Mercury & Venus Greatest Elongations in 2026–2027: Best Morning and Evening Views
Timing is everything in astronomy, and elongation is the key to catching the elusive planet Mercury. The planet reaches its next greatest elongation on October 12, so don’t miss the opportunity. Let the Sky Tonight app guide you to the perfect viewing moments: download it now and explore the night sky like never before! Plus, dive into our article on elongation and uncover the celestial mechanics behind these events.
👉At greatest elongation, Mercury and Venus appear farthest from the Sun in our sky — which is usually your best chance to spot them in twilight. Elongation is the angular distance between a planet and the Sun as seen from Earth, measured in degrees.
Contents
- Upcoming greatest elongations of Mercury and Venus
- What is elongation?
- Inferior and superior planets’ configurations
- Greatest elongation of Mercury and Venus: upcoming events (maximum elongation dates)
- October 12, 2026: Mercury at greatest eastern elongation
- November 20, 2026: Mercury at greatest western elongation
- January 3, 2027: Venus at greatest western elongation
- February 3, 2027: Mercury at greatest eastern elongation
- March 17, 2027: Mercury at greatest western elongation
- May 28, 2027: Mercury at greatest eastern elongation
- Elongation and phases of the planets
- FAQ: Elongation in astronomy
- What is elongation in astronomy?
- What is the maximum elongation of Mercury? Is it 28 degrees?
- Greatest eastern vs. greatest western elongation — what’s the difference?
- When is Mercury visible in the night sky?
- Why are some Mercury elongations “better” than others?
- Is the greatest elongation the same as the greatest brilliancy?
- Elongation of planets: to sum up
Upcoming greatest elongations of Mercury and Venus
Use the table below to find the next greatest eastern elongation (best in the evening sky) and greatest western elongation (best in the morning sky) for Mercury and Venus.
Tip: A larger elongation separation does not always mean a better view. Planets’ altitude during twilight, their brightness, and the angle of the ecliptic also affect visibility.
| Date | Planet | Greatest elongation | Separation |
|---|---|---|---|
| Oct 12, 2026 | Mercury | Eastern (evening) | 25°09′ |
| Nov 20, 2026 | Mercury | Western (morning) | 19°37′ |
| Jan 3, 2027 | Venus | Western (morning) | 46°57′ |
| Feb 3, 2027 | Mercury | Eastern (evening) | 18°18′ |
| Mar 17, 2027 | Mercury | Western (morning) | 27°37′ |
| May 28, 2027 | Mercury | Eastern (evening) | 22°55′ |
How to spot elusive Mercury at greatest elongation (quick guide):
- Look 30–60 minutes before sunrise (western elongation) or after sunset (eastern elongation).
- Choose a location with a clear horizon (sea, field, rooftop).
- Remember that morning elongations of Mercury are best in autumn, and evening elongations are best in spring (for either hemisphere).
Safety Tip: never sweep binoculars near the Sun; wait until the Sun is fully below the horizon (evening) or stay well before it rises (morning).
What is elongation?
In astronomy, elongation is the angular distance between a planet (or other Solar System body) and the Sun as seen from Earth — measured in degrees. For example, an elongation of 90° means the object appears 90 degrees away from the Sun in our sky.
As the brightest object in the sky, the Sun can obscure any other star or planet. Knowing the Sun’s position, you can choose the best time for observations (when the object is high enough above the horizon in a sufficiently dark sky). Let's look at what elongation is, using the Solar System planets as an example.
Key takeaways:
- Elongation distance matters mostly for Mercury and Venus, because they are never far away from the Sun.
- Greatest eastern elongation = best after sunset (evening).
- Greatest western elongation = best before sunrise (morning).
- For Mercury, “in the night sky” usually means twilight near the horizon, not late-night hours.
Inferior and superior planets’ configurations
The superior planets (planets that are farther from the Sun than Earth), which include Mars, Jupiter, Saturn, Uranus, and Neptune, can range in elongation from close to 0 to nearly 180 degrees. For the inferior planets (planets that are closer to the Sun than Earth), which include Mercury and Venus, the maximum elongation is about 28 degrees for Mercury and about 48 degrees for Venus. That’s why bright Mercury is so difficult to see — even at its best elongations, it stays relatively close to the Sun compared to Venus.
Some of the elongation values have specific names. Let’s go over them.
Solar conjunction
Solar conjunction is an event in which an object aligns with the Sun from Earth's perspective. As a result, the object has an elongation close to 0 degrees, meaning it is at the same ecliptic longitude as the Sun, appearing very close to it in the sky. This alignment results in the object being obscured by sunlight, making it almost impossible to observe directly¹. Both superior and inferior planets can reach solar conjunction.
The terms “inferior solar conjunction” and “superior solar conjunction” are used in particular for Mercury and Venus. At inferior solar conjunction, the planet is between Earth and the Sun. At superior solar conjunction, the planet is passing behind the Sun as seen from Earth.
¹In rare cases, an inner planet can still be observed at inferior conjunction during a transit, when it crosses the Sun’s disk as a tiny black dot. The next transit of Mercury is on November 13, 2032, and the next transit of Venus is on December 11, 2117.
Quadrature
Quadrature is a position where the Sun, Earth, and the object form a right angle. As a result, the object has an elongation of 90 degrees. At eastern quadrature, a planet is generally highest in the evening; at western quadrature, it is generally highest in the morning. A good example of quadrature is the First Quarter Moon, as this phase occurs when the Moon is at a 90-degree angle from the Sun. The Moon, outer planets, and many other Solar System bodies can reach quadrature. Mercury and Venus cannot, because they orbit closer to the Sun than Earth does; they are physically too close to the Sun to ever appear at a 90-degree angle from our viewpoint.
Opposition
Opposition is a celestial alignment where an object lies opposite the Sun in ecliptic longitude and appears in roughly the opposite direction in the sky. This is also the greatest elongation for the superior planets. During opposition, the object and the Sun lie on opposite sides of Earth, so the object is fully illuminated by sunlight and visible throughout the night. Opposition is considered to be the best time for observing a celestial body. In the dedicated article, we have a list of celestial bodies — planets, dwarf planets, and asteroids — that will reach opposition soon.
Greatest elongation of Mercury and Venus: upcoming events (maximum elongation dates)
The inferior planets, Venus and Mercury, cannot reach quadrature and opposition because their orbits lie inside Earth’s orbit around the Sun. The greatest elongation possible for them is about 28 degrees for Mercury and 48 degrees for Venus. At greatest elongation, they are farthest from the Sun in the sky, so skywatchers get a great opportunity to spot the planets. At greatest eastern elongation, Mercury and Venus are visible as evening objects. At greatest western elongation, they are visible as morning objects. Here's a list of the upcoming greatest elongations for Venus and Mercury.
October 12, 2026: Mercury at greatest eastern elongation
On October 12, at 10:02 GMT (06:02 EDT), Mercury (mag 0.0) will reach its greatest eastern elongation, appearing 25°09′ from the Sun. Look for it in the constellation Libra, above the western horizon after sunset.
This is the best evening appearance of Mercury in 2026 for observers at southern mid-latitudes. There, the ecliptic — the approximate path the planets follow across the sky — makes a steep angle with the horizon in the evening. This keeps Mercury higher above the horizon as twilight fades, making it easier to spot. At mid-northern latitudes, the ecliptic lies at a shallow angle, so Mercury stays low and may be lost in the sunset glow.
A very thin waxing crescent Moon will appear nearby. From locations around or south of the equator, you may also spot brilliant Venus (mag −4.4), lower in the twilight.
Choose a viewing spot with no buildings, trees, or hills blocking the sunset direction. You can look for Mercury on several evenings around October 12; there’s no need to catch the exact moment of greatest elongation. Binoculars may help you find it, but wait until the Sun has completely set before using them.
November 20, 2026: Mercury at greatest western elongation
On November 20, at 23:29 GMT (18:29 EST), Mercury (mag −0.5) will appear at 19°37′ from the Sun. The planet will be visible in the constellation Libra before sunrise. Above Mercury, see brilliant Venus (mag −4.8) in the constellation Virgo.
