4 ms·

if we could manufacture the telescopes on the moon, we could build massive ones (and size matters). And, why not have both?

post-it 3y ago
Couldn't we manufacture more massive ones in orbit around the moon, since they won't collapse under their own weight? We'd need extra fuel to get resources or parts off the surface of the moon, but that's nothing in comparison to the fuel needed to get off the Earth. Edit: I forgot the moon has a much lower gravity than Earth. It might still be worthwhile to build in orbit, but we can build a lot bigger on the moon than on Earth.
- sandworm101 3y ago
  Moon orbits are very unstable. Maintaining anything so large there for an extended period would be difficult.
  - shagie 3y ago
    (on the unstable lunar orbits...) https://en.wikipedia.org/wiki/Lunar_orbit https://en.wikipedia.org/wiki/Lunar_orbit > Gravitational anomalies slightly distorting the orbits of some Lunar Orbiters led to the discovery of mass concentrations (dubbed mascons) beneath the lunar surface caused by large impacting bodies at some remote time in the past. These anomalies are of sufficient magnitude to cause a lunar orbit to change significantly over the course of several days. They can cause a plumb bob to hang about a third of a degree off vertical, pointing toward the mascon, and increase the force of gravity by one-half percent. > ... > Study of the mascons' effect on lunar spacecraft led to the discovery in 2001 of "frozen orbits" occurring at four orbital inclinations: 27°, 50°, 76°, and 86°, in which a spacecraft can stay in a low orbit indefinitely. Consider that - there are only four inclinations where you an orbit the moon without needing to do constant adjustments. Whereas with the Earth basically all the inclinations are available. https://en.wikipedia.org/wiki/Frozen_orbit https://en.wikipedia.org/wiki/Frozen_orbit and https://science.nasa.gov/science-news/science-at-nasa/2006/06nov_loworbit/ https://science.nasa.gov/science-news/science-at-nasa/2006/0... for more on this.
- bryanlarsen 3y ago
  It would mass a lot more in orbit, since the moon itself is providing most of the structure for the proposed telescope.

post-it 3y ago

Couldn't we manufacture more massive ones in orbit around the moon, since they won't collapse under their own weight? We'd need extra fuel to get resources or parts off the surface of the moon, but that's nothing in comparison to the fuel needed to get off the Earth. Edit: I forgot the moon has a much lower gravity than Earth. It might still be worthwhile to build in orbit, but we can build a lot bigger on the moon than on Earth.

sandworm101 3y ago
Moon orbits are very unstable. Maintaining anything so large there for an extended period would be difficult.
- shagie 3y ago
  (on the unstable lunar orbits...) https://en.wikipedia.org/wiki/Lunar_orbit https://en.wikipedia.org/wiki/Lunar_orbit > Gravitational anomalies slightly distorting the orbits of some Lunar Orbiters led to the discovery of mass concentrations (dubbed mascons) beneath the lunar surface caused by large impacting bodies at some remote time in the past. These anomalies are of sufficient magnitude to cause a lunar orbit to change significantly over the course of several days. They can cause a plumb bob to hang about a third of a degree off vertical, pointing toward the mascon, and increase the force of gravity by one-half percent. > ... > Study of the mascons' effect on lunar spacecraft led to the discovery in 2001 of "frozen orbits" occurring at four orbital inclinations: 27°, 50°, 76°, and 86°, in which a spacecraft can stay in a low orbit indefinitely. Consider that - there are only four inclinations where you an orbit the moon without needing to do constant adjustments. Whereas with the Earth basically all the inclinations are available. https://en.wikipedia.org/wiki/Frozen_orbit https://en.wikipedia.org/wiki/Frozen_orbit and https://science.nasa.gov/science-news/science-at-nasa/2006/06nov_loworbit/ https://science.nasa.gov/science-news/science-at-nasa/2006/0... for more on this.
bryanlarsen 3y ago
It would mass a lot more in orbit, since the moon itself is providing most of the structure for the proposed telescope.