Mercury (Budh in Hindi)
“God of commerce and communication, and the messengers of the gods.”
- Symbol
- Age 4.5 billion years
- Diameter 4879.4 km
- Mean radius 2,439.7 km
- Volume 6.083 x 1010 km
- Mass 3.3011 x 1023 kg
- Mean density 5.427 g/cm3
- Natural satellite/ moon none
- Composition 70% metallic and 30% Silicate
- Discovered by Galileo Galilee and Thomas Harriot
- Colour Dark Grey
- Distance from Sun 57.6 million km
- Rotation period 58.7 Earth days
- Revolution period/orbital period 88 Earth days
- Direction of rotation west to east (antic clock wise)
- Nickname Swift planet
- Classified as terrestrial planet/rocky planet, interior or inferior planet, inner planet
- Position in Solar system 1st
- Second hottest planet in the solar system after Venus.
- Second densest planet after Earth.
- Fastest planet zipping around the Sun every 88 Earth days.
- Mercury’s neighbouring planet is Venus.
- First planet from the Sun.
- Smallest planet of our solar system.
- Closest planet to the Sun, is a unique celestial body.
- Mercury’s sidereal year is 88.0 Earth days and Sidereal day is 58.65 Earth days which is 3:2 ratio.
- It consists of approximately 70% metallic and 30% silicate material.
- From the surface of the Mercury, the Sun would appear more than three times as large as it does when view from the Earth and sunlight would be as much as 11 times brighter.
- The rays of Sun take 3.2 minutes to reach Mercury.
- Mercury is named after the ancient Roman god Mercurius (Mercury), god of commerce and communication, and the messenger of all the gods.
- The surface of the mercury is heavily cratered, as a result of countless impact events that have accumulated over billions of years. The largest known crater is Caloris Planitia or Caloris Basin with a diameter of 1,550 km.
- It is classified as one of four terrestrial planets which means that it is made up thin and rocky crust.
- Mercury is one of two inferior or interior planet. Inferior means the Planet which orbit closer to the Sun than the Earth).
- It is little bigger than Earth’s moon and Smaller than two natural satellites in the solar system named Ganymede and Titan.
- Mercury’s highly eccentric, egg-shaped orbit takes the planet as close as 46 million kilometre (When it is in Perihelion it moves fast) and as far as 69.82 million kilometres (When it is in Aphelion it moves slowly) from the Sun.
- First space craft mission to study Mercury was NASA’s Mariner 10 in 1974-75 (takes 146 days)
- Second space craft mission to orbit Mercury was NASA’s MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) was launched on 3rd August 2004.
- Bepi Colombo is a joint mission of European Space Agency and the Japanese Aerospace Exploration Agency to the Mercury. It was launched on an Ariane rocket on 20th October and 2018 with an arrival at mercury planned for on 5th December 2025.
- It is 5.25 times as dense as water.
- Because of high temperature on Mercury, it almost lost in the glare of the sun and it is not seen properly from the earth in spite of its rather short distance from the earth.
- The planet has no traces of water and gases.
- It has no enough gravity to hold an atmosphere.
- Because of no atmosphere on planet. During day time, temperature of the surface can reach 430 degree Celsius and during night time temperature on surface can drop to -180degree Celsius
- Sometimes Mercury can be seen before the sunrise and after the sunset.
- It was first observed through telescopes in the 17th century by astronomers Galileo Galilei and Thomas Harriot.