Sunday, March 30, 2008

ATV closing in on the ISS - follow it in the sky

Yesterday the big Automated Transfer Vehicle approached the ISS in a first of two dress rehearsals to within 3.5 km; later that evening the pair - with the ATV leading the ISS - was photographed and filmed over Europe (another picture and more). From the ISS the ATV was also seen during the demonstration. The day before the two had been flying much farther apart as two movies show. Here are the plans for another demonstration tomorrow (when the ATV will come to within 11 meters of the ISS around 16:45 UTC; the go-ahead came minutes ago) and docking on Thursday at 14:41 UTC. You can follow the action via an ESA blog and see where the ATV and ISS are right now. Weather permitting there are one or two nicely lit overflights for Europe every evening in the coming days as Heavens Above tells us.

In other news two satellite fuel tanks apparently survived reentry and were found in recent days, one in Australia and one in Brazil. • The three sunspot groups from the old cycle are now near the middle of the disk: a white light and an H-Alpha view (another one) of March 29 and a white light/H-Alpha blinking image and a calcium view of March 28. • An old impact crater may have been found in the U.K. • Yesterday's Earth Hour was followed in some places and could even inspire some stargazing - and caused controversy in Oz. • And here is an unusual panorama of a halo.

Friday, March 28, 2008

12 mag. supernova in Sculptor galaxy NGC 7793!

Finally a (compared to most other discoveries) pretty bright supernova that medium-sized amateur telescopes should show well: In the spiral galaxy NGC 7793, located at -32° declination in the constellation Sculptor, a supernova of 12th magnitude has been discovered on March 25. SN 2008bk is located approximately 2.3 arcminutes north of the nucleus of NGC 7793, a bright flocculent spiral galaxy of type Scd.

In other news there are now three sunspot groups on the disk, all from the old cycle: White-light images of Mar. 27 (attn.: wrong AR numbers) and Mar. 25 show the three activity regions well as do H-Alpha images of Mar. 26 and Mar. 25. • There are also impressive aurora pictures taken 'from above' during the last shuttle mission. • The Google-discovered Aussie impact crater is making more news. • And the reentry of the ATV (which hasn't even docked to the ISS yet) will be a subject of scientific study ...

Tuesday, March 25, 2008

Comet Holmes still naked eye; meets Chen-Gao

Exactly 5 months after its outburst the famous comet was still "was faintly, fleetingly visible with the naked eye on 2:15 UT March 24 under transparent skies (mag. 6.5 stars visible)," reports one Bob: "The comet appeared as a uniform smudge approximately 1/2 degree across. 10x50 binoculars showed a dim puff that was 1 1/4 degrees across". Tomorrow and the day after Holmes will be visited by Chen-Gao which will approach it to within 1° and may actually be seen in front of the coma - interesting especially for astrophotographers. While Holmes has been estimated at 5th mag recently, Chen-Gao is at 9th - and will be occulted by the Moon in April for East Asia, another photo challenge.

In other news three papers in the mail today deal with the extraordinary "naked-eye GRB" (42 pages, only 5 days after the event!), the demise of a bizarre 'discovery' in spiral galaxy statistics (already discussed by the Galaxy Zoo and Bad Astronomy blogs in January - an interesting cautionary tale) and the statistics of exoplanet discoveries at Keck: One can extrapolate "17-20% of stars having gas giant planets within 20 AU".

• Here's an unexpected March 24 Mars with details, caught in daytime. • The two sunspot groups are still growing and also nice in H-Alpha. • Finally the new "Bond" is currently shooting on Cerro Paranal: The producers liked the futuristic residential complex of the European Southern Observatory's main site. Only that "Residencia" and the airstrip will be used as locations, the actual telescopes or their buildings will not be involved - in contrast to another movie years ago ...

