Solar System Phenomena — Mars in 2020

The path of Mars against the background stars in 2020

The upper chart shows the path of Mars across the background stars over the course of the year. Stars to magnitude +4.5 are shown with some fainter objects included to complete constellation patterns. 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 Mars changes over the year. Below each image is listed the date, the apparent magnitude, the apparent diameter of the disk (in arc-seconds), the geocentric distance (in au) and the percentage of the disk which is illuminated. Note that Mars appears distinctly gibbous near the times of quadrature.

The red planet is found in Libra at the start of 2020. It is a morning sky object, slowly distancing itself from the Sun after last September's conjunction. It is a relatively dim magnitude +1.6 at the beginning of January but slowly brightens to −2.6 as it approaches opposition in October. Mars spends the first half of the year tracking across the sky before entering Pisces in July where, except for a brief few days in Cetus, it stays for the remainder of 2020. Mars is occulted by the Moon five times this year and is found close to both Jupiter and Saturn in the latter part of March.

07 JanuaryLibraScorpius
15 JanuaryScorpiusOphiuchus
20 January2.3° south of the Moon
01 Februarydescending node
11 FebruaryOphiuchusSagittarius
18 February0.7° north of NGC 6530, an open star cluster within M8, the Lagoon Nebula
lunar occultation: 0.8° south of the Moon
21 Februarymaximum declination south
28 February0.3° north of globular cluster M22
18 Marchlunar occultation: 0.7° north of the Moon
20 Marchplanetary conjunction: 0.7° south of Jupiter
30 MarchSagittariusCapricornus
31 Marchplanetary conjunction: 0.9° south of Saturn
08 Aprilequinox: autumn in the northern hemisphere and spring in the southern hemisphere
16 April2.0° north of the Moon
08 MayCapricornusAquarius
15 May2.8° north of the Moon
06 Junewest quadrature
13 June2.7° north of the Moon
planetary conjunction: 1.6° south of Neptune
24 JuneAquariusPisces
08 JulyPiscesCetus
11 July2.0° north of the Moon
16 JulyCetusPisces
03 Augustperihelion
09 Augustlunar occultation: 0.8° north of the Moon
02 Septembersolstice: winter in the northern hemisphere and summer in the southern hemisphere
06 Septemberlunar occultation: 0.03° south of the Moon
09 Septemberstationary point: direct → retrograde
03 Octoberlunar occultation: 0.7° north of the Moon
06 Octoberminimum distance from Earth: 0.415 au
13 Octoberopposition: magnitude −2.6, apparent diameter 22.2 arc-seconds
29 October3.0° north of the Moon
15 Novemberstationary point: retrograde → direct
02 Decemberascending node
31 Decembermaximum declination north


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. Seasonal information was obtained from A post-Pathfinder evaluation of areocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies, Michael Allison and Megan McEwen, Planetary and Space Science, 48, 215–235 (February 2000).