How comets shaped history
In ancient skies, a comet’s sudden appearance provided both spectacle and portent — and savvy leaders took advantage.
Scroll through the past to see just how good a comet can be.
Journey to the heart of the Milky Way
Astronomers know a supermassive black hole anchors our galaxy’s core. But they struggle to understand the origins of fast-moving stars that swarm it.
Did a medium-sized black hole drag a cluster of hot young stars to the Milky Way’s core?
On the trail of hydrogen’s heavy sibling
With twice the mass of ordinary hydrogen, deuterium plays a weighty role in trying to comprehend the early universe, galactic evolution, and life’s extent.
Where has all the water gone?
New results from Mars Reconnaissance Orbiter suggest the Red Planet’s past may not have been so warm and wet after all.
The High Resolution Imaging Science Experiment onboard the Mars Reconnaissance Orbiter continues to amaze scientists with its detailed images.
Illustrated: Explore Jupiter’s moons
Tenuous dust rings, glowing gas clouds, and a ring of plasma arise from Jupiter’s closest moons.
Observe winter’s forgotten star clusters
Begin your observing year with 16 bright, but little-known, open clusters.
Your tour of great open star clusters is just beginning.
The darkest sky under the stars
Observing and imaging are top priorities at Arizona Sky Village, a remote community that may be amateur astronomers’ paradise.
Meade’s mySKY teaches you the stars
Beginning astronomers take note: You can identify celestial objects like a pro.
This Month in Astronomy
Bob Berman’s strange universe
Phil Harrington’s binocular universe
Meet the colorful Gemini twins
Stephen James O’Meara’s secret sky
The sky this month