There are 8 planets in our solar system, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Mercury, named for the Roman messenger to the gods, is the smallest and closest planet to the Sun and due to its proximity it is not easily seen except during twilight. It circles the sun faster than all the other planets. Below are some interesting facts about Mercury. Also Read: Important GK Topics for Competitive Exams
Mercury is the smallest planet — it is only slightly larger than Earth's moon.
Mercury, one of the five planets visible with the naked eye, is just 4,879 Kilometres across its equator, smallest in the solar system.
One solar day (the time from noon to noon on the planet’s surface) on Mercury lasts the equivalent of 176 Earth days.
Mercury orbits the sun once every 88 Earth days. So one year on Mercury is 88 Earth days. But a day on Mercury is longer than an Earth day.
The sidereal day (the time for 1 rotation in relation to a fixed point) lasts 59 Earth days.
Mercury also has the highest orbital eccentricity of all the planets with its distance from the Sun ranging from 46 to 70 million km.
Mercury is the second densest planet after Earth. Each cubic centimetre has a density of 5.4 grams. This is largely due to Mercury being composed mainly of heavy metals and rock.
Mercury has a molten core. It is estimated Mercury’s core makes up 42% of its volume, while the Earth’s core makes up 17%.
Mercury is the second hottest planet. Despite being further from the Sun, Venus experiences higher temperatures. Mercury's surface temperature can reach a scorching 450 degree celcius.
Mercury has just 38% the gravity of Earth, this is too little to hold on to what atmosphere it has which is blown away by solar winds.
Since it doesn't have an atmosphere to entrap any heat, at night temperatures can plummet to minus 170 degree celsius, a temperature swing of more than 600 degree C, the greatest in the solar system.
Since it has no significant atmosphere to stop impacts, the planet is pockmarked with craters.
The Caloris Basin is the largest impact crater on Mercury covering approximately 1,550 km in diameter and was discovered in 1974 by the Mariner 10 probe. Any crater larger than 250 kilometres in diameter is referred to as a Basin.
Thirteen times a century Mercury can be observed from the Earth passing across the face of the Sun in an event called a transit, the next will occur on the 13th Nov 2032.
Images obtained by the MESSENGER spacecraft in 2004 have revealed evidence for pyroclastic flows (vulcanicity) and water ice at Mercury’s poles.
When viewed from Earth, the planet can only be seen near the western or eastern horizon during the early evening or early morning. It may appear as a bright star-like object but is less bright than Venus.
Important Links : Current Affairs — SSB Interview Material — English Study Material — UPSC Prelims State PCS CDS NDA NCERT Notes
Recommended : Important NCERT Notes Compilation for UPSC IAS PCS CDS NDA CAPF AC etc
