Last night, Jupiter, the largest planet in our Solar System, appeared at its best and brightest as it aligned with Earth and the Sun (also known as opposition). But worry if you missed this: tonight the gas giant is still well-placed for observing – and you’ve probably already noticed Jupiter as a bright point of light, low in the evening sky.
So, how can you spot Jupiter in the night sky? How can you tell it's not a star? And when will it enter opposition again? Here's all you need to know.
When is Jupiter in opposition?
Jupiter reached opposition in the morning of 3 November 2023 at 5am in the UK (1am in New York City, 10am on 2 November in Los Angeles). At this time, the Sun, the Earth, and Jupiter will be in a perfectly straight line, with Earth in the middle. This is much in the same way that Earth is exactly between the Sun and the Moon during a full Moon.
Don't worry if you missed this – Jupiter is still easy to stop days after opposition.
If you’ve looked up at the night sky recently, you’ve probably already spotted Jupiter in the run-up to opposition:
“Jupiter is the largest planet in our Solar System, 11 times larger than Earth. It’s now dominant in the night sky,” explains veteran astronomer and BBC Sky at Night presenter, Pete Lawrence.
“If clear, Jupiter currently shines brighter than all other objects around it, save for the Moon when about. Jupiter reaches opposition on 3 November when it’ll appear at its brightest and best for 2023,” Lawrence notes.
What is opposition?
In astronomy, opposition refers to the alignment of a planet (or the Moon) with the Earth and the Sun. During opposition, these three celestial bodies are positioned in a perfectly straight line, with the Earth in the middle.
“Opposition describes an object being opposite the Sun in the sky. For some planets this can be a big deal, the weeks around opposition giving us our best views of them. At opposition, a planet is also visible all night long,” explains Lawrence.
This means that during opposition, Jupiter is fully illuminated by the Sun, so it appears particularly bright and easily visible in the night sky. Opposition provides an excellent opportunity to observe, study and photograph the planet's features, as it’s well-illuminated and easily seen. And, because it’s opposite the Sun, Jupiter will remain above the horizon all night.
Only planets beyond Earth's orbit can be in opposition. These are Mars, Jupiter, Saturn, Uranus, and Neptune. Because Mercury and Venus are orbiting the Sun inside Earth’s orbit, Earth will never be positioned between Mercury or Venus and the Sun, and therefore these two planets can never go into opposition.
How can I spot Jupiter in the sky?
Jupiter is relatively easy to spot, even for the beginner. It’s currently one of the brightest objects in the night sky, and can be seen all night long.
Jupiter will rise in the constellation Aries. It’s a dim constellation, so can be a little tricky to locate. First, look towards the Pleiades star cluster, a cute little asterism packed full of baby stars in the Taurus constellation (November is actually the best time to view the Pleiades), and look for a crooked line of three stars nearby. This is Aries, and you’ll easily be able to identify a bright Jupiter loitering below the constellation.
Expert Pete Lawrence shares his top tips for viewing Jupiter:
“Jupiter is wonderful to view with a bit of optical aid. Let’s start small with binoculars. Here, steadiness is key. One trick is to use a household broom, inverted so the brush is pointing up, the handle tip on the ground. You can steady the binoculars against the brush, using a cloth or towel over the broom head to keep yourself clean,” Lawrence says.
But it’s not just the planet you’ll be able to see with binoculars:
“With a steadier view, focus as accurately as you can. The planet has many moons – 95 at the last count. However, only four are large and bright enough to see easily with a small kit. Orbiting the planet, their positions relative to Jupiter vary. When separated from Jupiter they should be visible through steadied binoculars,” he says.
Here are some tips to help you spot Jupiter in opposition:
- Time: Look for Jupiter low on the eastern horizon shortly after sunset. If you’re not sure which way is east, look for where the Sun set, and physically turn around so you’re facing the opposite direction.
- Brightness: Jupiter is exceptionally bright, currently at magnitude -2.76.
- Consistency: It doesn't twinkle like stars, because it doesn't have a point source of light; it appears as a small, steady, and bright disc.
- Motion: Over several nights, you can observe Jupiter's motion relative to the stars. Planets move against the background stars, while stars maintain fixed positions.
- Binoculars or telescope: If you have them, use binoculars or a telescope to view the four large Galilean moons, which appear as tiny points of light near the planet.
