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Effects of a large convective storm on Saturn's equatorial jet
Showman, Adam P.; Sayanagi, Kunio M.
Hubble Space Telescope observations revealed that Saturn's equatorial jet at the cloud level blows at ∼275 m s -1 today, approximately half the ∼470 m s -1 wind during the Voyager flybys in 1980-1981. Radiative transfer calculations estimate the clouds to be significantly higher today than in 1980. The higher clouds make it d…
Meridional variations in stratospheric acetylene and ethane in the southern hemisphere of the saturnian atmosphere as determined from Cassini/CIRS measurements
Fletcher, L. N.; Irwin, P. G. J.; Teanby, N. A. +4 more
These are the first results from nadir studies of meridional variations in the abundance of stratospheric acetylene and ethane from Cassini/CIRS data in the southern hemisphere of Saturn. High resolution, 0.5 cm -1, CIRS data was used from three data sets taken in June-November 2004 and binned into 2° wide latitudinal strips to increase…
Observations of Comet 9P/Tempel 1 around the Deep Impact event by the OSIRIS cameras onboard Rosetta
Bertaux, Jean-Loup; Naletto, Giampiero; Debei, Stefano +36 more
The OSIRIS cameras on the Rosetta spacecraft observed Comet 9P/Tempel 1 from 5 days before to 10 days after it was hit by the Deep Impact projectile. The Narrow Angle Camera (NAC) monitored the cometary dust in 5 different filters. The Wide Angle Camera (WAC) observed through filters sensitive to emissions from OH, CN, Na, and OI together with the…
Wind variations in Jupiter's equatorial atmosphere: A QQO counterpart?
Simon-Miller, Amy A.; Orton, Glenn S.; Poston, Bradley W. +1 more
Jupiter's equatorial atmosphere, much like the Earth's, is known to show quasi-periodic variations in temperature, particularly in the stratosphere, but variations in other jovian atmospheric tracers have not been studied for any correlations to these oscillations. Data taken at NASA's Infrared Telescope Facility (IRTF) from 1979 to 2000 were used…
Degree-one convection and the origin of Enceladus' dichotomy
Grott, M.; Hussmann, H.; Sohl, F.
Recently, the Cassini spacecraft has detected ongoing geologic activity near the south pole of Saturn's moon Enceladus. In contrast, the satellite's north-polar region is heavily cratered and appears to have been geologically inactive for a long time. We propose that this hemispheric dichotomy is caused by interior dynamics with degree-one convect…
Dynamics, evolution, and structure of Uranus' brightest cloud feature
Sromovsky, L. A.; Fry, P. M.; Showalter, M. R. +3 more
The brightest cloud feature ever observed on Uranus at near-infrared wavelengths was detected on 14 and 15 August 2005, in images obtained with the NIRC2 instrument and adaptive optics (AO) at the 10-m Keck II telescope. The feature has been tracked forward and backward in time, and appears to have existed almost certainly from 5 November 2004 (po…
Aggregate impacts in Saturn's rings
Karjalainen, Raine
Ring particle aggregates are formed in the outer parts of Saturn's main rings. We study how collisions between aggregates can lead to destruction or coalescence of these aggregates, with local N-body simulations taking into account the dissipative impacts and gravitational forces between particles. Impacts of aggregates with different mass ratios …
Saturn's auroral/polar H +3 infrared emission . II. A comparison with plasma flow models
Melin, Henrik; Miller, Steve; Stallard, Tom +5 more
We present a detailed analysis of the H +3 intensity and velocity profiles crossing Saturn's auroral/polar region, as described by Stallard et al. [Stallard, T., Miller, S., Melin, H., Lystrup, M., Dougherty, M., Achilleos, N., 2007. Icarus 189, 1-13], with a view to understanding the magnetospheric processes with which they …
A deeper look at the colors of the saturnian irregular satellites
Bauer, James; Grav, Tommy
We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Ph…
Discharge experiments simulating chemical evolution on the surface of Titan
Fischer, Georg; Rucker, Helmut O.; Lammer, Helmut +7 more
Saturn's moon Titan has been considered as one of the few places in our Solar System, where atmospheric and surface conditions could have produced organic compounds essential as precursors for an evolution of life. The Cassini-Huygens mission has provided new data on Titan's atmosphere and surface, which enabled us to simulate the chemical process…