Pluto probe set for distant horizon The US space agency is set
to shed light on Pluto with the launch of the New Horizons
spacecraft this week. The spacecraft, which is due to be
launched at 05:24 AEDT on Wednesday (18:24 UTC, Tuesday) will
also investigate a new class of planet-like objects, called ice
dwarfs, that exist beyond the orbit of Neptune. Over the
decades, NASA has launched probe after probe for close-up
studies of Earth's sister planets. But distant Pluto has
remained shrouded in mystery, with only a few fuzzy telescope
pictures for scientists to ponder. "What we know about Pluto
today could fit on the back of postage stamp," says Dr Colleen
Hartman, NASA's deputy associate administrator for science. And
New Horizon's principal investigator Dr Alan Stern, with the
Southwest Research Institute in Boulder, Colorado, agrees we
have much to learn about the history of these distant objects.
"These are objects that were growing to planethood, but
something stopped that process of growth mid-gestation,"