Our Sun and its well-known and charming family of planets, moons, asteroids and comets formed when a dense drop of matter took refuge in the undulating folds of one of the many huge, cold and dark molecular clouds that haunted our Milky Way. collapsed under the powerful and ruthless pull of his own gravity. These cold, ghost-like clouds consist mainly of hydrogen gas – with the addition of dust to an intriguing mixture – and they serve as a strange cradle for planetary systems like ours. In July 2015, a team of astronomers announced that they had discovered that Earth-like alien planets orbiting stars outside our sun were three times more likely to have the same type of minerals as Earth than they thought. In fact, the precious ingredients that make up the building blocks of terrestrial rocks are ubiquitous in our huge stellar spiral galaxy!
The results of this new study of the chemical evolution of our Milky Way were presented on 9 July 2015 by Dr. Brad Gibson of the University of Hull, UK, at the annual national astronomical meeting of the Royal Astronomical Society (RAN) in London. , Llandudno, Wales.
Minerals, consisting of building blocks of elements such as oxygen, carbon, magnesium and silicon, are thought to determine the landscape of rocky planets in the Earth’ group, similar to ours, which originated in solar systems around similar distant relatives of stars under the sun. A small difference in mineralogy can play a big role when it comes to plate tectonics, as well as warming and cooling the planet’s rocky surface – all of which could affect whether the planet will eventually become a livable world. Until now, planetary scientists have believed that rocky planets and planets in the Earth’s group are clearly divided into three distinct groups: those that have the same set of building blocks as our Earth, those that have a much higher concentration of carbon, and those that contain much more silicon than magnesium.
“The interconnection of elements on Earth means that chemical conditions are “perfect” for life.” Too much carbon, and your rocky planet may be more like graphite in your pencil than on the surface of a planet like Earth,” Dr. Gibson said in a Press Release of the Russian Academy of Sciences on July 9, 2015.
Worlds of rocky land
In our solar system there is a quartet of planets of the Earth group: Mercury, Venus, our Earth and Mars. Of these four, it is known that only the Earth has an active hydrosphere.
Dwarf planets such as Ceres and Pluto, and some large asteroids resemble the four planets of the Earth’s group in our solar system. In fact, these smaller bodies have a solid surface, but on average they are made of more icy materials. Ceres and Pluto have a density of 2.1 grams per cubic centimeter. The density of Earth’s planets in our solar system tends to decrease as we move away from our Sun. For example, the rocky Subplanet Vesta – the second largest inhabitant of the main asteroid belt between Mars and Jupiter – orbits Mars and has a lower density than Mars – 3.4 grams per cubic centimeter.
Planets of the Earth group, sometimes called planets of the Terrestrial group or rocky planets, are mainly composed of silicate rocks or metals. In our solar system, all four terrestrial worlds inhabit the innermost region of our solar system – where they are closest to our star. The terms “planet earth” and “planet of the Earth type” are derived from the Latin words denoting the earth (Terra and Tellus). Indeed, the composition of these planets “similar to earth.”
All the planets of the Earth group have solid surfaces that contrast with the four very different gas giant planets that orbit our Sun in the outer solar system. The quartet of giant outer planets – Jupiter, Saturn, Uranus and Neptune – consists mainly of a mixture of hydrogen, helium and water, which exists in different physical states.
All planets of the Earth group have almost the same structure: the central metal core, usually iron, surrounded by silicate mantle.
On the planets of the Earth group can be mountains, volcanoes, craters and other features of the surface, depending on tectonic activity and the availability of water. In addition, these rocky worlds have secondary atmospheres formed as a result of volcanism or collisions of comets, unlike the gas giant planets of the Outer Solar System, whose atmospheres are primary and were directly related to the gravity of the solar form.
Astronomers have discovered a series of swirling protoplanetary accretion discs orbiting young stars. These discs are formed around the same time as their stars, in a darkened opaque package. The protoplanetary accretion disk feeds a hungry and extremely hot star – or protostar – with the nutrient gas and dust needed to become a full member of the star population. In these very ancient times the accretion disk was hot and massive – it can remain near its gentle, young and fiery star up to 10 million years.
By the time the shiny star-studded baby reached the T Taurus stage in its development, the massive, thick, swirling accretion disk of gas and dust had cooled and became much thinner. The T Taurus star is a young and active solar star, whose age is “only” 10 million years old or even younger. These toddlers from the star community have about the same mass – or slightly less – than our Sun, but their diameter is several times larger. However, young active brands continue to decline. This is because young stars, such as the sun, narrow with age. By the time the shimmering star reaches this stage, less volatiles begin to condense near the center of the surrounding swirling accretion disk. This condensation eventually leads to the formation of very small and very sticky dust particles. These very small and naturally sticky, delicate dust particles contain crystalline silicates.
Tiny sticky dust particles collide with each other in a very dense environment of the protoplanetary accretion disk and eventually ‘stick together’, creating ever larger objects – the size of a pebble the size of a stone.