Part 9/10:
This resonance also causes specific observational phenomena. For example, approximately every 7 years, Mercury's orbit aligns such that it is only visible from Earth when positioned just in front of the Sun, due to the 7-degree tilt in its orbital plane relative to Earth.
Minimal Axial Tilt
Mercury’s axial tilt is nearly zero—about 0.027 degrees—making its rotation axis almost perpendicular to its orbital plane. This results in minimal variation in obliquity and contributes to the planet’s unique day-night cycle.
Observing Earth from Mercury
Using spacecraft images, like those captured by NASA’s MESSENGER mission, an almost pixel-sized Earth can be seen from Mercury—highlighting the vastness of space and the interconnectedness of our solar system.