For some scientific purposes, eliminating 99.6% of the Earth’s atmosphere is approximately the same as eliminating 100% of it. E.g. precise imaging and characte

For some scientific purposes, eliminating 99.6% of the Earth’s atmosphere is approximately the same as eliminating 100% of it. E.g. precise imaging and characterization of nearby interstellar bodies, those projects get Hubble-tier data thousands of times cheaper. For other scientific purposes, eliminating 99.6% of the Earth’s atmosphere is approximately the same as eliminating 0% of it. E.g. trying to divine the values of physical constants in the earliest moments of the universe by looking as far into the past as possible, those projects are far too sensitive and their observations would be completely swamped by the noise of the remaining 0.4% of Earth’s atmosphere.