Noble in space

Compounds of noble gas elements are rare on earth, but now a team from Cardiff University in the UK has found one in space. The find was made using data from an instrument aboard Europe's Herschel Space Observatory. The molecule, argon hydride, was seen in the Crab Nebula, the remains of a star that exploded 1000 years ago. The discovery was made almost by accident during studies of the dust in the nebula. We were really concentrating on studying the dust in the filaments and out pops these two bright emission lines exactly where we see the dust shining, says team member Haley Gomez. The team had a hard time figuring out what these lines were from, as no-one had seen them before. The isotopic ratio of the argon in this new interstellar substance is different from that which is seen in terrestrial rocks and so might provide new clues as to the processes that led to the explosion and the Crab Nebula 1000 years ago.