Monday, March 24, 2008

Finally some notable sunspots to be seen

Two groups with several small spots each are now on the white-light Sun, AR 10987 and 10988. There is also some prominence activity now. Fortunately observing both phenomena - with proper techniques! - is free, in contrast to the 2009 Total Solar Eclipse in Japan where some well-placed small islands will charge an "entrance fee" of 300,000 yen or EUR 2000, just for the permission to come ashore ...

In other news here are detailled optical light curves of the March 19 GRB from Polish and Russian astronomers. • Once again actual data show no cosmic ray climate effects, a dubious topic that comes up all the time. • A nice Moon halo was seen at Easter. • And USA 193 reacted differently to the rocket attack than expected.

Saturday, March 22, 2008

Rare event tonight: asteroid and its moon to occult star in Europe!

"Another important occultation will occur in the next Saturday to Sunday night near 2:30 UT (i.e. on Easter morning)," advises J.Lecacheux on the PLANOCCULT mailing list: "The shadows of the big asteroid 22 Kalliope and of Linus, its 30 km satellite, will cross Near Orient and Europe diagonally, separated by 1094 km. Detecting Linus by occultation can provide a very accurate astrometric position, ten times better than the VLT or Keck Airy resolution, thus very useful to improve the satellite orbit. Only one previous successful occultation is known for Linus : when the Japanese observers caught both asteroid and satellite from the region of Tokyo on 2006 Nov.07. It allowed us to revise down the diameter of Linus from 38 to 30 km."

Here are more maps of Kalliope's path. According to Lecacheux, the 40 km path of Linus "will fly over Syria, w.Turkey, n.Grece or s.Bulgaria, all the states of former Yugoslavia, n.e.Italy or s.Austria, Switzerland or s.Germany, n.e.France or Belgium, and finally s.England and Ireland. Assuming 50 km as '1 sigma' accuracy of the Linus ephemeris relative to Kalliope, the probability of positive occultation should be 15 % for any observer staying at the middle of the Linus track [...]. For example this probability should be 7.5 % from Brussels, Bern or Paris." The path of Kalliope, 255 km wide, will be centered 500±180 km "SSW from the Linus centre line. It will cover a part of Jordania and almost whole Israel, s.Greece (Crete and Peloponnese), a part of s.Italy, and finally a large strip running across the south and west of France."

Lecacheux is a bit pessimistic, though, in his circular from yesterday, noting two circumstances that "will keep the situation far from idyllic. 1/ The bad weather now expected from many regions; 2/ The faint drop predicted, only 0.16 magnitude. The observation itself will be quite easy, even with modest telescopes and despite lunar vicinity, as the combined magnitude of the target (asteroid + star) will be V~10.7." Analyzing the measurements will be diffucult, though, and Lecacheux has an "advice: recording a two minutes dark sequence (with the telescope covered) just after the occultation, then subtracting at processing stage to every video image the so obtained 'mean dark pattern', will boost by a factor ~2 the SNR of a Watec 902x camera. This is an efficient way of improvement."

In other news Arthur C. Clarke has been laid to rest in Sri Lanka today. • More results from Hinode have been published, • auroral activity may be up a bit due to the season, • and the last Hubble Servicing Mission may face delay because there aren't enough external tanks ready. • Readers should also be aware of repeated misleading meteor 'recommendations' from one (otherwise o.k.) website.

• The particularly early Easter Sunday this year (in the western world, that is) should make us all ponder the complex rules that actually contradict astronomy one year in ten! German readers find more here or here - fortunately there are able online calculators available that obey to all the church math. • And if that's all too much, here's a celestial Easter Bunny ...

Friday, March 21, 2008

"Naked-eye Gamma Ray Burst" becomes mainstream knowledge

1 1/2 days after the event NASA has finally reacted with a Press Release to its satellite's success: "NASA Satellite Detects Record Gamma Ray Burst Explosion Halfway Across Universe". The story stresses that "the Very Large Telescope in Chile and the Hobby-Eberly Telescope in Texas measured the burst's redshift at 0.94. [...] A redshift of 0.94 translates into a distance of 7.5 billion light years, meaning the explosion took place 7.5 billion years ago, a time when the universe was less than half its current age and Earth had yet to form. This is more than halfway across the visible universe."

