* Astronomy

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RE: The Cassini spacecraft

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Title: High Angular Resolution Stellar Imaging with Occultations from the Cassini Spacecraft I: Observational Technique
Authors: Paul N. Stewart, Peter G. Tuthill, Matthew M. Hedman, Philip D. Nicholson, James P. Lloyd

We present novel observations utilising the Cassini spacecraft to conduct an observing campaign for stellar astronomy from a vantage point in the outer solar system. By exploiting occultation events in which Mira passed behind the Saturnian ring plane as viewed by Cassini, parametric imaging data were recovered spanning the near-infrared. From this, spatial information at extremely high angular resolution was recovered enabling a study of the stellar atmospheric extension across a spectral bandpass spanning the 1 - 5 µm spectral region in the near-infrared. The resulting measurements of the angular diameter of Mira were found to be consistent with existing observations of its variation in size with wavelength. The present study illustrates the validity of the technique; more detailed exploration of the stellar physics obtained by this novel experiment will be the subject of forthcoming papers.

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Cassini Spies Bright Venus From Saturn Orbit

A distant world gleaming in sunlight, Earth's twin planet, Venus, shines like a bright beacon in images taken by NASA's Cassini spacecraft in orbit around Saturn.
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Cassini sheds light on cosmic particle accelerators

During a chance encounter with an unusually strong blast of solar wind arriving at Saturn, the international Cassini spacecraft detected particles being accelerated to ultra-high energies, similar to the acceleration that takes place around supernova explosions.
Shock waves are commonplace in the Universe, for example in the aftermath of a stellar explosion as debris accelerates outwards in a supernova remnant, or when the flow of particles from the Sun the solar wind impinges on the magnetic field of a planet to form a bow shock.
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A Scroll Through Memory Lane With Cassini

A new, interactive version of a timeline of NASA's Cassini mission to Saturn is now available online. The journey starts with launch on Oct. 15, 1997, and presents illustrated milestones and discoveries since then, including the finding of geysers on the moon Enceladus and lakes on the moon Titan. The timeline runs through the expected completion of the mission in 2017.
Source

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A Long and Winding Road: Cassini Celebrates 15 Years

Today, NASA's Cassini spacecraft celebrates 15 years of uninterrupted drive time, earning it a place among the ultimate interplanetary road warriors.
Since launching on Oct. 15, 1997, the spacecraft has logged more than 6.1 billion kilometres of exploration - enough to circle Earth more than 152,000 times. After flying by Venus twice, Earth, and then Jupiter on its way to Saturn, Cassini pulled into orbit around the ringed planet in 2004 and has been spending its last eight years weaving around Saturn, its glittering rings and intriguing moons.
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The Cassini-Huygens mission to Saturn

On the morning of Wednesday 15 October 1997, an ambitious voyage began with the launch of the joint NASA-ESA mission Cassini-Huygens from Cape Canaveral, Florida. This was the start of a seven-year journey to the planet Saturn and its moons.
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Cassini Plasma Spectrometer Turns Off

The Cassini plasma spectrometer instrument (CAPS) aboard NASA's Cassini spacecraft was turned off between Friday, June 1 and Saturday, June 2, when a circuit breaker tripped off after the instrument experienced some unexpected voltage shifts.
Engineers are currently investigating this issue, which they believe is due to short circuits in the instrument. In June 2011, the instrument was turned off because of similar problems, but was switched on again in March 2012 once investigators determined that tin plating on electronic components had grown "whiskers" large enough to contact another conducting surface and carry electrical current, resulting in a voltage shift.
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Cassini to Probe Enceladus Gravity, Take Pictures

NASA's Cassini spacecraft will be flying within about 74 kilometres of Saturn's moon Enceladus on Wednesday, May 2, aiming primarily to learn more about the moon's internal structure. The flyby is the third part of a trilogy of flybys -- the other two took place on April 28, 2010, and Nov. 30, 2010 -- for Cassini's radio science experiment. The radio science team is particularly interested in learning how mass is distributed under Enceladus' south polar region, which features jets of water ice, water vapour and organic compounds spraying out of long fractures. A concentration of mass in that region could indicate subsurface liquid water or an intrusion of warmer-than-average ice that might explain the unusual plume activity. Cassini's scientists learn about the moon's internal structure by measuring variations in the gravitational pull of Enceladus against the steady radio link to NASA's Deep Space Network on Earth.
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Cassini spacecraft sees Saturn moon geysers

The Cassini spacecraft has captured striking images from flying by three moons of Saturn, including new pictures of Enceladus's gushing geysers. Cassini made its lowest pass yet over the south pole of Enceladus, at at an altitude of 74km.
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