Why is it called Mercury?Was named by the Romans in honor of Mercury,messenger of gods.Mercury wore a hat and sandals with wings on them,allowing him to travel quickly.The planet was named after him because it movesaround the sun faster than any other planet in thesolar system.
cratersMercury is a battered and baked planet just larger than Earthsmoon. Evidence of heavy bombardment from the chaos of theformation of the solar system is left in the hundreds of cratersand resulting lava flows on this small, barren planet. The largestcrater is Beethoven at 643 km in diameter and is the largest inthe solar system. The largest feature, Caloris Basin, is 1300 km indiameter and was probably caused by an impact from an objectlarger than 100 km in diameter. Some craters have ice in themeven though the planet is so hot because the sun never reachesinto the shadows due to the planets tilt and orbit. With noatmosphere, there is a temperature difference of about 600degrees between the coldest spots and hottest spots on theplanet.
CHARACTERISTICSTemperature Range -- -173° C to 427° CAtmosphere - Some Hydrogen, Helium, OxygenWinds – NoneTilt - 0.00°Rings – NoneOrbital Period - 0 Years, 87 Days, 23.3 HoursRotation - 58 Days, 15.5 Hours
CHARACTERISTICSComposition - Iron Core, Silicate SurfaceMagnetic Field - Slight
Years and days• A day on mercury is almost twice as long as a year• If you stand on the surface of Mercury from one sunrise to another, it is equal to 176 Earth days.
measurementsDistance from sun – approximately 58 millionkilometersDiameter - 4,879km (3,032mi)Volume and mass – 1/18 of earthMean density – 5.4g/cm3Force of gravity on planet’s surface – 1/3 of that onearth’s surface
Axis, rotations and orbitsThe orbit of Mercury has the highest eccentricity of all theSolar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every twoorbits.The perihelion of Mercurys orbit precesses around the Sunat an excess of 43 arcseconds per century; a phenomenonthat was explained in the 20th century by AlbertEinsteins General Theory of Relativity.Mercury is the innermost and smallest planet in the SolarSystem,[a] orbiting the Sun once every 87.969 Earth days.
Axis, rotations and orbitsMercury orbits the sun at an average distance ofabout 36 million miles (58 million kilometres),compared with about 93 million miles (150 millionkilometres) for Earth.
When viewed from earthMercury is bright when viewed from Earth, ranging from−2.3 to 5.7 in apparent magnitude, but is not easily seen asits greatest angular separation from the Sun is only 28.3°Since Mercury is normally lost in the glare of the Sun,unless there is a solar eclipse it can be viewed from EarthsNorthern Hemisphere only in morning or evening twilight,while its extreme elongations occur in Declinations southof the celestial equator, such that it can be seen atfavorable apparitions from moderate latitudes in theSouthern Hemisphere in a fully dark sky.
When viewed from earthThis event takes place about thirteen or fourteentimes each century.Last time was November 8 2006The next time will be on May 9 2016
Comparing to our moonMercury is similar in appearance to the Moon: it isheavily cratered with regions of smooth plains, hasno natural satellites and no substantial atmosphere.However, unlike the Moon, it has a large iron core,which generates a magnetic field about 1% as strongas that of the Earth.It is an exceptionally dense planet due to the largerelative size of its core.
temperaturesSurface temperatures range from about 90to 700 K (−183 °C to 427 °C) subsolar point being the hottest and the bottoms ofcraters near the poles being the coldest.Temperatures also change from day to night
NameThe Greeks gave it two names: Apollo for when itappeared as a morning star and Hermes when it cameas an evening star.
factsBecause of Mercury’s weird orbit and rotation, themorning Sun appears to rise briefly, set and rise again.The same thing happens in reverse at sunset.Mercury is roughly the same age as the Sun, 4.5 billionyears.Mercury is the fastest moving planet in our SolarSystem and is the nearest planet to the Sun. Mercuryis one of the four terrestrial planets, being a rockybody like the Earth. It is the smallest of the four.