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

These are the best walking treadmills you can buy in every category, from Mobvoi Home Treadmill to Bluefin Fitness Task 2.0 Treadmill.

BUYING GUIDE These are the best treadmills you can buy in every category, from NordicTrack x22i and Mobvoi Home Treadmill to Peloton Tread.

Buyers guide These are the best running shoes you can buy in every category, from Saucony Ride 16 and Brooks Glycerin 20 to Hoka Mach X.

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.