Moonlight, Planets, and PerseidsIn the predawn sky on August 13, two planets were close. And despite the glare of a waning gibbous Moon, bright Jupiter and even brighter Venus were hard to miss. Their brilliant close conjunction is posing above the eastern horizon in this early morning skyscape. The scene was captured in a single exposure from a…Read More

M13: The Great Globular Cluster in HerculesIn 1716, English astronomer Edmond Halley noted, “This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent.” Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the…Read More

Trapezium: In the Heart of OrionWhat lies in the heart of Orion? Trapezium: four bright stars, that can be found near the center of this sharp cosmic portrait. Gathered within a region about 1.5 light-years in radius, these stars dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars,…Read More

Perseids from PerseusWhere are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tonight is known as the Perseids — the meteors all appear to come from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris…Read More

Zodiacal RoadWhat’s that strange light down the road? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently just after sunset — or just before sunrise — and is called zodiacal light. Although the origin of this dust is still being researched, a leading hypothesis holds…Read More