Sunday Sunday: Mars, Pluto and WTF hits the atmosphere

CuriosityMars has been in the news a lot this last week, thanks to both the Curiosity rover and the MAVEN orbiter.

Curiosity’s science capabilities received a boost when a upgrade to the ChemCam test system on Earth increased the number of Earth-rock geochemical samples examined by the system tripled to some 350, vastly increasing the science team’s ability to improve their interpretation of data gathered by Curiosity’s ChemCam system – the laser and telescope / camera which vaporises small amounts of rocks on Mars and them images the plasma that’s given of for chemical and mineralogical analysis.

In particular, the upgrade has allowed the science team to re-examine data the rover gathered about a site with the most chemically diverse mineral veins so far examined on Mars. Called “Garden City”, the site sits above the “Pahrump Hills” area at the foot of “Mount Sharp”, which the rover examined in detail in late 2014 / early 2015. Of particular interest to scientists were a series of raised mineral veins criss-crossing the surface of the rocks in the area.

"Garden City", an outcrop about 1 metre (39 inches) high, examined by Curiosity in March 2015, and which exhibited mineral veins criss-crossing the surface of the rocks, and which exhibited different chemical signatures. New analysis capabilities on Earth have helped determine how the veins formed and what they may say about early conditions in Gale Crater.
“Garden City”, an outcrop about 1 metre (39 inches) high, examined by Curiosity in March 2015, and which exhibited mineral veins criss-crossing the surface of the rocks, and which exhibited different chemical signatures. New analysis capabilities on Earth have helped determine how the veins formed and what they may say about early conditions in Gale Crater

These new Earthside capabilities have allowed the science team to better analyse the minerals within the veins and make finer distinctions between them, revealing their mineral and chemical compositions vary one to another, and also appear to vary with age.

These findings suggest that, rather than being the result of a single extended wet period in Gale Crater during which water percolated down through fissures in the rock to leave the minerals behind, the veins are the result of several individual wet periods in Mars’ ancient past. These wet periods appear to have occurred somewhat later than the more extensive wet periods which gave rise to a successive series of lakes within Gale Crater, the sediments from which form the lowest slopes of “Mount Sharp”. As such, the veins give further hints to atmospheric changes going on at a time at which Mars’ climate was undergoing extraordinary changes and fluctuations in its ancient past.

Prominent mineral veins at the "Garden City" site examined by NASA's Curiosity Mars rover vary in thickness and brightness, as seen in this image from Curiosity's Mast Camera (Mastcam). The image covers and area roughly 2 feet (60 centimeters) across. Types of vein material evident in the area include: 1) thin, dark-toned fracture filling material; 2) thick, dark-toned vein material in large fractures; 3) light-toned vein material, which was deposited last.
Prominent mineral veins at the “Garden City” site examined by NASA’s Curiosity Mars rover vary in thickness and brightness, as seen in this image from Curiosity’s Mast Camera (MastCam).  The image covers and area roughly 60 cm (24 inches) across, and shows a mix of thin, dark-toned fracture filling material, likely deposited first, thick, dark-toned vein material in large fractures, and light-toned vein material, which was deposited last.

What Happened to Mars’ Atmosphere? The Answer is Blowin’ in the Wind

Atmospheric changes are also at the heart of the latest data to be analysed from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN). This data, part of the mission’s long terms studies of the planet’s atmosphere and environment greatly clarifies the key role played by the solar wind in the gradual loss of Mars’ once dense atmosphere and the transition of the planet’s climate from a warm and wet environment to the cold, arid planet we see today.

The solar wind is a stream of particles, mainly protons and electrons, flowing from the Sun’s atmosphere at a speed of about 1.6 million kilometres (1 million miles) per hour. The interaction of this solar wind generates an electric field around Mars, much like a turbine on Earth generates electricity. This electric field interacts with the upper reaches of Mars’ atmosphere, accelerating the ions there and shooting them into space.

