ELI5, Why do some extrasolar planets revolve much faster than planets here in the Solar Sytem?

Question

For example:

55 Cancri b: 0.7 days
Kepler-1649c: 19.5 days
Gliese 581g: 32 days

Compare it to Earth, which is 365 days and Mercury which is 88 days. What are the factors that cause these exoplanets revolve much faster?

In: 5

Answer 1

This is mostly about distance from the star. The closer something is to the star, the faster it orbits it (and the less time it takes).

Our methods of detecting planets have a much easier time finding planets that are close to their stars, so we tend to spot a lot of fast-orbiting planets.