Records, records: "No other known object or type of explosion could be seen by the naked eye at such an immense distance," and "GRB 080319B's optical afterglow was 2.5 million times more luminous than the most luminous supernova ever recorded, making it the most intrinsically bright object ever observed by humans in the universe." Observing reports are still streaming in, though the afterglow - imaged at 19th mag. later on the 19th by Finnish amateurs - of the remarkable GRB has now dropped to below 20th mag.

Thursday, March 20, 2008

So who did mention geostationary telecom sats first?

Arthur C. Clarke will be buried - in a strictly secular ceremony - on Saturday, and few of the uncountable obituaries fail to mention that he 'predicted' or even 'invented' the idea of geostationary satellites for telecommunications, like the one launched last night. Even Eutelsat is celebrating him as the Father of the Geostationary Orbit, but this is not the case: The all-knowing Wikipedia tells us that the "idea of a geosynchronous satellite for communication purposes was first published in 1928 by Herman Potočnik" alias Hermann Noordung, and that Clarke role was that of a popularizer of the concept. In his famous Oct. 1945 Wireless World paper Clarke indeed quoted Noordung and others - and a recent study showed that the special role of the geostationary orbit was pointed out even in the 19th century. Clarke struggled in vain to set the record straight during his lifetime, now it may be even harder ...

Meanwhile many more obituaries and tributes to Arthur C. Clarke have come in, e.g. from an Indian SF author, in a Sri Lankan editorial or an Indian Leader or in the LA and NY Times' or Physics World. Details about his last interview, a growing collection of tributes and the strange travels of some Clarke DNA are there, a 1977 article on a rare U.S. visit has been re-published, and we even learned how to hold a moment of silence in cyberspace ... The fascination of space lives on, of course, and if it comes in the form the recovered video tapes from the STS-123 SRBs: The best 'action' starts at 2:08, 4:35, 5:35, 7:40 and 10:05!

In other news a real unknown impact crater seems to have been discovered via Google Earth. • The MIT has students hunt asteroids via remote observing at the IRTF. • The NASA Eclipse Website has moved to a new URL and older ones will vanish; you find here e.g. all Eclipse Bulletins or info on the next TSE. • There has been no NOAA update on the coming 24th solar cycle for 11 months now, because these predictions are hard near the current minimum, but predictions by a single researcher now see a steep rise in sunspots beginning later this year. • Meanwhile be happy with three prominences seen today.

Wednesday, March 19, 2008

Gamma Ray Burst might have been visible naked-eye this morning

Probably nobody looked at the right spot at the right time - but when GRB 080319B erupted this morning at 6:13 UTC, it would have been visible as a star of at least magnitude 5.8 for a few seconds at 14h 31m 40.7s +36° 18' 14.7" (2000.0)! According to THE ASTRONOMER Electronic Circular No 2432 a camera "located at Las Campanas Observatory imaged the region of GRB 080319b before, during and after the GRB with 10s exposures (IR-cut filter only)." Nothing was visible from 6:12:33 to 6:12:43 UTC down to 12th mag., but from 6:12:47 - 6:12:57 UTC a 10 mag. "star" was seen which from 6:13:01 - 6:13:11 UTC had risen to a maximum brightness of about 6th mag. Now a call is out whether someone by chance photographed this sky field at the right time - and observers with larger telescopes are encouraged to take deep exposures even now.

