Space Sunday: Europa’s water and a Starship’s mishap

An artist’s impression of what the 2012 water plume might have looked like if seen from the vicinity of Europa. Credit: NASA / ESA / M. Kornmesser.

What has long been suspected has likely now confirmed: water is present under the ice of Jupiter’s moon Europa.

As I’ve noted on numerous occasions in this space Sunday articles, it’s long been thought that an ocean of water exists under the cracked icy crust of Europa, potentially kept liquid by tidal forces created by the moon being constantly “flexed” by the competing gravities of Jupiter and the other large Moons pulling on it, thus generating large amounts of heat deep within its core – heat sufficient to keep an ocean possibly tens of kilometres deep in a liquid state.

Europa’s internal structure, showing the subsurface ocean that could be up to 100 km deep

Circumstantial evidence for this water has already been found:

  • During its time studying the Jovian system between 1995 and 2003, NASA’s Galileo probe detected perturbations in Jupiter’s magnetic field near Europa – perturbations scientists attributed to a salty ocean under the moon’s frozen surface, since a salty ocean can conduct electricity.
  • In 2012 the Hubble Space Telescope (HST) captured an image of Europa showing what appeared to be a plume of water vapour rising from one of the many cracks in Europa’s surface – crack themselves pointed to as evidence of the tidal flexing mentioned above. The plume rose some 200 km from the moon.
  • In 2014, HST captured images of a similar plume rising some 160 km above Europa.
A composite image showing suspected plumes of water vapour erupting from Europa at the 7 o’clock position, as imaged by the Imaging Spectrograph on the Hubble Space Telescope in 2014. They rose 160 km, and are believed to have come from the sub-surface ocean. Note that the image of Europa is superimposed on the original, and comprises a mosaic of images taken by the Galileo and Voyager missions. Credit: NASA, ESA, W. Sparks (STScI), and the USGS Astrogeology Science Centre

Now a new paper, A measurement of water vapour amid a largely quiescent environment on Europa, published on November 18th, 2019 in Nature, offers the first direct evidence that water is indeed present on Europa. Specifically, the team behind the study, led by US planetary scientist Lucas Paganini, claims to have confirmed the existence of water vapour on the surface of the moon.

Essential chemical elements (carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulphur) and sources of energy, two of three requirements for life, are found all over the solar system. But the third — liquid water — is somewhat hard to find beyond Earth. While scientists have not yet detected liquid water directly, we’ve found the next best thing: water in vapour form.

– Lucas Paganini

Evidence of plate tectonics have been found on Europa, again pointing to the influence of tidal flexing. This conceptual illustration shows the subduction process where a cold, brittle, outer portion of Europa’s 20-30 km thick ice shell moved into the warmer shell interior and was ultimately subsumed. This resulted in a low-relief subsumption band at the surface in the overriding plate, alongside which cryolavas containing water vapour may have erupted. Credit: Noah Kroese, I.NK

Using the W.M. Keck Observatory in Hawaii, Paganini and his team studied Europa over a total of 17 nights between 2016 and 2017. Using the telescope’s spectrograph, they looked for the specific frequencies of infra-red light given off by water when it interacts with solar radiation. When observing Europa’s leading hemisphere as it orbits Jupiter, the team found those signals, estimating that they’d discovered sufficient water vapour to fill an Olympic-size swimming pool in a matter of minutes. However, the discovery has been somewhat tempered by the fact water may only be released relatively infrequently.

Such infrequent releases help explain why it has taken so long to confirm the existence above Europa, but there are other reasons as well. The components that comprise water have long been known to exist on the moon whether or not they indicate the presence of water. Thus, detecting these components within a plume doesn’t necessarily equate to the discovery of water vapour – not unless they are in the right combinations. There’s a further pair of complications in that none of our orbital capabilities are specifically designed to seek signs of water within the atmospheres of the other planets or expelled from icy moons. So Earth-based instruments  – like the Keck telescope spectrographs – must be used, and these deal with the naturally occurring water vapour in our own atmosphere.

