Why is a light year better than an astronomical unit? It is a question asked by many people, especially students of science and geology, as the light year and the astronomical unit are units of measurement of distances between galaxies and celestial bodies, so the light year is the distance that light can travel in one year, and in the coming lines we will talk about the answer to this question and we will learn about the year optical in more detail.
Why is a light year better than an astronomical unit?
The answer is Because the distance between galaxies is very large, greater than the distances in the solar system, so it needs a unit of measurement as large as the light year, which is greater than the astronomical unit.A light year is a unit of distance. It is the distance light can travel in one year. Light moves at a speed of about 300,000 kilometers per second, which means that in one year it can travel about 10 trillion kilometers. More precisely, one light year equals 9,500,000,000,000 kilometers.
In our solar system, we tend to describe distances using an astronomical unit (AU), defined as the average distance between the Earth and the Sun. It’s about 150 million kilometers (93 million miles) across. It can be said that Mercury is about a third of an astronomical unit away from the sun and Pluto is about 40 astronomical units away from the sun, but the astronomical unit is not large enough to measure distances to objects outside our solar system.
What is a light year and how far is it?
A light year is a measure of distance, not time (as the name might suggest). A light year is the distance a light ray travels in one Earth year, or 6 trillion miles (9.7 trillion km). In a vacuum, light travels at 670,616,629 miles per hour (1,079,252,849 km/h). To find the distance of a light year, we multiply this speed by the number of hours per year (8766), so one light year equals 5,878,625,370,000 miles (9.5 trillion km). At first glance, this might seem like a very long distance, but the colossal size of the universe reduces this distance.
Examples of the use of a light year
Some examples of the use of a light year are:
The distance between us and the cancerous supernova is 4,000 light years. Our galaxy, the Milky Way, is about 150,000 light-years across. The Andromeda Galaxy, the closest galaxy to the Milky Way, is 2.3 million light-years away.
Finally, we have answered a question Why is a light year better than an astronomical unit? We also learned about the light year and how far away it is, and we gave some examples of using the light year.