In other news the death of Arthur C. Clarke has brought out numerous items of interest on the web such as the last ever interview he gave (transcript), a statement by NASA, a BBC piece with videos, an NPR piece with a radio feature, and obituaries galore from everywhere around the world, e.g. from the Planetary Society, the New York, Los Angeles and London Times', the Washington Post, ABC, the Guardian, CNN, the BBC, CBC and And in the blogosphere responses came e.g. from SpaceRef, SpaceWeather, Wired, AstroProf, Planetary Soc., Nature, SpaceWriter, Voltage Gate, New Scientist, Univ. Today, Centauri Dreams, Cocktail Party Physics and NASA Watch.

• Meanwhile, the storm on Saturn seems to be fading, the 2009 ring plane crossing is approaching, and it has been decided that we now have an Encke Gap - and not Division - in Saturn's rings. • Here's a DIY Deimos. • And March 29 features both an (international) Earth Hour in which cities should turn off their lights for one hour at 8 p.m. local time and the start of the (U.S.) Nat'l Dark-Sky Week, as the International Dark-Sky Association reminds us. Light pollution has become a big media topic now.

Tuesday, March 18, 2008

STOP PRESS: Arthur C. Clarke dead at 90

Deeply saddened this blogger has just learned moments ago that A.C. Clarke has died in Sri Lanka at the age of 90. Links to more detailled obituaries will follow.

State of the art of meteor astronomy evident at German conference

As every year the - already 27th - AKM-Seminar, this time in Freital near Dresden, gave a great overview about the state of the art of meteor observation and analysis: This is one of the fields of astronomy where the level of amateur work is not much different anymore from what the (few) professionals in the field do.
  • This is particularly evident in the IMO Video Meteor Network to which now 20+ cameras contribute (15+ of them every clear night) and which netted 75,070 meteors in 2007 - the annual yield has been climbing linearly for years now. The 330,000 meteors in the data base will be analyzed for known and unknown meteor streams again this summer by sophisticated (and extremely CPU-intensive!) software: While visual observations still form the traditional base of our knowledge of meteoroid clouds moving through the solar system and being intercepted by Earth, the never-tiring video cameras add more and more insights. And mysteries: This March 6 and 9, the two meteors were recorded travelling in close proximity at the same time, something never seen before in 100,000s of cases ...

  • While meteor stream modelling has greatly advanced in the past ten years, thanks to the Leonid storms, there are still surprises happening (so one should be observing at every opportunity): For example in 2006 and again in 2007 the Orionids were more active than usual, with Zenithal Hourly Rates in the 60s instead of 20-25. This has since been explained by a 6:1 resonance with Jupiter of the meteoroids which not only explains enhanced Orionid activity in 1936, 2006 and 2007 but also predicts high rates of these bright meteors in 2008 as well as 2009 and 2010. Unfortunately the 2008 Orionids will suffer from moonlight as will the Geminids: The Perseids - with an expected ZHR of 110 - will be the only major shower this year free of lunar interference.

  • When major fireballs light up the sky anywhere over Europe Thomas Grau will travel there, interview eye (and ear!) witnesses and go on a hunt for meteorites if a strewnfield is deemed likely and its location has been calculated. The results from extensive witness 'interrogation' can at times be more precise than using imagery from fireball camera networks, says Grau, who reported on three recent cases.

    • The famous 1 March 2008 fireball had at first been suspected to have dropped small meteorites near (or even into) Lake Constance - simply because many early eyewitness reports had come from that area. But further reports have now made it clear that any meteorites would have fallen in central Switzerland instead where going after them will be tough. The characteristics of the fireball could also mean, though, that no solid matter reached the ground at all.

    • Similarly confusing were the first reports about a fireball in France on 25 January 2008, 15 minutes after sunset. A cloud in the sky remained and was photographed, but because of wind drift its use for determining the trajectory was limited. Fireball sighting vectors from reliable witnesses, however, meet near one location, in the vicinity of Montpellier - and several mentioned strange "red and blue flames" trailing the fireball. No meteorites yet either.

