７０ A planet inhabited by creatures has Discovered！【Space Travel】 Dialogue with the Universe

７０　A planet inhabited by creatures has Discovered！【Space Travel】 Dialogue with the Universe

December 05, 2011 ＮＡＳＡ released
Discovered planet (Kepler 22b) is about 600 light years from Earth at a distance. Its size is about 2.4 times of Earth's. It rotates around the star similar to the Sun by over 290 days, and the planet's surface temperature is about 22 degrees.

Source: National Geographic News
http://www.nationalgeographic.co.jp/news/news_article.php?file_id=20111206003&expand#title

・By the way, the current speed of the spacecraft, you can go to this planet in about 30 000 years.
【Reference】
(1) The use of stone tools first began about 1.8-2.5 million years ago. Homo sapiens (current human) appeared approximately 190,000- 200,000 years ago.
(2) The Distance to the closest terrestrial planet(Gliese 581) is15 light-years.