Final answer:
Mercury has the most extreme temperature difference between day and night, with around 600 °C variation, whereas Mars has a significant but lesser variation of approximately 165 °C due to its thin atmosphere.
Step-by-step explanation:
The world with the greatest difference in temperature between its day and night sides is Mercury. On Mercury, temperatures can soar to a scorching 430 °C on the sunlit side and then plummet to a frigid -170 °C during the long nights, resulting in an extreme temperature range of about 600 °C. This significant temperature variation is due to Mercury's lack of a significant atmosphere to retain heat, allowing for rapid cooling after sunset.By comparison, Mars also experiences a wide range of temperatures between day and night, with a difference of approximately 165 °C. This variance is because Mars has a thin atmosphere that does not retain heat as efficiently as Earth's, coupled with its distance from the Sun. However, the range on Mars is not as extreme as on Mercury.Earth's own temperature variation is much less drastic due to our thicker atmosphere which acts as an insulating blanket, keeping the surface warmer at night and cooler during the day. Another factor is the greenhouse effect, which traps heat within the atmosphere, contributing to a more stable temperature environment.