Part 8/10:
Mercury’s orbit is highly eccentric, causing its distance from the Sun to fluctuate between approximately 46 million and 70 million km. Completing an orbit around the Sun takes about 88 Earth days.
One intriguing aspect of Mercury is its rotational period. It completes three rotations on its axis for every two orbits around the Sun—this is known as a 3:2 spin-orbit resonance. As a result, a single Mercury day (sunrise to sunrise) lasts about 176 Earth days, which is twice its orbital period. This means that when standing on Mercury, a day lasts nearly two years in Earth time. Consequently, the Sun appears to rise, set, and then rise again in a pattern different from Earth’s.