Saturday, November 28, 2009

Two well-videotaped bolides, right after poorly performing Leonids

Once it was a rarity that a meteor fireball was accidentally caught by a surveillance or a police car dashboard camera - but now it has happened twice within three days, first in the U.S. during the maximum night of the (otherwise unimpressive) Leonids and unrelated to them, then in South Africa. • From the South African bolide of 21 November an overview & many reports, a video (also here, plus three stills), a different video (also here and here), a video of the sky brightening and more news coverage here, here and here. • From the November 18 bolide over Utah which caused a lot of excitement (and was also seen from other states) many videos exist, e.g. shown here (nice TV report), here and here, also this (also here), this, this, this, this, this and this one. One could try to triangulate a possible strewn field, unfortunately in a restricted area, to the chagrin of would-be meteorite hunters ... A report, several more, the residual cloud in the sky and a lot of coverage here, here, here, here, here, here, here, here and here, with more news linked here, here, here, here and here.

The Leonids of 2009, according to the worldwide visual data as of today, fell below even the most pessimistic predictions, with a peak ZHR of barely 100 (around 20:30 UTC on Nov. 17) - this would be less than half of what any of the three Perseids peaks reached this year: an early summary and links collection just 24 hours later, another early summary, more reports - and videos! - from the Philippines, Singapore, Nepal, India (again, plus preparations), Canada and the U.S., a picture, a less than informative wire story, one more model, a preview of net sources and more, more and more previews (also a bad and another bad one). • More recent fireball reports here (hi-res pic), here, here, here, here and here and stories about the European Network of fireball cameras and an Aussie meteorite problem. • The Barbara occultation event was observed: Here is a one lightcurve apparently confirming its binarity. • Cometwise we have C/2007 Q3 in the Virgo Cluster: pictures of Nov. 13 and Nov. 25 - plus a call for vigilance re. 107P.

In other news modest activity on the Sun (but a nice prominence and news about solar 'tsunamis' and a possible climate role in past centuries). • The eclipse of Eps Aur is progressing, a nova in Scu reached 7th mag. while Nova Eri even reached 5th mag. (but now it's down to 8 mag.), Mira is near maximum, Eta Car is brightening and should be watched as might be Zeta Aur. • There are now 50 named moons of Jupiter. • A nice video of the Oct. 21 Antares occultation by the Moon. • An amateur observatory designed with wheelchairs in mind. • A new Galaxy Zoo project involving galaxy mergers (more, more, more, more, more, more und mehr. • And finally four amateur astronomy personality stories about Jones, Boles, Legault and Mellinger.

Tuesday, November 10, 2009

RANT EXTRA: On the state of the astro-blogosphere

(Too) much has been written lately on how old-fashioned journalism is gonna die and to be replaced by blogs or tweets or wiki-whatevers. In the field of science and esp. space-related reporting the borders are blurred anyway, and the volume of 'copy' produced by bloggers is way outweighing the classical formats in any case. Just watch what the blog feed catcher of the Portal to the Universe (in the creation of which this blogger was actually involved) sucks in all the time. There is a lot of redundancy here, as noted by the PTTU editors early on, often little more than copy-&-past-ing of press releases, and only occasional original work. The watchdog function many blogs in the political area play is mostly missing - and just recently so many examples of poor reporting and/or judgement have come across my screen that this rant just had to get out. I won't name - or link to - individual 'sinners' here: You know who you are, as do your readers. Three examples:
  • On Nov. 5 the British Natural History Museum put online a story about a meteorite with unusual properties that had been recovered thanks to an Australian camera network imaging its fall. Many blogs, including several 'famous' ones, treated this as a news story - when in fact the respective paper had been published in Science on Sep. 18, together with a press release by CSIRO and lots of timely news coverage, e.g. in the New Scientist. Apparently none of the blogger stars had recalled this major astronomy news event from less than two months ago - what does it say about how serious they are with their reporting work? Particularly shocking is that this oversight happened to a number of the 'big names' in the business.

