10 Interesting Mercury Facts
Mercury facts is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits. The perihelion of Mercury’s orbit precesses around the Sun at an excess of 43 arcseconds per century, a phenomenon that was explained in the 20th century by Albert Einstein’s General Theory of Relativity. Here are the list of 10 Interesting Mercury Facts.
1. Half of Mercury had never been seen. Until NASA’s MESSENGER spacecraft made its first flyby of Mercury in 2008, NASA only had close up pictures of one half of Mercury’s surface. During its closest flyby, Mariner came within 327 km of the surface of Mercury, and detected its magnetic field. Just after its final close approach, Mariner 10 ran out of fuel, and has probably been orbiting the region ever since.
2. Mercury has a magnetic field. During its closest flyby, Mariner 10 detected a faint magnetic field around Mercury. This magnetic field is very similar to the one we have on the Earth, which protects are planet from the Sun’s solar wind. Since Mercury cooled down a long time ago, it can’t have the kind of dynamo running inside the Earth.
3. There might be ice on Mercury. Mercury facts is that there are regions on the surface of Mercury which are never heated by the Sun. These are craters around the poles of the planet which are eternally in shadow. And because they’re in shadow, they can be hundreds of degrees below zero. Water could form ice in these craters that could last for millions of years.
4. You can see Mercury with your own eyes. Mercury facts is actually a difficult planet to observe. Because it orbits closer to the Sun than the Earth, it appears to stick close to the Sun in the sky. The only times you can actually observe it is when the Sun has just set, or is about to rise. You only have a short amount of time to spot it, and you need a place that has a clear view to the horizon.
5. We have known about Mercury for millennia. Unlike Uranus, Neptune, and Pluto, which were discovered in the last few hundred years, ancient peoples have known about Mercury for thousands of years. There are recorded observations of Mercury made by the ancient Greeks and Romans; they named it after the god Hermes, who pulled the Sun across the sky.
6. Mercury has an atmosphere. Mercury facts is so small that it has too little gravity to hold an atmosphere like Earth or Venus. But it does have a tenuous atmosphere of hydrogen, helium, oxygen, sodium, calcium and potassium around it. They don’t form a stable atmosphere. Instead, there’s a constant flow of these atoms into orbit around Mercury, and then the Sun’s solar wind blasts it away into space.
7. It has the most eccentric orbit of all the planets. Now that Pluto is no longer a planet, Mercury facts takes the record for the most eccentric orbit. This means that its orbit is an ellipse, varying its distance to the Sun. At its closest point, Mercury gets to within 46 million km, and then it ranges out to 70 million km from the Sun.
8. The orbit of Mercury helped prove Einstein’s theories of relativity. As astronomers got more and more accurate instruments, and a way to mathematically describe the motions of the planets, they realized there was something wrong with Mercury’s movements around the Earth. They noticed that the closest point of Mercury’s orbit (its perihelion) was slowly moving around the Sun.
9. Hubble can’t look at Mercury at all. The Hubble Space Telescope has never been used to observe Mercury, and it never will be. The planet is so close to the Sun that the light from the Sun would overwhelm Hubble, and could permanently damage its optics and electronics.
10. Spacecraft are on their way. It’ll pass the planet several more times, and finally go into orbit around the planet in 2011. The European Space Agency is working on a mission with Japan called BepiColumbo. This spacecraft will orbit Mercury with two probes; one to map its surface, and the other to study its magnetic field. Unfortunately Mercury facts, the concept of a lander was shelved.