1. Mercury is the smallest planet in our solar system, with a diameter that is just slightly bigger than the moon of the Earth.
2. Mercury was given its name by the Romans, who were the first to do so. It was really their messenger God who was credited with being very swift-footed who was called after the planet.
3. Heraclitus, a Greek philosopher who lived before the time of Socrates, was certain that Mercury and Venus did not revolve around the Earth, but rather around the Sun, as was commonly thought.
4. Humans have been aware of the existence of this planet for at least 5,000 years. The Sumerians linked the planet with their deity of writing, Nabu, whom they worshipped.
5. On Mercury's surface, the morning Sun seems to rise briefly before setting, then rising again because of the planet's elliptical—egg-shaped—orbit and slow rotation, which causes the morning Sun to appear to rise briefly, set, then rise again from certain areas of the planet's surface. At sunset, the same thing occurs in the other direction.
6. The ancient Greeks distinguished between the evening star Hermes and the morning star Apollo, thinking them to be two distinct things that should be named accordingly.
7. Mercury is a rocky planet, sometimes known as a terrestrial planet, since it has a rocky surface. Mercury's surface is solid and cratered, similar to that of the Earth's moon.
8. Scientists believe that ice may be found inside the craters of Mercury. The planet's north and south poles are both frigid and gloomy, which may enable them to retain water ice longer than other parts. Alternatively, ice may have been supplied to such regions by meteorites and comets, or water vapour from Mercury's internals could have leaked out and frozen.
9. When it comes to density, the Earth ranks top, but Mercury isn't far behind. Mercury has a metallic core that extends between 3,600 and 3,800 kilometres (or 2,200 and 2,400 miles) in diameter, making it the second-densest planet in our Solar System.
10. Mercury has a speed of 180,000 kilometres per hour, or 112,000 miles per hour, as it goes around the sun. As a result, Mercury is the planet with the greatest speed in the whole Solar System.
11. Mercury may be viewed as an evening "star" near the location where the sun has set, or as a morning "star" near the location where the sun will rise in the morning.
12. Mercury's thin atmosphere, known as the exosphere, is mostly comprised of oxygen (O2), hydrogen (H2), sodium (Na), potassium (K), helium (He), and with trace amounts of other elements (K). Mercury's exosphere is made up of atoms that have been blasted off the planet's surface by the solar wind and micrometeoroid impacts.
13. Mercury's maximum distance from the Sun during a full rotation is 70 million kilometres (43 million miles) or 43 million kilometres per hour. Aphelion is the name given to the furthest point on the horizon.
14. Mercury has been circling the sun since 2011, and NASA's MESSENGER spacecraft has returned some stunning pictures of the planet, which is the nearest planet to the sun. Researchers utilised those pictures to construct the first-ever comprehensive map of the surface of Mercury, which was published in Science.
15. It is the nearest planet to the Sun, with a distance of about 36 million miles (58 million kilometres) or 0.39 astronomical units (AU) between them.
16. Scientists have found that Mercury has streams of particles sloughing off its surface, which they believe are caused by a chemical reaction. However, although scientists aren't certain what is responsible for the forms of the tails, they suspect that it has something to do with the magnetosphere of the planet and the wind from the sun.
17. On Mercury, one day (the amount of time it takes for Mercury to revolve or spin once in relation to the stars) is equivalent to 59 Earth days. Mercury's day-night cycle takes 175.97 Earth days to complete one cycle. Mercury completes one complete circle around the Sun (equivalent to one year in Mercury time) in just 88 days on Earth.
18. Mercury has been determined to be devoid of any signs of life. Temperatures during the day may reach 430 degrees Celsius (800 degrees Fahrenheit), while temperatures at night can plummet to -180 degrees Celsius (-290 degrees Fahrenheit). It seems doubtful that life (as we know it) will be able to persist on this planet in its current form.
19. Mercury was one of the five planets that the ancients were aware of. These planets were referred to as "wandering stars." by the ancients.
20. The two spacecraft of the BepiColombo mission, operated by the European Space Agency and Japan Aerospace Exploration Agency, are on their way to Mercury. Mariner 10 was the first mission to investigate Mercury, launched by NASA in 1977. The MESSENGER spacecraft of NASA was the first to circle the innermost planet.
21. We previously said that Mercury does not have an atmosphere. This is not completely correct. Mercury has a very thin atmosphere, which makes it difficult to breathe. In this very thin atmosphere, there are traces of potassium, 6 percent helium, 22 percent hydrogen, 29 percent sodium, 42 percent oxygen, and trace quantities of neon, krypton, and xenon. There are also traces of nitrogen, carbon dioxide, water, and the element argon in the atmosphere.
22. Mercury's atmosphere is thin that it can only be detected with great difficulty.
23. While standing on the surface of Mercury during the moment of its closest approach to the Sun, our star would seem more than three times bigger than it appears from Earth.
24. Mercury's surface is comparable to the surfaces of the Earth's moons in terms of composition.
25. Mercury is the smallest planet in the solar system, with a diameter of just 450 kilometres. Mercury is similar in size to the Earth's moon, but it is somewhat bigger than it.
26. On Mercury, there are no seasons at all. It just has a faint atmosphere with gravity that is only 38 percent that of the gravity experienced on Earth.
27. Scientists have photographed Mercury nearly completely with the assistance of spacecraft that have been deployed on different exploration missions over the last several decades.
28. BepiColombo is the name of an ESA mission to Mercury, which will be launched in 2018. It is named after a renowned Italian mathematician and physicist, Giuseppe (Bepi) Colombo (1920-1984), who was born in the same year that the project was launched. It will take at least 7 years for the multi-spacecraft project to reach its orbit around the planet Mercury. The Japan Aerospace Exploration Agency and the European Space Agency will collaborate on this project. During its voyage to Mercury, the mission will make nine flybys of the planets Earth, Venus, and Mercury, among other places.
29. For Mercury, the most eccentric and least circular orbit in the solar system is the result of a collision with the planet Venus. And keep in mind that the orbit of a planet has a great deal to do with the other conditions that exist on it, such as temperature and atmosphere.
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