Meteorites Make a Big Splash on Mars: New Images of Secondary Craters by HiRISE

A few irregularly shaped craters from secondary, low energy impacts on the Mars surface (NASA)

They look like pockmarks caused by shrapnel from a huge explosion. Actually they are surface features on Mars as seen by the High Resolution Imaging Science Experiment (HiRISE) on board the Mars Reconnaissance Orbiter (MRO). But what are they? They’re not potholes formed by geological processes, they’re not openings to ancient lava tubes, they are impact craters… but not like any impact crater you’ve seen before…

The whole range of secondary impact craters in Chryse Planitia (NASA)

Most meteorite impact craters are roughly circular. If they are fairly new, ejected debris will be obvious emanating from the impact site. However, recent images by the HiRISE instrument appear to show tiny impact craters, in a swarm, each looking like they have been chiselled roughly out of the Martian regolith (pictured left).

The area of the image covers roughly 0.5×1.5 kilometres (25cm/pixel; features down 85cm can be resolved) of a large outflow channel in the Chryse Planitia region. The craters are actually secondary impact craters caused by large chunks of Martian rock being thrown up into the air after an energetic impact from a meteorite. To give an idea of size, the largest craters are about 40 meters across, a little smaller than an Olympic-sized swimming pool. It is not clear where the primary impact crater is in relation to the debris craters in the full-resolution image.

There appears to be dark material inside these small craters, possibly from the debris digging into layered deposits of different minerals just below the surface. Ripples of sand and dust are also evident. As these small craters are quite shallow, they will fill up and level out with wind-blown material quickly, so these secondary craters are fairly young when compared with geological timescales.

Source: HiRISE mission site

Did a Cooked Meteorite Seed Life on Earth?

Earth, four billion years ago, was a lifeless, hot and violent place. Not exactly a world where you’d expect life to form. But this was the scene where the first life-forming amino acids appeared. And how did this happen? According to new research, a lump of rock floating though space may have been irradiated by neutron star emissions, chemically altering amino acids hitching a ride on it. This rock then impacted the Earth and injected these altered chemicals into the desert wastes, possibly seeding the beginning of life on our planet… and this life was left-handed…

We’ve heard about this possibility before: life on Earth being seeded by some extra-terrestrial body, like a comet, meteorite or asteroid impact. In fact the prime reason for analysing comets and objects in the Oort Cloud (hovering around the outer reaches of our solar system) is to look for pre-life chemicals and organic compounds such as amino acids. Indeed, the discovery of organic compounds by the recent Cassini flyby of Saturn’s moon last month is another piece in the puzzle toward understanding the extent of life-giving chemicals on planets other than Earth.

Amino acids are a type of protein found in all life forms on Earth, it seems reasonable to search for the presence of these proteins on bodies other than our planet, possibly giving us more information about how life formed and where life came from.

There are two forms of amino acids, one left-handed and one right-handed, giving an indication of the orientation of the acid. For life to be seeded, these proteins must contain only one “chirality” (i.e. either left or right), it’s no good having mixed chirality.

At the 235th national meeting of the American Chemical Society, new research has been presented describing how our amino acid signature may have come from outer space. Ronald Breslow, a university professor at Columbia University points out that the vast majority of life on Earth has a “left chirality”. And his reason for this? The polarized light emitted from neutron stars many billions of years ago irradiated rocky bodies, with amino acid compounds on their surface, selectively destroying most of the “right-hand” acids. Although this theory may sound outlandish, it does give a possible reason for the prevalence of left-hand proteins in amino acids on Earth.

The irradiated meteorite will have impacted the Earth carrying amino acids with a dominance of left chirality which dropped into the “primordial soup”, evolving into the first forms of life. All life as we know it will have the same chirality as this soup of pre-biotic life.

These meteorites were bringing in what I call the ‘seeds of chirality’ […] If you have a universe that was just the mirror image of the one we know about, then in fact, presumably it would have right-handed amino acids. That’s why I’m only half kidding when I say there is a guy on the other side of the universe with his heart on the right hand side.” – Ronald Breslow.

Breslow and his team simulated the events after such a meteorite hit the surface. As the left-hand dominated amino acids from space combined with existing amino acids (of mixed chirality) on Earth, the desert-like temperatures and a dash of water amplified the left-hand proteins, giving them dominance, thus sparking the basic building blocks of life. He argues that these acids were most likely brought to Earth via meteorite, and not chemically altered by radiation in-situ, “…the evidence that these materials are being formed out there and brought to us on meteorites is overwhelming,” said Breslow.

