Day: August 28, 2016

Space Sunday: exoplanets, dark matter, rovers and recoveries

Posted on by Inara Pey
An artist's impression of Proxima b with Proxima Centauri low on the horizon. The double star above and to the right of it is Alpha Centauri A and B. Credit: ESO
An artist’s impression of Proxima b with Proxima Centauri low on the horizon. The double star above and to the right of it is Alpha Centauri A and B. Credit: ESO

On August 15th, I wrote about rumours that an “Earth-like” planet has been found orbiting our nearest stellar neighbour, Proxima Centauri, 4.25 light years away from our own Sun. The news was first leaked by the German weekly magazine, Der Spiegel, which indicated the discovery had been made by a team at the European Southern Observatory’s (ESO)  La Silla facility – although ESO refused to comment at the time.

However, during a press conference held on August 24th, ESO did confirm the detection of a rocky planet orbiting Proxima Centauri. Dubbed Proxima b, the planet lies within the so-called “Goldilocks” habitable zone around its parent star – the orbit in which conditions are “just right” for the planet to harbour liquid water and offer the kind of conditions in which life might arise.

Comparing Proxima b with Earth. Credit: Space.com
Comparing Proxima b with Earth. Credit: Space.com

The ESO data reveals that Proxima b is orbits its parent star at a distance of roughly 7.5 million km (4.7 million miles), at the edge of the habitable zone, and does so every 11.2 terrestrial days and is about 1.3 times as massive as the Earth. The discovery came about by comparing multiple observations of the star over extended periods using two instruments at La Silla to look for signs of the star “wobbling” in its own spin as a result of planetary gravitational influences. Once identified, ESO called on other observatories around the world to carry out similar observations / comparisons to confirm their findings.

Although the planet lies within the “Goldilocks zone”, just how habitable is it likely to be is still open to question. Stars like Proxima Centauri, which is roughly one-seventh the diameter of our Sun, or just 1.5 times bigger than Jupiter, are volatile in nature, all activity within them entirely convective in nature, giving rise to massive stellar flares. As Proxima-B orbits so close to the star, it is entirely possible that over the aeons, such violent outbursts from Proxima Centauri have stripped away the planet’s atmosphere.

Proxima Cantauri compared with other stellar bodies - and Jupiter (Credit: Space.com)
Proxima Cantauri compared with other stellar bodies – and Jupiter. Credit: Space.com

In addition, the preliminary data from ESO suggests the planet is either tidally locked to Proxima Centauri, or may have a 3:2 orbital resonance (i.e. three rotations for every two orbits) – either of which could make it an inhospitable place for life to gain a toe-hold. The first would leave one side in perpetual daylight and the other in perpetual night, while the second would limit any liquid water on the surface to the tropical zones.

Nevertheless, the discovery of another world in one part of our stellar backyard does raise the question of what NASA’s upcoming TESS mission might find when it starts searching the hundreds of nearby stars for evidence of exoplanets in 2018.

Juno’s Second Pass Over Jupiter

NASA’s Juno space craft made a second successful close sweep over the cloud-tops of Jupiter on Saturday, August 27th to complete its first full orbit around the planet. Speeding over the planet at a velocity of 208,000 km/h (130,000 mph) relative to Jupiter, Juno passed just 2,400 km (2,600 miles) above the cloud tops before heading back out into space, where it will again slowly decelerate under the influence of Jupiter’s immense gravity over the next 27 days, before it once again swing back towards the gas giant.

“Early post-flyby telemetry indicates that everything worked as planned and Juno is firing on all cylinders,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory, as telemetry on the flyby started being received on Earth some 48 mins after the flyby, which occurred at 13:44 UTC.

A twin view of Jupiter captured by Juno on August 23rd, when the spacecraft was some 4.4 million km (2.8 million miles) from the gas giant and approaching Jupiter to complete its first full orbit. On the left is a colour image from JunoCam, on the right an infra-red image Credit: NASA/JPL-Caltech/SwRI/MSSS
A twin view of Jupiter captured by Juno on August 23rd, when the spacecraft was some 4.4 million km (2.8 million miles) from the gas giant and approaching Jupiter to complete its first full orbit. On the left is a colour image from JunoCam, on the right an infra-red image. Credit: NASA/JPL / SwRI / MSSS

All of Juno’s science suite was in operation during the passage over Jupiter’s clouds. However, due to speed at which the gathered data can be returned to Earth, and given it cannot all be relayed in one go or necessarily continuously, it will be a week or more before everything has been transmitted back to Earth. Nevertheless the science team are already excited by the flyby.

