Brothers

For humans, 500 light-years seems infinite. When looking at the stars, we can't help thinking: in the boundless universe, do we have other brothers or partners? Actually, the optimistic scientists have told us that there must be partners with high wisdom like humans. And the distance between our hearts may be 500 light years.

In April 2014, the national aeronautics and space administration (N A S A) announced that they had discovered a terrestrial planet located in the “habitable zone” for stars by Kepler space telescope. The distant cousin of this plaanet is Kepler-186f, locating in Cygnus, and is the fifth planet around the star Kepler-186, its size is about 1.1 times of the earth. So far, the Kepler-186f is the planet most like the earth people have found.

Cygnus is the main sign in the summer night sky, it appears in the eastern sky, at the shore of the milky way at 9 or 10 oclock in the summer night. Its main bright stars form a cross, therefore is also known as “north cross”, which is quite easy to recognize. The bright star at the swan tail tip is a blue and white super star called Deneb, which forms the summer triangle together with the Altair and Vega.

The 500th

extrasolar planet

people discovered

The 500th extrasolar planet people found is Kepler-8b, which is one of the first batch of five planets found by Kepler telescope. Kepler-8b is a “hot Jupiter”, whose radius is 1.4 times of that of Jupiter, surface temperature is up to more than 1000 degrees. As close to its parent star, it takes only three and a half days for it to orbit the parent star.

500 light-years, the distance of other life

At present, the Kepler telescope has found dozens of extrasolar planets within the habitable zone. Don't forget that its detection distance is only a few thousand light years, searching for only a very small area in the sky, less than 1/4000 of the area throughout the universe. Its search has a high requirement on the angle, only the planetary systems whose quotation is similar to our gazing direction could be found, every confirming of the terrestrial planet of the same size of the earth takes 3 years of continuous analysis of data. Therefore, the planets already found are only a small part of all the planetary system. And the astronomers estimate that throughout the galaxy, the earth-like planets within the habitable zone in the galaxy may be 40 billions, of which about 11 billion stars rotate around the star similar to the sun.

500 light-years, now is the limit distance for the radio telescopes receiving the civilization informations. But apparently, the distance of the high wisdom capable of star international communication is more than 500 light years away. Therefore, to seek for signals coming from alien civilisations, the large telescopes and new observation techniques are needed in the future.