Source: Physorg.com

Supernova Precursor Discovered in Spiral Galaxy NGC 2397

It’s a bit like trying to find a needle in a haystack when looking for a star in a galaxy. Although hard to do, astronomers using images from the Hubble Space Telescope (HST) are doing just that, trying to find stars before they explode as supernovae. In 2006, supernova SN 2006bc was spotted in spiral galaxy NGC 2397, so astronomers got to work, sifting through previous images taken by the HST. They found that star, in the rising stage of brightness as it exploded. Usually we don’t get to see this stage of a supernova, as we can’t predict which star is going to blow. But retracing years of HST observational data, scientists are able to piece together the cosmic forensic evidence and see the star before it died…

SN 2006bc was seen in the spiral galaxy NGC 2397, located nearly 60 million light years from the Milky Way, back in 2006. There was no warning or any indication that that star was going to blow in that galaxy (after all, there’s a lot out there), but Hubble’s Advanced Camera for Surveys (ACS) captured the galaxy after it happened. So astronomers watched the afterglow of the event. While a lot of good science can be done by analysing the remnants of a supernova, wouldn’t it be great to see a star before it explodes? Perhaps then we can analyse the emissions from an unstable star before it dies…

Predicting cosmic events is no new thing, and much effort is being put into various forecasting techniques. A few examples include:

  • Solar radiation: The main focus for solar physicists is to predict “space weather” to help protect us against the dangerous onslaught of high energy particles (particularly solar flares).
  • Detecting supernova neutrinos: An “early warning” system is already in place to detect the neutrinos that are blasted from a star’s core at the moment of a star’s collapse (leading to a supernova). The SuperNova Early Warning System (SNEWS) has been set up to detect these neutrinos.
  • Gamma ray bursts (GRBs): The Polish “Pi of the Sky” GRB detector is an array of cameras looking out for optical flashes (or transients) in the night sky above the Chilean mountains. Combined with NASA’s Swift gamma ray observatory in orbit, the burst is detected, immediately signalling other observatories to watch the event.

The above examples usually detect the sudden event of a solar flare, GRB or surge of neutrinos right at the point of initiation. Fortunately for solar physicists, we have a vast amount of high-spatial and high-temporal resolution data about our closest star. Should a flare be launched, we can “rewind the tape” and see the location of flare initiation and work out the conditions before the flare was launched. From this, we are able to be better informed and possibly predict where the next flare will be launched from. Supernova astronomers aren’t so lucky. The cosmos is a big place after all, only a tiny proportion of the night sky has been observed in any great detail, and the chances that the same region has been imaged more than once at high resolution are few and far between.

Although the chances are slim, researchers from Queen’s University Belfast in Northern Ireland, led by Professor Stephen J. Smartt used Hubble Space Telescope (HST) images to “rewind the tape” before supernova SN 2006bc occurred. By confining their search for “pre-supernova” stars in local galaxies, there was a better chance of studying galaxies that have been imaged at high resolution and imaged more than once in the past. SN 2006bc turned out to be the perfect candidate.

The group has done this before. Of the six precursor stars discovered to date, Smartt’s team found five of them. From their analysis, it is hoped that the characteristics of a star before it dies can be worked out as the conditions for a supernova to occur is poorly understood.

After ten years of surveying, the group presented their discoveries of supernova precursor stars at this year’s National Astronomy Meeting 2008 in Belfast, last week. It appears that stars with masses as low as seven times the size of our Sun can explode as supernovae. They go on to hypothesise that the massive stars may not explode as supernovae and may just die through collapse and form as a black hole. The emission from such an event may be too faint to observe and the most energetic supernovae may be restricted to the smaller stars.

However, six supernova precursor stars are not a large number to make any big conclusions quite yet, but it is a big step in the right direction to better understand the mechanisms at work in a star just about to explode…

Source: ESA

UK “Time Machine” Reveals The Formation Of Distant Galaxies

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If you thought the Hubble Deep Field galaxy photo was the most incredible thing you’ve ever seen, wait until you lay eyes on the most sensitive infrared map of the distant Universe ever taken. Over the last three years, UK astronomers have compiled data from the United Kingdom Infrared Telescope (UKIRT) in Hawaii and their results are nothing less than astounding.

Today, Dr. Sebastien Foucaud from the University of Nottingham presented his first results to the April 4 National Astronomy Meeting of the Royal Astronomical Society. These results only form part of the Ultra-Deep Survey (UDS) – an image containing over 100,000 galaxies over an area four times the size of the full Moon – and a look into the formation of the most distant galaxies yet witnessed.