If you're still struggling to spot Jupiter, there are astronomy apps that you can download - all you need to do is point your phone at the sky, and the app will tell you what you’re looking at.
What will Jupiter look like through a telescope?
If you look at Jupiter through a telescope, it may appear squashed, bulging at the equator. This is down to the fast spin of the planet; it takes less than 10 hours for it to complete one rotation. It’s the fastest spinning planet in the Solar System, and subsequently, has the shortest day of all the planets in the Solar System.
“With a small telescope, the moons appear clearer, and Jupiter appears as a disc. Relax and take time to let your eye get used to the view. Eventually, you’ll see the two dark belts which encircle the planet’s globe parallel to its equator; the north and south equatorial belts (NEB and SEB),” explains Lawrence.
“Notice also that the planet’s disc isn’t round but appears squashed. This is because Jupiter is a rapidly spinning gas planet, one day on Jupiter being less than 10 hours long!”
“If you have a 100mm or larger telescope and if the timing is right, you may see an oval patch embedded within the SEB. This is the Great Red Spot, a persistent anticyclonic storm in Jupiter’s atmosphere which may have been around for at least 358 years.”
How often do oppositions occur?
All of the planets in our Solar System go into opposition on a roughly annual basis. This is because Earth has a faster orbit, passing between these planets and the Sun.
“For superior planets (larger orbits than Earth) the effect of opposition decreases with distance,” says Lawrence.
There is, however, one exception to this rule: Mars. Mars reaches opposition every 26 months, because it takes Earth a bit less than two years to ‘lap’ Mars in their respective orbits. This regular pattern makes Mars reach opposition about every 26 months.
“Nearby Mars reaches opposition every 2.1 years. Most of the time it appears small and distant, but for a few months either side of opposition Mars becomes bright, and through a telescope, its size increases noticeably. The next opposition of Mars is in January 2025,” Lawrence adds.
Jupiter goes into opposition every 13 months.
What constellation is Jupiter in?
Jupiter is currently in the dim constellation of Aries the Ram, and is slowly making its way towards Taurus the Bull.
Jupiter resides within the zodiac band of the sky, and it moves through approximately 1/12 of its orbit every year, making a single orbit around 12 years.
That means it takes around 12 months for Jupiter to travel across one of the zodiac constellations and move on to the next. Jupiter goes into opposition roughly every 13 months, and the gas giant will pass through all the zodiac constellations over a period of 12 years.
Before going into opposition, Jupiter will look as though it’s moving backwards for a time, and this is called apparent retrograde motion. Prior to the 2023 opposition, Jupiter entered retrograde in September. Here is what Jupiter has been up to this year:
- 4 September 2023: Jupiter entered retrograde and started moving backwards
- 1 November 2023: Jupiter reached perigee, the point in its orbit nearest the Earth
- 3 November 2023: Jupiter reaches opposition, the point in its orbit opposite the Sun
- 31 December 2023: Jupiter ends retrograde and starts moving forwards
How bright will Jupiter get?
Jupiter will appear bright in the night sky during opposition. In fact, it will appear much brighter than Sirius, the brightest star in the sky.
Astronomers use ‘magnitude’ to describe how bright objects in the night sky appear. The lower the magnitude number, the brighter the object.
For example, a star with a magnitude of 1 is brighter than a star with a magnitude of 5. It's a logarithmic scale, meaning each whole number increase represents a decrease in brightness by a factor of about 2.5. If an object has a minus number, then it’s very bright and easy to spot with the naked eye.
Back in September when Jupiter entered into retrograde, it was already bright at magnitude -2.48. Now as we approach opposition, and being fully illuminated by the Sun, it will reach magnitude -2.76.
For comparison, the brightest star in the night sky is Sirius, which shines at magnitude -1.4.
When are the planets next in opposition?
- Mercury: Never
- Venus: Never
- Mars: 15 January 2025
- Jupiter: 3 November 2023
- Saturn: 7 September 2024
- Uranus: 13 November 2023
- Neptune: 20 September 2024
- The Moon: 27 November 2023 (Beaver Moon)
About our Expert
Pete Lawrence is an experienced astronomer and astrophotographer, and a presenter on BBC's The Sky at Night.
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