“We are getting some intriguing early data returns as we speak,” Scott Bolton, principal investigator of Juno from the Southwest Research Institute, stated. Some of that data included initial images of Jupiter captured as Juno swept towards the planet during the run-up to periapsis. “We are in an orbit nobody has ever been in before, and these images give us a whole new perspective on this gas-giant world,” Bolton added.

Continue reading “Space Sunday: exoplanets, dark matter, rovers and recoveries” →

Of hounds, time, mysteries and awakenings

Posted on by Inara Pey

It’s time to kick-off a week of 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, August 28th

13:30: Tea Time at Baker Street

Tea-time at Baker Street returns for the summer, featuring a new location – 221B Baker Street at the University of Washington iSchool in Second Life. Caledonia Skytower, John Morland and Kayden Oconnell invite you to join them as they return to what is quite possibly the most famous of Sir Arthur Conan Doyle’s works, and present their fourth reading from The Hound of the Baskervilles.

Baskervilles-1902The third full-length novel written about Sherlock Holmes, this is likely to be the one Holmesian story which – at least in outline – known to most, whether or not they have actually read any of Holmes’ adventures.

But how many of us know the story as it was originally written? Over the decades it has been adapted for film and television more than 20 times, starting as early as 1914/15 with the 4-part series, Der Hund von Baskerville, and continuing on through to Paul McGuigan’s The Hounds of Baskerville, featured in the BBC’s brilliant Sherlock series.

All of these adaptations have offered their own take on the tale. Some – such as McGuigan’s, have simply taken the title of the story and used it to weave a unique tale of their own; others have stayed true to the basics of the story whilst also adding their own twists and turns quite outside of Conan Doyle’s plot in order to keep their offering fresh and exciting to an audience.

So why not join Cale, John and Kayden as they read from the 1902 original, and discover just how Sir Arthur Conan Doyle unfolded this apparently supernatural tale of giant hounds and murder, and the pivotal role played by John Watson himself?

18:00: Magicland Storytime

It’s a Small World of Folktales at The Golden Horseshoe in Magicland Park with Caledonia Skytower.

Monday August 29th, 19:00: The Crucible of Time

crucibleGyro Muggin’s takes his audience into the fix-up by John Brunner. First published as two-part story which appeared in Isaac Asimov’s Science Fiction Magazine, it’s an ambitious tale of alien intelligence which grew to a series of six linked tales pushed as a single novel in 1983.

Far off in space is an alien race which is so much like us, yet so un-alike. From the birth of their earliest civilisation through to their attainment of star flight as their star system passes through the galaxy, we follow their development through the ages.

Aquatic by nature, this race presents some significant challenges well outside the realms of anything encountered by humanity. But they are also driven by all too familiar hopes, fears, desires, needs, wants, prejudices, impact of religious ideologies, and the quest for knowledge we have experienced in the growth of our own civilisation.

Charting six periods of time, each a thousand years after the previous, the six stories focus on the efforts of a group of individuals in each era as they face one or more challenges, their success in overcoming these challenges inevitably leading them towards a greater understanding of their planet’s plight, and ultimately, the ability to deal with that plight and the survival of their civilisation.

Tuesday August 30th, 19:00: TBA

Please check the Seanchai Library blog for updates.

Wednesday August 31st, 19:00: A Monstrous Regiment of Women (Mary Russell #2)

MonstrousReturn to 221B Baker Street at the University of Washington’s iSchool, Second Life, for the latter-day adventures of Mr. Sherlock Holmes (retired) and his young orphaned protégé, Mary Russell, originally from the United States, as written by Laurie R. King.

Taking a trip to London, Mary encounters Veronica Beaconsfield, a friend from Oxford, who in turn introduces her to the charismatic and enigmatic Margery Childe, leader of something called “The New Temple of God.” Sect-like, and seemingly involved with the suffrage movement, the New Temple and its leader offer both curiosity and intrigue for Mary, who is not convinced either are entirely above-board.

Her suspicions appear to be correct when several of the Temple’s wealthy young female volunteers and financial contributors are murdered. With Holmes keeping a watchful eye in the background, Mary turns her curiosity into an investigation; in doing so, she faces her greatest danger yet.

Thursday, September 1st, 19:00: Rey’s Story from Star Wars the Force Awakens

With Shandon Loring (In Second Life and Kitely. Check Kitely event announcements for specific grid location).

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 July-August is WildAid: seeking to end the illegal wildlife trade in our lifetimes by reducing demand through public awareness campaigns and providing comprehensive marine protection.

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