Planetary Opposition 2025: Best Time to See Planets
The next planet to reach opposition will be Saturn — mark your calendar for September 21. With the Sky Tonight app, you can easily find Saturn in your sky. Read this article to learn more about oppositions and find out the best dates to see planets and asteroids.
Contents
- What does opposition mean in astronomy?
- Planetary oppositions
- Upcoming planetary oppositions
- Other upcoming oppositions
- F.A.Q.
- Planet oppositions: Bottom line
What does opposition mean in astronomy?
Astronomical opposition means that a planet is located on the opposite side of the Earth from the Sun. From our perspective, it means a planet at opposition is precisely 180 degrees from the Sun in the sky — so, when the Sun sets in the west, a planet appears in the east. In addition to planets, an opposition can be reached by comets, asteroids, and some other Solar System objects. A well-known example of opposition is a Full Moon. During this event, the lunar disk is opposed to the Sun, therefore fully lit by the star’s light.
Planetary oppositions
Next opposition: Saturn (September 21, 2025)
Saturn will reach opposition on September 21 at 05:10 GMT (1:10 a.m. EDT). For a few weeks around opposition, Saturn will look big and bright in the sky (mag 0.6-0.7). The planet will be in the constellation Pisces, visible all night. To find Saturn in the sky in your location, use the free Sky Tonight app.
What planets can be seen at opposition from the Earth?
Since an opposition can only occur when the Earth is between the Sun and another celestial body, this event happens for the planets further from the Sun than the Earth. These are Mars, Jupiter, Saturn, Uranus, and Neptune.
The planets’ oppositions occur roughly every year when the Earth reaches the proper configuration with them relative to the Sun. The only exception here is Mars. The Red Planet’s orbit and orbital speed are similar to the Earth’s, so the Earth “outraces” Mars only about every 27 months. That’s why Mars oppositions occur only once in about two-three years. Mercury and Venus are located inside the Earth’s orbit, so we’ll never see them at opposition.
How to find a planet at opposition?
To find a planet at opposition, look in the opposite direction from the sunset. The planet will be well-placed for a few weeks around the exact moment of opposition. So, check a forecast for your location, find a date close to the opposition when the skies are clear, and get outside to observe the bright planet.
You can easily locate and identify a planet using a stargazing app like Sky Tonight:
- To locate your desired planet, use the app's search function. Tap the magnifier icon in the bottom-left corner of the main screen and type the object’s name in the search bar. Tap the blue target button next to the matching result, and then tap the blue compass button in the lower right corner of the screen. Move your device in the direction of the white arrow until you see the planet on the screen. This is the direction in which you will find the planet in the real sky above you.
- To identify any bright dot in the sky, launch the app and point your device at the sky. On the app’s interactive sky map, you’ll see what celestial objects are in that direction. You can tap the object to learn its name and tap its name for more information.
At opposition, you can spot most of the planets with the naked eye, but you’ll see them even better through a pair of binoculars or a telescope. For instance, with a small 4-inch telescope, you should be able to observe Saturn’s rings, including the Cassini Division between them.
Why are planetary oppositions interesting?
Opposition is the best time to observe a planet or another celestial body. At that time, objects are fully illuminated by the Sun and shine brightly in the sky. Moreover, planetary oppositions occur near a planet’s closest approach to the Earth, when a planet appears at its biggest. Mars experiences the most striking size change because it’s the closest superior planet to the Earth. Most importantly, an opposition gives us plenty of time for stargazing! A celestial object is seen through the night and well-placed in the midnight sky. It is no coincidence that asteroids and other faint Solar System objects are often discovered at their opposition.
Upcoming planetary oppositions
The complete calendar of all the planetary and other celestial events is available in the stargazing app Sky Tonight.
September 21, 2025: Saturn opposition
Saturn will be in opposition to the Sun on September 21, 2025, at 05:10 GMT (1:10 a.m. EDT). It will shine at a magnitude 0.6, which is its maximum brightness for 2025. The planet will look like a bright yellowish dot in the constellation Pisces. It will rise in the east at sunset and will be visible to the naked eye all night.
You won’t be able to see Saturn’s famous rings either with the naked eye or through binoculars, but a small telescope will reveal them to you. However, the rings will be tilted at only 2 degrees and appear nearly edge-on from Earth, so it might be hard to see them.
Around opposition, Saturn will come closest to Earth for 2025 — at a distance of about 8.55 astronomical units. Saturn’s disk size will also be at its largest, measuring 19.4 arcseconds across.
September 23, 2025: Neptune opposition
Neptune will be in opposition to the Sun on September 23, 2025, at 12:45 GMT (8:45 a.m. EDT). It will have a magnitude 7.8, which is its maximum brightness for 2025. The planet will rise in the east at sunset and will be visible all night in the constellation Pisces. Neptune can’t be seen with the naked eye, so you will need good binoculars or a telescope to observe it. If you have a medium-sized telescope, you can see Neptune’s brightest moon, Triton.
