Mercury at aphelion
The orbit of Mercury around the sun is not perfectly circular. As a result, the distance of Mercury from the sun changes over time.
Mercury reaches aphelion, meaning it reaches the farthest point from the sun in its elliptical orbit. Here, aphelion comes from two words: apo, meaning far away, and helios, meaning sun, more specifically the god of the sun in Greek mythology.
The average distance of Mercury from the sun is 57,909,000 km, and at aphelion, it is 69,818,000 km, according to NASA.
Mercury takes about 88 days to orbit the sun once. So it reaches aphelion every 88 days in its orbit.
When is the next aphelion of Mercury in 2024?
Mercury will reach its next aphelion on Wednesday, October 23, 2024, at 15:00 UTC (11 a.m. EDT), according to NASA.
Distance from the sun: During the aphelion, the distance of Mercury from the sun will be 0.46665 A.U. or 69,809,846 km.
Distance from the earth: During the aphelion, the distance of Mercury from the earth will be 1.36121 A.U. or 203,634,118 km.
Brightness: During the aphelion, Mercury will shine with a magnitude of +0.3 in our sky.
Disk size: During the aphelion, the angular diameter of Mercury will be 4.9 arcseconds.
Phase of Mercury: During the aphelion, Mercury will be in its waning gibbous phase and 92% illuminated.
Upcoming dates of aphelion of Mercury
| Date | Time (UTC) | Distance from the sun (A.U.) |
|---|---|---|
| October 23, 2024 | 15:00 | 0.46665 |
| January 19, 2025 | 14:00 | 0.46665 |
| April 17, 2025 | — | 0.46666 |
| July 14, 2025 | 13:00 | 0.46667 |
Related article: What is perihelion of Mercury and when is the next one?
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