|How far away are stars?|
|Question Date: 2014-10-02|
Really far! As you probably know, the closest
star to Earth is none other than our friendly sun
- and that's almost 93 million miles away! To
give you an idea of how far away that is, if you
were driving in a car at the same speed you go on
a highway, it would take you 177 YEARS to get from
here to the sun.
The next closest star to us is called
Proxima Centauri and that's almost 300,000
times farther away from Earth than the sun is!
Because stars are so far away, measuring the
distance to them in miles isn't very useful - you
always get huge numbers. Instead, astronomers
measure distance by how long it would take light
(which can travel 186,000 miles every second) to
go somewhere. So for example, since it takes
light about eight minutes to get to the Earth from
the sun, we say that the sun is eight
light-minutes away from Earth. Similarly, Proxima
Centauri is 4.2 light years away from Earth.
So those are the closest stars. What about the
ones further away? Well, as a star gets farther
and farther away, it gets dimmer, so the farthest
stars you can see with your eyes when you look out
at the night sky are about 4,000 light years away.
That means it takes light 4,000 years to travel
from those stars to your eyes!
How about even farther? Well, the solar
system lives in the Milky Way galaxy, which is
a huge blob of stars. The center of the Milky Way
galaxy is 27,000 light years from Earth, while the
entire galaxy is about 100,000 light years across.
But you can only see stars that far away with a
What about even further? Sure! The Milky Way
is just one of tons of galaxies - one of the
closest galaxies to us is the Andromeda
galaxy, which is about 2.5 million light years
away. It's so far away that you can't see
individual stars in it - you just see an glowing
blob. The very farthest galaxies we can see with
our fanciest telescopes are about 13 BILLION
light-years away - that means that the light that
we see from those galaxies left them not very long
after the universe was born! So when you look at
galaxies that are very far away, you're also
looking back in time at what the universe used to
look like. It is the closest we've got to a time
It varies drastically. The closest star is the
sun, which is about 93 million miles away. Farther
than that, we use the term "light years" to
tell distance. A light year is the distance light
can travel in a year. Although it looks
instantaneous to us, light actually has a speed,
about 300,000,000 meters every second. That's fast
enough to get to the moon in about 1.2 seconds. We
haven't been able to build anything that can
travel nearly as fast as light, but it is a good
way to measure distance. Pluto is about 6 hours
away by light. The nearest star is four light
years away, or about 23,500,000,000,000 miles. The
galaxy is about 100,000 light years across, or
about 588,000,000,000,000,000 miles (588
quadrillion miles). This sounds ridiculous but is
true. That means that if you were to drive a car
from one side of the galaxy to the other (assuming
someone built that road), at 80mph it would take
839,000,000,000 years. Since the universe is
13,000,000,000 years old approximately, it would
take well over the entire lifetime of the universe
to travel that distance by car.
The short answer is REALLY REALLY FAR away.
The distance between galaxies is even larger, so
some stars in other galaxies are millions or
billions of light years away. Space is big.
The closest star to Earth is the sun, which
is 92,960,000 miles from earth. The furthest group
of stars visible to the naked eye is the Andromeda
Galaxy, which is 2.3 million light years away .
The furthest stars found by astronomers in 2013
was 13.1 billion light years away .
 Dunbar, B. (2006, October 3). Amazing
Andromeda Galaxy. Retrieved October 3, 2014, from
 Croswell, K. (2013, October 23). Farthest
confirmed galaxy is a prolific star creator.
Retrieved October 3, 2014, from
There is a wide spectrum of distances that a star
might be from Earth. For instance, our solar
system's sun, which is just shy of 150 million
kilometers away from the Earth, is the closest
star to us. After the sun, though, the next
closest star is 4.3 light years away, where 1
light year is about 10 trillion kilometers! And
the farthest stars that have been measured are
around 13.1 billion light years away (around
1023 kilometers away)!
Some stars are closer than others. The sun, the
nearest star, is 150 million kilometers, or
eight light minutes (that is, it takes light from
the sun eight minutes to reach the Earth, due to
the distance from the sun to the Earth). The
nearest star in the sky other than the sun,
Proxima Centauri, is four light years away.
I don't know how far away the "average" star in
the night sky is. There are many many stars that
are far, far away, but are too faint in the sky
for the human eye to see them.
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