Getting RADical about REMs while Odyssey flips

The recent focus on the NASA / JPL Mars Science Laboratory mission has been on Curiosity’s soil sampling activities in the region of Gale Crater scientists have called “Rocknest”.  However, this is not all that the rover has been up to. Through the sample gathering operations, two other instruments have been hard at work, measuring and monitoring the environmental conditions around the rover. These are the The Radiation Assessment Detector (RAD) and the Rover Environmental Monitoring Systems (REMS) – each of which has been working away day and night since Curiosity first arrived on Mars.

RAD is particularly focused on the amount of radiation, both from the sun (solar radiation) and in the form of cosmic rays, reaching the surface of Mars. While Mars has an atmosphere, it is extremely thin and tenuous in comparison to that of Earth – at ground level it is about as dense as Earth’s atmosphere at an altitude of several miles. The Martian atmosphere is primarily carbon dioxide and it does not have any ozone layer. This, coupled with the lack of a strong magnetic field means that the surface of Mars is subjected to far higher levels of both solar and cosmic radiation than are experienced on Earth.

However, even though the atmosphere around Mars is tenuous, it is still enough to have an effect on incoming radiation, and RAD is designed to measure the levels of radiation common to the surface of Mars and, working with REMS, help give further insight into the processes which go into altering that radiation as it passes through the atmosphere. Both of these studies will in turn help scientists understand the impact incoming radiation is having on the local environment and increase out understanding of surface conditions on Mars in preparation for human missions there in the future.

Curiosity: increasing our understanding of the Martian surface environment for future human missions

REMS is the rover’s meteorological station, comprising instruments mounted both on the body of the rover and on the forward mast. It is responsible for monitoring wind, pressure, humidity and temperature, and is being used to establish a track record of atmospheric conditions and changes experienced by Curiosity. Despite the wind measurement instrument on the rover’s mast being damaged during the landing phase of the mission – mostly likely due to a stone being thrown up by the Descent Stage engines and striking the instrument – REMS has been returning huge amounts of data about the Martian atmosphere, helping scientists develop a clearer understanding of the complex mechanics at work in the Martian atmosphere.

As mentioned about, the Martian atmosphere is largely carbon dioxide and very tenuous. Both of these points factor into large seasonal variances in the Martian atmosphere. Due to the tenuous nature of the atmosphere, temperatures are extremely low. During the colder winter months, these low temperatures cause a significant amount of the atmosphere to “freeze out” into the polar ice caps (most notably the southern polar cap, which is predominantly carbon dioxide ice).  In the southern hemisphere, the warmer temperatures, while still low by Earth terms, are enough for much of this carbon dioxide to sublimate into the atmosphere with the result that season changes can cause the Martian atmosphere to shrink / grow by some 30% through the course of a year.

These thermal processes also operate on a day/night cycle, and also affect the radiation signature being recorded by Curiosity’s RAD instrument. Essentially, what is happening is this: during daylight hours, the atmosphere heats up rapidly and expands, causing the atmosphere to “bulge out”. Convection currents cause the atmosphere to flow outwards from this bulge to equalise the pressure either side of it. This leaves the atmosphere below the bulge at a lower pressure than the air on the night side of the planet. As the day passes and the sun sets, the atmosphere cools and the bulge contracts increasing the surface air pressure beneath it.

The daily thermal cycle on Mars: by day, as the planet rotates, the atmosphere warms and expands. Air flows out from the heated “bulge” in order to equalise the pressure with the atmosphere around it, with the result that while the bulge causes a “thicker” atmosphere, it is one that is less dense and at a lower pressure than the air on the “night side” of the planet

Overall, this daily fluctuation can amount to a 10% variation in air pressure over the day / night cycle as measured by REMS. Taken alongside the RAD measurements, this has revealed an interesting correlation with the amount of radiation being measured around the rover. As the air temperature increases through the day and the atmosphere expands to lower the local air pressure, so to does the amount of radiation being measured by RAD increase. Then, as the temperature drops during the evening into night, so to does the atmospheric density and pressure increase – and surface level radiation doses fall, with between a 3% and 5% variation in radiation levels being recorded by REMS during a single day / night period.

A 5-Sol chart showing the relationship between radiation and air pressure during the day / night cycle. As the air is warmed during each day, so the air pressure drops (blue) and the amount of radiation being recorded (red) increases. As night draws is, so the blue line increases, indicating an increase in atmospheric pressure – and radiation levels drop

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Of Sound Mind

Of Sound Mind is a collaborative piece lead by Lorin Tone which explores the nature of sound and the ways in which it can be employed to add depth to a virtual environment such as Second Life. It opened on Saturday 17th November as a part of the Linden Endowment for the Arts Full Sim Art, and features Lorin’s work along with that of other SL artists and builders such as Madcow Cosmos (who with Lorin, brought the delightful Through the Lens of Dreams to Art Screamer last year), Glyph Graves, P4ndor4 Quintessa, Meriadne Merlin, Inventor Alchemi, Marcus Parrott, Mia Anais, Judi Newall, and will feature seminars and demonstrations from these and other SL artists.

Of Sound Mind

The installation comprises a landscape  – sometimes whimsical in nature, sometimes more natural, sometimes with the obligatory spookiness (you’ll understand why I say that when you visit), and always inviting further exploration. Here one can experience and learn about the many and varied ways in which in-world sounds can by used in a virtual environment. As an aural, as well as visual experience, one obviously needs to have their sound on when exploring the region – although there is no requirement for either streaming or Voice to be enabled.

