Back to Article List Michael’s Miscellany: 25 Questions About Astronomy Test your knowledge with this short quiz about the cosmos.

Planck’s constant is one of the most important numbers in all of physics. It is, essentially, the ultimate guide to the quantum world. It tells us where quantum effects are important, the ...

Paul Levesque Popular Astronomy Club Jul 14, 2025 Updated Aug 10, 2025 0 ...

This week's Junior Forecaster, Nathan, loves all things space. His favorite subjects in school are astronomy and space, ...

Monisha Ravisetti is Space.com's Astronomy Editor. She covers black holes, star explosions, gravitational waves, exoplanet discoveries and other enigmas hidden across the fabric of space and time.

My astronomy books are packed, as are many of our belongings. In a few days, I will lose Internet access. We are going through that particularly difficult move: "The Downsize". Then will come the ...

Before defining what a light-year is, we should define what a light-year is not: It is not a measure of time, but rather a measure of distance ...