An artist's impression of the solar wind shredding ions from Mars' atmosphere
An artist’s impression of the solar wind shredding ions from Mars’ atmosphere

MAVEN measurements indicate that gases are being stripped away in this manner from the Martian atmosphere at a rate of about 8.6 million tonnes per day. “Like the theft of a few coins from a cash register every day, the loss becomes significant over time,” said Bruce Jakosky, MAVEN principal investigator. “We’ve seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active.”

The impact of solar storms on the rate of loss from Mars’ atmosphere was directly observed by MAVEN at the start of 2015, when the planet was bracketed by a series of large-scale outpouring from the sun – the same solar activity which gave rise to the massive increase in auroral activity at that time (see my October 26th Space Sunday report).

“Solar-wind erosion is an important mechanism for atmospheric loss, and was important enough to account for significant change in the Martian climate,” Joe Grebowsky, MAVEN project scientist said of the data gathered by the mission. “MAVEN also is studying other loss processes – such as loss due to impact of ions or escape of hydrogen atoms – and these will only increase the importance of atmospheric escape.”

Continue reading “Sunday Sunday: Mars, Pluto and WTF hits the atmosphere”

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Of baseball, southern living, children’s tales and classic nior

It’s time to kick-off another week of fabulous story-telling in voice, brought to our virtual lives by the staff and volunteers at the Seanchai Library. As always, all times SLT, and events are held at the Library’s Second Life home at Bradley University, unless otherwise indicated.

Sunday, November 15th 14:00: Tea Time with Caledonia

Caledonia Skytower reads the final story from her soon to be published collection Two Houses.

Monday November 16th, 19:00: The Mighty Casey

Rod Sterling“Mouth” McGarry, the manager of a broken-down baseball team called the Hoboken Zephyrs on its last legs, allows a robot named Casey to play on his team. Casey can throw super-fast balls that cannot be hit. Just what is his secret?

His secret is discovered after he is struck by a ball and made to undergo a physical examination in which it is discovered he is an android. When the National League learns of this, they he must be taken off the team because he is not human. So Casey’s inventor gives him an artificial heart so he might be classified as human.

But now the team has another problem – with his new heart, Casey gains an emotional capacity which leads him to gaining empathy with the opposing teams’ batsmen. As a result, he refuses to throw his super-fast balls any more, as he has no desire to ruin the batting careers of others, and it seems the Zephyrs are on the road to nowhere once more unless something can be done. But what?

Join Gyro Muggins as he relates a story written by Rod Sterling for the 35th episode  of The Twilight Zone’s first season.

Tuesday November 17th 19:00: Mama Makes Up Her Mind

Mama makes up her mindWelcome to the unique world of Bailey White. Her aunt Belle may take you to see her bellowing pet alligator. Her uncle Jimbuddy may appal you with his knack for losing pieces of himself. Most of all, you may succumb utterly to the charms of Baileys mama, who will take you to a joint so raunchy it scared Ernest Hemingway or tuck you into her antique guest bed that has the disconcerting habit of folding up on people while they sleep.

White’s indelible vignettes of Southern eccentricity have entranced millions who have heard her read them on NPR. Mama Makes Up Her Mind is as sweetly intoxicating as a mint julep and as invigorating as a walk in Whites own overgrown garden.

Join Trolley Trollop, Kayden Oconnell, and Caledonia Skytower as they commence a romp through this wonderful series of vignettes

Wednesday, November 18th 19:00 The Wonderful World of Roald Dahl

Roald Dahl’s short stories are known for their unexpected endings and his children’s books for their unsentimental, macabre, often darkly comic content, featuring villainous adult enemies of the child characters. Join Faerie Maven-Pralou as she brings more of these tales to life.

Thursday, November 19th 19:00: American Noir

American Noir is the hard-boiled nightmare of flawed souls with big dreams and the  precise how and why of the all-time sure thing that goes bad. Classic stories from the typewriters of Mickey Spilane, James M.Cain, Edward Anderson, and other masters of the genre. Presented by Shandon Loring.

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Please check with the Seanchai Library SL’s blog for updates and for additions or changes to the week’s schedule.

The featured charity for October – December is Reach Out and Read, one of the most highly rated literacy charities in the USA which reaches 4.4 million children annually and distributes 1.6 million books.

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