What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly […]

A broad expanse of glowing gas and dust presents a bird-like visage to astronomers from planet Earth, suggesting its popular moniker: the Seagull Nebula. This portrait of the cosmic bird […]

What’s that over the horizon? What may look like a strangely nearby galaxy is actually a normal rocket’s exhaust plume — but unusually backlit. Although the SpaceX Falcon 9 rocket […]

What glows in the night? This night featured a combination of usual and unusual glows. Perhaps the most usual glow was from the Moon, a potentially familiar object. The full […]

What kind of celestial object is this? A relatively normal galaxy — but seen from its edge. Many disk galaxies are actually just as thin as NGC 5866, the Spindle […]

Is this a painting or a photograph? In this celestial abstract art composed with a cosmic brush, dusty nebula NGC 2170, also known as the Angel Nebula, shines just above […]

What’s happening across that field? Pictured here are not auroras but nearby light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer can see a […]

Murriyang, the CSIRO’s Parkes radio telescope points toward a nearly Full Moon in this image from New South Wales, Australia, planet Earth. Bathed in moonlight, the 64 meter dish is […]

In 46 BC Julius Caesar reformed the calendar system. Based on advice by astronomer Sosigenes of Alexandria, the Julian calendar included one leap day every four years to account for […]

How does the sky turn dark at night? In stages, and with different characteristic colors rising from the horizon. The featured image shows, left to right, increasingly late twilight times […]