1St & 3Rd Tuesdays

Stratford-upon-Avon Astronomical Society www.astro.org.uk www.facebook.com/StratfordAstro June 2012

Venus soon after it began to move into the "mesosphere," where the sunlight is sun." refracted. According to some models, the Researchers now understand that mesosphere is key to the physics of backlit by the sun, Venus's atmosphere super-rotation. By analyzing the lightcurve refracted sunlight passing through layers of the arc, researchers can figure out the of air above the planet's cloudtops, temperature and density of this critical creating an arc of light that was visible in layer from pole to pole. amateur telescopes and spacecraft alike. When the arc appeared in 2004, the It turns out that researchers can learn a lot apparition took astronomers by surprise; about Venus by observing the arc. Indeed, as a result, their observations were not it touches on some of the deepest optimized to capture and analyze the fast- mysteries of the second planet. changing ring of light. This time, however, they are ready. Together, Pasachoff and Widemann have organized a worldwide effort to monitor the phenomenon on June 5th, 2012. "We're going to observe the arc using nine coronagraphs spaced around the world," says Pasachoff. "Observing sites include Haleakala, Big Bear, and Sacramento Peak. Japan's Hinode spacecraft and MEETINGS : NASA's Solar Dynamics Observatory will 1ST & 3RD TUESDAYS also be gathering data."

(7:30 PM FOR 8PM ) http://venustransit.gsfc.nasa.gov/ JUNE 19 TH A MOON PUZZLE “Venus Express Explore (CHRISTOPHER TAYLOR ) Earth’s Evil Twin” The arc (or aureole) of Venus as seen by (Prof Andrew Coates) NASA’s Solar Dynamics Observatory during the Dear All, June 2012 transit. JULY 3RD Here's one I made yesterday: "We do not understand why our sister Club Night "What object, while falling in empty space, planet's atmosphere evolved to be so JULY 17 TH different than Earth's," explains planetary slows down?" “Exploring Mars with Satellites” scientist Thomas Widemann of the Note the 'empty space' there - this has nothing to do with aerodynamic drag on (Dr Helen Walker) Observatoire de Paris. objects falling through a planetary Earth and Venus are similar distances AUGUST 7TH atmosphere. Club Night from the Sun, are made of the same basic materials, and are almost perfect twins in Answer: THE MOON. AUGUST 21 ST terms of size. Yet the two planets are Think about it: at the Full, the Moon's own “The View From Saturn: wrapped in stunningly dissimilar blankets geocentric orbital velocity is pointing in the Images from the Cassini spacecraft” of air. Venus's atmosphere is almost 100 forward direction of its (& the Earth's) orbit (Prof Carl Murray) times more massive than Earth's and about the Sun, so the resultant lunar consists mainly of CO , a greenhouse gas SEPTEMBER 4TH 2 velocity relative to the Sun is obtained by that raises the surface temperature to Club Night adding those two contributions; half a almost 900°F (482 °C). Clouds of SEPTEMBER 18 TH lunar month later, at the New, this is sulphuric acid tower 14 miles high and “Discover the Secrets of reversed and the Moon's resultant whip around the planet as fast as 220 Astrophotography” heliocentric velocity is the difference of mph. For the most part, planetary (Philip Perkins) those two contributions. In short, the result scientists have no idea how Venus turned of the Moon's falling nearly half a million OCTOBER 2ND out this way. miles in the Sun's gravity-field is that it Club Night "Our models and tools cannot fully slows down! explain Venus, which means we lack the OCTOBER 16 TH “A Warwickshire Eclipse” tools for understanding our own planet," (Mike Frost) points out Widemann. One of the biggest mysteries of Venus THE ARC OF VENUS is super-rotation. The whole atmosphere (DR TONY PHILLIPS : SCIENCE @NASA ) circles the planet in just four Earth days, much faster than the planet's spin period When Venus crossed the sun this month, of 243 days. "The dynamics of super- an armada of spacecraft and ground- rotation are still a puzzle despite a wealth based telescopes were on the lookout for of data from landmark missions such as something elusive and, until recently, NASA's Pioneer Venus, Russia's Venera unexpected: The Arc of Venus. and VEGA missions, NASA's Magellan

"I was flabbergasted when I first saw it and more recently ESA's Venus Express." during the 2004 transit," recalls Prof Jay This is where the Arc of Venus comes Anyone care to venture a resolution of this Pasachoff of Williams College. "A bright, in for the brightness of the arc reveals the 'paradox'? temperature and density structure of glowing rim appeared around the edge of Yours aye, C. Venus's middle atmosphere, or

