NASA has celebrated the 23rd anniversary of the launch of the Hubble Space Telescope by released a stunning infrared image of the Horsehead Nebula, along with a fascinating video describing how it was obtained. The agency reports:
Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery more than a century ago. The nebula is a favorite target for amateur and professional astronomers. It is shadowy in optical light. It appears transparent and ethereal when seen at infrared wavelengths. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that easily are visible in infrared light.
The nebula is part of the Orion Molecular Cloud, located about 1,500 light-years away in the constellation Orion. The cloud also contains other well-known objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard's Loop. It is one of the nearest and most easily photographed regions in which massive stars are being formed.
In the Hubble image, the backlit wisps along the Horsehead's upper ridge are being illuminated by Sigma Orionis, a young five-star system just out of view. Along the nebula's top ridge, two fledgling stars peek out from their now-exposed nurseries.
Scientists know a harsh ultraviolet glare from one of these bright stars is slowly evaporating the nebula. Gas clouds surrounding the Horsehead already have dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being stripped away by intense stellar radiation evaporating the hydrogen cloud, and a pillar structure forms.
There's more at the link. You can view and download a much larger version of the image here. Here's the video accompanying the news release. I recommend watching it in full-screen mode.
Space never ceases to fascinate me. There's so much we can see, but not touch; so much we can imagine, or guess at, but not know for sure at this distance. I daresay the human race won't last long enough to see it all . . . but wouldn't it be fun to try?