Where exactly does space begin? Explore the fascinating debate among scientists about the true boundary between Earth's atmosphere and outer space. From the Kármán line to NASA’s definitions, uncover ...

As soon as Thursday, Virgin Galactic plans to fire the rocket motor of its spacecraft and fly to an altitude of more than 50 miles. If it accomplishes that goal, it would proclaim it has reached the ...

Recently, during the first Ars Live event of this year, two noted space journalists joined Ars space editor Eric Berger for a discussion of NASA’s future in the age of the second Trump administration.

The 2025 Orionid meteor shower peak begins overnight on Oct. 20-21, when 10-20 shooting stars may be visible streaking across ...