The sizes of the planets of the solar system in ascending order and interesting information about the planets. What makes Earth an ideal place to live? III

"The first exoplanet orbiting a star similar to our Sun was discovered in 1995. Exoplanets, especially small, Earth-like worlds, only emerged from the realm of science fiction 21 years ago. Today, after thousands of studies, astronomers are ready to announce the discovery what people have dreamed of for thousands of years - another Earth," the announcement says.

The briefing, which will be broadcast on the NASA website, will be attended by NASA management representative John Grunsfeld and three scientists - John Jenkins, Jeff Coughlin and Didier Chielo.

Later at a briefing, scientists reported that they had indeed found new earth- an exoplanet comparable in size to the Earth, in the “habitable zone” of a system similar to the Solar one - Kepler-452b. There should be liquid water on it.

Kepler-452b at 60% more than Earth in size and mass five times greater. It receives 10% more heat from its star than the Earth from the Sun. This does not harm the planet due to its massiveness and fairly open water surface. Considering the evolution of the central star and the orbit of Kepler-452b, it has already spent six billion years in the “habitable zone” of its star and will remain there for another 500 million years. A year on the planet “Kepler-452b” lasts 385 days - only 20 days longer than that of Earth. The distance to this planet from us is 1.4 thousand light years.

The central star belongs to the spectral class "G2" - it is exactly the same star as our Sun in mass and temperature. This star alone is 1.5 billion years older than the Sun (six billion years). This planetary system is located in the constellation Cygnus. The distance from the star to the planet Kepler-452b is 1.05 AU. (157.5 million km.).

Previously, Kepler took a break from observing distant stars and kept an eye on Neptune and its moons for 70 days, allowing scientists to produce a 30-second video of their cosmic “dance.”

Kepler, designed specifically to search for exoplanets, was launched in May 2009. The device constantly monitored the stars in a small area of ​​the sky in the area of ​​the constellation Cygnus and looked for planets, recording weak fluctuations in the brightness of these stars as the planets passed across the disk of the luminary.

In May 2013, the telescope failed, but experts found a way to continue its operation as part of the so-called K2 mission.

Last May, NASA officially approved the telescope's resurrection and extended its funding for two years. In December, Kepler made its first "second life" discovery, discovering the super-Earth exoplanet HIP 116454b in the constellation Pisces.

Before the breakdown, Kepler was aimed at one point in space and monitored only a small corner of the sky, which is located at the junction of the constellations Cygnus and Lyra. After the “resurrection,” the telescope monitors different parts of the sky, since NASA specialists have to constantly rotate it in such a way that sunlight did not fall into the telescope lens.

Our Solar System consists of the Sun, the planets orbiting it, and smaller celestial bodies. All of these are mysterious and surprising because they are still not fully understood. Below are the sizes of the planets solar system in ascending order, and briefly talks about the planets themselves.

There is everything famous list planets, which lists them in order of their distance from the Sun:

Pluto used to be in last place, but in 2006 it lost its status as a planet, as larger celestial bodies were found further away from it. The listed planets are divided into rocky (inner) and giant planets.

Brief information about rocky planets

The inner (rocky) planets include those bodies that are located inside the asteroid belt separating Mars and Jupiter. They got their name “stone” because they consist of various hard rocks, minerals and metals. They are united by a small number or absence of satellites and rings (like Saturn). On the surface of rocky planets there are volcanoes, depressions and craters formed as a result of the fall of other cosmic bodies.

But if you compare their sizes and arrange them in ascending order, the list will look like this:

Brief information about the giant planets

The giant planets are located beyond the asteroid belt and therefore are also called outer planets. They consist of very light gases - hydrogen and helium. These include:

But if you make a list by the size of the planets in the solar system in ascending order, the order changes:

A little information about the planets

In modern scientific understanding, a planet means a celestial body that revolves around the Sun and has sufficient mass for its own gravity. Thus, there are 8 planets in our system, and, importantly, these bodies are not similar to each other: each has its own unique differences, as in appearance, and in the components of the planet themselves.

