Science · Facts & sources
5 sourced facts about outer space, each with the context behind the number. 4 more are in today's round and appear here after it closes.
Answer6,366 confirmed planets
The count has soared in just over three decades since the first exoplanets were found, and scientists believe billions exist.
Source: NASA Exoplanet Archive exoplanetarchive.ipac.caltech.edu
Answer238,855 miles (384,400 km)
That's enough room to fit 30 Earth-sized planets between Earth and the Moon.
Source: NASA Science, Moon Facts science.nasa.gov
Answerabout an inch per year
The Moon is also tidally locked to Earth, which is why we always see the same side.
Source: NASA Science, Moon Facts science.nasa.gov
Answer687 Earth days (669.6 sols)
A Martian day, called a sol, lasts 24.6 hours — very close to an Earth day.
Source: NASA Science, Mars Facts science.nasa.gov
Answer13 minutes
Mars orbits at an average of 142 million miles from the Sun, or 1.5 times Earth's distance.
Source: NASA Science, Mars Facts science.nasa.gov