Terrestrial
Physical Data
Terrestrial
Physical Data
| Average Distance from the Sun | 5.79 x 107 km = 0.387 AU |
| Aphelion | 6.98 x 107 km |
| Perihelion | 4.60 x 107 km |
| Orbital Velocity (ave.) | 47.9 km/s |
| Sidereal Period | 87.969 Earth days |
| Rotation Period | 58.65 days |
| Tilt of Rotation Axis | 2 degrees |
| Equatorial Diameter | 4,878 km |
| Mass | 3.303 x 1023 kg |
| Density (ave.) | 5430 kg/m3 |
| Escape Velocity | 4.3 km/s |
| Surface Temperature (ave.) | Day: 350o C=662oF=623K
Night: -170oC=-274oF=103K |
-Definition: Astronomical Unit (AU) - the average
distance between the Earth and the Sun.
-Definition: Perihelion - the minimum distance
from the Sun.
-Definition: Aphelion - the maximum distance
from the Sun.
-Definition: Sidereal Period - the actual time
it takes for Mercury to orbit the Sun, with respect to the background stars
and not the position of the Sun.
Reference: Kaufmann, William J. Universe. Fourth Edition. W. H. Freeman and Company, New York. 1994.