How much do we know about space? Actually not as much as we would like. Every time you open a stargazing app like “Sky Tonight” or “Star Walk,” you might be surprised at how many different things you can find there. But what if we told you that all those planets, stars and other visible objects Less than 5% of what is in space Represent?
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Space is vast and full of secrets. Many of them remain unsolved, although science has come a long way. Let's summarize what is known so far.
What is space?
Space is an almost perfect vacuum without air. It is not empty: it contains many forms of radiation, as well as gas particles, dust and other materials floating in the void.
From Earth we can observe planets, stars and galaxies 46.5 billion light-years away in any direction from our planet. This region of space is called the observable universe. The estimated age of the universe is 11.4 billion to 13.8 billion years.
What is outdoor space?
From our Earth-bound perspective, outer space is anything beyond the boundaries that separate Earth from space. There are different definitions of exactly where an outdoor space begins. The most commonly used limit is Karman lineWhich is located at an altitude of 100 kilometers above sea level. From this point on, the air becomes too thin for regular aircraft (which rely on lift) to fly.
Space regions
The outdoor space can be divided into different areas. It is defined by the magnetic fields and “winds” that dominate within it.
- Geographic space It is part of outer space near Earth. It is located between the Earth's upper atmosphere and the outer limits of the Earth's magnetic field.
- Interplanetary space It is outer space within the solar system. It is defined by the solar wind that forms the heliosphere – a giant “bubble” around the Sun and its planets. At the edge of the heliosphere (the outer edge of the heliosphere) it merges into interstellar space.
- Interstellar space It is the physical space between star systems in a galaxy. It is filled with the interstellar medium (ISM), which consists of gas and dust.
- Intergalactic space It is the physical space between galaxies. It is very close to completely vacuum because it is generally free of dust and debris.
What is space made of?
Scientists believe that the universe consists of three types of matter: ordinary matter, dark matter, and dark energy.
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Ordinary matter, also called ordinary or baryonic matter, consists of protons, neutrons, and electrons Shape any visual object. Everything we can see – stars, planets, trees, animals, people – is made of ordinary matter. The proportion of natural matter in the universe is surprisingly small – less than 5%.
Dark matter
Dark matter neither emits nor absorbs light and energy Therefore it is completely invisible. Scientists assume that it consists of non-baryonic matter, such as WIMPs (weakly interacting massive particles), neutralinos and neutrinos. Although dark matter cannot be observed directly, astronomers hypothesize that it exists due to the effect of gravity on ordinary matter. For example, the study of spiral galaxies has shown that they contain more mass than can be seen. Without dark matter, galaxies would simply fly apart, because the gravity of ordinary matter alone is not enough to hold all the particles together. Dark matter is said to make up about 27% of the universe.
Dark energy
Dark energy is one A hypothetical form of energy that repels gravity: It pulls cosmic objects apart while gravity brings them closer together. Scientists have proposed the concept of dark energy to explain why the universe is not only expanding, but expanding at an increasing rate. At the moment, scientists have not determined its nature and origin: here “dark” means “unknown” and not literally dark, as is the case with dark matter. Dark energy is estimated to make up about 68% of the universe.
What can you find in the Outer Zone: Top 5 Strange Things
The deeper scientists delve into the cosmic depths, the more unusual objects and sites they discover. Here are some of the most notable space record holders.
The coldest body in space
The coldest place yet found in the universe is… Bounce nebula. It is located about 5,000 light-years from Earth in the constellation Centauri. The temperature inside the Earth is -272 degrees Celsius, which is one degree away from absolute zero.
The hottest place in space
Quasar 3C 273 Located in the constellation Virgo One of the hottest regions in space. The temperature here ranges from 20 to 40 trillion degrees Celsius. 3C 273 is also the first quasar ever discovered and the brightest quasar as seen from Earth (its apparent magnitude is 12.9).
The oldest star in space
Methusela (HD 140283, HIP 76976) is 16 billion years old, making it the oldest star in space — somehow. Even older than the universe (Scientists are still trying to figure out how this is possible.) The star is located in the constellation Libra and can be seen with binoculars (apparent magnitude 7.2).
The largest object in space
The Great Wall of China Hercules-Corona Borealis, or simply the Great Wall The largest known structure in the visible universe. It is 10 billion light-years across and could contain billions of galaxies. It is located about 10 billion light-years away, towards the constellations Hercules and Corona Borealis.
The largest source of water in space
The largest reservoir of water in space contains 140 trillion times more water than all the oceans on our planet. It is a cloud of water vapor surrounding the quasar APM 08279+5255 located in the Lynx constellation, 12 billion light-years away from us.
The list of the strangest objects in space may not end: it may also include a diamond planet, the only planet in the solar system with a tail, and the celestial body in which a man was buried. Read more about these space objects in our article.
Instructions
How old is the space?
There are two competing estimates based on two different measurements, which suggest that the universe may be between 11.4 billion and 13.8 billion years old. To help you visualize the history of the universe, we compressed it into one Earth year and got a cosmic calendar. Check it out in our chart.
How old is the universe? Take a look at our cosmic calendar to see how short human history is compared to the age of the universe.
See chart
Where does space begin?
Space does not begin at a certain height above the Earth's surface. There is a traditionally accepted boundary called the Karman Line which lies at an altitude of 100 km (62 mi) above sea level.
How big is the outdoor space?
The size of the observable universe – the part that we can see and measure visually – is estimated at about 46.5 billion light-years in each direction from Earth. If we imagine it as a sphere surrounding our planet, its diameter would be about 93 billion light-years. Find our location in the observable universe using our chart.
Where are we in the Milky Way? Where is the Milky Way galaxy located in the universe? How many galaxies are there in the observable universe? Find out the answers in this infographic.
See chart
What is the room temperature?
The core temperature of the outdoor area is -270°C. However, there are some extreme places: the temperature in the coldest place in space is -272 degrees Celsius; The temperature in the hottest places ranges from 20 to 40 trillion degrees Celsius.
What color is the room?
We know from experience that space is black. However, if we take into account the fact that the universe is infinite and contains billions of stars, shouldn't it be bright white? This peculiarity is known as Olbers' paradox. See possible solutions in our dedicated article.
Why can't sound travel through space?
Sound is a mechanical wave that requires a physical medium, such as air or water, to travel. Space is a vacuum: there is no air, and sound has no way to travel. Therefore, the room is generally quiet.
Is the room completely silent?
Although space is empty, it is not completely empty: it is full plasmaOr charged particles. These particles can generate (or be affected by) electric and magnetic fields, and thus can Magnetic waves Transmission – the plasma equivalent of sound waves. Their sound pressure level is about -100 dB. The human hearing threshold is about +60 dB, so we can't hear these waves every day, but we can detect them using instruments designed for this purpose, such as geostationary satellites. To hear them, we must Record them and turn them into audible tracks – a kind of strange-sounding “space music.”.
Quick summary: Basic space facts to remember
Space is a vacuum in which radiation and matter particles float. The estimated age of the universe ranges between 11.4 billion and 13.8 billion years. The observable universe is about 46.5 billion light-years in each direction from Earth (or 93 billion light-years in diameter). Everything that exists in the universe consists of ordinary matter, dark matter, and dark energy; Scientists are still investigating the nature and origin of the last two substances.
All About Space: Get more information about space
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