Mercury
Being the closest planet to the Sun, its temperature can reach 430°C during the day and -173.15°C during the night. These long ranges occur because of its thin atmosphere, being essentially a vacuum because of its low gravity (38% of the Earth's) making it possible for solar waves to blow away whatever atmosphere it has left onto outer space.
Table of Facts
| Mass | 3.3022 x 1023 kg |
| Orbit Period | 88 days (Sun) |
| Radius | 2400 km (0.0035 *R☉) |
| Gravity | 3.7 m/s2 |
| Temperature | Day: 700 *K Night: 100 *K |
| Moon(s) | None |