A search is under way for "vulcanoids", a group of asteroids that may orbit near the Sun. Astronomers think these rocks, up to tens of kilometres across, may be in stable orbits between Mercury and the Sun. But they've never been seen, possibly because they're too hard to spot from the ground due to the Sun's glare as well as turbulence in the atmosphere. Now astronomers from the Southwest Research Institute in Texas are using digital cameras on board a NASA jet to get a clearer view from the stratosphere, 49,000 feet above the Mojave Desert. Any vulcanoids they find might contain exotic new combinations of minerals cooked up in the Sun's heat.