10 Interesting Facts About Mercury (The Smallest Planet!!!)

Mercury is the closest planet to the Sun and due to its proximity it is not easily seen except during twilight. Mercury is only the second hottest planet. Despite being further from the Sun, Venus experiences higher temperatures. Being so close to the Sun, the daytime temperature on Mercury is scorching – reaching over 400 °C (752 °F). At night however, without an atmosphere to hold the heat in, the temperatures plummet, dropping to -180°C (-292°F). The surface of Mercury is very similar to our moon. It has a very barren, rocky surface covered with many craters.

Interesting Facts about Facts:

1. Mercury has been known to humanity since ancient times and although its discovery date is unknown, the first mentions of the planet are believed to be around 3000 BC by the Sumerians.
2. A year in Mercury is 88 days, yet a Mercury day is 176 Earth days. Mercury is nearly tidally locked to the Sun – also known as a gravitational lock – and over time this has slowed the rotation of the planet to almost match its orbit around the Sun.
3. Mercury is the smallest planet in the solar system with a diameter of 4,879 km and is one of five planets that is visible to the naked eye.
4. After the Earth, Mercury is the second densest planet. Despite its small size, Mercury is very dense because it is composed mainly of heavy metals and rock, the main characteristic of terrestrial planets.
5. Mercury is only the second hottest planet. Venus, though farther from the Sun than Mercury, actually experiences higher temperatures. This is because Mercury has no atmosphere to regulate temperature and results in the most extreme temperature change of all the planets, ranging from -170°C or -280°F during the night to 430°C or 800°F during the day.
6. The planet has just 38% of the gravity on Earth. This means that Mercury isn’t able to hold the atmosphere it has and it instead gets blown away by solar winds. However those same solar winds are also bringing in new gases, radioactive decay and dust from micrometeorites, replenishing the atmosphere.
7. Mercury has a weak magnetic field whose strength is about 1% of the magnetic field on Earth.
8. Mercury has no moons or rings because of its low gravity and lack of atmosphere.
9. Mercury has a large iron core that is around 40% of its volume (compared to a core volume of 17% for Earth) in its center whose radius is 1800 to 1900 kilometers (1100 to 1180 miles). Scientists believe the core of Mercury is probably molten.
10. It is difficult to reach the planet due to its proximity to the Sun and any spacecraft visiting would need to travel 91 million kilometers into the Sun’s gravitational potential well. The Mariner 10 visited during 1974-75, flying by Mercury three times and mapping half its surface. On March 24, 1975 it ran out of fuel and is still believed to be orbiting the Sun. The MESSENGER probe was launched in 2004 to explore Mercury’s high density, its geological history, the nature of its magnetic field and more. Another mission, Bepi Colombo, is to be launched in 2015 by the European Space Agency and Japan is expected to reach Mercury in 2019.