John Waller (Membership & Treasurer) 024 7644 0778 ([email protected]) Julia Waller (Newsletter Editor & Librarian) Mike Whitecross (Chair) 12 Badger Road, Binley, Coventry, CV3 2PU. 01789 731784 ([email protected]) Jim Dean (Events Secretary) 024 7644 0778 ([email protected]) [email protected]

Stratford-upon-Avon Astronomical Society www.astro.org.uk www.facebook.com/StratfordAstro June 2012

VENUS TRANSIT 15 minutes before the end of the transit, It was windy, cloudy and cold. The the clouds parted for ten minutes and we prospect of a sighting was literally not on Below is a photo taken by Andrew Baxter got to see Venus on (actually half-off) the the horizon. Zero chance, we thought. of the transit of Venus from Burton Sun. (Timings may not be accurate) Many other astronomers had peeped out Dassett Country Park shortly after dawn of their bedroom windows before th A most agreeable spectacle! on June 6 Venus is the black dot at daybreak and decided not to bother. We about 11 o’clock just leaving the Sun’s Mike Frost did, and we were rewarded for our disc. Also visible are a number of sunspot optimism. groups.

Our San Francisco correspondent (Ashley Niblock, the Editor’s brother) posted the following on Facebook…

Just took a look at the Transit of Venus through a variety of telescopes. I wish I'd brought my camera! The observing car park

Burton Dassett is a Country Park in South Warwickshire. It is a lovely spot to have a

picnic on a summer's afternoon. Children Dick Cluley emailed to say… love the landscape, being open fields and old quarries. But it was a bleak place on My wife and I went up Ebrington Hill at the morning of 6th June 2012. We chose it 4.30 yesterday morning. It was cloudy but because there is a good view to the north we waited an hour and got this. east over the Midland Plain. Photo: Andrew Baxter Our only companions at first were the sheep, who safely graze on those upland Joining Andrew to witness this rare event acres. But then came a Dad with his were Ian Galletly, John Waller and Julia daughter. They were from Loughborough, Waller along with a professional miles away from up north. "Why are you photographer (on his day off!) and a down here?" we asked. Dad replied that number of other keen astronomers. he had done a lot of last minute research and found that the Banbury area was the best place within 100 miles of Loughborough that showed some broken

cloud at dawn. Good decision. Phil Wesby posted…

I was also up at 4:15 and saw the transit above Long Compton at the Roll Right Stones. [Ed – I’ve enhanced the central portion to bring out Venus] I was not alone – there must have been 25 people or more with a variety of scopes TRANSITUS VENERIS from the Chipping Norton Astronomy (A NDREW BAXTER ) Group. Jubilee weather greeted four astro friends There was even someone from Witney TV as they set up their telescopes at 4:30 am shooting 1080HD of the gathering for local on top of The Burton Dassett Hills to see TV. the last “Transit of Whotsit” for 105 years. Not bright enough for the Coronado Loughborough astronomers & John

Solarscope but some good images to be And sure thing, behind us to the seen through conventional scopes. south west, the pale silvery

Regards Phil moon appeared through the overcast skies. The prospects of a sighting rose to 50%, we guessed.

