How ground-based astronomers overcome Earth’s atmosphere | by Ethan Siegel | Starts With A Bang! | Apr, 2024
Lasers, mirrors, and computational advances can all work together to push ground-based astronomy past the limits of our atmosphere.
One of the most profoundly remarkable properties about our atmosphere is that it’s transparent to not only sunlight, but to starlight as well. As we turn our eyes skyward after the Sun goes down, a glittering tapestry of planets, stars, galaxies, and nebulae illuminates the heavens. If we want to view it, all we have to do is look with the proper tools.
But our view of what’s out there, from here on Earth, is limited in ways we rarely think about. Even on a cloudless night, any light coming to us from space must pass through over 100 kilometers (more than 60 miles) of atmosphere, which itself has continuous variations in density, temperature, and molecular composition. Any light coming in has to contend with the atmosphere, and even though the atmosphere is transparent, that light inevitably gets distorted.
For the first time, astronomers are finally capable of overcoming Earth’s atmosphere. Here’s how.
The best way to view the Universe is with the largest, most powerful, and most accurate telescope you can possibly create. The larger your telescope is, the more wavelengths of light can fit across it, increasing its resolution. Larger telescopes also mean better light-gathering power, enabling you to see fainter objects more quickly and in greater detail. This is the reason why the Astro2020 decadal survey recommended the construction of two new ground-based telescopes of an all-new 30 meter class, and why a short-sighted decision from the National Science Foundation to only build one is one that ought to be reversed and overruled.
Once you have a large-aperture telescope, you have to figure out where to put it to gather the needed data optimally. You want the darkest skies possible, as far away from any and all significant sources of light pollution, including cities, squid fisheries, and even the Moon. You want to build your telescope at the…