- This is the planet closest to the Sun and the smallest among the others. She weighs 20 times smaller than Earth! But, despite this, it has a fairly high density, which allows us to conclude that there are a lot of metals in its depths. Due to its strong proximity to the Sun, Mercury is subject to sudden temperature changes: at night it is very cold, during the day the temperature rises sharply.

- This is the next planet closest to the Sun, in many ways similar to Earth. It has a more powerful atmosphere than Earth, and is considered a very hot planet (its temperature is above 500 C).

- This is a unique planet due to its hydrosphere, and the presence of life on it led to the appearance of oxygen in its atmosphere. Most of The surface is covered with water, and the rest is occupied by continents. A unique feature is the tectonic plates, which move, albeit very slowly, resulting in changes in the landscape. The Earth has one satellite - the Moon.

– also known as the “Red Planet”. It gets its fiery red color from large quantity iron oxides. Mars has a very thin atmosphere and much smaller atmospheric pressure, in comparison with earthly. Mars has two satellites - Deimos and Phobos.

is a real giant among the planets of the solar system. Its weight is 2.5 times the weight of all the planets combined. The surface of the planet consists of helium and hydrogen and is in many ways similar to the sun. Therefore, it is not surprising that there is no life on this planet - there is no water and a solid surface. But Jupiter has a large number of satellites: on this moment known 67.

– This planet is famous for the presence of rings consisting of ice and dust revolving around the planet. With its atmosphere it resembles that of Jupiter, and in size it is slightly smaller than this giant planet. In terms of the number of satellites, Saturn is also slightly behind - it has 62 known. large satellite– Titan, has big sizes than Mercury.

– the most light planet among external ones. Its atmosphere is the coldest in the entire system (minus 224 degrees), it has a magnetosphere and 27 satellites. Uranium consists of hydrogen and helium, and the presence of ammonia ice and methane has also been noted. Because Uranus has a high axial tilt, it appears as if the planet is rolling rather than rotating.

- despite its smaller size than , it is heavier and exceeds the mass of the Earth. This is the only planet that was found through mathematical calculations, and not through astronomical observations. The most recorded on this planet strong winds in the Solar System. Neptune has 14 moons, one of which, Triton, is the only one that rotates in the opposite direction.

It is very difficult to imagine the entire scale of the solar system within the limits of the studied planets. People think that the Earth is huge planet, and, in comparison with other celestial bodies, this is true. But if you place giant planets next to it, then the Earth already takes on tiny dimensions. Of course, next to the Sun, all celestial bodies appear small, so representing all the planets in their full scale is a difficult task.

Most well-known classification planets are calculated by their distance from the Sun. But a listing that takes into account the sizes of the planets of the Solar System in ascending order would also be correct. The list will be presented as follows:

As you can see, the order has not changed much: the inner planets are on the first lines, and Mercury occupies the first place, and in other positions - outer planets. In fact, it doesn’t matter at all in what order the planets are located, this will not make them any less mysterious and beautiful.

Ecology

All the main publications on the planet have recently talked about the closest star system to us: a planet comparable in size to the Earth revolves around the star Alpha Centauri B. By astronomical standards, this planet is very close to us.

Despite the fact that this planet is similar in size to Earth, it is most likely completely barren, the researchers reported.

Astronomers have discovered an exoplanet near the Sun-like star Alpha Centauri B, which is part of a three-star system located just 4.3 light-years from the Solar System. Called Alpha Centauri Bb, the planet is roughly the same mass as Earth, but its surface is likely covered in hot rock as its orbit is 25 times closer to its star than Earth's orbit is to the Sun.

"We're pretty sure there's no chance for life on this planet."- said the researcher planets Sara Seager. But what allows our planet to support life? Why is our Earth so special?

There are several components necessary for life to exist, according to scientists, but debate continues over what limitations living things might actually have. There are some special species on Earth that exist and thrive in the most seemingly extreme and unsuitable conditions for life.

