Magazine | Astronomy.com

Alpha Centauri (the yellow star just to the right of center) is the closest bright star to Earth. At 4.35 light-years away, on a scale model where Earth is the size of a bacterium, this star would sit 4.34 miles (nearly 7 km) distant.

Strange Universe: Empty conclusions

Venus and Jupiter over Lake Louise

Sky This Month: December 2023

Dishes of the Karl G. Jansky Very Large Array in New Mexico line up beneath the starry sky. Radio waves are just one of the numerous signals from space that comprise the soundtrack of the cosmos.

Scientists search for the soundtrack of the universe

A composite of two different times, as seen by Curiosity on Mars

Robotic Spaceflight, Solar System

What time is it on Mars?

It may not look like much, but capturing photons from the distant quasar 3C 273 is one of the most awe-inspiring observations you can make with a small telescope.

Deep-Sky Objects

Target acquired: Observe Quasar 3C 273

The assembled scope was small, light, and essentially useless.

Telescopes and Equipment

Are cheap telescopes worth it? The answer is no.

Illustration of a kilonova

Is gravity instantaneous?

A spectacle of sparkling stars and shining planets dance in hues of yellow, orange, and blue, as if creating a painting made by nature during the transition from civil twilight to nautical twilight.

Discover the three kinds of twilight

Stunning celestial sights such as the Milky Way under clear skies require absolutely zero magnification at all.

Observing Basics

Strange Universe: Zero-power love affair

A close-up image of M51 properly calibrated.

Observing Basics

Observing Basics: Coming to terms

The Large Hadron Collider at CERN

Does E = mc^2 hold true for dark matter and dark energy?

Mars is a dynamic world that continues to intrigue us. This image, captured by the Hubble Space Telescope, shows the planet wreathed in late-afternoon clouds.

Robotic Spaceflight

Experience Mars in 3D