Merry Yosemite Christmas!

Merry Yosemite Christmas!

[CLICK ON IMAGE FOR HIGH RESOLUTION / Wally Pacholka / AstroPics.com, TWAN A starry band of the Milky Way climbs over Yosemite Valley, Sierra Nevada Range, planet Earth. Jupiter is the brightest celestial beacon on the wintry scene, though. Standing nearly opposite the Sun in the constellation Taurus, the wandering planet joins yellowish Aldebaran and […]

Interstellar dust clouds make the dark skies blue

Interstellar dust clouds make the dark skies blue

[CLICK ON IMAGE FOR HIGH RESOLUTION.] This lovely blue cosmic cloud begins the van den Bergh Catalog (vdB) of stars surrounded by reflection nebulae. Interstellar dust clouds reflecting the light of the nearby stars, the nebulae usually appear blue because scattering by the dust grains is more effective at shorter (bluer) wavelengths. The same type […]

Orion’s Horsehead Nebula, 1,500 years ago

Orion’s Horsehead Nebula, 1,500 years ago

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the […]

Stars of the Trapezium light up the spectacular Orion Nebula

Stars of the Trapezium light up the spectacular Orion Nebula

Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest […]