Web PlanetariumPlanet viewing calendarOppositions of Mars, Jupiter and Saturn; greatest elongations of Mercury and Venus
| Date (JST) | Event | What you see | |
|---|---|---|---|
| Sun, Oct 4, 2026 | Saturn at opposition | Up all night, and at its brightest and largest for the year | See the sky → |
| Mon, Oct 12, 2026 | Mercury at greatest eastern elongation | Farthest from the Sun in the evening sky, low in the west after sunset | See the sky → |
| Sat, Nov 21, 2026 | Mercury at greatest western elongation | Farthest from the Sun in the morning sky, low in the east before sunrise | See the sky → |
| Mon, Nov 30, 2026 | Venus at greatest brilliancy | At its brightest (magnitude −4.9) | See the sky → |
| Mon, Jan 4, 2027 | Venus at greatest western elongation | Farthest from the Sun in the morning sky, low in the east before sunrise | See the sky → |
| Wed, Feb 3, 2027 | Mercury at greatest eastern elongation | Farthest from the Sun in the evening sky, low in the west after sunset | See the sky → |
| Thu, Feb 11, 2027 | Jupiter at opposition | Up all night, and at its brightest and largest for the year | See the sky → |
| Sat, Feb 20, 2027 | Mars at opposition | Up all night, and at its brightest and largest for the year. Closest to Earth the same day | See the sky → |
| Wed, Mar 17, 2027 | Mercury at greatest western elongation | Farthest from the Sun in the morning sky, low in the east before sunrise | See the sky → |
| Fri, May 28, 2027 | Mercury at greatest eastern elongation | Farthest from the Sun in the evening sky, low in the west after sunset | See the sky → |
| Fri, Jul 16, 2027 | Mercury at greatest western elongation | Farthest from the Sun in the morning sky, low in the east before sunrise | See the sky → |
| Sat, Sep 25, 2027 | Mercury at greatest eastern elongation | Farthest from the Sun in the evening sky, low in the west after sunset | See the sky → |
| Mon, Oct 18, 2027 | Saturn at opposition | Up all night, and at its brightest and largest for the year | See the sky → |
| Thu, Nov 4, 2027 | Mercury at greatest western elongation | Farthest from the Sun in the morning sky, low in the east before sunrise | See the sky → |
“See the sky” opens your place at 11 p.m. for an opposition, and at dusk or dawn (when the Sun is 6° below the horizon) for an elongation. Dates marked JST are Japan dates (UTC+9); in the Americas and Europe the same event may fall on the previous day.
Opposition: Mars, Jupiter and Saturn
When a planet outside Earth’s orbit is exactly opposite the Sun as seen from Earth, it is at opposition. It rises in the east around sunset, is up all night and is highest around midnight. It is also near its closest to Earth, so it looks brightest, and largest in a telescope.
Greatest elongation: Mercury and Venus
Mercury and Venus orbit inside Earth’s orbit, so they always appear near the Sun: in the west after sunset or in the east before sunrise. Greatest elongation is when they appear farthest from the Sun, which makes them easier to find. Eastern elongation is in the evening sky, western elongation in the morning sky. Mercury never gets far from the Sun, so even then it is low and can be hard to spot.
Greatest brilliancy: Venus
Venus changes brightness as its phase and distance change. Its brightest point is called greatest brilliancy. It then shines brighter than magnitude −4, bright enough to be seen at times in a blue daytime sky.
Sources
- NAOJ, sky guide (Hoshizora Jōhō), October 2026 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), November 2026 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), January 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), February 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), March 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), May 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), July 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), September 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), October 2027 (in Japanese)
- NAOJ, sky guide (Hoshizora Jōhō), November 2027 (in Japanese)
Credit: National Astronomical Observatory of Japan (NAOJ). Dates and times are from NAOJ, checked on 2026-09-23. NAOJ bases meteor shower peaks on predictions by the International Meteor Organization (IMO). Moon illumination, radiant heights and the “See the sky” times are calculated by this site.