How many years is one light year in Earth years?
It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More p recisely, one light-year is equal to 9,500,000,000,000 kilometers.
A light-year is the distance light travels in one year. How far is that? Multiply the number of seconds in one year by the number of miles or kilometers that light travels in one second, and there you have it: one light-year. It's about 5.88 trillion miles (9.5 trillion km).
- The light-year is a unit of length used to express astronomical distances. It is about 9.5 trillion kilometres or 5.9 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days).
- There are 6 trillion miles in a light-year (approximately), so the distance we need to go is 6 trillion miles / light-year times 4 light-years, or 24 trillion miles. So, this trip would take 1.2 billion hours. There are 24 hours a day and 365.25 days per year, so this time in years is 137 thousand years.
- Because that's how far away Mars is! The speed of light is roughly 300,000 km/second. Mars is on average about 225 million km from Earth (the distance varies greatly, depending on both planets' position in their orbits). That translates to an average distance of 12.5 light minutes.
It really is an incredibly long distance -- a lightyear is roughly 6 trillion miles or nearly 10 trillion kilometers. Here's how you calculate it. You start with the speed of light, which is about 186,000 miles per second. Then you multiply that by 3,600 seconds in an hour.
- It is most commonly used for the distances to stars and other galaxies. The nearest star is 4.2 light years away from our sun. We are 8.3 light minutes away form the Sun. the distance to the outer most planet Pluto is about 13 light hours.
- Mankind's speediest spacecraft so far is travelling 33,000 MPH. At that rate it takes it roughly six hours to go as far as light light goes in one second. That's a ratio of one to 21,600. So that means current technology could get us to our nearest neighbor two LY away in 43,000 years.
- Light travels at "the speed of light" which has been measured to be about 300,000 km/s (kilometers per second) or 186,000 m/s (miles per second) in empty space. Doing the math, a Light-year is 9.46 trillion km, or 5.88 trillion miles. Trillion is 10^12.
This duration is a bit of a problem, as it makes space exploration a painstakingly slow process. Even if we hopped aboard the space shuttle discovery, which can travel 5 miles a second, it would take us about 37,200 years to go one light-year.
- If an object tries to travel 186,000 miles per second, its mass becomes infinite, and so does the energy required to move it. For this reason, no normal object can travel as fast or faster than the speed of light. That answers our question, but let's have a little fun on the next page and modify the question slightly.
- The planet is about 1,400 light-years away from the Solar System. At the speed of the New Horizons spacecraft, about 59,000 km/h (37,000 mph), it would take approximately 26 million years to get there.
- The Galileo spacecraft launched in October 1989. It took just over six years to reach the gas giant, arriving in December 1995. But the craft took a very circuitous route, traveling a distance of 2.5 billion miles. It traveled around Venus, Earth, and the asteroid Gaspra to reach Jupiter.
Updated: 2nd October 2019