Of Sound Mind

The arrival point features a number of introductory notice boards which will deliver various notecards to you explaining some elements of the installation and introducing you to some of the artists. Similar notice boards are scattered across the region, introducing the various elements and other artists involved in the collaboration. However, the secret here is to simply explore, experience and touch.

Of Sound Mind: the mighty SLurlitzer organ

And there is a lot to explore. Each area of the installation features demonstrations of how sound can be used (musically, to emphasise visual events, to create additional ambience, and so on) and the ways in which it can be triggered (by touching, by animating an avatar, though avatar/object collision, through object/object collision, and so on). Each area is visually and imaginative presented, with Madcow Comos’ visual genius very evident throughout, as well as elements created by the other participating artists. You can walk overground and underground, dive underwater, meet a certain homicidal computer with a door problem and pick up various scripts and other items along the way – and do much more.

Of Sound Mind

There is much to see overhead as well – bumper cars (in the form of chess pieces) demonstrate the use of vehicle sounds (as well as providing further comical boings and squeaks during collisions), there is also a stunning live performance stage area. Both of these can be reached via teleporter.

Also in the sky is Lorin and Madcow’s wonderful Castle of Airs, which can be reached via tour discs, available from the ground-level welcome area. Both the sound stage and the Castle of Airs have featured in the Machinima The Joy of Music by Chantal Harvey and featuring the work of several of the artists participating in Of Sound Mind.

Of Sound Mind

The live performance area was the venue for DRUM (Divine Rhythms of Universal Music), who featured during the opening of the installation on November 17th. DRUM describe their aim being, “To bring the world to you via the power of drumming. Our aim is to have fun and to create incredible, beautiful rhythms – live.” They are possibly unique in that their performances are not pre-recorded or simply streamed: they are created directly within SL, captured and then streamed to the listening audience. Definitely worth witnessing in-world.

Of Sound Mind

Seminars and presentations on the use of sound is SL will also be a feature at Of Sound Mind – although currently, only one is currently scheduled – Lorin Tone will be discussing environmental sound effects in SL on Monday, November 19th at 12:00 noon SLT. Expect notices of additional events to appear in the Upcoming Events noticeboard at the arrivals area.

Of Sound Mind is both visually and aurally immersive and a fun. Well worth a visit.

Of Sound Mind

Of Sound Mind (LEA19) (Rated General)

Food, Friends, Family, Lovers – and a Little Chocolate Now and Then

The Seanchai Library will be presenting another round of stories and readings in Voice this week, which will see the continuation of two of their serialisations, together with a lot of other goodies.

As always, all times SLT, and unless otherwise stated, events will be held on the Seanchai Library’s home on Imagination Island.

Sunday 18th November, 10:00 – To  the Moon!

Join Seanchai Library’s founder, Derry McMahon and her partner, Bear Silvershade at the Fruit Islands Plantetarium for tales of space and time to spark the imagination.

Monday 19th November, 19:00 – Kite Fighters

Gina Pralou-Maven presents a riveting narrative set in the fifteenth-century.

Seoul, Korea, 1473. Lee Young-sup and his elder brother, Kee-sup share a bond through their love of kites, Young-sup flying them and Kee-sup in making them. However, their father, a rice merchant, has designs on the family’s fortunes by having Kee-sup become a court official, forcing him to study for the position when Kee-sup would rather be making kites for his brother…

Linda Sue Parks’ The Kite Fighters is a touching and suspenseful story, filled with the authentic detail and flavor of traditional Korean kite fighting mixed with the pressures of upholding family traditions, brings a remarkable setting vividly to life.

Tuesday 20th November, 19:00 – Food, Friends, Family, Lovers – and a Little Chocolate Now and Then

Stories with a flavour with Derry McMahon and her partner, Bear Silvershade.

Wednesday 21st November, 19:00 – Peter Pan

Illustration from “Peter and Wendy” by James Matthew Barrie, Published 1911 by C. Scribner’s Sons, New York

Caledonia Skytower presents the fourth (of 6) readings of novelist and playwright J. M. Barrie’s most famous work.

While Peter Pan first appeared in another of Barrie’s works, The Little White Bird, written for adults in 1902, it was in the 1904 stage play, Peter Pan, or The Boy Who Wouldn’t Grow Up in which he first came to widespread public attention. The play was later expanded upon by Barrie to form the 1911 novel, Peter and Wendy, which later became Peter Pan and Wendy and, eventually, simply Peter Pan.

Both the stage play and the novel tell the story of Peter Pan, a mischievous little boy who can fly, and his adventures on the island of Neverland with Wendy Darling and her brothers, the fairy Tinker Bell, the Lost Boys, the Indian princess Tiger Lily, and the pirate Captain Hook.

Sunday, November 25th

16:00 – Community Virtual Library Fundraiser

Seanchai Library hosts a special fundraiser for the CVL, featuring jazz and blues singer Gina Gracemount performing her popular burlesque show

18:00 – Peter Pan, Part 5

Caledonia Skytower continues the story of Peter’s adventures with Wendy and The Lost Boys as she returns to the Seanchai Library to read part three of this six-part retelling of J.M. Barrie’s classic, this time reading at Magicland.

Please note that as this is Thanksgiving week in the US, there are no Seanchai Library events scheduled for Thursday, November 22nd