American physicists have predicted a new molecule made of two rubidium atoms whose electron cloud (simulated above) would resemble a trilobite, the marine invertebrate that lived more than 300 million years ago. They claim the molecule could be made from two rubidium atoms inside the ultracold, dense environment of a Bose-Einstein condensate: first, using laser pulses or electromagnetic fields, an electron in one atom must be coaxed into a very high orbit; then the molecule could form as this outermost electron attracts another atom. This unusual molecule would be huge, with the two atoms separated by up to 50 000 Å, compared with the typical atomic size of just 1 Å. The trilobite-shaped electron cloud means the molecule would have a very large permanent electric dipole moment, as much as 1000 times larger than that of any other polar diatomic molecule. AIP