The distance between Mercury and the Sun varies between 28.6 million miles (46 million km) and 43.4 million miles (69.8 million km). At its closest point, Mercury is about 0.5342 astronomical units (au) away from the Sun.
This means that one mercury arc minute occurs when the two bodies move apart from each other by 1 degree. Astronomical units are a standard unit of distance used in astronomy. One au equals 150 million miles (241 million km) or approximately 1095971000 feet (32300 miles or 55200 kilometers).
Thus, one mercury arc minute is about 507,500 miles (800,000 km), or 3% of an AU at its closest approach to the Sun.
Mercury orbits the Sun in587 days, but because it takes it longer for Mercury to go around the Sun than it takes for the Earth to go around the Sun, these planets are never actually closer than when they are opposite each other with respect to the Sun. At their closest approach, Mercury is about 0.5342 AU from the Sun, while the Earth is 1 AU away from the Sun.
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).
Because Mercury orbits the Sun once every 87 days, this means it travels around 6,000 miles (9,600 km) for each orbit. Its average speed, therefore, is 50 miles per hour (80 kph).
It takes Mercury about 90 days to complete one orbit, so it takes 2½ years to cover the distance from one end of its orbit to the other. During these two and a half years, the planet will have covered a distance of nearly 60 million miles (97 million km), or almost half way across the solar system!
The reason why we can see all parts of the sky except when the Sun is out is because the Moon gets in the way. If the Earth wasn't moving around the Sun, then the only time you would be able to see all parts of the sky is when the Moon is out.
As we know, the Moon always shows up bright against the night sky, even when it's not directly facing us.
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 for other planets are as follows: Venus - 483 km, Earth - 239 km, Mars - 378 km.
Mercury's orbit is almost entirely made up of parabolic arcs; that is, orbits that return to exactly the same place in the sky each time they pass it. The only other planet known to have an atmosphere that extends far enough to influence its motion around the sun is Venus, and even it does not reach all the way to its perihelion position.
As Mercurys orbit rotates around the Sun, so too does its day. However, because Mercury orbits so close to the Sun, one complete orbit takes 58 days 5 hours 45 minutes, which means that during a single orbit, Mercury crosses the celestial equator twice: once when it is west of the celestial pole, and again when it is east of the pole. Because of this, astronomers believe there is something unusual about the nature of gravity on Mercury; perhaps there is a large mass concentrated somewhere near the planet's center.
Light takes 3.21 minutes to reach Mercury from Earth at an average distance of 36 million miles. This duration ranges between 2.56 and 3.88 minutes as the planets round the Sun. Light took 4.37 minutes to reach Venus, which travels around the Sun at a distance of 740 million miles, so Mercury is quite close to the Earth.
Mercury orbits the Sun every 88 days, but it takes 72 hours for Mercury's orbit to rotate around the Sun, so it always faces towards the center of the Solar System. Because of this constant face-forward orientation, Mercury has no global landscapes that we can see from space; all we can make out from hundreds of miles away is a rusty red color caused by iron oxide particles in the planet's atmosphere.
Venus is almost always hidden from view by the Sun, even from Earth with its own atmosphere. When it is visible from our planet, it is because a solar eclipse is happening somewhere on Earth. During a total lunar eclipse, however, everyone on Earth will be able to see it because neither the Moon nor the Sun are covered up by any other object.
Earth's closest neighbor is only 375 miles away, but because it is so small and dark compared to the Earth, you would need a telescope to see it.
Mercury is 48 million miles (77 million kilometers) from Earth on average. 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, 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.
However, because it orbits so close to the Sun, it is subjected to very high temperatures: 450°C (842°F) on the surface and over 1000°C (1832°F) in its interior. These temperatures are well above what any other planet in the Solar System can withstand. The only other planet that experiences conditions similar to those on Mercury is Venus. Humans have never visited Mercury, but several missions have been sent there by scientists interested in learning more about it and other aspects of Earth's history and future.
Missions to Mercury have been made by the United States, Russia, and Japan. The first mission was launched in 1973 by NASA with the goal of determining if Mercury has any environment that would be suitable for life. Although no evidence of water has been found so far, many questions have been answered thanks to these visits. For example, we know now that there was liquid water on Mercury's surface as early as 4.5 billion years ago, which is earlier than anyone thought before the mission.