    • The last major success happened in Spain after a daylight fireball on 10 May 2007 which was accompanied by loud noises and shaking ground like during an earthquake. Although only 5 really good witnesses could be located, from their sightings and acoustical recollections a search zone could be located - and soon five small meteorites were found (among tons of meteowrongs in olive plantations). A further search by Grau yielded 10 more, and overall 100+ meteorites have been found in a 7 x 3 km zone, with together 800 grams - and they are eucrites, i.e. most likely splinters of asteroid Vesta.
Apart from meteors (and meteorite hunts and investigations of impact craters - real ones, not this one) the Arbeitskreis Meteore also deals with atmospherical optics of the traditional and also very non-traditional kind. Classical halo phenomena by ice crystals (in the atmosphere or elsewhere) are nowadays accompanied by optical effects of all kinds, be it in bacteria slime layers on ponds or in cat hairs. Some AKM members also love to do experiments, and it order to demonstrate his insights into rainbow physics C. Fenn actually performed a spectacular show for the conference crowd - with a rotating laser beam and water spray in a nightly parking lot ...

In other news the Moon and Saturn will meet tomorrow, a Saturn animation clearly shows its elusive rotation pattern, and even with 8" but modern electronic cameras amazing Saturn images are possible today.

Another impact on the Moon has been videographed, this time from Maryland, astonishing lunar images with cell phone cameras, just held behind a telescope eyepiece, are possible - and you can bring out color on the Moon (that normally just looks yellowish) with clever image processing!

Sunday, March 16, 2008

Google's Sky service now also on the web - no extra software!

The planetarium/visualization software released last year is no longer necessary to bring the sky to your computer: a website is offering the same, with highly zoomable real images from sky surveys. It works just like Google Maps and is pretty fast and smooth.

In other news it is noteworthy that many Cassini images from the Enceladus flyby have stars in the background as the Saturn moon was in the shadow! The flyby was not as smooth as it first seemed, with a key dust instrument failing at a bad time. • Here's an unusual paper about micrometeorite impacts into space telescopes of the grazing kind - which are pretty common.

• Clips from a live TV report from 1979 from the last total solar eclipse in the U.S. are available, 10 minutes in total (fine picture and sound quality)! And there are thoughts about observing solar eclipses from the Moon which has been done only once and in poor quality. • The light curve of Halley's comet at all timescales has been analyzed in Russia. • And there are speculations about another real planet in our solar system ...

Thursday, March 13, 2008

Cassini makes it past Enceladus and through a plume

As reported in several postings on NASA's Enceladus flyby blog the daring maneuver yesterday went well as did the downlink of many pictures - like this one! - and other data.

In other news yesterday's lunar visit to the Plejades was a nice photo opportunity (an alt. presentation and more pictures), NEA 2008 ED8 has been observed, the Canadian bolide makes news, the most impressive wide-angle video of the Endeavour launch yet has emerged - and some look for quark nuggets among NEAs ...

Wednesday, March 12, 2008

Hale-Bopp sets record: comet still active 26 AU from the Sun!

"Eleven years after its perihelion, comet C/1995 O1 (Hale-Bopp) is still active," we learn in a paper for ApJL: Last October a diffuse coma 180,000 km in diameter was seen, with an integrated brightness of 20.04 mag. "The coma was relatively red at V-R=0.66 mag, which is consistent with that of the dust in other comets. The observed properties and the overall fading in brightness between 10 AU and 26 AU follow the predicted behaviour of CO-driven activity (Capria et al. 2002). This is the most distant cometary activity ever observed."

In other news the mystery of the small impact crater in Peru last September - where no large solid mass should have reached the ground - was discussed at a conference: The strange event could change scientists' thinking about how meteorites act and how other craters on Earth were formed.

• Here is an excellent picture of the Moon's ashen light on Mar. 9, two days after new. • The night launch of Endeavour was big fun for bystanders who saw the shuttle vanish in low clouds from nearby but arcing away from a distance. MECO and ET separation may also have been observed, but interpreting STS observations can be difficult. • Meanwhile no more fragments of USA 193 have been spotted for sure, so they must be pretty small.

