Distance from Sun
Perihelion 28.6 mil mi
Semi-major axis 0.38710 AU
Aphelion 43.4 mil mi
Period of revolution around Sun 87.97 d
Orbital eccentricity 0.20563
Orbital inclination 7 deg 0m 18s
Synodic day (midday to midday) 175.97 d
Sidereal day 58.65 d
Rotational inclination ~0.1 deg
Mass (Earth = 1) 0.0553
Mean radius 1,516 mi
Mean density (Earth = 1) 0.98
Natural satellites 0
Average surface temperature 333 deg F
Hindi Name : Budh Gra
Mercury, the nearest planet to the Sun, is the 2d-smallest of the 9 planets known to be orbiting the Sun. Its diameter is 3,032 mi; its mean distance from the Sun is 36,000,000 mi. Mercury moves with great speed in its journey about the Sun, averaging about 30 mi a second to complete its circuit in about 88 Earth days. Mercury rotates upon its axis over a period of nearly 59 days, thus exposing all its surface periodically to the Sun.
Because its orbital period is only about 50% longer than its sidereal rotation, the solar (synodic) day on Mercury, or the time from one sunrise to the next, is about 176 days, twice as long as a Mercurian year. It is believed that the surface passing before the Sun may reach a temperature of about 840 deg F, while the temperature on the nighttime side may fall as low as 300 deg F.
Although Mercury is the closest planet to the Sun, it has by far the largest range of temperature change from day to night. Uncertainty about conditions on Mercury and its motion arises from its shorter angular distance from the Sun as seen from Earth. Mercury is always too much in line with the Sun to be observed against a dark sky, but is always seen during either morning or evening twilight. Mariner 10 passed Mercury 3 times in 1974 and 1975.
Less tha half of the surface was photographed, revealing a degree of cratering similar to that of the Moon. A very thin atmosphere of hydrogen and helium may be made up of gases of the solar wind temporarily concentrated by the presence of Mercury.
The discovery of a weak but permanent magnetic field was a surprise to scientists. It has been held that both a fluid core and rapid rotation are necessary for the generation of a planetary magnetic field. Mercury may demonstrate the contrary; the field may reveal something about the history of Mercury.
Venus Planet Information (Shukra Grah)
Mars Planet Information (Mangal Grah)
Jupiter Planet Information (Guru Grah)
Saturn Planet Information (Shani)
Uranus Planet Information (Arun Grah)
Neptune Planet Information (Varuna Grah)
Pluto Planet Information (Yama Grah)
Moon Planet Information (Chandra)
Sun Planet Information (Surya)