Solar system

A conjunction is a good time to reflect on our cosmic heritage, and on the long shadows cast by the gas giants.Illustration by SN VFX / Shutterstock Today, December 21, Jupiter and Saturn will appear extremely close to each other in the sky, less than a tenth of a degree apart, about one fifth the […]

‘Oumuamua may be a piece of a torn-apart comet, gravitationally launched into interstellar space, that roamed the galaxy before dropping on our doorstep.ESO / M. Kornmesser / Wikicommons Our solar system’s first houseguest—at least, the first one we have seen in our midst—is a strange one. Scientists have taken to calling it ‘Oumuamua (pronounced “Oh-MOO-ah-MOO-ah”), […]

This system is completely stable—I double-checked with computer simulations. But nature would have a tough time forming this system. If it exists, it could only have been built by a super-advanced civilization.Image by Sean Raymond / planetplanet.net When Frank Drake was a boy, growing up in 1930s Chicago, his parents, observant Baptists, enrolled him in […]

Before I could string full sentences together, I used to wander outside past my bedtime. I would push open the sliding glass door and immediately look up, searching for stars sprinkled beyond the silhouetted trees. At the time, I couldn’t even begin to comprehend what I was seeing. Instead, each beacon of light represented a […]

Imagine that two very similar-looking neighbors undergo a genetic test. The exam shows that the pair’s genetic fingerprints are virtually identical. They feel a flash of shock and excitement. What does this mean? Could they be long-lost twins, separated in a hospital mixup?The Earth and Moon share a similar issue, one that poses a major […]