Mercury is the closest planet to the Sun and due to its proximity it is not easily seen except during twilight.
Mercury is only the second hottest planet.Despite being further from the Sun, Venus experiences higher temperatures.
Being so close to the Sun, the daytime temperature on Mercury is scorching – reaching over 400 °C (752 °F).
At night however, without an atmosphere to hold the heat in, the temperatures plummet, dropping to -180°C (-292°F).
The surface of Mercury is very similar to our moon. It has a very barren, rocky surface covered with many craters.
Mercury has wrinkles.As the iron core of the planet cooled and contracted, the surface of the planet became wrinkled. Scientist have named these wrinkles, Lobate Scarps. These Scarps can be up to a mile high and hundreds of miles long.
For every 2 orbits of the Sun, which takes around 88 Earth days, Mercury completes three rotations of its axis.
Mercury is the smallest planet in the Solar System.One of five planets visible with the naked eye a, Mercury is just 4,879 kilometers (3,031 miles) across its equator, compared with 12,742 kilometers (7,917 miles) for the Earth.
The planet has just 38% of the gravity on Earth. This means that Mercury isn’t able to hold the atmosphere it has and it instead gets blown away by solar winds. However those same solar winds are also bringing in new gases, radioactive decay and dust from micrometeorites – replenishing the atmosphere.
After the Earth, Mercury is the second densest planet. Despite its small size, Mercury is very dense because it is composed mainly of heavy metals and rock – the main characteristic of terrestrial planets.
Mercury is the most cratered planet in the Solar System.Unlike many other planets which “self-heal” through natural geological processes, the surface of Mercury is covered in craters. These are caused by numerous encounters with asteroids and comets. Most Mercurian craters are named after famous writers and artists.
Scientists think that a huge asteroid slammed into Mercury about 4 billion years ago, creating a giant crater about 1,545 km (960 miles) across. Called the Caloris Basin, the crater could fit the whole state of Texas inside it. Researchers have calculated that the asteroid that created the basin had to have been about 100 km (60 miles) wide.
The orbit of Mercury is an ellipse rather than circular. It has the most eccentric orbit in the solar system and the least circular of all of the planets, according to scientists and astronomers.
Mercury has a weak magnetic field whose strength is about 1% of the magnetic field on Earth.
Mercury’s iron core takes up about 75 percent of the planet’s radius. The huge core has more iron in it than any other planet’s in the solar system. Scientists aren’t exactly sure how Mercury’s giant iron core formed, but researchers think it has something to do with its formation. If the planet formed quickly, it could have left a thin shell of crust over the relatively large core.
Mercury has a molten core. In recent years scientists from NASA have come to believe the solid iron core of Mercury could in fact be molten. Normally the core of smaller planets cools rapidly, but after extensive research, the results were not in line with those expected from a solid core.
Mercury is named for the Roman messenger to the gods.The exact date of Mercury’s discovery is unknown as it pre-dates its first historical mention, one of the first mentions being by the Sumerians around in 3,000 BC.
There is no water on the surface of Mercury, it is possible however that there could be water underneath the surface.
Also, there is no air on the surface but it could be trapped underneath.
Only two spacecraft have ever visited Mercury. It is difficult to reach the planet due to its proximity to the Sun and any spacecraft visiting would need to travel 91 million kilometers into the Sun’s gravitational potential well. The Mariner 10 visited during 1974-75, flying by Mercury three times and mapping half its surface. On March 24, 1975 it ran out of fuel and is still believed to be orbiting the Sun. The MESSENGER probe was launched in 2004 to explore Mercury’s high density, its geological history, the nature of its magnetic field and more. Another mission, BepiColombo, is to be launched in 2015 by the European Space Agency and Japan is expected to reach Mercury in 2019.
The Hubble Space Telescope cannot view Mercury. This is because Mercury is too close to the Sun and the brightness would harm the electrical components of the telescope.