Space
Asteroid Bennu’s boulder mystery solved
Asteroid Bennu's boulder mystery has now been solved, scientists say. Highly porous rocks explain the abundant large rocks but lack of fine sand-like regolith.
Space
Today's Image
Andromeda Galaxy photos, 2021
Enjoy a photo gallery of the best Andromeda Galaxy images from EarthSky readers! The Andromeda Galaxy is a great observing target on fall evenings.
Earth

The fate of Arctic sea ice

Our warming world means the fate of Arctic sea ice could be in peril, along with the plants, animals and rich ecosystem that call it home.
Astronomy Essentials
Space

Heads up! Famous comet 67P/C-G nearly closest

Famous comet 67P/C-G will sweep closest to Earth in November. Finder charts help you locate this comet before it leaves for another 193 years.
Astronomy Essentials
Human World

Halloween is an astronomical holiday

The 4 cross-quarter days fall between equinoxes and solstices. Halloween is the spookiest one. It comes from a festival of ancient Celts and Druids.
Space

Watch the Progress 79 cargo launch October 27

On October 27, 2021, Russia’s uncrewed Progress 79 cargo craft will launch from the Baikonur Cosmodrome in Kazakhstan. Here’s how to watch.
Astronomy Essentials

Flashing star in autumn? Here are 3 candidates

Some October night, check out 3 of the flashiest stars in the night sky ... at least at this time of year. Why a flashing star flashes, here.
Earth

True polar wander: A shift 84 million years ago

The fossil magnetism of rocks in Italy revealed true polar wander - a major shift in Earth's outer shell relative to its spin axis - 84 million years ago.
Clusters Nebulae Galaxies

Double Cluster in Perseus on October evenings

The Double Cluster in Perseus is a breathtaking pair of star clusters, easy to see in October. How to find it in your sky.
Space

See 42 of the largest asteroids in new images

Astronomers with the European Southern Observatory (ESO) have obtained new and more detailed images of 42 of the largest asteroids in the main asteroid belt.