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.