Tuesday, March 11, 2008

Coming attractions: Cassini to graze Enceladus, Moon to graze Plejades

This 75th posting since "Cosmos 4 U" was launched is mainly dealing with the - immediate - future:
  • On March 12 the Cassini spacecraft will approach Enceladus to within 50 km and pass through a plume (as this video nicely explains). NASA has started an official blog to get all the details about this unique event out in near-real time!

  • Also on March 12 - actually within the same hour that Cassini gets closest to Enceladus! - he Moon will come close to the Plejades star cluster and may occult some of its stars: This video shows the situation from Berlin, Germany.
In other news a Cassini image of the current Saturn storm, an updated Holmes vs. the CA nebula sequence, an unusual video of Endeavour's launch into low clouds, the complete NASA launch video with cool plasma effects at MECO & ET sep (jump to 5:00 or better yet 6:40!) and a still frame.

Monday, March 10, 2008

Another (minor) outburst of comet Holmes - in progress right now?

This blog reported in depth about a possible weak 2nd outburst of comet Holmes in late January - and now THE ASTRONOMER Electronic Circular No 2430 has news about a third outburst in progress! "Images and photometry by several observers [...] suggest that comet 17P/Holmes has shown a further mini-outburst, which appears to have initiated on 2008 March 7," we learn: The R-magnitude of a 10 arcsec square aperture, equivalent to a physical aperture of 22000 km at the comet, went up from 16.1 to 15.7. Which for Mark Kidger and Richard Miles means a lot: "The three events detected so far have taken place at 44.6±0.6, 89.5±0.6 and 135.1±0.8 days after the initial outburst on 2007 October 23.7, giving a mean interval of 45.0±0.5 days determined from a least squares fit. The correlation coefficient of the fit is r2=0.99997. It is likely that this periodicity corresponds to the rotation period of the nucleus whereby the same area is activated when receiving insolation and thus it is concluded that 17P/Holmes is a very slow rotator, comparable to 29P/Schwassmann-Wachmann 1, which from Spitzer observations of its jets [...] appears to rotate with a period of 60 days or more."

In other news the 2008 ED8 vs. EZ7 mystery remains unsolved, but the 2nd NEA is now close. • The first ATV has been seen at +0.5 mag one day after its Kourou launch. • And claims about connections between galactic cosmic rays and Earth's climate take another hit - from astrophysics itself.

Near Earth Asteroid immediately followed by another one

As announced, 2008 EZ7 flew by Earth - but there is another one on a somewhat similar orbit. Or may be not, as the orbits are not that similar after all, raising questions about a direct connection of the two. In any case the 2nd asteroid, meanwhile named 2008 ED8, is in Earth's vicinity right now, again very briefly reaching mag 12 to 13.

In other news the Moon is back in the evening sky, already 2 days old (here it is 3/4 of a day earlier). • The new Nova Cygni 2008 is easy to find and was at mag 7.8 last morning. • There are updates on the state of Holmes' coma and the March 1 bolide which may have dropped meteorites in the Schaffhausen area.

• And you can listen to TA's Guy Hurst on the radio (Broadcasting House on BBC 4 yesterday morning), talking about the state of amateur astronomy at minutes 44-49, or to other cosmic sounds from all kinds of sources.

