Day: June 28, 2015

Space Sunday: metal rain and glass on Mars, HoloLens into orbit

Posted on by Inara Pey
Comet Siding Spring's passage through the solar system 2013-2014
Comet Siding Spring’s passage through the solar system 2014

In October 2014, I wrote about comet Sliding Spring and it’s close approach to Mars as it swung through the solar system.

The comet had been identified as coming from the Oort cloud (or the Öpik–Oort cloud, to give proper recognition both astronomers who initially and independently postulated its existence), a spherical cloud of debris left-over from the creation of the solar system, occupying a huge area starting some 2,000-5,000 AU (2,000 to 5,000 times the distance from the Earth to the Sun) and extending out to around 50-100,000 AU – or about one light year away.

There is nothing odd about comets from the Oort cloud per se, but Sliding Spring appeared to be making its very first journey into the inner solar system, and so astronomers were keen to try to study it as best they could. Given the close pass at Mars, the vehicles on and orbiting that planet stood to have something of a grandstand view of things – providing certain precautions were taken, as I noted at the time.

An artist's impression of MAVEN in orbit around Mars (NASA / JPL)
An artist’s impression of MAVEN in orbit around Mars

Now data released by NASA shows that the comet’s flight past Mars did result in something very unusual: the comet’s tail, which brushed the Martian atmosphere, resulted in a “rain of metal” over the planet.

The data was obtained by NASA’s Mars Atmosphere and Volatile EvolutioN Mission (MAVEN), which at the time of the comet’s passage was so recent an arrival at Mars, that all its instruments hadn’t been fully commissioned. Hence, in part, the delay in releasing the data – NASA wanted to be sure MAVEN was recording things accurately.

According to MAVEN, the direct detection of sodium, magnesium, aluminium, chromium, nickel, copper, zinc, iron and other metals high in the Martian atmosphere can be linked directly to material sloughing off of the comet as it passed.

“This must have been a mind-blowing meteor shower,” said Nick Schneider of the Laboratory of Atmospheric and Space Physics at the University of Colorado, commenting on the data returned by the orbiter. Such is the strength of the signal of magnesium and iron measurements, the hourly meteor rate overhead on Mars must have been tens of thousands of “shooting stars” per hour over a period of many hours.

An artist's impression of meteors resulting from comet Siding Spring in the sky over NASA's MSL Curiosity rover
An artist’s impression of meteors resulting from comet Siding Spring in the sky over NASA’s MSL Curiosity rover

“I’m not sure anyone alive has ever seen that,” Schneider added, “and the closest thing in human history might the the 1833 Leonids shower.” The metal ions were the remains of pebbles and other pieces shed from the comet that burned up, or “ablated” into individual atoms as they struck the Martian atmosphere at 56 kilometres per second (125,000 miles per hour).

What is particularly important about the event is that as scientists know the source of the dust particles, it’s speed, and key information about Mars’ upper atmosphere, it is possible to learn more about Mars’ ionosphere, the comet’s composition, and even the workings of Earth’s ionosphere when it is hit by comet or asteroid debris.

Impact Glass

There is glass on Mars, and it might just be the ideal place in which to find any evidence of past microbial life.

The type of glass in question is referred to as “impact glass”, and is formed as a result of the heat generated by the impact of a meteorite melts the surrounding rock into glass. when a meteorite strikes the surface of a planet or moon, melting the surrounding rock into glass, preserving and organic matter that existed on or in the rock prior to the meteorite impact occurring.

In 2014, a research team examining impact glass formed millions of years ago as a result of meteorite strikes in Antarctica form found organic molecules and plant matter within the glass. Their work spurred a group of planetary science graduates at Brown University, Rhode Island, to simulate the spectral composition of possible Martian impact glass by using chemicals, compounds and powders matching those known to compose the surface material on Mars, and then melting the mix at high temperatures to form glass, which they then subjected to spectrographic analysis.

The team then compared the results of their analysis with spectral analyses of the surface of Mars carried out by the Imaging Spectrometer aboard NASA’s Mars Reconnaissance Orbiter (MRO) – and found a very similar spectral signature in areas where such impact glass would be expected to form, such as around the central peaks of craters caused by meteorite impacts.

A spectrographic image of the central peak of the Alga Crater impact zone, taken by MRO. The green colours indicate the presence of impact glass
A spectrographic image of the central peak of the Alga Crater impact zone, taken by MRO. The green colours indicate the presence of impact glass

Continue reading “Space Sunday: metal rain and glass on Mars, HoloLens into orbit” →

Mystery, murder, mermaids, and cats in Second Life

Posted on by Inara Pey

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 below.

