Orion nebula, infrared IRAS image. The Orion nebula (M42 and M43) is the bright yellow region just below centre. Above and to the left of this is the nebulosity surrounding the star Alnitak (Zeta Orionis), which contains the Horsehead nebula. Above and left of this is the reflection nebula M78. In the infrared part of the spectrum, warm dust appears brighter than stars, although the red supergiant Betelgeuse (Alpha Orionis) is seen as the blue dot at upper left. IRAS was launched in January 1983 and imaged the entire sky before running out of coolant and ceasing operations in November the same year.