Here are the components that a planet needs in order for life to arise on it, at least in our usual understanding:

Water

“First, you need some kind of liquid medium in which the molecules can react.”, says Seeger. In such a soup, the ingredients for life as we know it, such as DNA and proteins, can float and interact with each other for the reactions that life requires to take place.

The most common liquid on Earth that is suitable for such a “solution of life” is water. Water is an excellent solvent in which many substances can dissolve. Water has special properties, for example, unlike other liquids, when it turns into a solid state - ice, it can remain on the surface of liquid water, that is, it acts as an excellent insulating substance, preventing the remaining layers from freezing. If ice sank in water, all layers of reservoirs would freeze, making chemical reactions impossible for life to exist.

Astronomers searching for extraterrestrial life often look to planets that are in the so-called habitable zone, orbiting their parent stars. In such orbits, planets receive just enough stellar heat to keep water in a liquid state. The Earth is located in just such a habitable zone. Mars and Venus, the planets closest to Earth, no longer fall into this zone. If the Earth were located even a little closer or further in relation to the Sun, life would probably never have arisen on it, it would have been the same lifeless desert as on Mars, or the Earth would have been a foggy oven like Venus.

Of course, alien life doesn't necessarily play by the same rules as Earth's inhabitants.

Astrobiologists are increasingly talking about looking beyond traditional habitable zones. For example, while liquid water does not currently dominate the surface of Mars or Venus, there may once have been a time when this was not the case. At that time, life could well have developed on these planets and either moved to safer places on these planets, for example, went underground, or adapted to a harsher environment, as organisms did extremophiles living on Earth in extreme conditions. Or both.

At the same time, the liquid environment of other planets can also harbor life. For example, Saturn's moon Titan contains liquid methane and ethane.

Energy

The second thing life requires is energy. Without energy, almost nothing will work. The most obvious source of energy for a planet or satellite is its parent star. In the case of Earth, sunlight triggers photosynthesis in plants. Nutrients, in turn, which are created as a result of photosynthesis, are the fuel on which almost all living things rely directly or indirectly.

An infinite number of living organisms on Earth, however, exist due to other sources of energy, such as chemical substances from deep-sea sources. There is no shortage of energy sources on Earth.

Time

Scientists say that inhabited worlds requires stars that live at least several billion years. This time is enough for life to evolve on them.

Some stars live only a few million years and die. However, life can arise relatively quickly, so age in this case is not so important, scientists say, but age is important when it comes to complex life forms.

For example, the Earth appeared approximately 4.6 billion years ago. The oldest known organism is about 3.5 billion years old, meaning life appeared 1.1 billion years or less after the planet's origin. However, these were very simple organisms. It takes much longer for complex life forms to arise on the planet. First multicellular organisms appeared on Earth only some 600 million years ago. Due to the fact that our star, the Sun, can be called a long-liver, there was enough time on the planet for man to evolve.

Circulation

Other researchers suggest that tectonic plates are essential for life to emerge in the world. That is, the surface of the planet must be divided into plates that are constantly moving. Plate tectonics is critical to the circulation of molecules necessary for life.

For example, carbon dioxide helps trap the sun's heat to keep the Earth's surface warm. This gas tends to accumulate in rocks over time, meaning the planet will eventually freeze. Plate tectonics allows these rocks to sink down, where they melt, and the molten rock releases carbon dioxide back into the atmosphere through volcanoes.

Additional factors

Other factors that allow life to exist on Earth include small fluctuations solar radiation compared to more volatile stars, and a magnetic field that helps protect us from any storms of charged particles that come from the Sun. Strong outbreaks of radiation could kill life at the most early stages development when she was too vulnerable.

Earth remains so far the only known planet on which life exists due to the unique combination of all the most important factors. However, constant exploration of alien worlds may one day change the situation. Maybe someday we will be able to find a planet that has all the similar or completely new attributes that allow life to exist on it.