The distance that light travells in one year. Since light travels at 3000,000 km/sec, or 186,000 miles/sec, that's a very long way! The distance that light travells in one year. Since light travels at 3000,000 km/sec, or 186,000 miles/sec, that's a very long way!
Because the universe is so large, they need something like light to at least reach large amounts of distance.
Light years are a unit of distance that represents how far light travels in one year, approximately 5.88 trillion miles (9.46 trillion kilometers). They are used to measure vast distances in the universe, such as the spaces between stars and galaxies, because these distances are often too large to be conveniently expressed in miles or kilometers. For example, when astronomers say a star is 4 light years away, it means that light from that star takes 4 years to reach Earth. This method allows for a clearer understanding of the scale of the universe.
They can't. The universe is only about 13 billion years old. If there are galaxies a trillion light years away their light has not reached us yet and due to the expansion of the universe, never will. At the edge of what we call the observable universe we cannot make out individual stars, but we can detect galaxies using infrared telescopes.
The observable Universe is the part of the Universe we can see from Earth because the light from all the objects in it has had enough time to reach us. Light from outside the observable Universe has yet to reach Earth. The reason we can only see part of the Universe is because of the limited speed of light, and the expansion of the Universe, which is faster than that speed. According to Einstein, nothing in the Universe can move faster than light, but nothing stops the expansion of space from moving faster than light. This results in a large part of the Universe being completely invisible to us.
Considering, we can only observe light, the furthest known object is UDFj-39546284 a stellar structure. At the time of observation it was about 13.2 billion light years from us.However, since that time, it is now possibly 32 billion light years from us and getting further away.
The observable Universe has a diameter estimated at 93 billion light-years.
Because the universe is so large, they need something like light to at least reach large amounts of distance.
light-years, parsecs, and megaparsecs
Astronomers have found a mind-bogglingly large structure so big it takes light 10 billion years to traverse in a distant part of the universe.
If you counted 1 galaxy per second, it would take ~3200 years to count all 100 billion galaxies in the universe.
This is the same question as how big is the universe. The size of the universe is determined by how far light would travel in the years since the Big Bang. So it is a sphere of 13.7 light-years radius. We can't see all the way to the edge, but pretty close.
universe's equator distance is about 150,000,000,000 light years.
Everything in the universe have different size. The smallest thing ever is the photon particle, and it is so small that nobody has been able to find it's exact size. The greatest thing in the universe is the great wall- a great sheet of galaxies which is 500 million light years long and 16 million light years thick.
Light years are a unit of distance that represents how far light travels in one year, approximately 5.88 trillion miles (9.46 trillion kilometers). They are used to measure vast distances in the universe, such as the spaces between stars and galaxies, because these distances are often too large to be conveniently expressed in miles or kilometers. For example, when astronomers say a star is 4 light years away, it means that light from that star takes 4 years to reach Earth. This method allows for a clearer understanding of the scale of the universe.
100,000 light years
A light beam that travels for the entire lifetime of the universe would cover a distance of approximately 13.8 billion light-years. This is because the observable universe is estimated to be about 13.8 billion years old in terms of light-travel distance.
In 'light years' or in 'scientific notation'