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Surveying is one of the most important tasks in astronomy, and because of the enormity of the universe, in astronomy we usually measure in units of enormous lengths, which are often used to describe the distances between planets, stars, galaxies, galaxy clusters, and other celestial bodies in the universe.
In our lives, we usually use units such as meters, kilometers, and miles to describe length, which are very commonly used on the earth scale, but cannot meet the needs of measurement on the cosmic scale, so astronomers have to use larger units of length to describe the distance between the universes.
In astronomy, what we commonly refer to as astronomical units, light years, and parsecs are the three most common units of length that describe the distances between objects within the solar system, within the Milky Way, and at greater distances.
Among these units, light-years are often used to describe the distances between more distant celestial bodies, so they are widely used in cosmological research.
So apart from light years, are there any larger units of length in the universe than light years?
1. Astronomical units.
Since the astronomical unit only uses the distance between celestial bodies in the solar system, it is the smallest unit of length, which is about the average distance from the Earth to the Sun.
An astronomical unit is defined as the average distance that the Earth has made around the Sun.
Since the distance from the Earth to the Sun changes from year to year, astronomers have set 1 AU at 12:00 on January 1, 1860, when the distance from the Earth to the Sun is 1 AU for the convenience of measurement.
At the same time, the abbreviation for astronomical units is AU.
The astronomical unit is a very simple unit of length, and its size is very easy to remember, so the astronomical unit is often used to describe the distance between the planets in the solar system, and is very useful when measuring the distance between the planets in the solar system and the sun.
At the same time, astronomical units are also a very practical method of measurement, because they have enough accuracy and convenience, and most of the distances between the planets and the sun are between several units, so astronomical units are very suitable for the measurement of the solar system.
Astronomical units also have the advantage of being easy to understand, and when ordinary people understand the definition and use of astronomical units, they can better understand the distance between the sun and the planets.
However, the limitations of the astronomical unit are also more obvious, the astronomical unit is only suitable for measurements within the solar system, so it cannot be used to measure the distance between celestial bodies such as planet-to-planet, planet-to-satellite, satellite-to-satellite, etc.
2. Light years.
A light-year is a common unit of length defined as the distance traveled by light in a vacuum in a straight line at a speed of 300,000 kilometers per second for one year.
Mathematically, the value of a light-year is about 10 trillion kilometers.
Light-year is usually abbreviated as ly, and light-year is often used to describe the distance between different stars and stars in the universe, which is not only easy to remember, but also very easy to understand during use.
A light-year is a very large unit, so a light-year is often used to describe the distance between distant stars and star clusters, in other words, a light-year is often used to measure the distance between distant objects in the universe.
In a light-year, there is a very important unit of length, and this unit of length is called the parsec, which is also a unit of length commonly used by astronomers.
Parallax is defined as the distance at a parallax of 1 arc second, and parallax is a common method used in astronomy to measure the distance between stars, when the observed position of a celestial body on Earth changes, we can use parallax to calculate the distance between the celestial body and the Earth.
Seconds are often used to measure the distance between stars, and when the parallax between two stars is 1 arc second, the distance between the two stars is 1 second, and the magnitude of 1 parsec is about 3.26 light-years.
Among the parsecs, there are also relatively large units, which are the thousand-second gap, the million-second gap, and the billion-second gap.
These units are often used to measure the distance between galaxies and clusters of galaxies, so it can be seen that the range of measurement also varies with the unit of length.
3. 100 million light years.
There are often some people who are very curious, we all say that it is possible to find aliens after reaching space, so are there really aliens on our planet?
In fact, there are countless galaxies in the universe, and our galaxy centered on the Milky Way, until now, human beings have not been able to discover any galaxy outside our galaxy, let alone aliens.
But galaxies beyond the Milky Way still exist, because the Milky Way is only a small galaxy, and if we take the Milky Way as the center, then the closest galaxy to us is also very far away.
In fact, there are two galaxies closest to us, namely Big Magellan and McGellan, which orbit the Sun with the same as the Milky Way, so the relationship between these two galaxies and the Milky Way is like siblings.
The reason why Big Magellan and Magellanli can be discovered by humans is that these two galaxies are the two largest companion galaxies in the Milky Way, so they can be observed by humans.
Human observations of the Great Magellan and the Big Magellan can be traced back to around 150 B.C., when an ancient Greek astronomer first discovered the traces of the Big Magellan and the Big Magellanic, and since then the two galaxies have been tracked for a long time.
And during this time, Magellan and Magellan have also experienced two closeness, and no galaxy in the galaxy has no human beings, not even single-celled organisms.
epilogue
In the process of human exploration of the universe, as our understanding of the universe continues to deepen, it is also possible that larger units of length will be needed to describe the distance between more distant celestial bodies in future work.
Therefore, there may be larger units of length in the future to meet the needs of human exploration of the universe.
In astronomy, the use of different length units depends on the distance range and accuracy requirements of the research object, and choosing the appropriate length unit can better describe and understand the vastness of the universe.