andlt;strongandgt;Orion nebula.andlt;/strongandgt; Hubble Space Telescope mosaic ofthe Orion nebula (M42; NGC 1976), which is 1500light years away in the constellation Orion. Thisis one of the most detailed astronomical imagesever produced (as of 2006). It shows thousands ofstars never seen before in visible light. Nebulaeare huge clouds of interstellar gas and dust. Thisis an emission nebula, a region of starbirth. Itglows red due to the ionisation of the hydrogengas it contains by radiation from four hot youngstars, the trapezium stars, at its core. M42andamp;apos;ssmaller neighbour M43 (NGC 1982) is seen at topleft.