References

We currently know of more than 5,800 planets beyond the solar system, but we've only found the tiniest fraction of the exoplanets that astronomers think lie elsewhere in the universe.

References Can running shoes ever be sustainable?

Discover interesting facts about Jupiter, its many moons, and whether the gas giant and its moons could host extraterrestrial life

BUYING GUIDE Our favorite cardio machines, from the iconic Peloton bike to the meaty NordicTrack X22i treadmill.

Discover interesting facts about Saturn, its rings and whether it could contain extraterrestrial life.

Earth Day is an annual global event on April 22 that celebrates Earth and raises public awareness about the environment.

Antarctica is the coldest, windiest, and driest continent. Because so little moisture falls as rain or snow, Antarctica is classified as a desert.

Discover interesting facts about the origins of primates, what they eat, and if they have thumbs.

Discover important facts about what climate change is, what's causing it, and what we can do to stop it.

Learn interesting facts about the flu, a viral infection that targets the respiratory system.