Transit of Mercury from Venus
Encyclopedia
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
passes directly between the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
, obscuring a small part of the Sun's disc for an observer on Venus. During a transit
Astronomical transit
The term transit or astronomical transit has three meanings in astronomy:* A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point...
, Mercury can be seen from Venus as a small black disc moving across the face of the Sun. A central transit may last up over 8 hours, although presently transit's duration rarely exceed 7 hours (last time it happened in 1899, next one is in 2064).
Transits of Mercury from Venus occur in an irregular fashion: sometimes there are several per decade, while on other occasions there are longer gaps. The overall frequency seems to be somewhat greater than the frequency of transits of Mercury from Earth
Transit of Mercury
A transit of Mercury across the Sun takes place when the planet Mercury comes between the Sun and the Earth, and Mercury is seen as a small black dot moving across the face of the Sun....
.
Naturally, no one has ever seen a transit of Mercury from Venus.
The Mercury-Venus synodic period is 144.5662 days. It can be calculated using the formula 1/(1/P-1/Q), where P is the orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of Mercury (87.968435 days) and Q is the orbital period of Venus (224.695434 days).
The inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
of Mercury's orbit with respect to Venus's ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
is 4.33°, which is less than its value of 7.00° with respect to Earth's ecliptic.
The transit that occurred on March 22, 1894 was particularly interesting because on the 21st, when it began, there were also transits of Venus
Transit of Venus from Saturn
A transit of Venus across the Sun as seen from Saturn takes place when the planet Venus passes directly between the Sun and Saturn, obscuring a small part of the Sun's disc for an observer on Saturn...
and of Mercury
Transit of Mercury from Saturn
A transit of Mercury across the Sun as seen from Saturn takes place when the planet Mercury passes directly between the Sun and Saturn, obscuring a small part of the Sun's disc for an observer on Saturn...
visible from Saturn. There was no overlap among the three transits, however.
Grazing transits
Sometimes Mercury only grazes the Sun during a transit. In this case it is possible that in some areas of Venus a full transit can be seen while in other regions there is only a partial transit (no second or third contact). The transit of October 25, 1344 was such a transit. The next such transit will occur on January 1, 2387.It is also possible that a transit of Mercury can be seen in some parts of Venus as a partial transit, while in others Mercury misses the Sun. Such a transit last occurred on May 21, 1027. The next such transit will occur on April 30, 3168.
Past and future transits
| Transits of Mercury from Venus |
|---|
| June 11, 1971 |
| December 25, 1976 |
| November 17, 2005 |
| June 4, 2007 |
| June 3, 2011 |
| December 18, 2012 |
| December 17, 2016 |
| July 2, 2022 |
| January 16, 2028 |
| August 1, 2033 |
| June 24, 2058 |
| June 24, 2062 |
| January 9, 2064 |
| January 8, 2068 |
| July 25, 2069 |
| July 23, 2073 |
| February 6, 2079 |
| August 22, 2084 |