Following the opening of the SL15B Community Celebration on Sunday, June 17th See my preview for notes and SLurls), Linden Lab has announced further festivities and events as part of the overall celebrations. Some of these can be found on the SL15B regions, others are located elsewhere across the grid.
At the time of writing, the performers line-up was as follows. All times are SLT, and not this schedule is subject to last-minute changes.
The SL15B Shopping Event
Occupying a total of four regions, the SL15B brings back the familiar shopping mall of recently Linden shopping events, now decorated with a crystal motif in keeping with the SL15B theme.
The 4-region mall brings together 80 of Second Life’s creators, each of whom is offering a free gift to celebrate SL15B as well as deals on some of their most popular items. In addition, many are also participating in a special sale on the Marketplace.
To mark the fifteen years Second Life has been open to the public, the Lab is running a weekly Gift Grab for the next 15 weeks.
Each week, one crystal-themed gift will be made available in-world, and a clue relating to its location will be published on the Second Life blog, and via their social media feeds. All you have to do is find and collect each gift – which will remain available for one week only, before the next gift is made available somewhere else on the grid. People can collect as many of the gifts as they want – however, the final Birthday Gift will only be available to those who have collected all 14 of the previous gifts.
This summary is generally published on 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.
Note that test viewers, preview / beta viewers / nightly builds are not recorded in these summaries.
Official LL Viewers
Current Release version 220.127.116.115811, dated May 31, promoted June 1 – formerly the Love Me Render Release Candidate – No change.
Dust storms on Mars are not unusual event; they occur in both hemispheres with the changing of the seasons, and can even grow to encompass the entire planet.
Just such world-girdling dust storm occurred in 1971, and was caught by the cameras on NASA’s Mariner 9 space vehicle when it arrived in the vicinity of Mars in November of that year. The images Mariner 9 returned from Mar as it entered orbit (becoming in the process the first man-made object to orbit another planet) show the entire surface of Mars totally obscured by a blanket of dust that reached high up into the atmosphere. It took some two months for the storms to abate – although scientists were treated to Mars gradually revealing itself to Mariner 9’s camera as the dust slowly settled, starting with the high peaks of Olympus Mons and the Tharsis Ridge volcanoes, which rise up to 25 kilometres above the mean surface level of Mars.
In 2001, the Hubble Space Telescope (HST) reveal just how all-encompassing these more massive storms on Mars can be, when it took two images of Mars just three months apart. In one, surface features are clearly visible; in the second, Mars appears to be devoid of any detail.
Now, another dust storm is engulfing a huge swathe of Mars. It grew quickly in the opening week and a half of June, While it has not – as yet – engulfed the entire planet, it is raising massive mounts of dust high into the Martian atmosphere, marking it as the “thickest” dust storm witnessed on Mars.
Of to two rovers currently operating on Mars, the Mars Exploration Rover Opportunity is particularly impacted by storms of this nature as it is solar-powered. Such is the volume of dust lifted into the Martian atmosphere when these more extreme storms occur that they can severely limit Oppy’s ability to gather sunlight to charge its batteries.
This is not the first such dust storm Oppy has encountered; in 2007, a large-scale storm resulted in a severe degradation in the amount of sunlight reaching the Martian surface where the rover was operating. At that time, we were treated to some remarkable images of just how all-pervasive the dust can become when lifted into the tenuous Martian atmosphere.
Even so the current storm is perhaps the most severe Oppy has had to face. So much so that even though the decision was quickly made to suspend all science gathering operations as it explores Endeavour Crater, and so reduce its power output, the rover has since switched itself into a further “safe” mode of power conservation.
This kind of more massive storm is particularly prone to occurring when summer comes to one of the hemispheres (in this case, the southern hemisphere). At this time, the increased sunlight warming the atmosphere causes an increase in wind activity, which results in more dust being lifted into the atmosphere. For so reason, this dust causes the winds to persist – and even increase, lifting more dust, and a feedback loop is created, turning the process into a self-driving storm that can take weeks or months to die down.
A couple of interesting points with these dust storms is that firstly, and for those familiar with the Matt Damon vehicle The Martian, the winds are nowhere near as violent as portrayed by that film. While wind speeds during these storms can reach speeds of 96-160 km/h (60-100 mph), the Martian atmosphere is so tenuous, the overall effect of such wind speeds is akin to a stiff breeze here on Earth. The second point is that while they do reduce the amount of sunlight reaching the surface of Mars, the dust is an effective insulator, both reducing the amount of heat being radiated away from Mars whilst simultaneously absorbing solar radiation, both of which serve to raise ambient surface temperatures.
This latter point is in part good news for Oppy, as it helps reduce the rover’s power outlay in keeping itself and its instruments warm. However, given that such intense storms can last for periods of several weeks to months at a time, there is genuine concerns as to how well Opportunity might survive if this storm is particularly drawn out, leaving the MER team on Earth reasonably confident the rover will be able to survive the storm without its systems becoming too cold to be restarted.
By June 10th, the storm had grown to a size where it was starting to make itself felt in Gale Crater, where NASA is operating the Mars Science Laboratory rover Curiosity, although the effects haven’t been as great as around Endeavour Crater, which Opportunity has been exploring. When it comes to dust storms, Curiosity has a significant advantage over Opportunity in that it is nuclear powered and is thus its power systems aren’t affected by any loss of sunlight.
By the time the dust storm reach Gale Crater, it was blanketing to 35 million square kilometres (14 million sq miles) of the Martian surface – or roughly one-quarter of the entire planet, and it was still growing. As well as bing observed by the two surface rovers, it is also being watched from space by the combined network of NASA’s Mars Reconnaissance Orbiter (MRO), Mars Odyssey and MAVEN space vehicles, as well as Europe’s Mars Express mission and India’s Mars Observer Mission.
Observing and probing this kind of storm is seen as vital on a number of counts. In the first place, the precise mechanism that causes the feedback loop of wind and dust mentioned above isn’t really understood, so seeing storms like the develop and abate can help scientists to fill-in the blanks. In addition, and as NASA’s Mars Programme Office chief scientist Rich Zurek explains:
Studying their physics is critical to understanding the ancient and modern Martian climate. Each observation of these large storms brings us closer to being able to model these events, and maybe, someday, being able to forecast them. That would be like forecasting El Niño events on Earth, or the severity of upcoming hurricane seasons.
This latter point is particularly important in terms of planning for future missions – including any human mission to Mars. Being able to predict the rises and potential scope of these storms could go a long way to ensuring human safety on Mars. However, for the duration of this storm, all eyes are on little Opportunity, caught in the midst of it, with the hope that the rover will come through the storm able to resume its record-breaking 14+ years of operations on Mars.