The bold question-askers at What If explore what could happen if a quasar entered our solar system. Lawmakers Start to Break Ranks Under Shutdown Pressures Slain motorcyclist’s sweetheart says $50K ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

Surrounding our solar system is a natural and enigmatic cosmic shield called the heliosphere — and a new mission has launched to help astronomers better understand it. Created by the solar wind, a ...

Voyager 1, launched in 1977, has traveled farther than any spacecraft in human history. After more than four decades of silent endurance through space, it now sails beyond the orbit of the outer ...

The European Space Agency's ExoMars Trace Gas Orbiter image of interstellar comet 3I/ATLAS as it passed close to Mars. (The European Space Agency) A mysterious interstellar comet — just the third such ...