Within Paganini’s team there is confidence that their findings are correct, as they diligently perform a number of checks and tests to remove possible contamination of their data by Earth-based water vapour. Even so, they are the first to acknowledge that close-up, direct studies of Europa are required – particularly to ascertain if any water under the surface of Europa does form a globe-spanning ocean, or if it is confined to reservoirs or fully liquid water trapped within an icy, slushly mantle. It is hoped that NASA’s Europa Clipper and Europe’s JUICE mission (both of which I’ve “previewed” in Space Sunday: to explore Europa, August 2019) will help address questions like this.

Continue reading “Space Sunday: Europa’s water and a Starship’s mishap”

A Seanchai Thanksgiving week in Second Life

Seanchai Library

It’s time to highlight another week of storytelling in Voice by the staff and volunteers at the Seanchai Library. As always, all times SLT, and events are held at the Library’s home at Holly Kai Park, unless otherwise indicated.

Sunday, November 24th 18:30: Ann Mary; Her Two Thanksgivings

Calaedonia Skytower reads Mary Eleanor Wilkins Freeman’s short story. First published in 1892, as a part of the short story collection, Young Lucretia and Other Stories. Though Thanksgiving preparations are often stressful, what’s most important is celebrating with family!

At The Golden Horseshoe, Magicland Park.

Monday, November 25th 19:00: Teacher’s Pet / War and Peace

Gyro Muggins returns to Larry Niven’s Known Space universe and the Man-Kzin Wars series to bring us two short stories from that series written by Matthew Joseph Harrington, and which appeared in the Man-Kzin volume 11 (edited by Niven), first published in 2005.

Set after the end of the war, the stories within Man-Kzin XI are predominantly set during a period where the Kzin are down (but not necessarily out) and having to adapt to no longer being the masters of all races they encounter, and are in roughly chronological order.

The two stories by Harrington follow the trio by established writer Hal Colebatch, and marked his début as a published author at the age of 35. They are regarded by many as being strong studies in the Man-Kzin lore, whilst also drawing on other literary sci-fi sources. The stories are also noted for Harrington’s ability to round-out a number of “loose ends” within the Man-Kin wars as well as offering new slants on the broader carves of Niven’s Known Space universe.

Both stories use a play on words in their titles, with War and Peace doing so both in the manner it reflects the period of peace following war, and also for the way it focuses on the life and work of Peace Corben, a human female Protector, who returns in Harrington’s sequel story, Peace and Freedom, published in the 2009 volume Man Kzin Wars XII.

Tuesday, November 26th 19:00 Spirit of Steamboat

Kayden Oconnell returns to the tales of sheriff Walt Longmire, reading the ninth volume of Craig Johnson’s tales about his laconic US Marine-turned-lawman protagonist.

It’s Christmas Eve, and Longmire is reading A Christmas Carol in his office when he is visited by a ghost of Christmas past: a young woman with a scar across her forehead. He doesn’t recognise her, but she clearly knows him and his predecessor, sheriff Lucian Connally, under whom Longmire started his career as a deputy sheriff in 1972.

His interest aroused, Longmire takes the the young woman to see Connally, now a resident at an Assisted Living Home. But Connally, a former US Army Air Force pilot who flew B-25 Mitchell bombers in the Second World War, fails to recognise her. This is in some ways hardly surprising, given Connally’s frequently inebriated state.

Disappointed at the two men’s reaction, the young woman whispers a single word, “Steamboat”. In doing so, she embarks on a tale that tales Longmire and Connally back to Christmas Eve 1988, when Longmire had been a deputy sheriff just two months. The holiday season had brought with it a record-breaking blizzard – and a road accident that left Longmire and the (again inebriated) Connally with no choice but to pull a B-25 out of mothballs and make a dangerous flight through the blizzard to Denver, Colorado, in order to save a life.

