The planet Mercury is the closest planet to the Sun in our solar
system. It has a highly eccentric orbit. Its
distance from the sun ranges from 46km to 70km depending on
where it was its orbit. It is unlikely that Mercury could
harbor life as it has the most extreme temperature variations in
the solar system. Surface temperatures range from -274ºF
(-170ºC) to 872ºF (467ºC). This is due to its close orbit
to the Sun. The planet Mercury speeds around the Sun every 88
days at 50km per second. That is faster than any other
planet.
Mercury has a very old surface with no plate tectonics, although
frozen water has been detected in some craters. It was
thought to have no geological activity, however, it is now
believed that Mariner 10 may have found evidence recent volcanic
activity. Mercury's surface is actually littered with
craters, but has large plains as well, much like our Moon.
It's interior is thought to be a large iron core which actually
comprises the majority of the sixe of the planet, leaving a thin
mantle and crust.. Mercury has a very weak magnetic field
compared to earth. Its atmosphere is very thin and
actually replenishes itself by the atoms that are ejected from
its surface by the solar wind. These atoms are also blown
out of the atmosphere by intense heat on Mercury. Mercury
does not have any moons.
Mercury orbits so close to the Sun, that the Hubble Space
Telescope can not safely view it. It was visited in 1974
and 1975 by the Mariner 10 spacecraft. NASA launched a
probe, MESSENGER, in 2004 to visit Mercury and will enter
Mercury's orbit in 2011. The pictures to the right were
all taken on NASA's Mariner 10 mission.
| Mass (kg)
| 3.3 x 1023
|
| Diameter (km)
| 4879.4
|
| Mean density (kg/m3)
| 5420
|
| Escape velocity (m/s)
| 4300
|
| Average distance from Sun
| 0.387 AU (57,909,175 km)
|
| Rotation period (length of day in Earth days)
| 58.65
|
| Revolution period (length of year in Earth days)
| 87.97
|
| Obliquity (tilt of axis degrees)
| 0
|
| Orbit inclination (degrees)
| 7
|
| Orbit eccentricity (deviation from circular)
| 0.206
|
| Mean surface temperature (K)
| 452
|
| Maximum surface temperature (K)
| 700
|
| Minimum surface temperature (K)
| 100
|
| Visual geometric albedo (reflectivity)
| 0.12
|
| Largest known surface feature
| Caloris Basin
(1350 km diameter)
|
| Atmospheric components
| trace amounts of
hydrogen and
helium
|
| Surface materials |
basaltic and anorthositic rocks and regolith |
|
Mercury Mosaic
composed of many pictures
Mercury Mosaic #2
from various phtographs
Image of
Mercury South Pole |
