*********************************** The SOCIETY for POPULAR ASTRONOMY *********************************** ==================================================== Electronic News Bulletin No. 276 2009 November 22 ==================================================== Here is the latest round-up of news from the Society for Popular Astronomy. The SPA is Britain's liveliest astronomical society, with members all over the world. We accept subscription payments online at our secure site and can take credit and debit cards. You can join or renew via a secure server or just see how much we have to offer by visiting http://www.popastro.com/ LEONIDS - FIRST IMPRESSIONS By Alastair McBeath, SPA Meteor Section Director Initial news coming through from this year's Leonid maximum suggests enhanced activity was indeed seen, but not quite to any of the predicted stronger-event timings (the possible storm-proportion rate predictions were heavily revised downwards to merely "good to strong" shortly after ENB 275 was published, archived at http://snipurl.com/tcn1s . It is too early for a proper assessment, with fresh data still arriving continually, but the "live" International Meteor Organization (IMO) Leonids webpage (at http://snipurl.com/tcn24 ) has indicated so far that there may have been two peaks with Zenithal Hourly Rates (ZHRs) of 100 or more on November 17, one for half an hour or so centred around 20:15 UT (possibly the more active, with ZHRs of ~110-120), the other for about fifteen minutes between 21:00-21:15 UT (ZHRs ~95-120). The predictions mostly suggested the highest Leonid activity would occur sometime between 21:00- 22:00 UT, as well as several lesser potential maxima on November 17 and 18. These preliminary ZHR values and timings are, of course, subject to revision. Results arriving at the SPA so far have suggested the better skies for British observers near the expected maxima were on November 16- 17, primarily from parts of central-southern England (Leics, Worcs & Oxon) and northwest Northern Ireland. November 17-18 seems to have been a lot poorer for most places, with yet more heavy rain. Some comments can be found on the Observing Forum's "Leonids" topic, at: http://snipurl.com/tcn2l . Intriguingly, several UK fireballs have been reported from November 15-16 and 16-17 so far, a couple of which appear to have been possible Taurids. However, the most spectacular was a Leonid at 05:47 UT on November 16-17, as witnessed from Lancashire and Co. Londonderry. The Northern Ireland observer, Martin McKenna, estimated it was brighter than full Moon, and left a persistent train for about ten minutes afterwards! Though not operating his camera at the critical instant, when the initial surprise wore off, Martin managed to secure a number of images of the event's train, as it twisted and changed with time due to high-altitude winds blowing in different directions only a few vertical kilometres apart. Some of his images can be seen among the Leonid reports on the UK Weather World's Space Weather Forum here: http://snipurl.com/tcobn . Any fresh observations of this fireball, or any others (a fireball is a meteor of magnitude -3 or brighter), made from the British Isles or nearby, would be welcomed by the Section. The minimum details needed are: 1) Exactly where you were (give the name of the nearest town or large village and county if in Britain, or your geographic latitude and longitude if elsewhere in the world); 2) The date and timing of the event; and 3) Where the fireball started and ended in the sky, as accurately as possible, or where the first and last points you could see of the trail were if you did not see the whole flight. More advice and a fuller set of details to send (including an e-mail report form) are given on the "Making and Reporting Fireball Observations" page of the SPA website, at: http://snipurl.com/tcnfi . Please keep sending in your "ordinary" Leonid observations too! ORIONIDS 2009 By Alastair McBeath, SPA Meteor Section Director As followers of the Observing Forum topic on this shower (at http://snipurl.com/tcmks ) will already know, the Orionids also produced an enhanced return this year, another in the consecutive series that began in 2006, and despite generally negative expectations for 2009 in advance (as discussed in ENB 275). A belated warning was issued by the IAU for possibly increased Orionid activity however, circulated just a few days before the expected peak. Unfortunately, weather conditions across much of the UK were again rather poor, and very few detailed observations have arrived from here covering what took place. Luckily though, we were fortunate in receiving some excellent support from meteor watchers overseas, including those of the North American Meteor Network (NAMN; http://www.namnmeteors.org ), data kindly provided very soon after the event by NAMN leader Mark Davis, and the radio observers who routinely report to the Radio Meteor