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 can 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

From empirical observation of transit dates, it appears that transits occur within separate series; 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.

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".

Simultaneous transits

The simultaneous occurrence of a transit of Mercury and a transit of Venus is extremely rare, but somehow more frequent than from Earth, and will next occur in the years , and .
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 transits of Mercury and Venus are separated by 14 hours.

ee also

* Astronomical transit

* Transit of Phobos from Mars
* Transit of Deimos from Mars

References

* Albert Marth, "Note on the Transit of the Earth and Moon across the Sun’s Disk as seen from Mars on November 12, 1879, and on some kindred Phenomena", Monthly Notices of the Royal Astronomical Society, 39 (1879), 513–514. [http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1879MNRAS..39..513M]

External links

* [http://space.jpl.nasa.gov/ JPL Solar System Simulator]