Seven Earth-sized planets orbit an alien star only 40 light-years away

A small, cool star in distant space plays host to something amazing.  Scientists have discovered that at least seven Earth-sized worlds circle the star TRAPPIST-1, a ultracool dwarf star only about 40 light-years (235 trillion miles) from Earth.  The planetary haul — which includes at least six rocky planets total, three of which were first discovered last year — is detailed in a new study published in the journalNature on Wednesday. SEE ALSO: Stop describing a planet