The Solar System
The Sun Mercury Venus Earth Mars
The Asteroid Belt Jupiter Saturn Uranus Neptune Pluto
Mercury
MercurySol 1
Mercury
Distance
from the Sun
  mil km 57.91
  mil miles 35.98
Orbital Period
(length of year)
  Earth days 87.969
  Earth years .241
Local Days per Year  
rotations per orbit  
1.5
Length of day  
in Earth Time  
58.646 days
Axial Tilt   0.00
Orbital Inclination  
from Earth's orbit  
7.004
Orbital Eccentricity  
from circular  
0.2056
Sidereal Rotation  
in Earth days  
58.6462
Mean Orbital Velocity km/s   47.87
Visual Geometric Albedo .10
Vo or Object's Visible
Magnitude at Opposition
-1.9
Mean Radius km     2,439.7
Mean  
Diameter  

at Equator  
  km 4,878
  miles 3,031
  x Earth .382
Mass   kg 3.303 e+23
  x Earth .055
Density (grams per cm3)   5.42
Gravity x Earth   .38
Escape Velocity in km per sec   4.2507
Mercury, messenger of the gods. The first planet out from the sun is more of a moon than a planet. In fact, it''s not much bigger than our moon, and only about half the size of Mars, which is about half the size of Earth. Because it between us and the Sun, Mercury is never far from the Sun, in the sky (from our perspective) - thus, is always either a morning or evening star, one of the brightest. Hence, was it noticed by the ancients, who gave it a name, and then made up stories about it.

Mercury has no moons, but resembles ours up close. Mind you, if you were up close to Mercury, you wouldn't be able to see our moon - at best it would be a very tiny gray dot, next to an only slightly bigger blue dot, and sometimes behind it. But if you were to hold up pictures of the two, you would see by comparison that they are equally, more or less, pockmarked with craters from countless collisions - giving the impression one gets from something which has spent billions of years within close proximity to the Sun, or some other large gravitational attractor.




The Solar System
The Sun Mercury Venus Earth Mars
The Asteroid Belt Jupiter Saturn Uranus Neptune Pluto