How is 600 light years

This means that we always see the Sun as it was about 8. The next closest star to us is about 4. All of the other stars we can see with our eyes are farther, some even thousands of light-years away. Stars are found in large groups called galaxies. A galaxy can have millions or billions of stars. The nearest large galaxy to us, Andromeda, is 2. So, we see Andromeda as it was 2. The universe is filled with billions of galaxies, all farther away than this. Some of these galaxies are much farther away.

It is That is only million years after the big bang. It is one of the first galaxies ever formed in the universe. Learning about the very first galaxies that formed after the big bang, like this one, helps us understand what the early universe was like.

This picture shows hundreds of very old and distant galaxies. The oldest one found so far in GN-z11 shown in the close up image. The image is a bit blurry because this galaxy is so far away. Oesch Yale University , G. Illingworth University of California, Santa Cruz. What Is a Light-Year? Even in their excitement, the researchers caution that they have found no proof that we are not alone.

The Kepler team has done a prodigious job of detection and mathematical calculation, but Kepler has not actually seen the planet or taken any chemical measurements. They know its host star is slightly smaller and cooler than the sun, and they found that its light dims ever so slightly once every Earth days. That means the dot of the planet is passing in front of it. It's a little closer to its sun than we are to our sun.

From there, they can extrapolate. For the planet to be in a nice, nearly circular orbit, not too hot and not too cold, they figured out that it's probably 2. That makes it among the smallest planets yet found orbiting other stars, but it's a smidgen larger than an ideal candidate for extraterrestrial life would be.

Scientists know, from looking at Earth's solar system, that rocky worlds like the Earth's are a precious commodity. If a world is too small think of Mercury or Earth's moon , any atmosphere will escape into space before life could possibly form. If a world is too large think of Jupiter or Neptune it's likely to be all atmosphere, a giant ball of gas or slush that thickens quickly as you plunge beneath its cloud tops, but probably has no solid surface where living things could thrive.

Keplerb might be the right temperature, but it is probably closer in mass to icy Neptune than to Earth.