  • There have been two 'incidents' with minute asteroids of 5 to 10 meters in diameter recently, one exploding over Indonesia on Oct. 8, the other missing Earth on Nov. 6. While the former case was at least unusual (bodies of this size hit Earth only every few years), the latter was not as similar approaches to Earth w/o impact are ten times as frequent. Yet there were those blog stories again about how Earth just escaped another "asteroid" collision. Of course nothing other than an Indonesia-style fireball would have occurred, and no distinction between harmless airbursting rocks and dangerous bodies of 25+ meters was made or at least emphasized. The headlines should have been "Earth missed another nice bolide event" ... but instead we got served the dire view that these (non-)cases are further proof that Earth is defenseless against grave danger from space - which does exist, of course, but on an entirely different scale.

  • One week from now the Leonid meteors may or may not produce a decent shower when the Earth encounters some dust trails left by the parent comet. Last year a crude model calculation by a French astronomer (now working at Caltech) had predicted a maximum Zenithal Hourly Rate - i.e. meteor/hour under the best possible viewing conditions - of 500 or more: This would have qualified as half a "storm", reminding meteor veterans of great drama a decade ago, and the prediction was picked up by NASA and even by the IAU in an IYA press release. But this high prediction always stood alone, with other experienced theorists predicting a much smaller outburst. Still NASA ignored the doubts and many bloggers - with rare exceptions - took the 500+ figure for granted, until today. Alas, some time ago the theorist retracted it and is now predicting some 200, while the main 'competitor' is at around 175 and yet another pioneer of the field sees around 100. Even NASA conceded today that the 500 are history (but still thinks 300 possible without presenting the calculations leading to this).
The same NASA website that promoted the high prediction (and was not particularly successful in picking the right model with other meteor events in the past) may also have played a - minor - role in the ongoing 2012 'end of the world' nonsense. For when it came to predictions of how high the next maximum of solar activity might be, it strongly promoted one theorist whose results were at the very high end. And when a big panel of solar physicists in 2007 determined that the next peak would be average at best and almost certainly not high, this finding - reinforced two years later - wasn't communicated well. It's hard to prove causalities in this emotionally charged field of astronomy, but said NASA site is being copied-and-pasted (and absorbed, one would think) a lot, especially by astronomy aficionados not necessarily reading the original literature. And now I hear the makers of the "2012" movie premiering this week in a making-of on German TV (last Sunday) stating as an undisputed scientific fact that the coming solar maximum will be extremely high. Who else is wondering where that "information" came from? And now back to our regular fare of actual astronomy news that are new and correct ...

Thursday, November 5, 2009

Pretty unusual stellar occultation by an asteroid highlight of November

Asteroids are always causing interest, be it a discovery in New Zealand or a very small one occulting a very bright star along a narrow strip (so far either negative or clouded-out reports have been received). A more promising and scientifically important event is coming up on the morning of Nov. 21, however, when (234) Barbara hits at 7.5 mag. star - and this asteroid is double and has been measured by optical interferometry. Chords from the occultation - visible in Florida and Europe - would provide a crucial test of this method and could actually deliver higher resolution. Other than that only the Leonids (with a max. ZHR between 150 and 200 according to the latest models) and a Jupiter/Moon conjunction on Nov. 23 seem to be important in November; other previews here, hier, hier, hier and/und hier.

In other news three comets in one picture (one undiscovered at the time), two comets in one view and LINEAR on Oct. 26 and Oct. 24. • Just for the record another impact hoax, this time in Latvia and obviously faked from the video alone (more, more, more, more, more, more, more, more, more, more, more, more, more, more and more links, more or less enlightened). • Detailed analysis of an Antares occultation by the Moon. • Mars inside Messier 44 (a preview and Mars close-up) plus a Moon/Jupiter conjunction from the Philippines. • The largest sunspot in ages on Oct. 30, Oct. 28 (more) and Oct. 26 (more). • Nova Sgr 2009 #4 (more). • A Bright Star Monitor at work. • The Mellinger mosaic has now a press release, copied e.g. here and here. • What an almost blind astronomer can do. • An ISS/Moon transit from Germany. • And a fullmoon rainbow in the headlines.