The hydrogen in your body, present in every molecule of water, came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in […]

On January 3, two space stations already illuminated by sunlight in low Earth orbit crossed this dark predawn sky. Moving west to east (left to right) across the composited timelapse […]

The first Full Moon of 2023 is in the sky tonight opposite the Sun at 23:08 UTC. Big and beautiful, the Moon at its brightest phase should be easy to […]

Look up tonight and see a whole bunch of planets. Just after sunset, looking west, planets Venus, Saturn, Jupiter and Mars will all be simultaneously visible. Listed west to east, […]

There, that dot on the right, that’s the largest rock known in our Solar System. It is larger than every known asteroid, moon, and comet nucleus. It is larger than […]

Makemake (sounds like MAH-kay MAH-kay), second brightest dwarf planet of the Kuiper belt, has a moon. Nicknamed MK2, Makemake’s moon reflects sunlight with a charcoal-dark surface, about 1,300 times fainter […]

At this year’s end Mars still shines brightly in planet Earth’s night as it wanders through the head-strong constellation Taurus. Its bright yellowish hue dominates this starry field of view […]

The Horsehead Nebula, famous celestial dark marking also known as Barnard 33, is notched against a background glow of emission nebulae in this sharp cosmic skyscape. About five light-years “tall” […]

Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood […]

Have you ever seen an entire rainbow? From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops. From the […]