To determine which of the given planets has the lowest temperatures, let's consider each planet briefly:
1. Jupiter: As a gas giant, Jupiter has a very thick atmosphere which helps in retaining heat. While its distance from the Sun is considerable, the planet itself emits a significant amount of internal heat.
2. Mercury: Mercury is the closest planet to the Sun, experiencing extremely high temperatures during the day. However, its lack of atmosphere means it also cools down significantly at night. Despite these cold nights, the average temperatures are relatively high.
3. Saturn: Similar to Jupiter, Saturn is also a gas giant with a thick atmosphere that retains heat. Although it is farther from the Sun compared to Jupiter, it still has substantial internal heat which affects its temperature.
4. Uranus: Uranus is a gas giant as well, but it is unique among the planets in that it radiates very little heat compared to what it receives from the Sun. It is also much farther from the Sun than Jupiter and Saturn. This distance greatly reduces the amount of sunlight it receives, leading to very low temperatures on the planet.
Given these points, the planet with the lowest temperatures among the options listed is Uranus.
