The Hubble Space Telescope was launched 23 years ago. Astronomers have used Hubble to make the above photograph of the iconic Horsehead Nebula in infrared light to mark the anniversary. The Horsehead Nebula has been a staple image in astronomy books for a century or so. While it’s shadowy in visible light (at left), it appears transparent and ethereal when photographed at infrared wavelengths as it pops out against a backdrop of stars and distant galaxies visible in infrared light.

Image Credit: NASA