Sunday, May 24, 2009

A solar cycle forecast, outer planet satellite mutual events and many meteorite stories

have amassed in the past three weeks. Firstly, after two years of confusion the Solar Cycle 24 Prediction Panel earlier this month has "reached a consensus decision on the prediction of the next solar cycle (Cycle 24). First, the panel has agreed that solar minimum occurred in December, 2008. This still qualifies as a prediction since the smoothed sunspot number is only valid through September, 2008. The panel has decided that the next solar cycle will be below average in intensity, with a maximum sunspot number of 90. Given the predicted date of solar minimum and the predicted maximum intensity, solar maximum is now expected to occur in May, 2013. Note, this is a consensus opinion, not a unanimous decision. A supermajority of the panel did agree to this prediction." More coverage (and occasional dissenting views, w/o actual arguments, though) here, here, here, here and here. Also why there won't be an ice age coming despite the low activity now, a flare causing some interest, if short-lived, and some media confusion about the situation documented. Plus no spots on May 11 (as also seen here) but faculae on May 10 and a prominence on May 3, a "stealth storm" from the Sun, a very detailled review of solar forcing of the terrestrial atmosphere, a well-prepared didactical video on the same topic - and details about the total solar eclipse of 2012 in Queensland, Australia.

Mutual events between the Jovian satellites have now begun, and observations have been many already - though mostly from Australia it seems: an Io/Europa event on May 17 (dito), Callisto/Io on May 16 (dito) and Europa/Ganymede on May 8 as a high resolution video (also discussed here) and lightcurves here and here. Less demanding are observation of satellite transits or the Neptune/Jupiter conjunction on May 27. Of Jupiter itself hi-res pictures of May 13, May 12 (with Ganymede resolved!), May 9, May 7 and earlier. • There are also pics of Saturn with a Rhea shadow transit (and the rings dimmed as the Sun hits them from the side - see also this comparision 2006 vs. 2009 or a May 23 pic), earlier pics, satellite mutual event on May 6. Finally a resolved Mars on May 17. • Scenic-wise here are Jupiter and Venus on the morning of May 24, the lunar crescent on May 23 (another hi-res view), the Moon/Jupiter/Venus chain on May 22 and the Moon/Venus/Jupiter triangle on May 21 (another one).

Meteor(ite)-wise there is now a prediction of a meteor storm in 2045, a "storm of slow fireballs" from the June Bootids this Russian astronomer - successful in the past - is forecasting. • A map of meteor stream radiants from a Japanese video network. • After the Canadian fireball last November hundreds of meteorites have now been collected but the biggest ones are still missing. A large chunck a farmer found has been donated to science. • More meteorite stories from Oman, Australia, the U.S. and Austria, also an expensive specimen and attempted fraud in Viet Nam. • Also more on the retrograde Apollo and three new NEO grants. • Comet-wise something has happened to 19P/Borrelly (earlier; see also here and earlier). • Plus C/2008 Q3 (Garrad) with a globular cluster, 107P recovered, a Lulin lightcurve, 33P/Daniel with a supernova, C/2006 W3 and comet origins questions.

In other news June 17 is now the launch date for LRO and LCROSS - which will impact the Moon on Oct. 8 if current plans hold. Amateur pictures of the lunar south pole are of interest in this context. • Ground-based observers tracking the satellites Herschel & Planck after their launch soon spotted several "UFOs" next to the Ariane's upper stage - by now it seems clear that there are only two unexplained bodies - and they are fading and changing orbits, both hinting at evaporating ice blocks. • An ISS flare in hi-res, an ISS trail with a flare, another one and another hi-res ISS of May 7. • Now amateur astronomers are actually hunting exoplanets with the transit method, not just following up professional discoveries. • An interview with A. Oksanen, a famous Finnish amateur, and hail to citizen astronomers (and other "citizen science"). • Hail also to for everyone! • Finally a truly giant Milky Way Center mosaic (also hailed here), a lunar picture with 500 m/pxl resolution and a 5-hour timelapse movie recorded at the Winter Star Party.

Sunday, May 3, 2009

Various Jupiter conjunctions, bright Venus main events in May

In the sky, that is - for space astronomy it promises to be a particularly exciting month with the launch of Atlantis to the HST on May 11 and the joint Ariane 5 launch of Herschel & Planck on May 14. Recent days brought a lot of action in the evening sky: Here are Mercury & the Pleiades, a lunar mosaic and another one from May 1, Mercury & the Pleiades (detail) and the Moon on April 28 and the Moon, the Pleiades and Mercury on April 26 in a stunning timelapse movie and still pictures (detail, detail, again, more, more, more, more and more) from the U.S. and the U.K., with simple tech. More pics of the constellation are also here and here. Mercury is now gone from the evening sky where now Saturn rules (great pictures galore from the Philippines and Saturn with Tethys and its shadow) while Venus - a stunning hi-res video of the lunar occultation on April 22, another report and another video - is now bright in the morning sky and Jupiter gets more interesting.In other news we have pictures of the comets 29P on April 29 and Lulin on April 30 (in fact tons more comet picture are being taken all the time, but they just don't look that interesting :-). • The first retrograde Apollo asteroid may have been discovered, while yet another amateur astronomer has resolved the disk of dwarf planet Ceres (here are details of the earlier success). • Here are a paper on micrometeorite ablation in the atmosphere - studied directly for the 1st time - and a nice Lyrid picture (the ZHR plot now shows a peak around 18). • A small sunspot group was sighted on April 29 and made some headlines before it went on the Sun's far side - where one STEREO can still see it. Also H-Alpha pics of May 3 and May 2 and a new study showing that cosmic rays don't influence our climate markedly. • Finally, B. Schaefer is predicting once more that U Sco will erupt soon, nice startrails from India, NASA links for citizen science projects, and an impressive ISS flare video.