# Transit of Venus from Mars

A transit of Venus across the Sun as seen from Mars takes place when the planet Venus passes directly between the Sun and Mars, obscuring a small part of the Sun's disc for an observer on Mars. During a transit, Venus could be seen from Mars as a small black disc moving across the face of the Sun.

## Frequency of occurrence

No one has ever seen a transit of Venus from Mars, but the next one will take place on August 19, 2030, and could be observed by space probes or hypothetical Mars colonists. Transits of Venus from Mars occur much more often than transits of Earth from Mars, and also much more often than transits of Venus from Earth.

The Venus-Mars synodic period is 333.92 days. It can be calculated using the formula 1/(1/P-1/Q), where P is the orbital period of Venus (224.701 days) and Q is the orbital period of Mars (686.98 days).

The inclination of Venus' orbit with respect to Mars' ecliptic is 1.94°, which is less than its value of 3.39° with respect to Earth's ecliptic.

## Series

Transits can be grouped within series similar to the Saros series for lunar eclipses or the series for transits of Venus from Earth. Within each series, the transits are separated by 24042.45 days (just under 65 years and 10 months). This corresponds to 72 Venus-Mars synodic periods, or 35 Mars orbital periods, or 107 Venus orbital periods. These groupings can be calculated by dividing the synodic period by the sidereal orbital period of Mars or Venus and converting this ratio into a continued fraction. For example, dividing the synodic period (333.92 days) by the sidereal orbital period of Mars (686.98 days) gives the decimal 0.48607, which can be approximated by the continued fraction [0;2,17,2] giving a ratio of 35/72. Using the sidereal orbital period of Venus gives the decimal 1.48607 with the same result.

In the table below, series names beginning with "A" are near the ascending node with respect to the Martian ecliptic, and occur when Venus has an angular diameter of approximately 23–24". Series names beginning with "D" are near the descending node with respect to the Martian ecliptic, and occur when Venus has an angular diameter of approximately 18–19".

Transits of Venus from Mars Series
May 3, 1703 Da1
September 20, 1730 Aa1
May 2, 1735 Db2
March 1, 1737 Db1
July 17, 1764 Ab1
February 27, 1769 Da1
July 17, 1796 Aa1
February 27, 1801 Db2
May 15, 1830 Ab1
December 27, 1834 Da1
May 15, 1862 Aa1
December 26, 1866 Db2
March 11, 1896 Ab1
December 25, 1898 Da2
October 24, 1900 Da1
March 12, 1928 Aa1
October 23, 1932 Db2
October 22, 1964 Da2
August 22, 1966 Da1
January 7, 1994 Aa1
August 21, 1998 Db2
August 19, 2030 Da2
June 18, 2032 Da1
November 5, 2059 Aa1
June 17, 2064 Db2
November 5, 2091 Ab2
June 16, 2096 Da2
April 16, 2098 Da1
September 2, 2125 Aa1
April 16, 2130 Db2
September 2, 2157 Ab2
April 14, 2162 Da2
February 12, 2164 Da1
June 30, 2191 Aa1
February 11, 2196 Db2
July 1, 2223 Ab2
February 11, 2228 Da2
December 11, 2229 Da1
April 27, 2257 Aa1
December 10, 2261 Db2
April 27, 2289 Ab2
December 8, 2293 Da2
February 23, 2323 Aa1
October 8, 2327 Db2
February 23, 2355 Ab2
October 7, 2359 Da2
August 4, 2393 Db2
December 20, 2420 Ab2
August 3, 2425 Da2
December 20, 2452 Aa2
August 2, 2457 Db3
June 2, 2459 Db2

## Simultaneous transits

The simultaneous occurrence of a transit of Mercury and a transit of Venus is extremely rare, but more frequent than from Earth, and will next occur in the years 18,713, 19,536 and 20,029.

On several occasions an almost identical event is predicted: a transit of Mercury and a transit of Venus, or transit of Earth will follow themselves, one after the other, in an interval of only several hours.

On January 16 18,551 transits of Mercury and Venus are separated by 14 hours.

The simultaneous occurrence of a transit of Venus and a transit of Earth is extremely rare, and will next occur in the year 571,471.