January 3, 2027: Venus at greatest western elongation
On January 3, at 17:58 GMT (12:58 EST), Venus (mag −4.5) will be at 46°57′ from the Sun. The planet will be visible in the constellation Libra before sunrise. A waning crescent Moon will shine nearby.
February 3, 2027: Mercury at greatest eastern elongation
On February 3, at 06:13 GMT (01:13 EST), Mercury will reach its greatest eastern elongation, appearing 18°18′ from the Sun. Look for the planet low above the western horizon after sunset. Although this is a relatively small elongation for Mercury, the days around this date offer an opportunity to catch the elusive planet in the evening twilight. Choose a location with an unobstructed view toward the sunset, and look before Mercury sinks too low.
March 17, 2027: Mercury at greatest western elongation
On March 17, at 06:49 GMT (02:49 EDT), Mercury will reach its greatest western elongation, appearing 27°37′ from the Sun — close to its maximum possible separation. Look for it above the eastern horizon before sunrise. This will be Mercury’s widest elongation of 2027, but a larger angle from the Sun doesn’t automatically mean better visibility: how high the planet climbs above your local horizon also matters.
May 28, 2027: Mercury at greatest eastern elongation
On May 28, at 09:56 GMT (05:56 EDT), Mercury will reach its greatest eastern elongation, appearing 22°55′ from the Sun. The planet will be an evening object, visible above the western horizon after sunset. Try looking on several evenings around this date. Don’t wait until the sky is completely dark: Mercury may already be too low to see clearly.
Elongation and phases of the planets
Just like the Moon, planets have phases. Although in space, half of a planet is always illuminated by the Sun, the portion of the illuminated side that we can see from Earth changes depending on the planet's elongation. These phases can be observed through a telescope, and Venus, the brightest planet, can even show its phases when viewed through binoculars.
Phases of the inferior planets
As shown in the image above, inferior planets go through a full cycle of phases: from a new phase at inferior conjunction to quarter phases near greatest elongations and a full phase at superior conjunction. However, observing the full and new phases is extremely challenging because during these phases, the planets are lost in the Sun's glare. Thus, the visible phases range from crescent to gibbous.
Phases of the superior planets
Superior planets do not display a full range of phases, but only subtle transitions between gibbous and full phases. They appear fully illuminated during oppositions, which is the best time to observe them.
FAQ: Elongation in astronomy
What is elongation in astronomy?
Elongation in astronomy is the angular separation between a planet (or another Solar System body) and the Sun as seen from Earth, measured in degrees.
What is the maximum elongation of Mercury? Is it 28 degrees?
The maximum value of Mercury’s greatest elongation is about 28°. For Venus, the maximum value can reach 48°.
Greatest eastern vs. greatest western elongation — what’s the difference?
Eastern elongation means the planet is best seen after sunset; western elongation means best before sunrise.
When is Mercury visible in the night sky?
Mercury is usually easiest to find during evening or morning twilight and most of the time stays near the horizon; the planet rarely rises high above the horizon in a fully dark sky. Your best chances to see Mercury are around the greatest elongation.
Why are some Mercury elongations “better” than others?
Besides elongation, visibility of Mercury depends on the tilt of the ecliptic and your latitude — some elongations place Mercury higher above the horizon than others.
Is the greatest elongation the same as the greatest brilliancy?
No, greatest elongation is not the same as greatest brilliancy:
- Greatest elongation is the moment when a planet is farthest from the Sun in the sky, meaning it has the maximum angular separation from the Sun as seen from Earth.
- Greatest brilliancy occurs when the planet reaches its maximum apparent brightness.
For example, Venus typically reaches its greatest brilliancy between inferior conjunction and greatest elongation — after greatest eastern elongation in an evening apparition, and before greatest western elongation in a morning apparition.
Elongation of planets: to sum up
Elongation is the angular distance between a planet (or other Solar System body) and the Sun in the sky. It is measured in degrees. Planetary phases and visibility depend on elongation, which is especially noticeable for inferior planets — Venus and Mercury. Want to find out when Mercury or Venus is visible from your location (tonight or this week)? Use the free Sky Tonight app. To learn the best times for viewing the superior planets, check out our article on opposition in astronomy.
