If the moon orbited Earth on the same plane that Earth circles the sun, then we'd have a total lunar eclipse at each full moon, and a total solar eclipse at each new moon. But that doesn't happen because the lunar orbit is inclined to Earth's orbit by about 5 degrees.
A podcast featuring Harvard theoretical physicist Avi Loeb, on the subject of whether 'Oumuamua - the strange object that swept through our solar system in 2017 - is an artifact of an alien intelligence.
The first of 2 spring supermoons in 2021 took place on April 26 or 27 (depending on your location on Earth). We received many wonderful submissions from you, our readers. Here's a gallery of some favorites. Thanks to all who submitted!
Orion the Hunter is one of the sky's most noticeable constellations. Sirius is the sky's brightest star. As Earth revolves around the sun, they're both about to disappear for awhile. Here's how to star hop from Orion's Belt to Sirius.
Data from ESA’s Gaia star-mapping satellite have revealed tantalizing evidence that the famous V-shaped Hyades - nearest star cluster to our sun - is being disrupted. The culprit may be a suspected population of dark matter sub-halos. Wow!