Mercury is the closest planet to the sun. Mercury’s orbit is severely elliptical meaning that the planet’s distance to the Sun varies.
At its closest, Mercury is 46 million kilometres (28.5 million miles or 0.31 AU) from the Sun, and at its farthest it is nearly 70 million kilometres (43 million miles or 0.46 AU) from the Sun.
VMercury’s surface is overall very similar in appearance to that of the Moon, showing extensive mare-like plains and heavy cratering, indicating that it has been geologically inactive for billions of years.e orbits of all the other planets are more elliptical (oval-shaped).
Venus tThis small, rocky planet has almost no atmosphere. Mercury has a very elliptical orbit and a huge range in temperature.
During the long daytime (which lasts 58.65 Earth days or almost an entire Mercurian year, which is 88 days long), the temperature is hotter than an oven; during the long night (the same length), the temperature is colder than a freezer. It takes 87.97 earth days to orbit around the sun.
Mercury is about 3,031 miles (4,878 km) in diameter. It is the smallest planet in our solar system (it used to be considered the second-smallest planet, when Pluto was still considered to be a planet).
Mercury is a bit over one third of the diameter of the Earth. Mercury is only slightly larger than the Earth’s moon. Unlike our moon however, Mercury has a large iron core, which generates a magnetic field about 1% as strong as that of the Earth.
There are no seasons on Mercury. Seasons are caused by the tilt of the axis relative to the planet’s orbit.
Since Mercury’s axis is directly perpendicular to its motion (not tilted), it has no seasons. If you were on the surface of Mercury, the Sun would look almost three times as big as it does from Earth.
Mercury has a huge range in temperatures. Its surface ranges in temperature from -270°F to 800°F (-168°C to 427°C). During the very long daytime (88 Earth-days long), the temperatures are very high (the second-highest in the Solar System - only Venus is hotter); during the long night, the thin atmosphere lets the heat dissipate, and the temperature drops quickly.
The rotation of Mercury is very strange. For hundreds of years, it was thought to rotate synchronously (going on at the same rate and exactly together), so that it always kept one face to the Sun, just as the Moon always keeps one face to the Earth.
Its actual rotation, however, causes it to turn exactly one and a half times each time it goes around the Sun, so that it turns one side toward the Sun in one orbit, and the other side toward the Sun in the next orbit, making the day on Mercury twice as long as the year.
In addition, at perihelion (the point in the orbit of a heavenly body where it is nearest to the sun). The motion of the planet around the Sun is faster than its rotation, so that the Sun actually seems to stop its normal (westward) motion, and move the other way for a little while.
year, for the Earth.
As Venus and the Earth travel around the sun, Venus can be seen near the opposite side of the sun about every Geologists estimate that Mercury’s core occupies about 42% of its volume; for Earth this proportion is 17%.
Recent research suggests Mercury has a molten core. Surrounding the core is a 500–700 km mantle consisting of silicates based on data from the Mariner 10 mission and Earth-based observation, Mercury’s crust is believed to be 100–300 km thick.
One distinctive feature of Mercury’s surface is the presence of numerous narrow ridges, and these can extend up to several hundred kilometers.
It is believed that these were formed as Mercury’s core and mantle cooled and contracted at a time when the crust had already solidified.
1. Crust— 100–300 km thick
2. Mantle— 600 km thick
3. Core— 1,800 km radius
Mercury’s core has higher iron content than that of any other major planet in the Solar System according to scientists, and several theories have been proposed to explain this.
The most widely accepted theory is that Mercury originally had a metal-silicate ratio similar to common chondrite meteors, thought to be typical of the Solar System’s rocky matter, and a mass approximately 2.25 times its current mass.