What Does Space Smell Like?

• When astronauts return from space walks and remove their helmets, they are welcomed back with a peculiar smell. An odour that is distinct and weird: something, astronauts have described it, like "seared steak." And also: "hot metal." And also: "welding fumes." 
• Once you leave our galaxy, the smells can get really interesting. In dark pockets of the universe, molecular clouds full of tiny dust particles host a veritable smorgasbord of odors, from wafts of sweet sugar to the rotten-egg stench of sulphur
• But if you travel 26,000 light years to a dust cloud at the centre of the Milky Way called Sagittarius B2, you might catch a whiff of raspberries and maybe rum. This cloud is stuffed with ethyl formate, an ester that gives both treats their flavour