Complex sentence: Because tidal forces can knead and compress the interstellar gas clouds inside galaxies, they induce large amounts of star formation in small satellites, making them appear brighter than they otherwise would be; the process is somewhat similar to making something hotter by squeezing it.
Split into simpler sentences: Because tidal forces can knead and compress the interstellar gas clouds inside galaxies, they induce large amounts of star formation in small satellites. The process is somewhat similar to making something hotter by squeezing it.