# Transit of Mars from Jupiter

A transit of Mars across the Sun as seen from Jupiter takes place when the planet Mars passes directly between the Sun and Jupiter, obscuring a small part of the Sun's disc for an observer on Jupiter.

During a transit, Mars can be seen from Jupiter as a small black disc moving across the face of the Sun. No one has ever seen a transit of Mars from Jupiter, nor is this likely to happen in any foreseeable future. The next one will take place on July 8, 2040.

## Explanation

A transit could hypothetically be observed from the surface of one of Jupiter's moons rather than from Jupiter itself. The times and circumstances of the transits would naturally be slightly different. Mars's satellites Phobos and Deimos would theoretically be visible at the same time. However, the angular diameter of Phobos would be about 0.01" and Deimos would be less than 0.005", and their maximum separation from Mars would be roughly 3.0" and 9.0" respectively, making them very hard to see, indeed.

The Mars-Jupiter synodic period is 816.51 days. It can be calculated using the formula period = 1/(1/P - 1/Q), where P is the orbital period of Mars (686.98 days) and Q is the orbital period of Jupiter (4330.595 days). The inclination of Mars's orbit with respect to Jupiter's ecliptic is 1.44°, which is less than its value of 1.85° with respect to Earth's ecliptic.

## Empirical observations

Transits sometimes repeat after 13062.8 days (about 35 years and 9 months). This corresponds to 15.998 Mars-Jupiter synodic periods, or 19.01 Mars orbital periods, or 3.01 Jupiter orbital periods. However, in many cases, the transit does not repeat because the second event is a near-miss instead. This period is analogous to the 8-year pairing of transits of Venus. Longer cycles with a closer match are a cycle with an approximately 56,333-day (about 154 years and 3 months) period that is equal to 69 Mars-Jupiter synodic periods and a cycle with an approximately 212,273-day (about 581 years and 2 months) period that is equal to 260 Mars-Jupiter synodic periods.

Transits of Mars from Jupiter
July 29, 1613
May 18, 1631
January 17, 1732
November 7, 1749
October 24, 1767
August 12, 1785
April 13, 1886
February 3, 1904
January 19, 1922
November 8, 1939
July 8, 2040
April 28, 2058
February 1, 2094
December 26, 2158
October 2, 2194
July 24, 2212
March 23, 2313
January 14, 2331
December 28, 2348
October 19, 2366
June 17, 2467