Mercury is the innermost planet of our solar system.
Difficult to observe with optical telescopes due to its proximity to the Sun.
Mercury has a rotation period of 59 Earth days.
It orbits the Sun in 88 Earth days.
A solar day on Mercury lasts as long as two Mercury years.
Its axis of rotation is perpendicular to its orbit.
Mercury has an undetectable atmosphere due to:
Extremely high temperatures.
Small size.
Proximity to the Sun.
High surface temperature reaches approximately 700 K on the day side.
Low night temperature drops to about 100 K.
Polar temperatures can reach around 125 K.
High surface temperature and low gravity lead to gases escaping into space.
Surface resembles that of the Moon, based on a flyby in 2008.
Craters are less prominent than on the Moon due to lower gravity.
Older craters may be filled due to past volcanic activity.
Scarps: long cliffs that cut across craters, formed by the cooling, shrinking, and splitting of the crust.
Caloris Basin:
Result of a large asteroid impact.
Measures about 1400 km in diameter with surrounding rings of mountains.
Indicates past volcanic activity that created intercrater plains.
Mercury possesses a magnetic field that is 1/100th as strong as Earth's.
The weak magnetic field is attributed to its slow rotation, which is insufficient to maintain a robust magnetic field.
Possible formation theories:
Rapid rotation in the past.
Presence of a liquid metal core.
The magnetic field is stronger at the north pole than the south pole.
Mercury is believed to have been geologically inactive for the last 4 billion years.
Historical geological activities include:
Volcanic eruptions.
Melting and differentiation processes.
Bombardment by meteors.
Slow cooling and formation of a thin crust.
Absence of plate tectonics due to rapid cooling.
The cooling of its metallic core caused the planet to contract, leading to the formation of scarps.
Mercury's orbit exhibits a daisy-like pattern.
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