* Astronomy

Blobrana · L

RE: Enceladus

Blobrana · L

At around 23.20 (BST) last night, Nasa's Cassini-Huygens spacecraft passed about 50km from Saturn's moon Enceladus.
With a diameter of 310 miles (just one seventh that of Earth's moon), Enceladus is Saturn's sixth largest moon. It orbits at a distance of 148,000 miles from the centre of the gas giant, taking 32.9 hours for each revolution.

Read more

Blobrana · L

NASAs Cassini orbiter is sweeping past Saturns icy moon Enceladus today to photograph geyser-like eruptions from the Southern Hemisphere. The hope is to find signs of the building blocks of life: NASA has pegged Enceladus as one of the most likely places in the Solar System (along with Mars and another of Saturns moons, Titan) to be able to support extraterrestrial life.
On a flyby earlier this year, the Cassini spacecraft detected organic chemicals like methane and propane in the contents spewing out of the moons interior. Such compounds have also been found in comets tails and just recently on Titan.

Source
Read more

Blobrana · L

Cassini flyby of Enceladus, Aug. 11, 2008

Click to Play | View Details

Blobrana · L

On Monday, the Cassini spacecraft will return to Saturn's icy moon Enceladus, passing within 50 kilometres of its south pole. NASA team members hope the flyby will provide evidence for subsurface liquid water containing the building blocks of life.
Previous encounters revealed huge plumes of ice and water vapour venting from blue-green fault lines, or "tiger stripes", that criss-cross the south pole. The source of these jets, which feed Saturn's rings, is hotly contested.

Read more

Blobrana · L

Enceladus Map

Blobrana · L

RE: Enceladus

Blobrana · L

The Cassini spacecraft has found what may be the strongest evidence yet that Saturns tiny moon Enceladus has an ocean beneath its icy surface. If the liquid water finding is confirmed, it would suggest that the moon may be one of the most promising places in the solar system to search for signs of past or present extraterrestrial life.
Enceladus is already known to vent geysers of water-ice and vapor that contain complex organic compounds. The new evidence for an underground ocean comes from the detection of sodium in Saturns E ring, the extensive band of ice particles believed to be fed and replenished by Enceladus.

Read more

Blobrana · L

Title: Saturn in hot water: viscous evolution of the Enceladus torus
Authors: Alison J. Farmer (Harvard)

The detection of outgassing water vapour from Enceladus is one of the great breakthroughs of the Cassini mission. The fate of this water once ionised has been widely studied; here we investigate the effects of purely neutral-neutral interactions within the Enceladus torus. We find that, thanks in part to the polar nature of the water molecule, a cold (~180 K) neutral torus would undergo rapid viscous heating and spread to the extent of the observed hydroxyl cloud, before plasma effects become important. We investigate the physics behind the spreading of the torus, paying particular attention to the competition between heating and rotational line cooling. A steady-state torus model is constructed, and it is demonstrated that the torus will be observable in the millimetre band with the upcoming Herschel satellite. The relative strength of rotational lines could be used to distinguish between physical models for the neutral cloud.

Read more (200kb, PDF)

Blobrana · L

The Cassini spacecraft tasted and sampled a surprising organic brew erupting in geyser-like fashion from Saturn's moon Enceladus during a close flyby on 12 March. Scientists are completely giddy as to why this tiny moon is so active, so hot and brimming with organics.
New heat maps of the surface show higher temperatures than previously known in the south polar region, with hot tracks running the length of the tiger stripe fissures. Additionally, scientists say the organics 'taste and smell' like some of those found in a comet. The jets themselves harmlessly peppered Cassini, exerting measurable torque on the spacecraft, and providing an indirect measure of the plume density.

Read more