These 10 super extreme exoplanets are out of this world

Upsilon Andromeda b is another exoplanet that is probably tidally locked to its host star, completing an orbit in just under five days. What makes this planet — which was previously known as Saffar — an extreme world is the radical difference in temperature between its dayside and nightside.

Whilst the dayside experiences temperatures as high as 2,912 degrees F (1,600 degrees C), the nightside is considerably cooler, reaching temperatures as low as minus 4 degrees F (minus 20 degrees C). This means that passing the hemisphere of this world could be considered equivalent to jumping into a volcano. 

While this is by no means the only tidally locked Hot Jupiter, the others we have discovered don't seem to feature such radical disparities in temperature between their star-facing and star-ignoring sides. The reason this exoplanet experiences such a radical difference in temperature could be due to the tremendous size of its parent star Upsilon Andromedae A, or the fact that the star possesses a hot spot almost directly "overhead" this exoplanet, according to NASA. 

By now, you might well be getting the impression that all exoplanets are hot, violent worlds that exist close to their parent stars. The fact is, the closer a planet's orbit brings it to its host star, the easier it is to spot. This means the exoplanet catalog is bursting with larger worlds that have tight orbits. There are some notable exceptions, however.