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Why do astronomers use both light years and astronomical units to measure distance?
Wiki User
∙ 12y ago
Astronomical units for closer objects in our solar system, such as other planets,
comets and such like and light year for other stars and galaxies which are much,
much further away. It's like comparing the distance of objects in your room using
meters and the distance to a city several miles away.
For the same reason you use inches, not miles, to describe the length of your shoe,
and miles, not feet, to describe the distance from your house to the library.
Technically, you can use any old unit of length you want, to describe any length or
distance. But it only makes sense to pick the unit that will produce a convenient
number for the length or distance you're trying to describe. That way, you wind
up with a number that's a lot easier to writer, to remember, and to tell other people
about.
For example, if you're talking about the wavelength of red light, you could say
that it's 0.000000000236 mile, and you'd be perfectly correct. But nobody would
remember that after you told them about it, and you'd be much better off telling
them that it's 380 nanometers.
If you're talking about the distance to the moon, you could say that it's around
15,080,000,000,000 millimeters. You'd be perfectly correct, but again, if you
walked up to anybody and told them about it, their eyes would glaze over and
they'd forget it as soon as they heard it. It would be much more convenient for
you and everrybody else if you said the moon is 238,000 miles away, or even
0.0026 AU.
And if we're talking about the distance from me to the nearest star past the sun,
how would you feel if I told you that it's 15,707,000,000,000 kilometers ? Most
likely not as comfortable as if I told you that it's 4.3 light-years, although they're
both correct.
It's all a matter of picking the unit that gives you the most convenient number.
That way, you give yourself a break, and make it a lot easier to remember the
number, write it down in your notebook, and tell other people about it.
Which is a big part of exactly what Astronomers must always do.
Wiki User
∙ 12y ago
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What is used to find a planet's distance from the sun?
When exploring space, astronomers use astronomical units, (AU) to measure the distance from one object to another. Since every distance from one object in our solar system to another object in our solar system, the distance of a planet from the sun would be measured in astronomical units
What is used to measure distance between stars?
Light year or astronomical units
What unit of distance do astronomers use to measure distances to stars?
Usually light-years, or parsecs.
What astronomical unit is the measure of distance between the earth and what other celestial body?
light year
Why do astronomers use light year to measure time in space?
They don't. Light years are a distance measurement, not a time measurement.
How do astonomers measure the distance to nearby stars?
Astronomers use the unit of measure "Light Years" to calculate the distance between pretty much anything in the Universe.
How do astronomers measure the distance to nearby stars?
Astronomers use a method called parallax to measure the distance to nearby stars. Astronomers can measure parallax by measuring the position of a nearby star with respect to the distant stars behind it. Then, they measure the same stars again six months later when the Earth is on the opposite side of its orbit.
What unit do astronomers usually use to measure the distance to a star?
They use light years, the distance light can travel in 1 year. It's equivalent to 5878499810000 miles.
The universe is so large that astronomers measure distance between stars instead of kilometers?
light-years, parsecs, and megaparsecs
How do you measure long distances in space?
In Light-years(how far light travels in 1 Earth year), AU(Astronomical Unit=distance between the Earth and the Sun), Parsecs( the distance from the Sun to an astronomical object which has a parallax angle of one arcsecond), or simply miles.
Why is a light year considered a distance and not a time interval?
A light year is considered a distance and not a time interval because it is an astronomical unit of length equal to just under 10 trillion kilometers. A light year is a measure of distance and not time.
What is the relation between light year and astronomical unit?
The astronomical unit is the average distance from the earth to the sun, and is 149 598 000 kilometres. A light year is the distance light will travel in a year, the speed of light is just under 300 000 kilometres per second, so light travels one astronomical unit in just over eight minutes. A light year is 9.46x1012 kilometres, or 63239.67 astronomical units.
