Mercury: The Closest Planet to the Sun and Its Characteristics

SPACE — Mercury is the closest planet to the sun and the smallest in the solar system. This small, cratered planet has no moon and orbits the sun faster than any other planet in the solar system. Therefore, the Romans named him after the agile messenger god.

Mercury is the second densest planet after Earth, with a massive metallic core roughly 2,200 to 2,400 miles (3,600 to 3,800 kilometers) wide, about 75 percent of the planet’s diameter. In comparison, Mercury’s outer shell is only 300 to 400 miles or 500 to 600 km thick. The combination of the core and its massive composition, which includes many volatile elements, has puzzled scientists for years.

The Sumerians knew Mercury at least 5,000 years ago. Mercury is often associated with Nabu, the god of writing, according to a site linked to NASA’s MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) mission.

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Mercury is also given separate names for its appearance as the morning star and evening star. However, Greek astronomers knew that the two names referred to the same object, and Heraclitus, around 500 BC, correctly thought that Mercury and Venus orbited the sun, not the Earth.

How Hot is Mercury?

Because the planet is so close to the sun, Mercury’s surface temperature can reach 840 degrees Fahrenheit (450 degrees Celsius). However, because those worlds don’t have much of an atmosphere to trap any heat, at night Mercury’s temperature can drop to minus 275 degrees Fahrenheit or minus 170 degrees Celsius. The temperature change of more than 600 degrees Celsius on Mercury makes it the largest in the solar system.

Surface Characteristics of Mercury

As close as Mercury is to the sun, in 2012, NASA’s MESSENGER spacecraft discovered water ice in craters around its north pole in 2017. The region may be permanently protected from the sun’s heat. The south pole may also contain pockets of ice, but MESSENGER’s orbit does not allow scientists to investigate the area. Comets or meteorites may have delivered ice there, or water vapor may have escaped from the planet’s interior and frozen at the poles.

Fact Mercury

– Average distance from the sun: 35,983,095 miles or 57,909,175 km. Equivalent to 0.38 Earth’s distance from the sun.

– Perihelion (closest approach to the sun): 28,580,000 miles or 46,000,000 km). Comparable 0.313 times Earth

– Aphelion (farthest distance from the sun): 43,380,000 miles or 69,820,000 km. Comparable 0.459 times that of Earth.

– Day length: 58,646 Earth days

– Color: Grey

As if Mercury wasn’t small enough, it has not only shrunk in the past, but continues to do so today. According to a 2016 report, the minor planet consists of a single continental plate atop a cooling iron core. As the core cools, it solidifies, reducing the planet’s volume and causing it to shrink. The process crushes the surface, creating escarpments, or lobe-shaped cliffs, hundreds of miles long and up to a mile high. Then, Mercury’s ‘Great Valley’ is about 620 miles long, 250 miles wide, and two miles deep or 1,000 x 400 x 3.2 km. It is larger than Arizona’s famous Grand Canyon and deeper than East Africa’s Great Rift Valley.

“The young age of the small steep slopes means Mercury is similar to Earth as a tectonically active planet with new faults possibly forming at this time as Mercury’s interior continues to cool and the planet shrinks,” said Smithsonian senior scientist at the Washington DC National Air and Space Museum, Tom. Watters.

Indeed, a 2016 study of cliffs in Mercury’s surface suggests the planet may still be rumbling with earthquakes or Mercury Quakes. In addition, in the past, Mercury’s surface was constantly reshaped by volcanic activity. However, another 2016 study suggests Mercury’s volcanic eruptions most likely ended around 3.5 billion years ago.

One 2016 study suggests Mercury’s surface features can generally be divided into two groups. First, it consists of older material that melted at higher pressures at the core-mantle boundary, and secondly, it consists of newer material that formed closer to Mercury’s surface.

Another 2016 study found the dark hue on Mercury’s surface is caused by carbon. This carbon was not deposited by colliding comets, as some researchers suspect. Instead, it may be the remnants of the planet’s original crust.