Mercury (planet)
Mercury is the smallest and innermost planet in the Solar System. Its orbit around the Sun takes 87. 97 Earth days, the shortest of all the planets. Mercury appears to have a solid silicate crust and mantle overlying a solid, iron sulfide outer core layer. Two spacecraft have visited Mercury: Mariner 10 flew by in 1974 and 1975. MESSENGER, launched in 2004, orbited Mercury over 4,000 times in four years.
About Mercury (planet) in brief
Mercury is the smallest and innermost planet in the Solar System. Its orbit around the Sun takes 87. 97 Earth days, the shortest of all the planets. It is tidally locked with the Sun in a 3: 2 spin–orbit resonance. Mercury appears to have a solid silicate crust and mantle overlying a solid, iron sulfide outer core layer. Two spacecraft have visited Mercury: Mariner 10 flew by in 1974 and 1975. MESSENGER, launched in 2004, orbited Mercury over 4,000 times in four years before exhausting its fuel and crashing into the planet’s surface on April 30, 2015. The BepiColombo spacecraft is planned to arrive at Mercury in 2025. Based on data from the Mariner. 10 mission, Mercury’s crust is estimated to be 35 km thick and estimated to. be 35 thick and up to several hundred kilometers in length. The most widely accepted theory is that Mercury’s core and crust formed as the mantle cooled and contracted at a time when the crust had already solidified. It was originally thought that Mercury had a metal–silicate ratio of a similar to that of Earth, but this is now thought to be a more likely explanation for its formation. The planet has no known natural satellites. Mercury’s surface appears heavily cratered and is similar in appearance to the Moon’s, indicating that it has been geologically inactive for billions of years. It has surface temperatures that vary diurnally more than on any other planet.
Mercury consists of approximately 70% metallic and 30% silicate material. Research published in 2007 suggests that Mercury has a molten core. Surrounding the core is a 500km mantle consisting of silicates and this core is 500km thick. Mercury is also smaller— albeit more massive—than the largest natural satellites in the solar system, Ganymede and Titan. Mercury has an equatorial radius of 2,439. 7 kilometres with a surface temperature of 100 K at night and 700 K during the day across the equatorial regions. Its density is the second highest in theSolar System at 5. 427 gcm3, only slightly less than Earth’s density of 5. 515 g cm3. If the effect of gravitational compression were to be factored out from both planets, the materials of which Mercury is made would be denser than those of Earth’s 4. 4 gcm3. Although Earth’s high density results appreciably from gravitational compression, particularly at the core, Mercury is much smaller and its inner regions are not as compressed. Therefore, for it to have such a high density, its core must be large and rich in iron. Mercury’s orbital eccentricity is the largest of all known planets. At perihelion, Mercury’s distance from the Sun is only about two-thirds of its distance at aphelion. It has almost no atmosphere to retain heat, and its surface temperatures range from 100-700 K.
You want to know more about Mercury (planet)?
This page is based on the article Mercury (planet) published in Wikipedia (as of Dec. 06, 2020) and was automatically summarized using artificial intelligence.
