Saturday, June 25, 2011

Tiny asteroid comes to visit Monday: closest approach to Earth surface 12,280 km

According to the latest calculation with JPL's Horizons ephemeris machine it will be Monday, June 27, at precisely 17:00 UTC ± a few minutes when asteroid 2011 MD - with a diameter of a dozen meters or two, i.e. roughly house-sized - will pass closest to Earth: It will then be only 0.0001247 AU = 18,665 km from the planet's center or about 12,280 km from its surface. As the all-time list of closest approaches shows, this is by no means a record: at least three asteroids that got provisional numbers came even closer - and another one was discovered and then hit us (2008 TC3 of course). Our newest visitor will reach its closest Earth approach point in extreme southern latitudes (in fact over the southern Atlantic Ocean).

The incoming trajectory leg - some helpful animations from different points of view! - passes several thousand kilometers outside the geosynchronous ring of satellites and the outgoing leg passes well inside the ring. One would expect an object of this size - 5 to 20 meters, depending on the albedo - to come this close to Earth about every 6 years on average: a little video shows it moving in the sky this morning. There had been initial speculation that 2011 MD might be old space junk, but this seems practically excluded today. Some coverage here, here (earlier), here and here - and we have already an early contender for the most stupid headline: 5 to 20 meters diameter = "giant asteroid" ... :-)

In other planetary system news we have new data about and a fuzzy pic of centaur Echeclus in outburst, new Afrho data - what that means - from Elenin and an info page about PANSTARRS; there is still some confusion regarding its orbit. • A big bolide in TX & OK on June 20, and yours truly gets quoted re. the Draconids 2011 outlook. • An occultation of a star by Pluto was observed with SOFIA - central flash included - and from the ground, and there will be another one shortly. • A great amateur pic of Mercury showing e.g. the Caloris basin and a montage of Saturn's motion near Porrima.

From the total lunar eclipse 10 days ago report of successful observations with the LRO's DIVINER instrument, another gallery of amateur pictures (more, more and more collections; much more), a German review of what happened, a timelapse video and more selected reports and pictures from the Philippines (more), Nepal (more), India (more and more reports and more, more, more and more pictures), South Africa (a precise lightcurve!), Namibia, Greece (with thunderstorm; alt.; more, Hungary, Ireland, Spain, Austria (unusual timelapse movie; more, more, more, more, more, more, more, more, more, more, more, more and more pics & stories) and Germany (Donauwörth, Garching, Munich, Ulm and Stuttgart), plus a serious and a funny and another weird story on the TLE.

Elsewhere in the Universe a lightbridge in AR 1236 on the Sun where spots were published 400 years ago, a flare & CME on June 20 (video; it was again w/o Earth effects), how Chandra coped with the June 7 flare and yet another (alt.) and another space wx scare story. • The SN 2011dh in M 51 - now at ~12.3 mag. - on June 23 vs. 4 blinking and paired, a June 20 drawing, confusion about the progenitor and how to locate it. • NLCs from Stockholm on June 18 and sky color FX from a Chilean volcano. • An amateur imaging spysats (more). • And another attempt to end leap seconds.

Friday, June 17, 2011

Deep total lunar eclipse enjoyed from Oceania to Europe

Tons of reports and gorgeous pictures have already come in from many countries, stretching in longitude from Portugal to New Caledonia: There the lunar eclipse of June 15/16 began at dawn while in western Europe it ended at dusk; only in western Asia, the eastern Mediterranean and parts of Africa the complete show could be enjoyed. One way to beat geometry was to follow the eclipse via webcasts of which the one arranged by SLOOH and Google delivered best. This page links to numerous images and reports and fine galleries can be found here, here, here, here = here, here, here, here, here, here and here. Selected pictures from New Caledonia, Australia (gorgeous wide-angle view; more, more, more, more, more and more), South Korea, India (more, more and more), Armenia, Iran (more), Turkey (more), Croatia, Rhodos, Greece (more, more, more and more), Italy (more), Poland, Denmark, Sweden, Portugal, Austria (continued; more, more, more and more) and the UK (no luck).

In Germany the eclipse was right 'on the edge' and visibility of totality depended strongly on your location, let alone the weather conditions. Some reports and image impressions from near Donauwörth (story), Ulm, Irschenberg, Weikersheim (scroll down), Münster, Freising, Leonding, Wasserkuppe, Munich, Vogtland, Plochingen, near Heidelberg, Bonn (little to see; story), Finsterwalde (no pictures) and Stuttgart (nothing; more). Some stories about the eclipse can be found here, here, here, hier and hier (alt.). There were also plans to use the LRO for temperature measurements at high resolution during the eclipse, and a paper just came out on the impact of the Kasatochi eruption on the Moon's illumination during the August 2008 lunar eclipse. Finally a moderately funny German satire about the eclipse and complete nonsense, also here and here ...• Nice pictures of the preceding solar eclipse in Lapland - and a paper on the TSE 10 years ago in Zambia.

In other solar system news another mutual event of Haumea & Namaka was observed and tweeted live from La Palma - the dip was shallower than expected and the live-tweeting of science made news of its own. • There is a new orbit for comet PANSTARRS (scroll down) which would improve visibility even more; since the IfA and the Pan-STARRS project are talking, the comet's got some press here, here, here, here and here. Let's just wait for the orbital calculations to stabilize; meanwhile C/2009 P1 (Garradd) could be fun.

