The history of the formation of Mercury is similar to that of the Earth. About 4.5 billion years ago the planet formed. This was a time of intense bombardment of the planets as they collected the material and the remains of the nebula from which they formed. At an early stage of this formation, Mercury probably differed into a dense metal core and a silicate bark.

Kepler was an astronomer and mathematician fascinated by Euclid's geometry. I saw in the Universe the work of a divine creator, the Perfect Geometric. In an effort to discover this geometry, he spent much of his life trying to associate the 5 Pythagorean solids with the orbits of the planets around the Sun, nesting inside each other, in what he called his "cosmic mystery", published in 1596.

Discovered in 1801 by the Italian astronomer Giuseppe Piáis, Ceres is one of the planets considered dwarfs. In 2015, bright spots or spots were observed on its surface, and thanks to NASA's Dawn space probe today we have images that confirm them. In Ceres' photograph, we can see two bright spots located inside a crater.

Chemical propulsion Astronomy dictionary, letter P The chemical propulsion engine is the most commonly used in rockets. The chemical process that feeds it is the combustion of propellants. While the propellant of a jet aircraft is composed of a single chemical component, the fuel that is burned by the oxygen that the engine extracts from the air, the propellant that feeds the engine of a rocket must have, in addition to the fuel, also an oxidant or oxidizer, that is, a chemical compound necessary to burn the fuel, because the rocket must fly mostly in the vacuum of space, where there is no oxygen.

Tierra del Fuego is an archipelago of South America located between the Atlantic, Pacific and Antarctic oceans. Its name comes from the conquerors who came to these lands, among other Magellan. They all watched terrified from their ships that large fires were seen on the ground. Actually, it was the fires that the Indians lit to warm up.

Leónidas Dictionary of astronomy, letter L The Leonids are an annual rain of shooting stars or meteors that arises in the sky between November 14 and 20, with a maximum frequency of 17, and that appear to radiate from a point in the sky located near the star Leonis, in the constellation Leo, where the name Leonidas comes from.