Observation Bulletins (RMOBs; see: http://www.rmob.org ), helpfully submitted by RMOB editor Chris Steyaert in the form of RMOB 195 for October 2009. Further comments, including some positive UK reports, can be read on the UK Weather World's Space Weather Forum "Orionids 2009" topic at: http://snipurl.com/tcpua . The list of contributing observers to date is as follows, where "R" means radio and "V" visual results were provided by that individual. Salvador Aguirre (Mexico; NAMN; V), Enric Algeciras (Spain; RMOB; R), "aliblincow" (Scotland; V), Orlando Benitez (Canary Islands; RMOB; R), Mike Boschat (Nova Scotia, Canada; NAMN, V & RMOB, R), Jeff Brower (British Columbia, Canada; RMOB; R), Willy Camps (Belgium; RMOB; R), John Coussens (Belgium; RMOB; R), Tibor Csorgei (Slovakia; NAMN; V), Mark Davis (South Carolina, USA; NAMN; V), Gaspard De Wilde (Belgium; RMOB; R), David Entwistle (England; RMOB; R), Karl-Heinz Gansel (Germany; RMOB; R), William Godley (Oklahoma, USA; NAMN; V), Richard Hill (North Carolina, USA; NAMN; V), Javor Kac (Slovenia; NAMN; V), Mike Linnolt (Hawaii, USA; NAMN; V), Grigoris Maravelias (Crete; NAMN; V), Pierre Martin (Ontario, Canada; NAMN; V), Paul Martsching (Iowa, USA; NAMN; V), Alastair McBeath (England; V), Martin McKenna (Northern Ireland; V), Mike Otte (Illinois, USA; RMOB; R), Jean-Louis Rault (France; RMOB; R), Steve Roush (Arizona, USA; RMOB; R), Wayne Sanders (British Columbia, Canada; RMOB; R), Andy Smith (England; RMOB; R), Chris Steyaert (Belgium; RMOB; R), Wesley Stone (Oregon, USA; NAMN; V), Dave Swan (England; RMOB; R), Richard Taibi (Maryland, USA; NAMN; V), Istvan Tepliczky (Hungary; RMOB; R), Dirk Van Hessche (Belgium; RMOB; R), Felix Verbelen (Belgium; RMOB; R), William Watson (New York, USA; NAMN; V), Graham Winstanley (England; V), Kim Youmans (Georgia, USA; NAMN; V). Orionid activity was not strongly enhanced, but ZHRs between 30-45 persisted from October 19-20 to 23-24, as shown by both the SPA data, and the more extensive IMO preliminary results. While ZHRs of about 30 were predicted for this year anyway, their persistence beyond the normal October 21 maximum date was not. The IMO's "live" Orionids page is still available off the http://www.imo.net homepage. In more detail, the IMO dataset has indicated average Orionid ZHRs were about 35 throughout October 20, 21 and 22. They then seem to have risen to around 40-45 on October 23, before falling back to ~25 by the 24th, and dropping further thereafter. These values remain preliminary only however, and may change later after a full analysis. On October 22, while the enhanced shower activity was still underway, the IAU were already claiming unusually high rates of bright Orionids had been seen on October 20. However, this seemed to have been based on just one observer's data. The SPA magnitude distributions over the whole of the shower's extended peak (based on 467 Orionids and 223 sporadics) yielded mean magnitudes, corrected to ideal sky conditions, of +2.6 and +3.4 respectively, both quite normal statistics, with no unexpected excess of bright Orionids at all. About 36% of Orionids left persistent trains, again much as usual. Assistant Meteor Director David Entwistle and I have examined various aspects of the radio meteor data during the best from the Orionids this year, with some additional input from observer-analyst Jeff Brower, which results overall demonstrated a quite clear Orionid response, lasting for a week or so centred around October 21-22. >From past years, similar radio meteor behaviour has tended to indicate above average, but not outstanding, Orionid activity, when compared with the visual findings. In greater detail, based on from 17 to 21 viable radio datasets a day (8 from North America and 13 from Europe), a reasonably obvious peak in echo counts due to the Orionids was registered on October 21, with good activity detected by most operational systems from October 19 to 23 inclusive, tailing off into October 24. There was an indication that modestly increased numbers of brighter meteors (assumed to be from echoes that produced longer than normal radio reflections) were present from October 21-24 inclusive, and that similar events may have been occurring, probably at a somewhat lower rate, from October 19. A loose "peak" in such longer echoes was suggested as lasting across both October 22 and 23. There seemed little evidence for a specific time-dependency beyond the "day" level in all this, as most systems registered generally increased meteor counts whenever the Orionid radiant was clear of the horizon on the dates above. It has not been possible to check so readily for these 'radio-bright' meteors during the Orionids before, thus it is not certain how significant this aspect may be. As always, some caution needs to be exercised when considering radio meteor results, because of the considerable difficulties in carrying out the analyses, but this is