Solar System Phenomena — Jupiter in 2021

The path of Jupiter against the background stars in 2021

The chart shows the path of Jupiter across the background stars over the course of the year. Stars to magnitude +7.5 are shown. The white circles represent the planet on the first day of the month and are scaled according to apparent magnitude. The faint paths before the first circle and after the last circle represent the planet's positions in December of last year and January of next. In general, the planet moves from right to left except when it's in retrograde and proceding in the opposite direction.

The lower chart shows how the appearance of Jupiter changes over the year. Below each image is listed the date, the apparent magnitude, the apparent diameter of the disk (in arc-seconds) and the geocentric distance (in au). Note that Jupiter appears distinctly larger and brighter near the time of opposition.

Having completed its 'Great Conjunction' with Saturn last December, Jupiter leaves the ringed planet behind. The gas giant begins the year in Capricornus before moving into Aquarius in late April. Retrograde motion causes Jupiter to backtrack and re-enter Capricornus for four months near the end of the year but it eventually finishes 2021 in the constellation of the water carrier. Jupiter is at conjunction near the end of January, rendering it difficult to observe for the first two months of the year. It is a morning sky object after conjunction, best viewed from the southern hemisphere. It rises before midnight as early as April for observers in southern latitudes but planet watchers farther north will have to wait until June before the gas giant appears in the east during the evening. Opposition occurs in August, during which the planet is visible all night. For the rest of the year, Jupiter may be observed during the evening hours. Jupiter's close approach to Venus in early February will likely go unobserved due to the close proximity of the Sun but Mercury makes an even closer pass the following month; this event should be visible low in the east before sunrise.

01 Januarymaximum declination south
11 Januaryplanetary conjunction: 1.4° north of Mercury
29 Januaryconjunction
11 Februaryplanetary conjunction: 0.4° north of Venus
14 Februaryplanetary conjunction: 3.9° south of Mercury
18 February0.03° north of θ Capricorni
05 Marchplanetary conjunction: 0.3° south of Mercury
02 Aprilstellar occultation: 44 Capricorni
25 AprilCapricornusAquarius
21 Maywest quadrature
16 Junemaximum declination north
21 Junestationary point in right ascension: direct → retrograde
19 AugustAquariusCapricornus
opposition: magnitude −2.9, apparent diameter 49.1 arc-seconds
18 Octoberstationary point in right ascension: retrograde → direct
15 Novembereast quadrature
14 DecemberCapricornusAquarius


The dates, times and circumstances of all planetary and lunar phenomena were calculated from the JPL DE406 solar system ephemeris using the same rigorous methods that are employed in the compilation of publications such as The Astronomical Almanac.