2016 viewer release summaries: week 47

Updates for the week ending Sunday, November 27th

This summary is published every Monday, and is a list of SL viewer / client releases (official and TPV) made during the previous week. When reading it, please note:

  • It is based on my Current Viewer Releases Page, a list of all Second Life viewers and clients that are in popular use (and of which I am aware), and which are recognised as adhering to the TPV Policy. This page includes comprehensive links to download pages, blog notes, release notes, etc., as well as links to any / all reviews of specific viewers / clients made within this blog
  • By its nature, this summary presented here will always be in arrears, please refer to the Current Viewer Release Page for more up-to-date information.

Official LL Viewers

LL Viewer Resources

Third-party Viewers

V4-style

  • No updates.

V1-style

  • Cool VL viewer Stable branch updated to version 1.26.18.34 and the Experimental branch updated to version 1.26.19.36, both on November 26th (release notes).

Mobile / Other Clients

Additional TPV Resources

Related Links

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Space Sunday: ring grazing and exoplanet gazing

On July 19th, 2013, Cassini captured this remarkable shot of Saturn and its entire ring system as they eclipsed the Sun. captured at a distance of 1.2 million km (746,000 mi) from the planet. It spans a distance of 651,591 km (404,880 mi) across and uses 141 wide-angle shots collected over a 4-hour period, and shows the haze of Saturns's outer most "E" ring and, inward of it, the "G" ring, with Earth a tiny dot (arrowed) sitting between them. The more discrete ring system from the "F" ring through to the innermost "D" ring are visible, together with seven of Saturn's moons, of which two are ringed: Enceladus, on the left (see below) and Tethys, lower left). The colours seen are true, and have not been artificially enhanced Credit: NASA/JPL / Space Science Institute
On July 19th, 2013, Cassini captured this remarkable shot of Saturn and its entire ring system as they eclipsed the Sun. Taken from a distance of 1.2 million km (746,000 mi) from the planet, it spans a distance of 651,591 km (404,880 mi) across and uses 141 wide-angle shots collected over a 4-hour period. In it can be seen the haze of Saturn’s outermost “E” ring and, inward of it, the “G” ring, with Earth a tiny dot (arrowed) sitting between them. The more visible rings, “F” ring through to the innermost “D” are visible, together with seven of Saturn’s moons, of which two are ringed: Enceladus, on the left and Tethys, lower left – click for full size to see clearly. The colours seen are true, and have not been artificially enhanced. Credit: NASA/JPL / Space Science Institute

In 2005, along with friends, I attended a dinner at which a UK scientist, John Zarnecki, was honoured. His name might not be familiar to some, but Professor Zarnecki, currently serving as the Director of the International Space Science Institute in Berne, Switzerland, has been involved in a number of high-profile space missions, including the Hubble Space Telescope, the Giotto probe that visited Halley’s Comet, and UK’s Beagle 2 mission to Mars. He is currently leading the European ExoMars rover mission, scheduled for 2020.

However, it is probably with the NASA / ESA Cassini-Huygens mission that he has the deepest association. At the time of the dinner, Professor Zarnecki had already been involved in that programme for fifteen years. His primary responsibility was the Huygens probe, which became the first vehicle to land there in January, 2005, and still holds the record for the furthest landing from Earth a spacecraft has so far made.

I mention this, because while the Titan surface mission effectively came to an end 90 minutes after the lander arrived there, the Cassini vehicle has remained in operation around Saturn and its moons, gathering a huge amount of data in the process. However, its own mission is now coming to an end after almost 20 years. In September 2017, Cassini will complete its last full orbit of Saturn and then fall to is destruction.

Saturn's complex ring system, the gaps between them crated by a mixture of so-called "shepherd moons" in orbits between the rings and stablising and destabilizing orbital resonances caused by Saturn's larger moons.
Saturn’s complex ring system, the gaps between them crated by a mixture of so-called “shepherd moons” in orbits between the rings and stabilising and destabilizing orbital resonances caused by Saturn’s larger moons.

Before then, however, and starting on November 30th, 2016, the orbiter will commence the penultimate phase of its mission. Having gradually shifted itself into a more polar orbit around Saturn Cassini will commence a series of “ring-grazing orbits”, coming to within 7,800 km (4,850 mi) of what is regarded as the outer edge of Saturn’s major series of rings, the F-ring.

These orbits, which will extend through April 22nd, 2017, will see the spacecraft dive through the more diffuse G-ring once every seven days for a total of 20 times in what will be the first attempt to directly sample the icy particles and gas molecules which are located at the edge of the rings and also image the tiny moons of Atlas, Pan, Daphnis and Pandora, which play a role in “shepherding” the rings around Saturn.

Over time it will slowly close on the outer edge of the denser F-ring, until in March and April 2017, it is passing through the outer reaches of that ring, some 140,180km (87,612.5 mi) from the centre of Saturn. The F-ring is regarded as perhaps the most active ring in the Solar System, with features changing on a timescale of hours.

A 2007 artist impression of the aggregates of icy particles that form the 'solid' portions of Saturn's rings. These elongated clumps are continually forming and dispersing. The largest particles are a few metres across. Credit: NASA/JPL / University of Colorado
A 2007 artist impression of the aggregates of icy particles that form the ‘solid’ portions of Saturn’s rings. These elongated clumps are continually forming and dispersing. The largest particles are a few metres across. Credit: NASA/JPL / University of Colorado

Exactly how the majority of Saturn’s rings formed is still unknown;, with ideas focused on one of two theories. In the first, the material in the rings is the original material “left over” from the formation of Saturn and its larger moons, pulled into a disc around the planet by gravitational tides. In the second, the material is all that remains of a form er – called Veritas after the Roman goddess –  which either crossed the Roche limit to be pulled apart by gravitation forces or was destroyed by the impact with another body such as a large comet or asteroid.

However, in both of these cases it is not unreasonable to assume that the material making up the rings would be of a mixed nature: dust, ices, rocky matter, etc. However the majority of the ring matter is icy particles, with little else. This has given rise to a variation on the destroyed moon theory: that the particles are all that remains of the icy mantle of a much larger, Titan-sized moon, stripped away as it spiralled into Saturn during the planet’s formation.

Geyser on Enceladus, orbiting within the E-ring through vast amount of ice particles into space, replenishing and supporting the E-ring. Credit: NASA/JPL / Space Science Institute
Geyser on Enceladus, orbiting within the E-ring, throw vast amounts of ice particles into space, replenishing and supporting the E-ring. Credit: NASA/JPL / Space Science Institute

Continue reading “Space Sunday: ring grazing and exoplanet gazing”