Images from Titan, Saturn’s moon are flooding down to Earth and intriguing scientists (NPR: Science Friday). The first radar images of Saturn’s smoggy moon show what appears to be a large lake, rolling ridges and lavalike flows of ice or ammonia, researchers at Jet Propulsion Laboratory said yesterday.
The Cassini- Huygens mission to Saturn will complete some 44 more scheduled flybys of Titan over the next four years — and until the European Space Agency’s Huygens probe is launched from Cassini in January — all they can do right now is speculate. The mission to Saturn, its rings, moons and magnetosphere was launched on October 15, 1997 from Cape Canaveral.
The October flyby is only 1200 km above the surface, the closest Titan flyby ever flown. Titan’s gravity will exert a braking effect on the spacecraft as it speeds past, reducing its orbital period to 48 days and retargeting for the next flyby on 13 December.
This second Titan flyby, at an altitude of 2500 km, will further reduce the orbital period to 32 days in preparation of the third Titan encounter on 14 January 2005, where Huygens will enter Titan’s atmosphere.
The Huygens probe is to parachute down through Titan’s atmosphere and — hopefully — land safely on the giant moon’s surface, where — hopefully again — its radio will work, however briefly, and signal home to tell what Huygens’ instruments have found.
Meantime, however, only two days after the Cassini spacecraft sped past Titan on its orbital flight around Saturn, the teams of mission scientists were overwhelmed with the instrument readings and hundreds of pictures taken during the flyby 728 miles above the moon’s surface.
Charles Elachi, director of the Jet Propulsion Laboratory and leader of the mission’s radar team, described the first radar survey, which captured a swath of Titan’s northern surface some 75 miles wide and 1,200 miles long — about the distance from Los Angeles to Seattle, he said — and show distinct but unexplained formations. They are “likely some kind of ridges that remind me of Venus,” he said.
The Huygens probe will usher in 2005 with its landmark mission at Titan. After a seven-year journey strapped to the side of the Cassini Orbiter, Huygens will be set free on Dec. 25, 2004. The Probe will coast for 21 days en route to Titan.
The probe will use S-band signals at 2040 and 2090 megahertz during the descent phase, on the two redundant chains. These signals, received by the orbiter high-gain antenna, will be passed on to the two S-band receivers located in the Probe Support Equipment (that part of the Huygens probe system which remains attached to the orbiter, once the probe is released).
The data relayed from the probe is collected and stored redundantly by the orbiter on its two solid-state recorders. Later (within hours or a few days), the recorded probe data will be transmitted to Earth at a bit rate of 35 kilobits per second and sent to the Huygens Probe Operations Centre (HPOC) at the European Space Operations Centre (ESOC). The probe telemetry data will be retained on board the orbiter until ESOC has confirmed a successful downlink.
Astrobiology Magazine and the Space Science Institute, Imaging Team have more. Yahoo has full coverage.