our best attempt at a full examination. Many thanks go to all our contributing observers and correspondents during the shower - with particular commiserations to those whose watching was thwarted by the weather. AUTUMN FIREBALLS UPDATE By Alastair McBeath, SPA Meteor Section Director Since the previous ENB, the autumn had been a relatively quiet one for fireball sightings reported to the Section, until close to the Leonid maxima, as noted above, probably because of some very unhelpful British skies overnight during the last couple of months. Our Recent Fireball Sightings page at: http://snipurl.com/tcoc3 , has continued to be updated with what reports have come through. Interestingly - and thankfully! - the number of "sky lanterns" mistaken for meteoric fireballs has fallen significantly in recent weeks, presumably as people realise meteors need a clear sky to be seen in, not the UK's persistent clouds! A couple of fireballs in October were of particular note, though not seen from the British Isles. The first was a spectacular detonating daylight event on October 8, at about 03:00 UT (around 11 a.m. local time) over the islands of Indonesia, which produced a blast wave that was detected by a number of infrasound detectors there. These detections enabled the object's atmospheric location to be determined as high above the city of Bone in southern Sulawesi. SPA and UK Weather World Forum topics at http://snipurl.com/tcpyj and http://snipurl.com/tcpz0 respectively had links to more information, including a published report on the event. Closer to home, a very bright fireball was imaged from the Netherlands around 18:00 UT on October 13-14, enabling Dutch Meteor Society analysts to estimate a trajectory for the object. David Entwistle's posting near the end of the SPA Observing Forum topic at http://snipurl.com/tcoca gave a link to the DMS's webpage, where more details can be found. METEOR SECTION WEBPAGE UPGRADE COMPLETED By Alastair McBeath, SPA Meteor Section Director October saw the completion of the Section's webpage upgrade, which has been on-going throughout IYA2009. Aside from a few fresh tweaks to existing pages, this final stage also saw the revision of the "Coping with very high meteor activity" page, in anticipation of the potential for a Leonid storm this month. As noted above, that prediction had evaporated before the amended page had gone online, but the information is something all meteor observers need to be aware of, in case unexpectedly strong meteor rates should appear one night when nothing is predicted. This page and all the Section's others can be accessed from the Meteor homepage, at: http://snipurl.com/tcqat . INTERNATIONAL METEOR CONFERENCE 2010 - IN BRITAIN! By Alastair McBeath, SPA Meteor Section Director For the first time, the International Meteor Conference (IMC) is to be held in the British Isles, from September 16 to 19, 2010, at Armagh in Northern Ireland, organized by IMO members currently working as professional astronomers at the famous Armagh Observatory. Details are still being finalized for bookings and costs, but registration is expected to open early in the New Year, and it is anticipated that the price to attend, which will include all Conference sessions, the excursion, full-board accommodation (in the Armagh City Youth Hostel), and a copy of the meeting's Proceedings, will be around 150 Euros. More information can be found on the IMC 2010 webpage, http://www.imo.net/imc2010 , while photos and notes from past IMCs can be found elsewhere on the IMO website. The IMC's official language is English, and all meteor enthusiasts, amateur or professional, will be welcome to attend. PROSPECTS FOR THE 2009 GEMINIDS By Alastair McBeath, SPA Meteor Section Director IYA2009's last major shower, the Geminids, have a moonless maximum expected on December 14 around 05h UT. New Moon is on December 16. The Geminid radiant rises around sunset and reaches a usefully-observable elevation for meteor watchers by about 20h UT from Britain. After this, it remains well-placed for the rest of the night, culminating around 02h. Highest ZHRs should be ~120 judging by recent returns, and observed rates from the UK on December 13-14 under clear, very dark skies could be a meteor a minute or more throughout the post-midnight hours, if its activity is of this strength again. This is because Geminid rates often remain close to their maximum levels for 6 to 10 hours to either side of their best, and activity is normally good, if lower, for a night or two before, and sometimes a night after, the maximum in an average year. Thus pleasing shower rates may be glimpsed then, even if clouds intervene on the peak night. Geminids are medium speed and often bright meteors, though few leave glowing persistent trains after them. Much lower Geminid rates may be seen away from the maximum in any moonless skies available between roughly December 7 to 17. For more information on December's meteor activity as a whole, and a Geminid radiant chart, see our December meteor activity webpage at: http://snipurl.com/tcqqi . Good luck, and clear skies! NEAR MISS ASTEROIDS IAU On Nov. 6 at 2132 UT, asteroid 2009 VA passed the Earth just 14,000 km above the surface, well inside the distance of geosynchronous satellites. If it had hit, the ~6-metre space rock would have disintegrated in the atmosphere as a spectacular fireball, causing no significant damage to the ground. 