary_mirrors.svg https://en.wikipedia.org/wiki/Extremely_Large_Telescope#/med...
- _ph_ 7y ago
  As a telescope, the ELT will be superior, but it is in the other hemisphere. So the TMT does not only give more observation "bandwidth", but also unlocks a high quality view into the northern hemisphere. Together, those two telescopes can cover the whole sky.
zxcb1 7y ago
Ok. So a space telescope would be prefered and this is the second best option, limited by budget?
- madaxe_again 7y ago
  Absolutely. The cost, even with current cheapening launch costs, would still be astounding. As long as we’re using chemical rockets fuelled from earth we are going to be really limited in terms of what we can put in space - and again, assembly - we couldn’t even get Hubble right first time, and it has taken thousands of hours of spacewalks to keep operating. It’s totally been worth it though. Stepping stones - if the new class of earth based telescopes finds something worth looking at, there will be space telescopes that make the JWST look like a toy - but not for a while yet. This is basically the “cheap” trial experiment.
  - dogsgobork 7y ago
    > it has taken thousands of hours of spacewalks to keep operating. The total eva time for all five servicing missions for Hubble is under 200 hours.
- Cthulhu_ 7y ago
  Budget and maintainability - I mean the Hubble telescope only managed to stay in operation for as long as it did thanks to a number of maintenance missions via the Space Shuttle. That extended its lifetime by a considerable margin. Meanwhile, this observatory will be much more easily accessible and will therefore have a lifetime many times that of the Hubble - and can become a museum after its lifetime.

It's planned as a general purpose observatory. Bigger mirror than any ever used would allow sharper, better images.

by pas 7y ago

It's planned as a general purpose observatory. Bigger mirror than any ever used would allow sharper, better images.

madaxe_again 7y ago

The ELT will be complete five years before the TMT, and has a forty meter aperture.

wumms 7y ago
First light: ELT 2025 (39.3m, 978m²) TMT 2027 (30m, 655m²) (Future first-light dates are provisional and likely to change. https://en.wikipedia.org/wiki/Extremely_Large_Telescope https://en.wikipedia.org/wiki/Extremely_Large_Telescope) Nice mirror size comparison: https://en.wikipedia.org/wiki/Extremely_Large_Telescope#/media/File:Comparison_optical_telescope_primary_mirrors.svg https://en.wikipedia.org/wiki/Extremely_Large_Telescope#/med...
_ph_ 7y ago
As a telescope, the ELT will be superior, but it is in the other hemisphere. So the TMT does not only give more observation "bandwidth", but also unlocks a high quality view into the northern hemisphere. Together, those two telescopes can cover the whole sky.

zxcb1 7y ago

Ok. So a space telescope would be prefered and this is the second best option, limited by budget?

madaxe_again 7y ago
Absolutely. The cost, even with current cheapening launch costs, would still be astounding. As long as we’re using chemical rockets fuelled from earth we are going to be really limited in terms of what we can put in space - and again, assembly - we couldn’t even get Hubble right first time, and it has taken thousands of hours of spacewalks to keep operating. It’s totally been worth it though. Stepping stones - if the new class of earth based telescopes finds something worth looking at, there will be space telescopes that make the JWST look like a toy - but not for a while yet. This is basically the “cheap” trial experiment.
- dogsgobork 7y ago
  > it has taken thousands of hours of spacewalks to keep operating. The total eva time for all five servicing missions for Hubble is under 200 hours.
Cthulhu_ 7y ago
Budget and maintainability - I mean the Hubble telescope only managed to stay in operation for as long as it did thanks to a number of maintenance missions via the Space Shuttle. That extended its lifetime by a considerable margin. Meanwhile, this observatory will be much more easily accessible and will therefore have a lifetime many times that of the Hubble - and can become a museum after its lifetime.