Around opposition, Neptune will come closest to Earth for 2025 — at a distance of about 28.9 astronomical units. Neptune’s disk size will also be at its largest, measuring 2.4 arcseconds across.
November 21, 2025: Uranus opposition
Uranus will be in opposition to the Sun on November 21, 2025, at 12:17 GMT (8:17 a.m. EDT). It will have a magnitude 5.6, which is its maximum brightness for 2025. The planet will rise in the east at sunset and will be visible all night in the constellation Taurus. Theoretically, you can glimpse Uranus with the naked eye under a dark sky, but in practice, it’s better to use good binoculars or a telescope for its observation. If you have a medium-sized telescope, you can see up to four moons of Uranus: Titania, Oberon, Umbriel, and Ariel.
Around opposition, Uranus will come closest to Earth for 2025 — at a distance of about 18.5 astronomical units. The planet’s disk size will also be at its largest, measuring 3.7 arcseconds across.
Other upcoming oppositions
Not only planets but also comets, asteroids, and other Solar System bodies can reach opposition. Such events are more challenging to spot, so they are more for experienced astronomers. Opposition is also the best time for asteroid hunters. If you want to discover a new asteroid, it’s better to look at night in the direction opposite to the Sun, and maybe you’ll get lucky!
Asteroids in opposition
Most asteroids are difficult to observe with regular binoculars. However, if you have 10x50 or larger binoculars, you can try spotting the asteroids that are brighter than 10th magnitude — we marked them with an emoji in our list. Just imagine the thrill of seeing a real asteroid with your own eyes!
- May 19, 2025: 354 Eleonora (mag 10.3), constellation Hercules.
- June 5, 2025: 5 Astraea (mag 10.6), constellation Ophiuchus.
- August 2, 2025: 63 Ausonia (mag 8.6), constellation Capricornus. ⭐
- August 5, 2025: 129 Antigone (mag 10.0), constellation Capricornus.
- August 6, 2025: 532 Herculina (mag 10.2), constellation Capricornus.
- August 7, 2025: 2 Pallas (mag 9.4), constellation Delphinus. ⭐
- August 10, 2025: 89 Julia (mag 8.5), constellation Aquarius. ⭐
- August 26, 2025: 6 Hebe (mag 7.6), constellation Aquarius. ⭐
- November 5, 2025: 12 Victoria (mag 9.9), constellation Aries. ⭐
- December 7, 2025: 16 Psyche (mag 9.7), constellation Taurus. ⭐
- December 25, 2025: 42 Isis (mag 11.3), constellation Gemini.
Dwarf planets in opposition
Being fainter than asteroids, dwarf planets are typically out of reach for casual stargazers without a powerful telescope. However, there is one exception — Ceres! Although this dwarf planet is the smallest in the Solar System, it is also the closest to Earth. During opposition on October 2, you can spot Ceres with 8x40 or 10x50 binoculars! Don't miss this rare opportunity to add a dwarf planet to your stargazing achievements!
- July 1, 2025: 50000 Quaoar (mag 18.7), constellation Scutum.
- July 10, 2025: 2002 MS4 (mag 20.3), constellation Aquila.
- July 24, 2025: 134340 Pluto (mag 15.0), constellation Capricornus.
- August 28, 2025: 225088 Gonggong (mag 21.4), constellation Aquarius.
- October 2, 2025: 1 Ceres (mag 7.6), constellation Cetus. ⭐
F.A.Q.
What planets are in opposition now?
Currently, no planets are in opposition. The most recent was the opposition of Mars on January 16, 2025. The next one will be Saturn’s opposition on September 21, 2025.
How often do planetary oppositions occur?
A planetary opposition occurs when the Earth passes between the Sun and a planet. It happens every year for the superior planets. The only exception is the Martian opposition. Since the planet is very close to the Earth and its orbit and orbital speed are similar to the Earth’s, our planet manages to pass between Mars and the Sun only every 27 months, so we get one Martian opposition in about two-three years.
How long does an opposition last?
A planet is said to be “at opposition” at the exact moment of time, but the period of opposition lasts for a few weeks. You can observe the planet on any convenient date around that time. It will rise on the opposite side to the Sun right after sunset, reach the highest point at midnight, and set at dawn.
What is the opposite of opposition in astronomy?
The opposite of opposition in astronomy is a conjunction. During the conjunction of a planet and the Sun, the planet is at the closest distance from the Sun in the sky. It’s the most difficult time to observe the planet because the Sun hinders the view. But there are other astronomical conjunctions that don’t involve the Sun: for instance, planetary conjunctions and lunar-planetary conjunctions. They are quite interesting to observe!
Planet oppositions: Bottom line
Opposition is the best time to observe planets because they appear at their biggest and brightest and are visible all night through. The next opposition we’re looking forward to is the opposition of Saturn on September 21, 2025. Download the stargazing app Sky Tonight to easily find Saturn or any other planet in the sky in your location.
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