How can we know the size, composition, and atmospheric makeup of distant exoplanets? NASA explains the details in this Alien Atmospheres video.
By observing periodic variations in the parent star’s brightness and color, astronomers can indirectly determine an exoplanet’s distance from its star, its size, and its mass. But to truly understand an exoplanet astronomers must study its atmosphere, and they do so by splitting apart the parent star’s light during a planetary transit.
A vortex ring is the phenomenon where a quantity of fluid or gas in a toroid (donut) shape, travels through a medium of fluid or gas, while spinning like a thick circular bracelet that is being rolled off of a person’s arm. (Except the spin is in the opposite direction as when a bracelet is rolled off in this way.)