2009 VA was discovered just 15 hours before closest approach by astronomers working at the Catalina Sky Survey. In early October, with no warning, a ~10-metre asteroid hit the atmosphere above Indonesia and exploded. The break-up was so powerful that it triggered nuclear-test-ban sensors thousands of kilometres away. A just-released analysis of infrasound data shows that the asteroid detonated with an energy equivalent to about 50,000 tons of TNT, similar to that of a `small' atomic bomb. SPACECRAFT SEE 'DAMP MOON SOILS' BBC News Data from three spacecraft, including India's Chandrayaan probe, show that very fine films of water coat the particles that make up the lunar soil. The rock and soil samples returned by the Apollo missions were found to be ever so slightly 'damp' when examined in the laboratory, but scientists could never rule out the possibility that the water in the samples got in only after they were brought back to Earth. The only safe scientific conclusion they could draw at the time was that the lunar surface was all-but bone dry. Now a remote sensing instrument on Chandrayaan-1, India's first mission to lunar orbit, has confirmed that there is a real water signal at the Moon. Two other satellites looking at the Moon -- the US Deep Impact probe and the US--European Cassini spacecraft -- confirm the Chandrayaan findings. Both collected their Moon data long ago (in the case of Cassini, 10 years ago), but the significance of what they saw is only now being realised. The quantity of water is seen to increase the closer the observations are made to the poles -- the very places the Apollo missions never went. Scientists suspect the water is created in the soil in an interaction with the solar wind, fast-moving particles that constantly stream away from the Sun. Harsh space radiation triggers a chemical reaction in which oxygen atoms already in the soil acquire hydrogen nuclei to make water molecules and the simpler hydrogen-oxygen (OH) molecule. Researchers have also said that preliminary data from the 'Lunar Crater Observation and Sensing Satellite' (LCROSS) indicate that water exists in a permanently shadowed lunar crater. On Oct. 9, the LCROSS spacecraft and a companion rocket stage made twin impacts in crater Cabeus near the Moon's south pole. A plume of debris travelled at a high angle beyond the rim of Cabeus and into sunlight, while an additional curtain of debris was ejected more laterally. Evidence of water was seen in both the high-angle vapour plume and the ejecta curtain created by the impact. PREVIOUSLY UNSEEN TERRITORY ON MERCURY OBSERVED Science Daily The MESSENGER spacecraft's third fly-by of Mercury has given scientists, for the first time, an almost complete view of the planet's surface and revealed some dramatic changes in Mercury's comet-like tail. The spacecraft's cameras and instruments revealed 6% of the planet's surface never before seen at close range, One of the spacecraft's instruments conducted its most extensive observations to date of Mercury's ultra-thin atmosphere or 'exosphere'. Material in the exosphere comes mainly from the surface of Mercury, knocked aloft by solar radiation, solar-wind bombardment and meteoroid vaporization. The wispy gaseous envelope is stretched by solar radiation pressure into a long, comet-like tail, which seems to be changing as Mercury moves round the Sun. The observations also show that calcium and magnesium in the exosphere exhibit different seasonal changes from sodium -- a difference that researchers do not understand. After MESSENGER enters Mercury orbit in 2011, it can make a continuous study of seasonal changes in all exospheric constituents. That will provide key information on the relative importance of the processes that generate, sustain, and modify Mercury's atmosphere. Approximately 98% of Mercury's surface has now been imaged. After MESSENGER goes into orbit, it will see the polar regions, which are the only remaining unobserved areas of the planet. ORIGIN OF MARS' REDNESS RAS The widespread idea that Mars is red owing to rocks being rusted by the water that once flooded the planet may not be correct. Recent laboratory studies show that red dust may be formed by the ongoing grinding of surface rocks, and liquid water need not have played any significant role in the formation process. Mars should really look blackish, between its white polar caps, because most of the rocks at mid-latitudes are basalt. Accurate