Saturn at opposition
Saturn reaches opposition when Earth passes between the sun and the ringed planet Saturn.
As the sun and Saturn are on opposite sides of the Earth during opposition, they appear on opposite sides, or 180° apart, in our sky.
As a result, Saturn rises in the east when the sun sets in the west, reaches its highest point in the sky at midnight when the sun is below your feet, and sets in the west when the sun rises in the east.
Saturn is best visible around opposition
Saturn at opposition marks the best time to see the outer planet, as it’s visible throughout the night under clear skies. More precisely, it signifies the middle of the best time of the year to observe the planet.
After opposition, Saturn disappears from the morning sky gradually as it rises and sets four minutes earlier each day.
So, one month after opposition, Saturn rises 4*30 minutes = 120 minutes = 2 hours before sunset and sets 2 hours before sunrise.
So, three months after opposition, Saturn is visible in the evening sky only as it rises 6 hours before sunset, i.e., at noon, and sets 6 hours before sunrise, i.e., at midnight.
Saturn is closest, largest and brightest around opposition
Saturn is closest to Earth around the time of its opposition because the sun, Earth, and Saturn are all lined up in a straight line, and Saturn is located on the same side of the sun as Earth around the time of its opposition.
Saturn at opposition and the closest approach of Saturn to Earth would occur at the same time if the orbits of Earth and Saturn were perfectly circular.
Saturn appears largest and brightest in our sky around the time of its opposition, as it marks the closest approach of Saturn to Earth.
Saturn at opposition in 2025
Saturn will reach opposition on September 21, 2025, at 05:00 UTC (1 a.m. EDT).
Best time to see Saturn in 2025: Saturn will be best visible from early September through early October in 2025, when the planet rises in the east around the time of sunset and is visible all night.
Closest approach of Saturn to Earth in 2025: Saturn will be closest to Earth on September 21, 2025, i.e., on the day of its opposition in 2025. During the closest approach, Saturn will be 8.55 A.U., i.e., 1.28 billion km away from Earth.
Brightness at opposition: At its September 21 opposition, Saturn will be brightest for 2025 and will shine with a magnitude of +0.6.
Disk size at opposition: At its September 21 opposition, Saturn will be largest in size for 2025 and will appear 18.8 arcseconds in diameter through a telescope.
Constellation at opposition: At its September 21 opposition, Saturn will be located in the zodiac constellation Pisces, the Fish.
How often does Saturn reach opposition?
Saturn takes about 29.4 Earth years to orbit the sun once. So when our Earth makes one full orbit around the sun, Saturn travels 1/29.4 of the way around the sun. So to create Saturn’s opposition, our Earth would have to travel an extra 1/29.4 of the way in its orbit, which takes about (1/29.4)*365 = 12 days to travel.
That’s why planet Saturn reaches opposition once every 1 year and 12 days, or 377 days.
Dates of Saturn’s opposition
Here are the dates of Saturn’s opposition from 2025 to 2029, according to NASA:
| Date of opposition | Date of closest approach | Distance of closest approach (A.U.) |
|---|---|---|
| September 21, 2025 | September 21, 2025 | 8.55 |
| October 4, 2026 | October 5, 2026 | 8.43 |
| October 18, 2027 | October 18, 2027 | 8.32 |
| October 30, 2028 | October 31, 2028 | 8.22 |
| November 13, 2029 | November 14, 2029 | 8.14 |
Related article: Jupiter at opposition 2024: Best time to see Jupiter
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