Saturday, March 8, 2008

8th magnitude nova erupts in Cygnus

Nova Cygni 2008 was discovered yesterday by Japanese amateur Hiroshi Kaneda during his sky survey with a digital camera + 105-mm f/2.5 telephoto lens: He found the nova at mag 8.2±0.3 on on Mar. 7.801 UTC. The 'new star' is at R.A. = 19h58m33s.4, Decl. = +29o52'04" (equinox 2000.0; uncertainty estimated to be ±15"), according to CBET # 1291 of today. Kaneda noted "that nothing is visible at this position on his patrol frames taken on 2007 Oct. 5, (limiting mag 10.5), 2008 Jan. 1 (limiting mag 10.7), and Feb. 18 (limiting mag 10.5); also, nothing is present on the Digitized Sky Survey within 20" of this position to mag 13.0." Numerous additional claims of independent discovery have since come in, the first being from Zhang-wei Jin and Xing Gao, using a Canon EOS 350D camera (+ 7-cm-aperture, 200-mm-f.l. f/2.8 telephoto lens) at Xingming Observatory, Mt. Nanshan, China - during the same nova survey that led to a comet discovery (later named Chen-Gao) a month ago!

In other news a just discovered NEA should reach mag 12 tonight, a Canadian fireball may have dropped meteorites, the Saturn storm is still around, there are views of comet Holmes at the CA nebula of March 8, 6 (dito, dito) and 4, Mira is fading after its recent maximum, and the Sombrero without a galaxy has been created with unusual image processing ...

Friday, March 7, 2008

"Dust halo" or "ring" found around Saturn's moon Rhea?

There has nothing been seen by any camera on Cassini, so the evidence is all indirect yet intriguing: a paper in today's Science (319, 1380-4) talks about "solid material that can absorb magnetospheric particles" which "Rhea's magnetospheric interaction region, rather than being exclusively induced by sputtered gas and its products, likely contains". The evidence for that is the finding that "energetic electrons are depleted in the moon's vicinity" in combination with the "absence of a substantial exosphere" which one would have expected. But what's the absorber? "Combined observations from several instruments suggest that this material is in the form of grains and boulders up to several decimetres in size and orbits Rhea as an equatorial debris disk," continues the abstract: "Within this disk may reside denser, discrete rings or arcs of material." For the JPL (and the media) these possible rings are worth a headline, the LANL goes with the "dusty halo" from the paper's original title instead.

In other news the Large binocular telescope has achieved its first binocular light, taking celestial images using its twin side-by-side, 8.4-meter (27.6 foot) primary mirrors together. • A particularly deep image of Holmes at the CA nebula, showing more coma than typical images. • There are now 131 catalogued pieces of USA 193. • One can observe aurorae in daylight from space, using narrow UV filters. • And if you don't like it here: Perhaps there's a hole into another dimension in plain sight ...

Thursday, March 6, 2008

5 years of WMAP data yield best-ever map, confirm & refine standard cosmology

A few hours ago the WMAP team has released its five year dataset, with 7 papers and new maps and power spectra. Highlights of the new results include definite evidence for light neutrinos: The presence of the neutrino background was necessary from Big Bang Nucleosynthesis results, but now the CMB requires their presence at 99.5% confidence. And we now know that the epoch of reionization is more than 3 sigma earlier than the redshift z=6 where the Gunn-Peterson effect blackens quasar spectra. Otherwise everything remains consistent with a flat universe comprised of 72% vacuum energy, 23% dark matter and 5% ordinary matter - the standard model of the Universe for the past 10 years, love it or hate it ...

In other news first pictures of the Moon very close to Venus are coming in, be it a low contrast close-up in daytime or nice conjunction views from New Zealand or Argentina. • Swiss TV just had a big story on the March 1 fireball in its evening news - click on the image next to the story but beware: While the off-voice speaks German, the people interviewed use Schwyzerdütsch. • And finally, here's how to build a globe of Phobos, the strangely shaped Martian moon ...

Wednesday, March 5, 2008

Holmes has made contact with the California nebula

The comet is now touching the big nebula as a picture of today shows - it had been creeping closer for weeks.

In other news a sixth Neptune trojan has been discovered, and the Moon visited Venus & Mercury this morning.