knowledge of the composition and mineralogy of the planet is vital in understanding the structure and evolution of the near-surface environment and its interaction with the atmosphere, as well as in searching for potential habitats on Mars. Fine red dust covers Mars' surface and is even present in the atmosphere, dominating the weather and sometimes becoming so thick that it plunges the planet into darkness. In a recent laboratory study, scientists at the Mars Simulation Laboratory used a novel technique to simulate sand transport on Mars. They sealed sand (quartz) samples in glass flasks and mechanically tumbled them for several months, turning each flask ten million times. After gently tumbling pure quartz sand for seven months, almost 10% of the sand had been reduced to dust. When scientists added powdered magnetite, an iron oxide present in Martian basalt, to the flasks they were surprised to see it getting redder as the flasks were tumbled. Reddish-orange material deposits, which resemble mineral mantles known as desert varnish, started appearing on the tumbled flasks. Subsequent analysis of the flask material and dust has shown that the magnetite was transformed into the red mineral haematite, through a completely mechanical process without the presence of water. The scientists suspect that, as the quartz sand grains are tumbled around, they get quickly eroded and an alteration of minerals through contact ensues. The first experiments show that this process occurs not only in air but also in a dried carbon dioxide atmosphere, i.e. in conditions that resemble those occurring on Mars. SATELLITES OF JUPITER AND (50000) QUAOAR IAU The IAU has approved a new designation and name for the 50th confirmed satellite of Jupiter, S/2003 J 17, which was re-discovered this past August. What a pity that the name is not recorded here! The IAU has also approved the name 'Weywot' for the satellite of the trans- neptunian minor planet (50000) Quaoar. SPITZER DISCOVERS SATURN'S LARGEST RING NASA Scientists using the Spitzer space telescope have discovered an enormous and previously unknown infrared ring around Saturn. If the ring could be seen in the night sky, it would span the width of two Full Moons. The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane. The bulk of its material starts about six million kilometres away from the planet and extends outward roughly another 12 million kilometres. One of Saturn's furthest moons, Phoebe, circles within the new-found ring, and is probably the source of its material. The ring is tenuous, consisting of widely dispersed particles of ice and dust. Spitzer's infrared camera was able to observe the glow of the cool dust, which has a temperature of only about 80 Kelvin. The discovery may help to solve a long-standing riddle of one of Saturn's moons. Iapetus has a strange appearance -- one side is bright and the other is really dark. Cassini first noticed the moon in 1671, and years later realized it has a dark side, now named Cassini Regio in his honour. Saturn's outsize ring could explain how Cassini Regio came to be so dark. The ring is circling in the same direction as Phoebe, while Iapetus, the other rings and most of Saturn's moons are all going the opposite way. According to the scientists, some of the dark and dusty material from the outer ring moves inward toward Iapetus and collides with it, blackening the leading hemisphere (like our Moon, Iapetus remains in a fixed orientation with respect to its orbital travel). Astronomers have also discovered a satellite orbiting within the outer B ring in Saturn's rings. The satellite, designated 2009 S 1, protrudes above the rings by approximately 150 m; the inferred diameter of the satellite, assuming an orbit co-planar with the ring material, is consequently approximately 300 m. EXOPLANETS CLUE TO SUN'S CURIOUS CHEMISTRY ESO Astronomers have found that Sun-like stars that host planets have destroyed their lithium much more efficiently than 'planet-free' stars. For almost 10 years astronomers have tried to find out what distinguishes stars with planetary systems from their barren cousins. They have now found that the amount of lithium in Sun-like stars depends on whether or not they have planets. The low abundance of lithium in the Sun, as compared to otherwise similar stars, has been known for some time but not understood. The astronomers made an analysis of 500 stars, including 70 planet- hosting ones. Most of the stars were monitored for several years with the 'High-Accuracy Radial-Velocity Planet Searcher' (HARPS) attached to ESO's 3.6-metre telescope. The astronomers looked in particular at Sun-like stars, almost a quarter of the whole sample. They found that the majority of stars hosting planets possess less than 1% of the amount of lithium shown by most of the other stars. Unlike most other elements lighter than iron, the light nuclei of lithium, beryllium and boron are not