Software glitch hits Saturn moon probe

A SOFTWARE malfunction prevented a key piece of equipment on the Cassini spacecraft from recording data as it flew through the plume from a geyser shooting off a moon of Saturn, NASA has said.

NASA called the problem “an unexplained software hiccup” that came at a very bad time, preventing Cassini’s Cosmic Dust Analyser instrument from collecting data for about two hours as it flew over the surface of the moon Enceladus on Wednesday.

A key objective of the fly-by was to determine the density, size, composition and speed of particles erupting into space from the moon’s south pole in a dramatic plume.

Cassini programme manager Bob Mitchell said the problem meant the instrument did not “taste” the data as the craft flew through the plume — a process lasting under a minute.

“When it went through the plume, it was not working properly,” Mr Mitchell said in a telephone interview, expressing disappointment. “We had tested that software very carefully. We don’t know why it didn’t work properly.”

The Cassini spacecraft, studying the giant gaseous planet Saturn and its moons in a joint US-European mission, flew as close as 50km over the surface of Enceladus on Wednesday.

The Cassini spacecraft, which first spotted the geysers in 2005, flew over the moon at 51,500km per hour in the first of four fly-bys of Enceladus scheduled this year.

One of about 60 moons of Saturn, Enceladus is considered among the most intriguing bodies in the solar system, owing to the geysers that spurt from fractures in the surface at the south pole and spew material about 800km into space at about 1,450km per hour.

Enceladus, whose diameter is 500km, is one of the solar system’s brightest objects. Encased in ice, it reflects almost all of the sunlight that strikes it.

Some scientists surmise hot water must exist under the surface to eject these plumes. The presence of liquid water raises the possibility Enceladus may boast conditions conducive to the development of life, perhaps in the form of microbes.

NASA said images taken by the spacecraft showed that the north polar region is much older, and more pockmarked with craters of various sizes, than much of the southern hemisphere, in particular the south pole.