Wednesday, November 27th 19:00: What’s Cookin’?

A favourite food stories and recipe exchange with Caledonia Skytower and friends. This week, the Thanksgiving Edition, with Turkeys and stuffing galore. All are welcomed to bring some of their favourite recipes to share, on note card.

Thursday, November 28th 10:00: Alice’s Restaurant Massacree

A Seanchai Library Thanksgiving tradition.

via Wikipedia

You can get anything that you want
At Alice’s restaurant.
You can get anything that you want
At Alice’s restaurant.
Walk right in, it’s around the back,
Just a half-a-mile from the railroad tracks
And you can get anything that you want
At Alice’s restaurant

As Thanksgiving arrives in the United States, Shandon Loring presents singer-songwriter Arlo Guthrie’s famous 1967 musical monologue, Alice’s Restaurant Massacree (also popularly known as Alice’s Restaurant, and the inspiration of the 1969 Arthur Penn film of that name, starring Guthrie himself).

Aside from the opening and closing chorus, the song is delivered as the spoken word accompanied by a ragtime guitar. The story is based on a true incident in Guthrie’s life when, in 1965, he (then 18) and a friend were arrested for illegally dumping garbage from Alice’s restaurant after discovering that the town dump was closed for the Thanksgiving holiday.

What follows is a complicated, ironic and amusing story told in a deadpan, satirical tone, which encompasses fines, blind judges, guide dogs, 27 8×10 copiously annotated glossy photos related to the littering, frustrated police officers, the Vietnam War draft and, ultimately, the inexplicable ways in which bureaucracy moves to foil itself, just when you’ve given up hope of foiling it yourself.

Also presented in Kitely (

2Lei and a return to a Lost Town in Second Life

Lost Town: Cecilia Nansen – 2Lei 10th edition

In previewing the 2019 2Lei No Violence! season to raise awareness of the annual International Day for the Elimination of Violence Against Women, I was surprised to see that one of the exhibition centres for this year is Lost Town – La Citta’ Perduta.

Surprised, because between 2012 and 2014, the Lost Town was a regular destination for me in exploring the arts in SL (in fact, it’s the place where I first made an attempt at a “full” SL machinima). However, somewhere along the way, I lost track of the location (I actually thought it had closed!) – so my apologies to sivi Kelberry, the region’s holder, for doing so.

Lost Town: Eve Pearl – – 2Lei 10th edition

For the 10th 2Lei edition, Lost Town is hosting exhibitions by Cecilia Nansen, Dixmix Source, Eve Pearl, Hillany Schofield, Mistero Hifeng, Moya Patrick, and Nevereux. This is an accomplished group of artists, and the art is equally so. As such, each of the displays presented in Lost Town has a particular attractiveness and message.

Some of the exhibits tackle the subject of violence against women head-on, as with Mistrero Hifeng’s Di quel che e’ stato non resta, which is startling in its context and presentation. Others focus more on the beauty and femininity of women, an approach that is particularly effective given the primary subject matter for the season. This can be seen through Eve Pearl’s images, for example.

Lost Town: Mistero Hifeng, – 2Lei 10th edition

Still others provide something of the hidden truths of the violence that can exists within a seemingly loving relationship. Note the hard, cold look evident in the male of Dixmix’s images, and the pose / look of the female – her looks suggestive of a desire to please that could go beyond a “simple” desire to show love.

However, I confess to finding Cecilia Nansen’s triptych of monochrome images especially powerful. From the hand raised in a appeal to stop / to be left alone, through the eyes closed against tears, to the line of blood trickling from a nostril, these three images convey all that needs to be said about the hurt and terror of domestic violence.

Lost Town: Dixmix Source – – 2Lei 10th edition

Evocative throughout, all of the displays offered in Lost Town are all emotive in content and should not be missed. For more information on the 10th Edition of 2Lei’s No Violence! season, please refer to my preview piece: No Violence! the 2Lei 10th edition in Second Life.

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