It was 4:45 am and counting. Mike Frost, who is coming to speak to us The Sun should be up, but the in October posted… band of cloud on the horizon showed no sign of lifting. Hi all, Prospects fell to 25%. Another visitor appeared. How did your transit viewing go? He was a freelance I joined the Rugby AS group at Anita's photographer from Coventry campsite in Mollington, just north of who needed to capture the Banbury on the Southam Road. When I transit. That's part of how he woke at 3:45 this morning the sky was earned his living. He won't get very overcast. However, there were gaps rich if he only photographed in the cloud, and so eleven of us stood in transits of Venus. He set up his a field just off the A423 for an hour camera with a telephoto lens watching the clouds - and at 5:40, about but with no solar filter. Surely If you would prefer a colour copy of Equuleus via email (in pdf format) then email Julia at: [email protected] Stratford-upon-Avon Astronomical Society www.astro.org.uk www.facebook.com/StratfordAstro June 2012 that will burn out his CCD chip? I wandered over to the photographer. He the relic radiation left over from the Big was clicking away, fiddling with zoom and Bang. F ratios. "I'm dead lucky," he informed me, Using data from NASA's Wilkinson "that there is some thin cloud over the Microwave Anisotropy Probe (WMAP) Sun." He was stopped down to the satellite, researchers from UCL, Imperial minimum aperture, set for max ASA with College London and the Perimeter the fastest shutter speed and was just Institute have performed the first search about on the limit. No matter. He was for textures on the full sky, finding no happy. He'll be able to sell those shots. evidence for such knots in space. And he did, and a few of his Burton Dassett photos appeared on The Daily Mail web site. Have a look on Google Images. I took a few shots of him and his Photographer, Dan James happiness. At 5 am the Moon was still visible but still I checked to see on my little camera no Sun. However, clear blue sky was what I had taken. A good set of photos of expanding overhead, with a leading edge the morning's events, but no transit photo, slowly edging towards the north east just a swirl of a smudged sun. Quick, just horizon. 50% chance again, we thought. about enough time left before the final As the Universe cooled it underwent a 5:15 am and the clouds there were exit. Fumble, fumble, a shot with Venus series of phase transitions, analogous to brightening as the sun was lifting itself well into egress. Fumble, fumble, a shot water freezing into ice. Many transitions higher and higher. 75% now. Will we see that could only have been seconds away cannot occur consistently throughout the transit before it finishes at 5:45? Ian from the final curtain. And that was that. space, giving rise in some theories to was glued to his eyepiece. Getting Was it worth the effort? Was it worth imperfections in the structure of the brighter. 80%.... 90% ...... The tension was getting out of a warm bed to stand cooling material known as cosmic mounting. amongst those sheep and shadows to textures. record one of the rarest of heavenly If produced in the early Universe, events? 100% yes! textures would interact with light from the CMB to leave a set of characteristic hot and cold spots. If detected, such signatures would yield invaluable insight into the types of phase transitions that John gets round the cloud cover by looking at the transit on the webcast from Hawaii occurred when the Universe was a "There she blows!" cried Ian (or the fraction of a second old, with drastic equivalent stargazing expression). Time: implications for particle physics. 5:20-ish am. We crowded around for a A previous study, published in Science fleeting view, as this might be all there in 2007, provided a tantalising hint that a was to see. The little black dot was clearly L to R: Ian, Andrew, Julia & John CMB feature known as the "Cold Spot" visible within the disc of the partially A celebratory cup of tea was drunk at could be due to a cosmic texture. clouded Sun. But no doubt about it. There Edge Hill whilst we downloaded the However, the CMB Cold Spot only she blowed. That pinch of darkness. The photos onto the computer. Not a bad set comprises around 3% of the available sky clouds could have swept in again, but no of photos, if I might say so. Ian, Julia and area, and an analysis using the full matter. We had seen it. The last transit John departed, and as the old saying microwave sky had not been performed. until 2117. That'll learn 'em, we thought, goes: "And so to bed." A new study places the best limits those bed huggers and hope shruggers. Yes, I snatched an hour before available on theories that produce That'll learn 'em to slip back between their switching the computer on again, not to textures, ruling out at 95% confidence sleepy sheets. work, but to see how the rest of the world theories that produce more than six "I can still see it." said Ian. Time for a had experienced their transit. They might detectable textures on our sky. photo through the lens. A bit of fumbling, have had longer to view, but our little hour Stephen Feeney, from the UCL focussing and clicking, and one shot can match theirs for memorability. Department of Physics and Astronomy, captured for the record. Ian and Julia It's not been a bad year for said: "If textures were observed, they couldn't contain their joy, so another photo astronomical events. First a fireball [Ed – would provide invaluable insight into the taken to record astronomical happiness. way nature works report featured in Equuleus March 2012 – available on the website].Then a transit. at tremendous What's next? energies, shedding light on the SPACE NOT KNOTTED unification of the physical forces. Theories of the primordial Universe predict The tantalizing the existence of knots in the fabric of hints found in a space - known as cosmic textures - which previous small- could be identified by looking at light from scale search the cosmic microwave background (CMB), meant it was extremely important to carry

