On Sunday, NASA鈥檚 Stardust spacecraft began a seven-year journey to visit a
comet. In 2004, the $165-million craft, launched on a Delta-II rocket,
will pass within 160 kilometres of Comet Wild-2.
It will trap dust from the comet and interstellar particles in 鈥渁erogel鈥�, a
light, transparent solid. It will then return and drop a capsule containing the
aerogel into the Earth鈥檚 atmosphere in 2006. The capsule will land in Utah.