normally produced in significant amounts in stars. Instead, it is thought that lithium, composed of just three protons and four neutrons, was mainly produced just after the Big Bang, 13.7 billion years ago. Most stars will thus have the same amount of lithium, unless they have destroyed it themselves. It seems still not to have been explained why having planets would destroy lithium. But the empirical result promises to provide astronomers with an effective way to search for planetary systems -- low-lithium stars are worthy of further significant observing efforts. ETA CARINAE IAU Astronomers using the Hubble telescope report that the central star in Eta Carina has recently brightened to magnitude 5.1. It now accounts for half of the total light seen in the Homunculus nebula, compared to less than 10% before 1995. Eta Carinae is one of the most massive and luminous stars in our galaxy, and is suspected to be a binary system with a period of 5.54 years. In 1822, the star brightened to 2nd magnitude, and in 1827 to 1st magnitude. Fifteen years later it outshone all stars in the sky apart from Sirius. It then faded to 8th magnitude in 1900 but has slowly been getting brighter since then. Such massive stars have a lifetime of only one million years and Eta Carinae is expected to end its life as a supernova within the next 100,000 years or so. NEW CLASS OF EXPLODING STAR University of California, Berkeley An unusual supernova rediscovered in 7-year-old data may be a new type of exploding star. The supernova was detected in 2002 in the galaxy NGC 1821, in the constellation Lepus, by the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory as well as by amateur astronomers, but at the time it was erroneously classified as a common Type II supernova. Now it has been realized to be an unusual kind of supernova more akin to a Type Ia. The spectrum had been obtained with the Keck I telescope, 7 days after discovery. Follow-up images made by KAIT showed that the brightness of SN 2002bj dropped off so rapidly that the supernova disappeared from sight 20 days after its discovery. An image of that area of the sky taken seven days prior to discovery showed no supernova, so it had brightened and dimmed into obscurity in less than 27 days, whereas most supernovae brighten and dim over 3 to 4 months. The supernova's rapidity, coupled with its faintness, the strong signature of helium in the spectrum of the explosion, and the absence of hydrogen points toward helium detonation on a white dwarf. A suggested theoretical explanation involves AM Canum Venaticorum (AM CVn) binary systems, which are composed of two white dwarfs, one of which is primarily made of helium that is being slowly transferred onto its companion. White dwarfs are stars that have burned their hydrogen down to carbon and oxygen or, in some particular cases, to helium. In AM CVn systems, when enough helium has been accumulated on the surface of the primary white dwarf, an explosion occurs; but the explosion is nothing like a regular Type Ia explosion because the white dwarf survives the detonation of the helium shell instead of being totally disrupted. The event has similarities to both a nova and a supernova. Novae occur when hydrogen falls onto a star and accumulates in a shell that can flare up as brief thermonuclear explosions. SN 2002bj is a 'super' nova, generating about 1,000 times the energy of a standard nova. SHEDDING LIGHT ON THE COSMIC SKELETON ESO Matter is not distributed uniformly in the Universe. In our cosmic vicinity, stars form in galaxies, and galaxies usually form groups and clusters. Some cosmological theories would like matter also to clump on a still larger scale in the so-called 'cosmic web', in which galaxies are embedded in filaments stretching between voids. The filaments are millions of light-years long and constitute the skeleton of the Universe: galaxies gather around them, and galaxy clusters form at their intersections. Scientists do not know how they would swirl into existence. Although massive filamentary structures have been observed at relatively small distances from us, solid proof of their existence in the more distant Universe has been lacking. Now astronomers have discovered a large structure around a cluster of galaxies about seven billion light-years away. They have studied the structure in some detail, estimating the distances of over 150 galaxies, and hence obtaining a three-dimensional view of the structure. They have identified several groups of galaxies surrounding the main cluster and were able to distinguish tens of such clumps, each typically ten times as massive as our own Milky Way galaxy (some as much as a thousand times more massive), while they estimate that the mass of the cluster amounts to at least ten thousand times the mass of the Milky Way. RAPID STAR FORMATION IN YOUNG GALAXIES RAS According to scientists at Durham University, 'stellar nurseries' within