Mariner 10 traveled from Earth to Mercury in 147 days. More recently, on August 3, 2004, NASA launched the MESSENGER mission to examine Mercury in orbit. On January 14th, 2008, it performed its maiden flyby. It takes 1,260 days to get from Earth to Mercury. The average distance between the planets is about 40 million miles (64 million kilometers).
Venus orbits closer to the Sun than does Earth. But because Venus is so much larger than Earth, it receives more heat from the sun. Today, Venus is hot enough to melt lead. It has extremely high atmospheric pressure, with over 90 times that of Earth's. Its clouds are made of sulfur dioxide gas. There may be water vapor under the clouds, but if there is, it's locked up in a rigid shell called ice VII.
Mercury shares many features with Venus, including intense heat and atmosphere made of carbon dioxide. However, because it is so much closer to the Sun, it is much hotter—500 degrees Fahrenheit (270 degrees Celsius) or worse. Its air is made of sulfur dioxide instead of carbon dioxide. Because of this, people would die instantly if they were caught outside their shelters on Mercury for any length of time. The only place where it might possibly be safe to walk around is near your home base, since there are rocks everywhere else.
There have only been two probes to the planet. Mariner 10, a spacecraft designed to research both Venus and Mercury, was the first. Mercury flew it three times in 1974 and 1975. The MESSENGER spacecraft was launched by NASA in 2004, and it successfully placed itself into Mercury's orbit in 2011.
Why do scientists want to go back to Mercury? It is our closest planetary neighbor, and as such offers us an opportunity to explore not only another world but also another environment on Earth. Being so close to the sun, however, makes life difficult for Mercury. The planet has no magnetic field, which means that its atmosphere is easily stripped away by solar winds. As a result, Mercury is completely covered by a thin layer of rock called schist, which forms the highest peaks around 150 miles (250 km) above the surface. The rest of the planet is cold and barren, with very little water or ice.
Why are scientists interested in learning more about Mercury? Our nearest planetary neighbor provides us with an opportunity to study not only another world but also another environment on Earth.
Mercury's future spacecraft exploration is planned to continue with the ESA-JAXA BepiColombo project. The mission is set to launch in October 2018 and arrive at Mercury in 2025 for a notional one-year mission. In addition to BepiColombo, NASA's MESSENGER spacecraft was also sent to orbit Mercury from 2011 to 2015.
BepiColombo will be the first ever joint European-Japanese mission to Mars. It consists of a Mercury Orbiter, which will perform science experiments on its journey there and back, and a Lander, which will touch down on the planet's surface.
NASA's MESSENGER spacecraft was launched in 2007 to study the history of Earth's inner planet by orbiting Mercury twice. The mission has revealed that conditions have been very different for our planet's inner world over time, with evidence of water erosion on the surface of Mercury, massive volcanoes, and changes to its magnetic field.
MESSENGER discovered that Mercury has a thin atmosphere made up of molecules including oxygen, carbon dioxide, and nitrogen. It also found that the planet is covered in craters caused by meteorite impacts.
Mercury's orbital parameters Mercury's oval-shaped orbit is very elliptical, putting it as near to the sun as 29 million miles (47 million km) and as distant as 43 million miles (70 million km). A unusual transit of Mercury occurred in 2016, when the planet crossed the face of the sun. This caused its atmosphere to evaporate, darkening its surface and creating a visible streak across the solar disk.
Yes, Mercury orbits the Sun, but like Earth it also rotates on its axis. The two processes together form a kind of perpetual motion: while one part of Mercury is moving away from the Sun, another part is advancing toward it. Since no part of Mercury is ever completely dark, day and night there always be something to see by. But because Mercury is so small, even though it has the most eccentric orbit of all the planets, it takes 87 days to make one trip around the Sun.
The answer depends on how you define "face the Sun." Yes, technically speaking, because it spins on an axis, every point on Mercury faces the sun at some time during its annual cycle. However, because most of Mercury is covered in clouds most of the time, only certain parts of it are exposed at any given moment. These regions include the two sides that are never entirely hidden from view, as well as the center, which is always fully illuminated.
People have been observing transits of Mercury for over 2,000 years.
Mercury enters the environment in three different ways. First, mercury is naturally released into the atmosphere by volcanoes, rock weathering, forest fires, and soils. Mercury, once released into the atmosphere, can travel hundreds of miles with the wind before landing on the earth's surface. Second, human activities such as gold mining, coal burning, and manure disposal add more mercury to the environment. Third, waste incineration is another major source of mercury emissions. The large amount of elemental mercury that is formed during this process cannot be removed by conventional methods of air pollution control.
Once in the environment, mercury can change from one form to another. In its elemental form, it is a soft, silvery metal that is easily vaporized at low temperatures. When exposed to air, mercury will usually take on one of two forms: liquid or solid. Liquid mercury is extremely toxic if it comes in contact with skin or if it is inhaled. Solid mercury is less toxic but still dangerous if it is ingested or absorbed through the skin. It is important to avoid both liquid and solid forms of mercury because they may cause serious health problems if not disposed of properly.
The most common form of mercury pollution is methylmercury. Animals eat fish or algae containing high levels of methylmercury and then eat food plants or soil contaminated with these animals' wastes.