Mercury By: Edwin C. Devon S. Eduardo B.

Mercury Mercury is the smallest planet in our solar system, and it is closest to the sun, although it is the first planet to appear it looks like a small ball of rock next to the sun. It only reflects 6% of the sunlight that is directed at it.

Mercury craters The most common topographic features on Mercury are the craters that cover much of its surface. Craters in Mercury range from a few meters to hundreds of kilo meters across. The largest known crater is the huge Caloris Basin, the impact was so severe that it caused lava eruptions and left a ring over 2 kilometers tall surrounding the impact crater. The shock wave produced by the Caloris impact was reflected and focused to this point, thus jumbling the crust and breaking it into a series of complex blocks.

Random craters

Fast facts Mercury is about the same age as the Sun: 4.5 billion years. It is about 58,340,000 km (36,250,000 miles) from the sun. It is about 4880 km (3032 miles) In diameter. Temperature variations on Mercury are the most extreme in the solar system ranging from –170º C (–270º F) to 430º C (800º F). Its solid surface is covered with craters and it has almost no atmosphere. There is evidence of ice in the protected shadows of craters near the north pole.

Until 1965, scientists thought that the same side of Mercury always faced the Sun. Mercury rotates precisely three times for every two orbits, known as a 3:2 orbital resonance.

Mercury has 0 satellites. The ancient Greeks called the evening star Hermes and the morning star Apollo, believing them to be different objects. The planet is named for Mercury, the Roman messenger of the gods. It is so close to the Sun that it can be seen only in the twilight sky of the Earth.

Mercury is intensely cratered, Moon-like surface and a faint atmosphere of mostly helium, resulting from solar wind bombardment.

Like the Earth ’ s Moon, Mercury has a very volatile atmosphere. What little atmosphere exists is made up of atoms or ions blasted off its surface by the solar wind and has less than a million-billionths the pressure of Earth's atmosphere at sea level. It is composed chiefly of oxygen, sodium, and helium. Mercury's extreme surface temperature enhances the escape of these volatile atoms into space. With no atmosphere or hydrosphere, there has been no erosion from wind or water. Mercury may have water ice at its north and south poles. The ice exists inside deep craters. The floors of these craters remain in perpetual shadow, so the Sun cannot melt the ice. Meteorites do not burn up due to friction as they do in other planetary atmospheres.

Mariner 10 spacecraft in mercury IN march 1974 Mariner 10's three flybys past Mercury mapped about half of the planet's surface, during which time a thin atmosphere and a magnetic field were discovered. The spacecraft made three separate passes by the planet, and obtained about 10,000 images which covered about 57% of the planet surface. The spacecraft is currently still orbiting the Sun, but is no longer sending data because it used up its gas supply

Mercury’s surface is… Highly cratered with smooth terrains. Relatively ancient, volcanic surface. Similar to Earth’s Moon, but fewer craters and more “plains”.

Messenger Spacecraft: In 2004, the United States launched the Messenger probe to Mercury. Messenger was scheduled to fly by Mercury twice in 2008 and once in 2009 before going into orbit around the planet in The probe was then to orbit Mercury for one Earth year while mapping Mercury's surface and studying its composition, interior structure, and magnetic field. Japan is planning a joint mission with the European Space Agency called BepiColombo, which will orbit Mercury with two probes: one to map the planet and the other to study its magnetosphere. An original plan to include a lander has been shelved. Russian Soyuz rockets will launch the probes in 2013.

Giant scarps (cliffs), called rupes, are believed to have formed when Mercury’s interior cooled and the entire planet shrank slightly as a result. This figure, recently published in Science magazine, shows one of these scarps (white arrows) that is about 270 kilometers (170 miles) long. Mercury’s density is similar to Earth’s, but planet is only ~1/3 the size of Earth. Large iron core, 75% of radius (~1850 km), Silicate mantle only ~550 km thick.

Mercury is the fastest moving planet in our Solar System. Mercury’s Basins contain smooth plains but is highly ridged and fractured.

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