Sundials use the location of a shadow to measure the Earth's rotation and indicate the time of day.

Only 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth.

Behold one of the most photogenic regions of the night sky, captured impressively.

Unlike most entries in Charles Messier's famous catalog of deep sky objects, M24 is not a bright galaxy, star cluster, or nebula.

South pole star Sigma Octantis (of the constellation Octans) is on the left of this starry expanse spanning over 40 degrees across far southern skies.

A small crystal ball seems to hold a whole galaxy in this creative snapshot.

They may look like round rocks, but they're alive.

How big is our Sun compared to other stars? In dramatic and popular videos featured on YouTube, the relative sizes of planets, stars, and even the universe are shown from smallest to largest.

Marked by an unusually bright central region, swirling dust lanes, and far flung tidal tails, peculiar NGC 3256 is the aftermath of a truly cosmic collision.

Volcanic activity on the Big Island of Hawaii has increased since this Hawaiian night skyscape was recorded earlier this year.