TIGHT FIT The star Kepler 11 (illustrated) is home to six planets, five of which would fit inside the orbit of Mercury. Most solar systems might form with planets squished even closer together.
Tim Pyle/NASA
TIGHT FIT The star Kepler 11 (illustrated) is home to six planets, five of which would fit inside the orbit of Mercury. Most solar systems might form with planets squished even closer together.
Tim Pyle/NASA