thumb|Earth and Moon from Mars, as photographed by the [[Mars Global Surveyor]]

A transit of Earth across the Sun as seen from Mars takes place when the planet Earth passes directly between the Sun and Mars, obscuring a small part of the Sun's disc for an observer on Mars. During a transit, Earth would be visible from Mars as a small black disc moving across the face of the Sun. They occur every 26, 79 and 100 years, and every ~1,000 years, there is an extra 53rd-year transit.

Conjunctions

Transits of Earth from Mars usually occur in pairs, with one following the other after 79 years; rarely, there are three in the series. The transits also follow a 284-year cycle, occurring at intervals of 100.5, 79, 25.5, and 79 years; a transit falling on a particular date is usually followed by another transit 284 years later. Transits occurring when Mars is at its ascending node take place in May, those at descending node happen in November. This cycle corresponds fairly closely to 151 Mars orbits, 284 Earth orbits, and 133 synodic periods, and is analogous to the cycle of transits of Venus from Earth, which follow a cycle of 243 years (121.5, 8, 105.5, 8). There are currently four such active series, containing from 8 to 25 transits. A new one is set to begin in 2394. The last series ending was in 1211.

View from Mars

No one has ever seen a transit of Earth from Mars, but the next transit will take place on November 10, 2084.

Dates of transits

{| class="wikitable"

|+ Transits of Earth from Mars (grouped by series)

|-

| November 10, 1595 || May 5, 1621 || May 8, 1700 || November 9, 1800 ||

|-

| November 12, 1879 || May 8, 1905 || May 11, 1984

See also

  • Astronomical transit
  • Transit of Phobos from Mars
  • Transit of Deimos from Mars
  • Transit of Mercury from Mars
  • Transits of Mercury as seen from Mars
  • Transits of Venus as seen from Mars

References

</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]
  • Andrew Crommelin, Observations of Mars, 1904–6, Monthly Notices of the Royal Astronomical Society, 64 (1904), 520–521 [http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1904MNRAS..64..506.&db_key=AST&page_ind=14&plate_select=NO&data_type=GIF&type=SCREEN_GIF]
  • Jean Meeus & Edwin Goffin, Transits of Earth as Seen from Mars, Journal of the British Astronomical Association, 93 (1983), 120–123 [http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1983JBAA...93..120M]
  • Charles Augustus Young, Measures of the Polar and Equatoreal Diameters of Mars, made at Princeton, New Jersey, U.S., The Observatory, 3 (1880), 471 [http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?journal=Obs&year=1880&volume=3&page_ind=420&letter=.&type=SCREEN_GIF]
  • SOLEX
  • Transits of Earth on Mars – Fifteen millennium catalog: 5 000 BC – 10 000 AD
  • JPL HORIZONS System
  • Near miss of the Earth-moon system (2005-11-07)