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Title: Ethyl cyanide on Titan: Spectroscopic detection and mapping using ALMA
Author: M. A. Cordiner, M. Y. Palmer, C. A. Nixon, P. G. J. Irwin, N. A. Teanby, S. B. Charnley, M. J. Mumma, Z. Kisiel, J. Serigano, Y.-J. Kuan, Y.-L. Chuang, K.-S. Wang

We report the first spectroscopic detection of ethyl cyanide (C2H5CN) in Titan's atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter array (ALMA). The presence of C2H5CN in Titan's ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C2H5CNH+. Here we report the detection of 27 rotational lines from C2H5CN (in 19 separate emission features detected at†>3sigma††confidence), in the frequency range 222-241 GHz. Simultaneous detections of multiple emission lines from CH3N, CH3CN and CH3CCH were also obtained. In contrast to HC3N, CH3CN and CH3CCH, which peak in Titan's northern (spring) hemisphere, the emission from C2H5CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C2H5CN. Radiative transfer models show that most of the C2H5CN is concentrated at altitudes 300-600 km, suggesting production predominantly in the mesosphere and above. Vertical column densities are found to be in the range (2-5)x1014†cm-2.

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Winter is coming... to Titan's south pole

Gigantic polar clouds of hydrogen cyanide roughly four times the area of the UK are part of the impressive atmospheric diversity of Titan, the largest moon of Saturn, a new study led by Leiden Observatory, the Netherlands Institute for Space Research and the University of Bristol has found. The research is published today in Nature.
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Titan's swirling polar cloud is cold and toxic

The international Cassini mission has revealed that a giant, toxic cloud is hovering over the south pole of Saturn's largest moon, Titan, after the atmosphere has cooled in a dramatic fashion.
Scientists analysing data from the mission found that this giant polar vortex contains frozen particles of the toxic compound hydrogen cyanide.

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Cassini Watches Mysterious Feature Evolve in Titan Sea

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NASA's Cassini spacecraft is monitoring the evolution of a mysterious feature in a large hydrocarbon sea on Saturn's moon Titan. The feature covers an area of about 100 square miles (260 square kilometers) in Ligeia Mare, one of the largest seas on Titan. It has now been observed twice by Cassini's radar experiment, but its appearance changed between the two apparitions.
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Title: HST observations of the limb polarisation of Titan
Author: Andreas Bazzon, Hans Martin Schmid, Esther Buenzli

Titan is an excellent test case for detailed studies of the scattering polarisation from thick hazy atmospheres. We present the first limb polarisation measurements of Titan, which are compared as a test to our limb polarisation models. Previously unpublished imaging polarimetry from the HST archive is presented which resolves the disk of Titan. We determine flux-weighted averages of the limb polarisation and radial limb polarisation profiles, and investigate the degradation and cancellation effects in the polarisation signal due to the limited spatial resolution of our observations. Taking this into account we derive corrected values for the limb polarisation in Titan. The results are compared with limb polarisation models, using atmosphere and haze scattering parameters from the literature.
In the wavelength bands between 250 nm and 2000 nm a strong limb polarisation of about 2-7 % is detected with a position angle perpendicular to the limb. The fractional polarisation is highest around 1 micron. As a first approximation, the polarisation seems to be equally strong along the entire limb. The detected polarisation is compatible with expectations from previous polarimetric observations taken with Voyager 2, Pioneer 11, and the Huygens probe.
Our results indicate that ground-based monitoring measurements of the limb-polarisation of Titan could be useful for investigating local haze properties and the impact of short-term and seasonal variations of the hazy atmosphere of Titan. Planets with hazy atmospheres similar to Titan are particularly good candidates for detection with the polarimetric mode of the upcoming planet finder instrument at the VLT. Therefore, a good knowledge of the polarisation properties of Titan is also important for the search and investigation of extra-solar planets.

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Cassini Tracks Clouds Developing Over a Titan Sea

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NASA's Cassini spacecraft recently captured images of clouds moving across the northern hydrocarbon seas of Saturn's moon Titan.
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Saturn moon may host its own Dead Sea

Titan, Saturn's largest moon, may have its own Dead Sea. A fake lake simulating conditions there hints that the moon may host ethane pools brimming with benzene, just as the Dead Sea on Earth is packed with salt.
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Ocean on Saturn Moon Could be as Salty as the Dead Sea

Scientists analyzing data from NASAs Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as the Earth's Dead Sea.
The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell. The findings are published in this weeks edition of the journal Icarus.

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Mysterious 'Magic Island' appears on Saturn moon

Astronomers have discovered a bright, mysterious geologic object - where one never existed - on Cassini mission radar images of Ligeia Mare, the second-largest sea on Saturn's moon Titan. Scientifically speaking, this spot is considered a "transient feature," but the astronomers have playfully dubbed it "Magic Island."
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Titan: Clue to 'Magic Island' mystery on Saturn moon

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Scientists have outlined their best explanations for a mysterious feature dubbed the "magic island", which has been spotted on Saturn's moon Titan.
The Cassini spacecraft captured the "island" during a flyby, but it had vanished by the time of the next pass.
The bright splodge is seen in Ligeia Mare, one of the seas of methane and ethane found at Titan's north pole.
Icebergs, waves and gas bubbling up from the lake bottom are all possibilities

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