Tuesday, March 4, 2008

Bright storm observed on Saturn since mid-February

Just around the time of opposition (coincidence!) an impressive storm in the STrZ of Saturn appeared, looking - at the resolution of amateur telescopes - like a bright spot. Now one of the best images (from Feb. 19) has been published, and you follow the storm's evolution e.g. with the ALPO Japan archive. It's well seen on images of March 3 and 1 and Feb. 23, 20 (from another source), 15 and 8 - this is the earliest report I could track down.

In other news the March 1 fireball over Central Europe is having some media impact, e.g. in Switzerland and Southern Germany - where some mass may have reached the ground. And in parts of the U.S. the Moon will occult Venus or come very close, during daylight on March 5.

Monday, March 3, 2008

MRO catches dusty avalanche on Mars in the act!

For a change here's a pointer to a most amazing image from the Mars Reconnaissance Orbiter's HiRISE camera: It shows at least four Martian avalanches, or debris falls, in action on Feb. 19! It is extremely rare to catch such a dramatic event in action. Recently the MRO also imaged Earth & Moon from Mars orbit, demonstrating its enormous resolution.

In other news the recent lunar eclipse has been analyzed for the dustiness of Earth's atmosphere (not much volcanic debris there) while in contrast the "536 AD climate event" that some thought was caused by a cosmic impact has now been shown to have a volcanic origin. And there are yet more technical details of the USA 193 attack being determined by eager amateurs.

Sunday, March 2, 2008

Mighty fireball seen, recorded over Europe on March 1

At 22:44 UTC on March 1 a major fireball lit up the landscape in Central Europe (some say for seconds it was as bright as daytime) and spawned numerous visual reports (more, more, more) - and a tremendous bang was also heard.

In other news the USA 193 debris situation remains a bit confusing as the NOTAM turns out to be old (issued just before the attack took place) and the delay of one satellite launch - but not of other missions - must not be blown out of proportion. In any case modelling of the known fragments' decays shows that they should all be gone by mid-month.

What March 2008 will bring to your skies

Not nearly as much exotic stuff as February, I'm afraid, but there's at least something happening this month:
  • March 4 to 12: Comet Holmes slides by the California Nebula, a feast for astrophotographers as images from Feb. 24 and 27 demonstrate. See also below for Holmes' behavior.

  • March 5, around noon UTC: Moon close to Venus & Mercury (here's a recent morning view from Hongkong).

  • March 23: Unusually early Easter Sunday (spring began on March 20 at 5:48 UTC, Full Moon was on March 21 at 18:41 UTC). Only in the year 2160 will we again have such an early Easter Sunday (the last one was in 1913) - to be beaten only in 2285 with the earliest possible Easter Sunday ever, March 22 (which last happened in 1818).
In other news the third-largest scattered disk object in (or rather beyond) the Kuiper Belt has been discovered, with only Eris and very scattered Sedna being bigger. Comet Holmes has changed its coma quite markedly, as a comparision of Feb. 25 vs. Feb. 5 shows, and there is now a combined lightcurve (from this site) which may or may not tell us what the comet's been doing ...

A small nebula around RY Tau that made news 3 years ago as an amateur target for the Gemini telescopes has now also been imaged with an amateur instrument, albeit a pretty large one. The first images of annularity of the Feb. 7 eclipse over Antarctica have been published as have been another nice view of the subsequent lunar eclipse from Hawaii (which was observed in many countries), a comparision of 12 eclipses and a stark demonstration of libration.

Finally USA 193 or what's left of it after been attacked quite precisely with a Standard Missile 3 is still making headlines: Some 45 fragments have now been numbered - and a most unusual NOTAM regarding falling debris has been issued! Pilots are asked to report anything unusual they see between now and March 9. The orbits of the numbered fragments look impressive indeed, but a "ring of steel" they are not: Space above Earth is still mostly empty, and we're just going through a minor spike - which also won't affect the next shuttle launch, although an unmanned one has been affected ...