the first galaxies gave birth to stars at a much more rapid rate than previously supposed. The research looked back 12.5 billion years to one of the most distant known galaxies, seen as it appeared about one billion years after the Big Bang. Taking advantage of gravitational lensing, the scientists observed the rapid bursts of star formation in the galaxy, called MS1358arc. Within the star- forming regions, new stars were being created at a rate of about 50 stars per year -- around 100 times faster than had been previously thought. The researchers say that the galaxy, which measures 6,000 light years across, has all the characteristics that would allow it to evolve into a galaxy such as our Milky Way. Given the size of the star-forming regions, we would expect it to be forming stars at a rate of about one Sun per year, but it seems to be much more active than that. 'MOST DISTANT' GALAXY GROUP OBSERVED NASA Astronomers using the Chandra X-Ray Observatory have discovered a group of galaxies at a record distance. The cluster, named JKCS041, is 10.2 billion light-years away -- a billion light-years further away than the previous record holder. Galaxy clusters are the Universe's largest objects bound by gravity, and experts hope that the findings will help them understand better how the cosmos has changed over time. Scientists think that JKCS041 is at the farthest point at which galaxy clusters could exist in the early Universe. They do not believe that gravity can work fast enough to make galaxy clusters much earlier, but have detected what they believe to be the light from individual galaxies out to about 13 billion light-years. SIGNATURE OF ANTI-MATTER DETECTED IN LIGHTNING National Geographic Designed to scan the heavens thousands to billions of light-years beyond the Solar System for gamma rays, the Fermi gamma-ray space telescope has also detected 17 gamma-ray flashes associated with terrestrial storms, and some of those flashes have contained a surprising signature of anti-matter. During two recent lightning storms, Fermi recorded gamma-ray emissions of a particular energy that could have been produced only by the decay of energetic positrons, the anti-matter equivalent of electrons. The observations are the first of their kind for lightning storms. The 17 flashes Fermi detected occurred just before, during and immediately after lightning strikes, as tracked by the World-Wide Lightning Location Network. During lightning storms previously observed by other spacecraft, energetic electrons moving toward the craft slowed down and produced gamma rays. The unusual positron signature seen by Fermi suggests that the normal orientation for an electric field associated with a lightning storm somehow reversed, Modellers are now trying to dream up how the field reversal could have occurred. Recording gamma-ray flashes -- which might harm aeroplanes in storms -- isn't new; the first were found by Compton in the early 1990s, and the RHESSI satellite, which primarily looks at X-ray and gamma-ray emissions from the Sun, has found some 800 terrestrial gamma-ray flashes. NASA AND ESA SIGN MARS AGREEMENT BBC News The US and European space agencies have signed a 'letter of intent' that ties their Mars programmes together. The agreement allows scientists and engineers to begin the joint planning of missions. The union will start with a European-led orbiter in 2016, and continue with surface rovers in 2018, and perhaps a network of landers in 2018. The ultimate aim is a mission to return Mars rock and soils. Bulletin compiled by Clive Down (c) 2009 the Society for Popular Astronomy The Society for Popular Astronomy has been helping beginners in amateur astronomy -- and more experienced observers -- for more than 50 years. If you are not a member then you may be missing something. Membership rates are extremely reasonable, starting at just £16 a year in the UK. You will receive our bright quarterly magazine Popular Astronomy, regular printed News Circulars, help and advice in pursuing your hobby, the chance to hear top astronomers at our regular meetings, and other benefits. The best news is that you can join online right now with a credit card or debit card at our lively website: http://www.popastro.com/ CHRISTMAS ASTRO GIFT GUIDE Be sure to have a look at the latest merchandise items from the SPA. They include a Sun mug, galaxy mouse mat, Universe calendar, 2010 Yearbook of Astronomy, RAS Astronomy Diary 2010, and lots more. Go to our secure web site at http://www.popastro.com Astronomica is sponsoring the SPA Electronic News Bulletin. SPA MEMBERS -- Get 10% off all purchases -- simply use voucher code SPA10 when you buy from our website http://www.astronomica.co.uk Astronomica is a firm set up by astronomers to sell astronomical equipment at affordable prices, and offers SPA members a 10% discount on all products. Details of any special offers can be found at http://www.astronomica.co.uk