Olympics legend Mary Lou Retton "fighting for her life" in ICU due to pneumonia, daughter says

NASA Suggests Nothing Could Survive on Our Nearest Earth-Like PlanetThe First White Dwarf Pulsar in The Universe Has Been Found After Half a Century

Astronomers Have Spotted a Black Hole So Ravenous, It's Pushing The Limits of PhysicsThis Ancient Martian Volcano Erupted Non-Stop For 2 Billion YearsOne of Betty White's final photos shared on what would have been her 100th birthday

WATCH: A Bright Green Meteor Just Streaked Above The USScientists Have Figured Out How to Actually Stop an Interstellar Spacecraft

The Days of Earth's 'Outer Space Treaty' Are Numbered, And Things Could Get Messy

Astronomers Spot a Strange, Supersonic Space Cloud Screeching Through Our GalaxyIf Planet Nine Exists, It Could Spell Disaster For Other Planets in The Solar System

How to Watch This Week's Breathtaking 'Ring of Fire' Solar EclipseNASA Plans to Send an Autonomous Submarine to Explore Titan's Oceans

New Solar System Objects Just Made The Case For Planet Nine Even StrongerScientists Just Emerged From a Year in Isolation After an Epic NASA-Funded Mars Simulation