Mercury's closest approach to the Earth is 28.6 million miles, while its furthest approach is 43.4 million miles. Mercury's eccentric orbit, which has the most eccentric orbit in our solar system with an eccentricity of 0.21, is responsible for the enormous difference between the nearest and furthest distances.
Its year is almost identical to the Earth's year, but because of its distance from the Sun it receives only half as much light and heat at its closest approach compared with at its farthest approach. This causes significant changes on the planet's surface. At perihelion (the point in its orbit when it is closest to the Sun) it is completely frozen over, with no signs of life except for a South Polar cap. But at aphelion (the point in its orbit when it is farthest from the Sun) the Sun's heat causes all the water under the ice sheet to melt, forming a large basin filled with water that may reach temperatures as high as 140 degrees Fahrenheit (60 degrees Celsius).
These are just some of the many interesting things we know about Mercury today. It is always exciting to learn new facts about our neighbor planet!
Mercury is about 46.0 million km from the Sun at "perihelion" (the orbital point closest to the Sun), and 69.8 million km at "aphelion" (the orbital point furthest from the Sun). Its average distance from the Sun is 57.9 million km.
The perihelion and aphelion distances are important parameters in understanding how planets move around the Sun. They also play a role in determining how much radiation each planet receives.
For example, if Mercury moved closer to the Sun then it would receive more solar heat and be able to retain more ice inside its body. This ice would eventually melt, causing Mercury's surface to change shape and possibly even disappear.
As far as we know, this hasn't happened yet, so Mercury must stay away from the Sun for some reason. This reason is probably related to its position in the Solar System: mainly because it lies so close to the Sun. If Jupiter had this location in our Solar System then it might suffer the same problem with heat and ice.
Currently, the best model to explain this situation is called "orbital shrinking". It says that all the planets have, over time, lost mass when particles of dust and other small objects hit their surfaces. This loss of mass has made their orbits shrink.
Mercury, at a distance of 57 million kilometers from the Sun, is the nearest planet to the Sun (35 million miles). Mercury is the smallest of the terrestrial planets. It is also the closest planet to the Sun out of the eight planets in our solar system.
Mercury has a very eccentric orbit, which causes it to come within 0.5 AU of the Sun every time it passes between the Earth and Sun. But because of this same effect, it can stay as close as 495,000 km to the Sun while orbiting it every 487 days.
The reason why Mercury is so important information for scientists is that they use its orbit around the Sun to determine how many years ago it was last contacted by humanity's most advanced probe, Mariner 10. They do this by looking at how much farther away it is from the Sun compared with where it should be based on known facts about its orbital motion.
This method cannot tell them anything new about Mercury's history that we did not already know from observations made by other methods, but it does give us an accurate value for its current mass since it has been observed to fall toward the Sun over time due to the loss of gas from its interior.
It calculates the distance between two planets as the average of all locations along their respective orbits. As a result, Mercury's orbit does not take it very far from the sun, but Venus's orbit takes it much further away from Earth. As a result, Mercury is closer. The distance between Mercury and the sun is about 0.5 astronomical unit (AU), while that between Venus and the sun is about 0.7 AU.
Mercury has only one satellite, Mercury, which is confined to an elliptical orbit around our planet at an average distance of 43 million km. As it orbits, Mercury passes through each of the eight zones of the solar system: the asteroid belt, the main asteroid belt, and then the inner, middle, and outer regions of the earth's atmosphere.
Venus has two moons, Venus and Mercury. Venus's moon moves in an ellipse with Venus, but at a slower rate; thus, they are called "satellites". However, because the distance between them and Venus changes during their joint journey around Earth, these objects do not follow exactly the same path as Venus itself. So, they are not considered to be in orbit around Venus, but rather in orbit around Earth-Sun Lagrange points 2 and 3. The average distance between Venus and Mercury is 744,000 km.
Mercury is 0.4 astronomical units distant from the Sun at an average distance of 36 million miles (58 million kilometers). The distance between the Sun and Earth is measured in astronomical units (abbreviated as AU). One astronomical unit is the mean distance between the Earth and the Sun, about 150 million miles (250 million km).
Because Mercury orbits the Sun in less than eight months, it moves around the Sun with a period of 87 days. The reason for this short period is that it takes the Earth approximately 93 days to orbit the Sun. Because Mercury's orbit is almost entirely inside Earth's orbit, they follow almost identical paths around the Sun, but because of this difference in speed, Mercury travels nearly 12 miles (19 km) farther from the Sun every hour it stays in Daytime Earth.
Daytime Earth sees only the Sun's rays when Mercury is over ocean or land. At night time Earth's shadow falls on Mercury in both western and eastern hemispheres. This occurs whenever Mercury is below the Earth's surface.
The direction of Mercury's orbit around the Sun is called its orbital phase. It takes Mercury about 59 days to complete one orbit, so it passes through all phases of the Moon during each trip around the Sun. The word "mercury" comes from Latin mensis'month' + Greek kerion 'grain'.