if Frauenhofer lines are created by a star’s photosphere, how can we determine a planet’s atmosphere when the light passes through? I don’t see earth’s atmosphere on spectra of our sun, or do we just ignore that?
In: 2
We measure the light before, during, and after the planet passes in front of the star behind it. We can see how the planet impacts the light.
Our atmosphere does impact the observation of our own Sun or anything else in space. This is called _telluric contamination_. There are techniques for accounting for it.
Having telescopes in space in orbit is handy for this reason.
Earth’s atmosphere will absolutely show up on a spectrum of the sun’s light *if we measure it from the ground*. Another planet’s atmosphere will only absorb light when it passes between the star and us.
Latest Answers