Regarding the Sun, a prediction of low solar activity in cycles 24 and esp. 25 - immediately attacked, BTW - has caused a lot of reporting, e.g. here, here, here, here, here, here, here, here, here, here, here, here, here, here, here, hier, hier, hier and here. • Other solar news addressed the impact of minima (alt.) and solar waves (related paper & story) and ropes; also Proba 2 saw the June 7 eruption (that had no effects on Earth whatsoever) and STEREO the farside of the Sun, plus a long and a short story on solar activity in general.

In deep space the supernova 2011dh in M 51 has brightened to about 12.7 mag.! A picture of June 7 and a paper and another one and a report and another one on the progenitor. • Finally a possible nebula discovery by an amateur astronomer - and NLCs during the lunar eclipse spotted in Austria of all places.

Thursday, June 9, 2011

There could be a bright comet in the sky ... in April 2013

This is just a pre-pre-warning with many caveats ... but if the first orbit for newly discovered comet C/2011 L4 (PANSTARRS) holds, it could put on quite a show when the visitor reaches a perihelion of only 1/3 AU in April 2013. A first visibility analysis by this blogger sees the comet very close to the horizon in the Northern hemisphere just after perihelion - when it may reach 2nd or 1st magnitude or even better - while it's better visible in the weeks before and right up to perihelion in the Southern hemisphere. Once the orbit stabilizes, these calculations will be repated in greater detail, and then it's up to the comet's brightness to perform. If it does work out as the standard formula implies, you read it here first ... • In other comet news the state of Elenin (and one more anti-BS article), new comet C/2011 L3 (McNaught) and continuing observations of the outburst of 174P/Echeclus. • On June 15 a faint asteroid will visit a bright star in Leo, and 2009 BD is feeling radiation pressure. • Opinion about the 2011 Draconids is still wildly split: Will there be hardly any meteors or 600 per hour or 1000 per hour ...?

Regarding larger bodies in the solar system the next Transit of Venus is (less than) a year away now, spawning this website and outreach ideas. • A close-up of Saturn & Porrima and another view with some Chronian satellites, too. • More previews of the June 15 total lunar eclipse here, here, here and here - and remember my old advice for the optimum experience! • Pictures of the June 3 lunar crescent here, here, here and here. • From the Midnight Eclipse the best movie (almost hypnotic ...), another one, one from Proba-2 and more coverage and image collections here, here, here, here, also great pictures from Norway (more) and Iceland. • A big solar eruption on June 7 (more and more animations and coverage here, here and here) led to some expectations for the Earth (see also here, here, here, here and here for some hysteria) that didn't materialize (see also here, here and here): Better look here first (and the U.N. will save us anyway :-). • Also the Sun on May 31, some wave phenomena and spectroscopy - and more details about Nova Sco.

The supernova 2011dh in Messier 51 is at about 13.4 mag. in the visíble right now as collected pictures & photometry and esp. visual estimates show. We have a gallery, calls by the Weizmann Inst. and Palomar Obs. for yet more (early) pictures of this apparent type IIb SN and selected pictures of June 7 (more), June 6 and June 3 (explained; more, more and more). As it has turned out this blogger played a role in the obtaining of the first-ever spectrum of the SN (also 'discussed' here and in the tweets here, here and here). There is a potential identification of the SN progenitor (easily visible in a public HST image of M 51), and the SN was seen in X-rays, by Swift's UVOT and in radio. Finally some more general coverage of the SN 2011dh here, here, here, here, here, here, here, here and here. • Finally a cool video with NLCs and aurora shot June 4 in Minnesota - and extremely detailled pics of the ISS & OV-105, also hailed here.

Friday, June 3, 2011

13th mag. supernova in famous Whirlpool galaxy M 51 - widely observed before even official ...

Normally there is an IAU Circular, spawning alerts through various astronomy news services, leading to observations - but with a supernova discovered in the night June 1/2 in the famous galaxy Messier 51 it was very different. As this blog 'goes to print' object "PSN J13303600+4706330" still hasn't been announced officially as a supernova, yet the web is full of great pictures and other data, including spectral information confirming a type II SN. There are early confirming pictures here, here (triggered by yours truly last night and spreading quickly), here, here (in the order in which I learned of them) and several here. Apparently the supernova was already there on May 31 but seems to be absent on May 30; here is also the regular view of M 51. • There is also a new Nova Scorpii, also discussed here (picture). • Epsilon Aurigae is almost back & in conjunction with the Sun now. • The H-Alpha Sun today, prominences on May 25 and ideas regarding dark sunspots.

The "midnight solar eclipse" was widely observed in northern Europe and also in Russia and N America: more previews here, here and here, pictures from Russia here and here, from Finland here (with sunspots!), here and here, from Sweden here and here, from Norway here, here and here, from Iceland here, here, here and here (later) and from Alaska here - picture collections can also be found here, here, here, here (related article) and here. • The 1-day Moon after the eclipse was imaged in the U.S., Mexico and Brazil. • More previews of the June 15 lunar eclipse here, hier and hier. • The color of the full moon enhanced. • Saturn at Porrima.

The morning planets and the Moon on May 31 from Poland, May 30 from Argentina, May 29 (and other dates) from South Africa and May 28 from California and Australia. • Centaur 174P/Echeclus in outburst, and image of 2009 P1 (Garradd) (which should be bright next year), new comets P/2011 JB15 (Spacewatch-Boattini) and C/2011 K1 (Schwartz-Holvorcen), Elenin still faint and still orbited by idiots - and anoth comet plunging into the Sun Mai 21st. • A fly-by by 2009 BD and a bolide in Georgia on May 20. • A little audio introduction to NLCs. • And glorious pictures by D. Caxete of the ISS & Endeavour in front of the Sun, plus some trails of the two later - and a video of the reentry over Yucatan.