Sunday, June 28th

13:00 Tea-time at Baker Street

Caledonia Skytower, Kaydon Oconnell and Corwyn Allen continue reading The Memoirs of Sherlock Holmes, originally published in 1894, and which brings together twelve (or eleven in US editions of the volume) adventures featuring Holmes and Watson, as originally published in The Strand Magazine. This week: The Adventure of the Gloria Scott, first published in 1893.

Holmes (l) and Watson discuss matters relating the The Adventures of the Gloria Scoot, Sidney Paget, 1893, The Strand Magazine
Holmes (l) and Watson discuss matters relating the The Adventures of the Gloria Scoot, Sidney Paget, 1893, The Strand Magazine

He handed me a short note scrawled upon a half-sheet of slate gray-paper.

“The supply of game for London is going steadily up,” it ran. “Head-keeper Hudson, we believe, had been now told to receive all orders for fly-paper and for preservation of your hen-pheasant’s life.”

As I glanced up from reading this enigmatical message, I saw Holmes chuckling at the expression upon my face.

“You look a little bewildered,” said he.

“I cannot see how such a message as this could inspire horror. It seems to me to be rather grotesque than otherwise.”

“Very likely. Yet the fact remains that the reader, who was a fine, robust old man, was knocked clean down by it as if it had been the butt end of a pistol.”

“You arouse my curiosity,” said I. “But why did you say just now that there were very particular reasons why I should study this case?”

“Because it was the first in which I was ever engaged.”

And so it is  – at last – that John Watson and Conan Doyle’s readers finally learn of the case that caused Sherlock Holmes to cease dabbling in matters of deduction, and make his career that of a consulting detective.

15:30: Special Performance: The Mask of Medusa

Peter Lorre, circa 1941, star of Mask of Medusa
Peter Lorre, circa 1941, star of Mask of Medusa

To launch a summer season of special hosted presentations, Seanchai Library welcomes the Cold Shot Players, a group of playwrights and readers. The season will feature presentations focused on the delights and drama of old time, classic radio shows.

The Mask of Medusa takes us back to the 1940s and the Mystery in the Air radio series starring Peter Lorre. The story, written by author Nelson S. Bond, focuses on Lorre’s character, one of 47 exhibits in a waxwork museum specialising in depicting murderers.

The waxwork is owned by one Aristide Zweig, a self-styled connoisseur of crime, who delights in regaling visitors in the art and artistry of his works and their exceptionally life-life appearance, all within earshot of Lorre’s character.

But the museum holds a dark secret, and Zweig is as much a monster as any of the figures displayed for Zweig’s delight and the titillation of patrons.

18:00 Magicland Storytime – Thomasina

thomasinaJoin Caledonia Skytower at Magicland Park as she continues reading Paul Gallico’s 1957 novel (and later a 1963 Walt Disney film starring none other that Patrick McGoohan, alongside Karen Dotrice – who also appeared in Disney’s Mary Poppins and The Gnome Mobile – and Susan Hampshire).

When Thomasina, young Mary’s cat, suffers injury, Mary’s veterinarian father and widower, is typically unsympathetic , and rather than treating the cat, has it put to sleep – earning himself the enmity of his daughter, who declares him dead to her.

Thomasina, meantime, finds herself in cat heaven, only to be returned to Earth because she has lived only one of her nine lives. Thus begins a series of adventures involving Thomasina, Mary, her father and a local woman regarded as a “witch” by the children, but who has a caring way with animals…

Monday June 29th, 19:00: Avimov’s Mysteries

Gyro Muggins reads a duo of classic short stories of the pen of Isaac Asimov. In What’s in a Name?, first published in June 1956 (albeit it under the title Death of a Honey-Blonde), we follow an unnamed detective as he investigates the mysterious death of a young woman at Carmody University.

First published in 1957, A Loint of Paw presents the theme of the story – that of a play on words – trough its title, as we follow a story of fraud, time-travel, justice, and the play on words upon which a judgement hangs.

Tuesday June 30th, Cat Night at the Library

Caledonia Skytower reads from her 2013 short story collection.

Meet “S” – a cat in the prime of her nine lives. From her superior feline perch, she swipes a paw at adventures in traveling, her favorite games, along with lessons in art and respect. A Trio of Cat Tales is a “feliniously” philosophical journey with plenty of insights and exploits for cat lovers and the “cat owned.”

Wednesday July 1st: 19:00: The Tail of Emily Windsnap Part 3

Faerie Maven-Pralou reads from the first volume in Liz Kesseler’s series about a young girl who, having always lived on a boat but having been kept away from the water by her mother, finally gets to have swimming lessons. With them comes a remarkable discovery that leads her into another world…

Thursday July 2nd 19:00: True UFO Stories

With 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 June / July is the The Xerces Society, at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programmes.

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