Venus
It will be the first U.S.-led mission to the Venusian atmosphere since 1978.
There may be bizarre microbes living in the sulfuric acid-laden clouds of the hothouse planet, scientists said.
"...two hundred and fifty degrees, and raining sulphuric acid."
Thank you, Tim Peake!
WHAT'S HAPPENING
Mercury, Venus, Saturn, Mars and Jupiter will align for first time in a decade.
Venus, Mars and Jupiter won't be visible together again for another six years.
Venus is on its radar.