| Mercury is the planet closest to the Sun. It is a rocky planet and it is the second smallest planet in our Solar System. It is the fastest of all planets to orbit the Sun. There is no moisture on the planet and it is exposed to X-rays, therefore it cannot support life in any form. Its equatorial temperature can reach 450 oC, while in the polar regions where sunlight cannot reach, temperatures can drop below 0oC, astronomers believe that ice may be found in those regions. Its surface is covered with craters, which is similar to the Moon. Its diameter is 40% larger than that of the Moon. Their major difference is that Mercury has a fault on the surface which is 3 kilometers high and several hundred kilometers long. It may be caused by alternate expansion and contraction due to large diurnal range of temperature. Astronomers believe that the diameter of its iron core is about three quarters of that of the whole planet. |
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Mercury Statistics:
Mass (kg): 3.3x1033 Diameter (km): 4878 Average Density (kg/m3): 5420 Escape Velocity (m/sec): 4300 Rotation Period (Earth days): 58.65 Tilt of Axis (o): 0 Orbit inclination (o): 7 Average Surface Temperature (oF): -279 to 801 Atmospheric Components: Sodium, Hydrogen, Helium, Oxygen Number of Satellites: 0 Number of Rings: 0 |
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