It speeds around the Sun every 88 days, traveling through space at nearly 29 miles 47 kilometers per second, faster than any other planet. Mercury spins slowly on its axis and completes one rotation every 59 Earth days. But when Mercury is moving fastest in its elliptical orbit around the Sun and it is closest to the Sun , each rotation is not accompanied by sunrise and sunset like it is on most other planets.
The morning Sun appears to rise briefly, set, and rise again from some parts of the planet's surface. The same thing happens in reverse at sunset for other parts of the surface. One Mercury solar day one full day-night cycle equals Earth days — just over two years on Mercury. Mercury's axis of rotation is tilted just 2 degrees with respect to the plane of its orbit around the Sun.
That means it spins nearly perfectly upright and so does not experience seasons as many other planets do. Mercury formed about 4. Like its fellow terrestrial planets, Mercury has a central core, a rocky mantle, and a solid crust. Mercury is the second densest planet, after Earth.
It has a large metallic core with a radius of about 1, miles 2, kilometers , about 85 percent of the planet's radius. There is evidence that it is partly molten or liquid. Mercury's outer shell, comparable to Earth's outer shell called the mantle and crust , is only about kilometers miles thick.
Mercury's surface resembles that of Earth's Moon, scarred by many impact craters resulting from collisions with meteoroids and comets. Craters and features on Mercury are named after famous deceased artists, musicians, or authors, including children's author Dr.
Seuss and dance pioneer Alvin Ailey. Very large impact basins, including Caloris miles or 1, kilometers in diameter and Rachmaninoff miles, or kilometers in diameter , were created by asteroid impacts on the planet's surface early in the solar system's history. While there are large areas of smooth terrain, there are also cliffs, some hundreds of miles long and soaring up to a mile high. Impact Basins Caloris Basin — Impact Site This is one of the largest impact basins in the solar system and the largest feature on Mercury.
Rembrandt — Young Impact Basin The Rembrandt Basin displays a "wheel and spoke" pattern on its central floor that has never been seen on any other planet or moon.
Rembrandt Comparison. A Shrinking Planet? Lobate Scarps. Image courtesy of T. Watters, M. Robinson, and A. Robinson, and AC Cook. Digital Elevation Model. Smooth Plains Between the heavily cratered regions of Mercury's surface lie large expanses of smooth plains. Smooth Plains. Flowing Lava. As Mercury is so hot, these atoms quickly escape into space and so its atmosphere is constantly being replenished.
Only two spacecraft have ever visited Mercury. The Mariner 10 visited during , flying by Mercury three times and mapping half its surface. On March 24, it ran out of fuel and is still believed to be orbiting the Sun. Mercury has more craters and impact marks that any other planet. Most of the Mercurian craters are named after famous writers and artists. If a crater is larger than km in diameter, it is known as a Basin. The largest Basin on Mercury, the Caloris Basin, is around 1, km in diameter and was discovered by the Mariner More information and facts about Mercury What remains intriguing about Mercury is how scant our knowledge has been regarding some of its key details until recently.
Atmosphere The Mercurial atmosphere is so thin that it is virtually non-existent. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits.
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These cookies ensure basic functionalities and security features of the website, anonymously. The cookie is used to store the user consent for the cookies in the category "Analytics". The cookies is used to store the user consent for the cookies in the category "Necessary". Because of this, ancient civilizations already knew about its existence.
Our current name for Mercury comes from Roman mythology after the god of commerce and communication. Greeks named the planet after Hermes because it was the planet that moved the fastest.
In modern Greece, they still refer to it with a variation of the name, they call it Ermis. What we do know is that in the modern era, the first person to see Mercury with a telescope was the Italian astronomer Galileo Galilei.
The other is Venus. Its closeness to the Sun can be the other factor. Only a couple of uncrewed probes have been sent to study the planet.
Mercury is so close to the Sun that it has one of the harshest environments for us humans. A manned mission to Mercury is not likely to happen any time soon.
Mercury is one of the four terrestrial planets in the Solar System. This means it has a rocky, solid composition. Liquid water is unlikely though.
Not likely. Scientists do not believe there is life on Mercury or that there has ever been.
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