How far away is Mercury from Earth? The first planet from the Sun is Mercury, while the third planet is Earth. On average, Mercury is 48 million miles (77 million kilometers) from Earth. It takes Mercury about 87 days to orbit the Sun, which is why it appears to move across the sky as the Earth orbits around it.
Mercury is also the smallest of the planets outside the Sun. It is almost entirely covered by a dense layer of atmosphere called magma that is made up of 75% iron and 25% silicon dioxide. The air inside the planet's atmosphere is 95% carbon dioxde and 5% nitrogen.
Earth's moon is more than three times as big as Mercury and can be easily seen with the unaided eye. From Earth-orbit, however, they appear equally small: About the size of a full moon when they are at their closest approach (called "syzygy") in January, and half that distance when they are at their farthest (known as "lunar eclipse").
It is not clear how long Mercury's atmosphere will remain intact because it is believed that it drains back into the planet over time due to tectonic activity and magnetic fields. Scientists have estimated that the planet's core may be completely liquid ooze as early as 10 million years from now.
On average, Mercury is 48 million miles (77 million kilometers) from Earth. Mercury's distance from Earth changes dramatically as both planets round the Sun. What is the distance between Venus and Earth?
|Average Distance from Earth to||kilometers and miles|
|Mercury||155 million km|
|Venus||170 million km|
|Mars||253 million 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 (241 million km).
Therefore, one mercury arc minute is equal to 15 degrees on Mercury's surface.
The map below shows how far away Mercury is from the Sun. The color shading indicates how far away it is: yellow for close up to solar maximum, red for far away during a solar minimum.
Source: NASA/Solar Dynamics Observatory
Learn more about planets outside our solar system by reading my articles on Mars and Jupiter.
Read about how astronomers discover new planets orbiting other stars.
Learn more about Venus, the Earth's twin planet.
And don't forget to visit my website at http://www.christopherfowler.com for the latest news on astronomy, science, technology and history.
Mercury is around one-third the size of Earth. It is the smallest planet in the solar system. Mercury is extremely near to the Sun and has no atmosphere. The temperature ranges from 500 degrees F at the sunlit side to 450 degrees F at the dark side.
It used to be thought that because of this heat source, Mercury had a large iron core like Earth's but new data shows it to be completely solid. Still, because it rotates so quickly, it must contain a lot of iron.
The average distance between Mercury and the Sun is 59 million miles, which is about half that of Earth's. But because it takes Mercury approximately 60 days to orbit the Sun, it experiences a significant amount of tidal force from him. This force increases as the square of the distance from the Sun, so Mercury's surface is stretched and squeezed as well as pulled away from it.
The result is that the far side experiences temperatures too high for water to exist, while those on the near side are too low for life as we know it. Scientists believe that most of Mercury's interior is made up of silica (silicon dioxide), with some magnesium oxide and iron oxides.
Its surface is mostly carbon and silicon carbide, with some sulphur and phosphorus.
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 energy each planet receives from the Sun over time. Energy comes in different forms, such as heat and light, and these effects can be used to determine a planet's climate.
For example, if a planet has perihelion far away from the Sun and aphelion close to it, then it will receive more energy from the Sun at perihelion than at aphelion. This is because radiation travels faster when something is closer to the source, so there will be more sunlight reaching the planet at perihelion than at aphelion.
This extra dose of solar energy at perihelion may cause problems for the planet's surface. The amount of energy received by a planet depends on its distance from the Sun, but also on how big it is. The bigger the planet, the more energy it can withstand before being destroyed or evolving into another state.