Stratford-upon-Avon Astronomical Society www.astro.org.uk www.facebook.com/StratfordAstro June 2012 out this full-sky analysis." volcanic activity on Io. Most of Io's Matt Johnson, from the Perimeter eruptions dwarf their contemporaries on Institute, Canada, said: "Although there is Earth. no evidence for these objects in the "This is the most comprehensive study WMAP data, this is not the last word: in a of Io's volcanic thermal emission to date," few months we will have access to much said Glenn Veeder of the Bear Fight better data from the Planck satellite. Institute, who led the study. His team Whether we find textures in the Planck examined data primarily from the NASA's data or further constrain the theories that Voyager and Galileo missions, but also produce them, only time will tell!" incorporated infrared data obtained from telescopes on Earth. A team of scientists has proposed a giant STAR SOUNDS "The fascinating thing about the impact to explain the ridge and that at one distribution of the heat flow is that it is not time Iapetus itself had a satellite, or moon, in keeping with the current preferred created by a giant impact with another big model of tidal heating of Io at relatively body. The sub-satellite’s orbit, they say, shallow depths," said Ashley Davies from would have decayed because of tidal JPL. "Instead, the main thermal emission interactions with Iapetus, and the sub- satellite would have gradually migrated occurs about 40 degrees eastward of its The reggae-rock band “Echo Movement” expected positions." toward Iapetus. At some point the tidal contacted the Georgia Tech Sonification "The pattern that emerges points to a forces would have torn the sub-satellite Laboratory with an unusual request. The complex heating process within Io," said apart, forming a ring of debris around the band, who mix reggae rhythm with Dennis Matson, also from JPL. "What we 735-kilometer-radius Iapetus that would ethereal melodies wanted to include a see indicates a mixture of both deep and eventually slam into the moon near its star’s actual sound into their music shallow heating." equator. It turned out that the Lab were happy to help and extracted data from two binary stars – Kepler 4665989 and 10291683. As the duo of Kepler 4665989 crossed paths the light from them dimmed and brightened in a periodic manner that could be used to create a rhythmic sequence. They input this data into special Sonification Sandbox software to produce varying pitches and then cleaned up the signal. Data from Kepler 10291683 was used to add a natural sounding tremolo to the sounds. A mystery has also emerged. The team “Imagine all of these particles coming The band then worked on the result to found that active volcanoes accounted for down horizontally across the equatorial create a four-part harmony by looping the only about 60% of Io's heat. This surface at about 400 m/s, the speed of a sequence. The six second melody is component mostly emanates from flat- rifle bullet, one after the other, like frozen available to download at: floored volcanic craters called paterae, a baseballs,” William McKinnon from the http://www.gatech.edu/inc/hgFile.php?fna common feature on Io. But where is the University of Illinois Chicago says. me=4-melody.wav "missing" 40%? "We are investigating the “Particles would impact one by one, over possibility that there are many smaller and over again on the equatorial line. At and the finished product can be heard in volcanoes that are hard, but not first, the debris would have made holes to September when the band release the impossible, to detect," said Veeder. "We form a groove that eventually filled up.” actual song “Love and the Human are now puzzling over the observed “When you have a debris ring around Outreach”. The Sonification Lab normally pattern of heat flow." a body, the collisional interactions steal concentrates on researching ways to Understanding this will help identify the energy out of the orbit,” Andrew Dombard present visual data as sound. tidal heating mechanisms not only within from the University of Illinois Chicago Io, but also may apply to neighbouring says. “And the lowest energy state that a IO’S HOT SPOTS Europa, a high-priority target for NASA in body can be in is right over the rotational A new study finds that the pattern of heat its search for life beyond Earth. bulge of a planetary body — the equator. coming from volcanoes on Io's surface That’s why the rings of Jupiter, Saturn, contradicts the generally-accepted model SATURN ’S WALNUT MOON Uranus and Neptune are over the equator. of internal heating. The heat pouring out “There are three critical observations A ridge that follows the equator of Saturn’s that any model for the formation of the of Io's hundreds of erupting volcanoes moon Iapetus gives it the appearance of a indicates a complex, multi-layer source. ridge has to satisfy,” Dombard says. “They giant walnut. The ridge, photographed in are: Why the feature is sitting on the These results come from data collected by 2004 by the Cassini spacecraft, is 100 km NASA spacecraft and ground-based equator; why only on the equator; and why (62 miles) wide and at times 20 km (12 only on Iapetus. I think we have telescopes. miles) high. (The peak of Mount Everest, A map of hot spots, classified by the something here that explains all those by comparison, is 5.5 miles above sea observations.” amount of heat being emitted, shows the level.) global distribution and wide range of If you would prefer a colour copy of Equuleus via email (in pdf format) then email Julia at: [email protected]