October 2: Mercury’s retrograde motion ends
On October 2, 2022, Mercury ends its retrograde motion that lasted from September 9. It means that the planet will appear to move prograde, or “normally” — from east to west — until the next retrograde period that will start on December 29, 2022. By the way, Mercury is not the only planet that appears to move backward sometimes: check our infographic to learn what other celestial bodies can be in retrograde.
October 6: Mercury at perihelion
On October 6, 2022, at 20:57 GMT, Mercury’s orbit will carry it to the closest point to the Sun. The distance between the star and the planet will be 0.31 AU. For comparison, at aphelion (farthest point from the Sun), the distance between these two objects is about 0.4 AU. The difference makes up more than 50%, meaning Mercury gets twice as much energy from the Sun at perihelion than it does at aphelion. Because of this, its surface heats up by about 1.5 times. However, it doesn’t affect Mercury’s appearance in the sky: you will not notice much difference even if you look through a telescope.
October 8: Mercury at greatest western elongation
On October 8, 2022, at 20:59 GMT, Mercury (magnitude -0.6) will appear farthest from the Sun in the sky: the apparent distance between the two bodies will be 18°. As the innermost planet, most of the time, Mercury is near the Sun and, therefore, hard to observe. One of the best chances to see it is during elongation when the planet gets the farthest from the star. This time, Mercury will rise about two hours before dawn and will not have time to rise high; stargazers better find a vantage point with an unobstructed horizon.