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Thanks. So what kind of improvements do they expect with this one?

by zxcb1 7y ago

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.
sq_ 7y ago
The larger the mirror of the telescope, the more light it can gather from a given source. The expanded light-gathering capability of a thirty meter aperture combined with the great conditions that exist at the top of Mauna Kea because of its altitudes will allow for a lot of observations that would've been impossible before because the data produced wouldn't have been clear enough.
madaxe_again 7y ago
That’s actually a better question than you think. The answer is “we don’t know”. The light gathering power will be greater than any current instrument. The spatial resolution will be better than any current non-interferometric system. The adaptive optics are in a new league, and the mirror coatings will allow a very broad spectrum to be sensed. But what will we discover? We honestly don’t know. It’s been a bit of a bone of contention as many in science would argue that you should define your goals and then devise the experiment and apparatus - but cosmology and astronomy are a bit different, as most of the huge discoveries have been utterly unexpected, and have “just happened” as a result of better telescopes and observations, from moons of other planets to heliocentricism to other galaxies to red shift to the Big Bang to quasars and pulsars - we didn’t expect any of these things, we just found them. So that’s the improvement - hopefully new science, new discoveries.

Thanks. So what kind of improvements do they expect with this one?

by zxcb1 7y ago

Thanks. So what kind of improvements do they expect with this one?

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.

sq_ 7y ago

The larger the mirror of the telescope, the more light it can gather from a given source. The expanded light-gathering capability of a thirty meter aperture combined with the great conditions that exist at the top of Mauna Kea because of its altitudes will allow for a lot of observations that would've been impossible before because the data produced wouldn't have been clear enough.

madaxe_again 7y ago

That’s actually a better question than you think. The answer is “we don’t know”. The light gathering power will be greater than any current instrument. The spatial resolution will be better than any current non-interferometric system. The adaptive optics are in a new league, and the mirror coatings will allow a very broad spectrum to be sensed. But what will we discover? We honestly don’t know. It’s been a bit of a bone of contention as many in science would argue that you should define your goals and then devise the experiment and apparatus - but cosmology and astronomy are a bit different, as most of the huge discoveries have been utterly unexpected, and have “just happened” as a result of better telescopes and observations, from moons of other planets to heliocentricism to other galaxies to red shift to the Big Bang to quasars and pulsars - we didn’t expect any of these things, we just found them. So that’s the improvement - hopefully new science, new discoveries.