CSIRO telescopes help rescue Titan experiment

February 15, 2005

CSIRO’s radio telescopes and others in Australia, China, Japan and the USA have revealed how the wind speeds on Saturn’s moon Titan vary with altitude-and have turned a disappointment into a triumph.

As the Huygens probe plummeted through Titan’s atmosphere on 14 January it transmitted a stream of data to its parent Cassini spacecraft. The ground-based radio telescopes ’eavesdropped’ on the probe’s signal. As the probe was buffeted by Titan’s winds, its radio signal was shifted in frequency. These ’Doppler shifts’ have been used to measure the wind speeds.

Another experiment to determine the Doppler shifts, the Cassini/Huygens Doppler Wind Experiment, was going to rely on data transmitted from the probe to Cassini. But the transmitted data was lost because because one of the receivers on Cassini was not properly configured. The data from the telescopes has plugged that gap.

The largest telescopes involved were the NRAO Robert C. Byrd Green Bank Telescope in the USA and CSIRO’s Parkes Radio Telescope in Australia. Thanks to special instruments borrowed from NASA, these telescopes were the first to directly ’see’ the probe’s signal.

The wind on Titan has been found to flow in the direction of Titan’s rotation-west to east-at nearly all altitudes. The winds are weak near the surface and increase slowly with altitude up to about 60 km. The maximum speed of about 430 km/hour was found at an altitude of 120 km. Above 60 km there are large variations in the Doppler measurements, which scientists think were caused by vertical wind shear.

The radio telescope network was coordinated by the Joint Institute for VLBI in Europe, JIVE, and NASA’s Jet Propulsion Laboratory, JPL. JPL and JIVE also made and processed the ground-based Doppler measurements, working with the Doppler Wind Experiment team.


Rank not rated yet
Tags

Related Stories
Relevant PhysicsForums posts

More news stories

Europe stakes billion-dollar bet on new rocket

A pencil-slim rocket is scheduled to lift into space from South America on Monday, carrying a billion-dollar bet that Europe can grab a juicy slice of the market to place satellites in low orbit.

Space & Earth / Space Exploration

created 2 hours ago | popularity 3.5 / 5 (2) | comments 0

NASA sees wide-eyed cyclone Jasmine

Cyclone Jasmine's eye has opened wider on NASA satellite imagery, as it moves through the Southern Pacific Ocean.

Space & Earth / Earth Sciences

created 18 hours ago | popularity 3.5 / 5 (2) | comments 2

NASA sees Giovanna reach cyclone strength, threaten Madagascar

Tropical Storm 12S built up steam and became a cyclone on February 10, 2012 as NASA's Terra satellite passed overhead. Residents of east-central Madagascar should prepare for this cyclone to make landfall ...

Space & Earth / Earth Sciences

created 18 hours ago | popularity not rated yet | comments 0

Political leaders play key role in how worried Americans are by climate change: study

More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of climate change, new research finds.

Space & Earth / Environment

created Feb 06, 2012 | popularity 5 / 5 (6) | comments 68

Humans may have helped the decline of African rainforests 3000 years ago

(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...

Space & Earth / Environment

created Feb 10, 2012 | popularity 4.3 / 5 (13) | comments 14 | with audio podcast report


Walney offshore wind farm is world's biggest (for now)

(PhysOrg.com) -- The Walney wind farm on the Irish Sea--characterized by high tides, waves and windy weather--officially opened this week. The farm is treated in the press as a very big deal as the Walney ...

GPS court ruling leaves US phone tracking unclear

A US Supreme Court decision requiring a warrant to place a GPS device on the car of a criminal suspect leaves unresolved the bigger issue of police tracking using mobile phones, legal experts say.

Anonymous briefly knocks CIA website offline (Update 2)

The website of the Central Intelligence Agency was briefly inaccessible on Friday after the hacker group Anonymous claimed to have knocked it offline.

Study finds that anti-diabetic medication can prevent the long-term effects of maternal obesity

In a study to be presented today at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in Dallas, Texas, researchers will report findings that show that short therapy with the anti-diabetic medication ...

Netflix settlement trims 14 pct off 4Q earnings

(AP) -- Netflix pressed the rewind button on its fourth-quarter earnings after settling allegations that the video subscription service violated a consumer-privacy law.

Employers feel no love for unscrupulous practice of 'service sweethearting'

A new study led by two Florida State University marketing professors finds that some frontline service employees who are rewarded for hikes in customer loyalty and satisfaction also may engage in "service ...