The 3.8-metre (12.5-foot) UK Infrared Telescope (UKIRT) became a time machine as the world’s largest telescope dedicated solely to infrared astronomy began its Deep Sky Survey in 2005. Even now, the UDS image is but only one element of a five-part project. Due to the constraints of the speed of light, these observations allow astronomers to literally look back 10 billion years in time. The images that UKIRT produces see our Universe in its distant infancy, and the formation galaxies which date to back where we believe expansion began. The image is so large and so deep that thousands of galaxies can be studied at these early epochs for the very first time. Through the technological advance of infrared imaging, astronomers can now peer even further back in time, since light from the most distant galaxies is shifted towards redder wavelengths as it travels through the expanding Universe.

“I would compare these observations to the ice cores drilled deep into the Antarctic,” said Dr. Foucaud. “Just as they allow us to peer back in time, our ultra-deep image allows us to look back and observe galaxies evolving at different stages in cosmic history, all the way back to just 1 billion years after the Big Bang”.

One of the goals of the project is to further scientific understanding about the time frame in which rare, massive galaxies formed in the distant Universe. It is a puzzle that has simply remained unsolved. Says Dr. Foucaud: “We see galaxies 10 times the mass of the Milky Way already in place at very early epochs. Now, for the first time, we are sampling a large enough volume of the distant Universe to be able to see them in sufficient numbers and really pin down when they were formed.”

The UKIDSS Ultra-Deep Survey will, in time, give us a complete census of galaxy formation in the infrared. So far over one hundred thousand galaxies have been detected and the final image will be 100 times larger than any equivalent survey to date. Determining precise distances to faint galaxies is very difficult, requiring long hours of spectroscopy. For the faintest objects in the UDS survey this is often impossible. Instead, by using optical and infrared colors, astronomers are very effectively able separate distant galaxies from those which are nearby, and further separate them into those which are forming stars and those which are not. UKIDSS aims to discover the nearest object to the Sun (outside the solar system) as well as some of the farthest known objects in the Universe.

Does the Ultra-Deep Sky Survey images shed light on the great cosmological mystery? Only time – and distance – will tell. Professor Andy Lawrence, Principle Investigator of UKIDSS from the University of Edinburgh, said “As we keep taking images over the next few years, we will see ever more distant galaxies.”

What’s Up – The Weekend SkyWatcher’s Forecast

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Greetings, fellow SkyWatchers! Right now is a splendid time of year for those who live in high northern latitudes to look out for auroral activity – the alert is out! For those who enjoy just keeping an eye on the sky, be on watch for the Kappa Serpentid meteor shower. Its radiant will be near the “Northern Crown,” the constellation known as Corona Borealis. The fall rate is small with an average four or five per hour. Even though the slender crescent Moon will be visible at sky dark this weekend, it’s time to dig through the archives and dance the Messier Marathon! Are you ready?

Friday, April 4 – Although a bit of Moon will light up the scene as evening begins, it won’t seriously hamper your observations. Beginning as soon as the sky darkens enough to find the guidestar Delta Cetus, the M77 spiral galaxy will be your first, and the M74 spiral galaxy east of Eta Pisces will be your second mark. Both of these galaxies are telescopic only and will be an extreme challenge at this time of year due to their low position. Even computer-assisted scopes will have some difficulty revealing this pair under less than optimal conditions. Next up is M33 west of Alpha Triangulum. With ideal skies, the “Pinwheel Galaxy” could be seen in binoculars, but skybright will make this huge, low surface brightness spiral difficult for even telescopes at low power. M31 – the Andromeda Galaxy – will, however, be a delightful capture for both binoculars and scopes just west of Nu Andromedae. For the telescope, two more on the list are companions to M31 – the elliptical M32 on the southeastern edge and M110 to the northwest.

Let’s head northwest as we take on two open clusters visible to both telescopes and binoculars. You can find M52 easiest by identifying Alpha and Beta Cassiopeia, drawing a mental line between them and extending it the same distance northwest of Beta. Next just hop north of Delta to pick up our ninth object – the M103 open cluster. Time to head south towards Perseus and go back to the telescope to locate M76, the “Little Dumbbell” planetary nebula, just north of Phi. Binoculars are all that’s needed to see the M34 open cluster also in Perseus, located roughly halfway between the “Demon Star” Algol and lovely double Almach, Gamma Andromeda.

Now that skies are truly dark and the fastest setting objects are out of the way, we can take a moment to breathe as we view M45 – the Pleiades. The “Seven Sisters” are easily visible to the unaided eye high in the west and their cool, blue beauty is incomparable in binoculars or telescopes. Our next “hop” is with the “rabbit” Lepus as we go back to the south and identify Beta and Epsilon. Triangulating with this pair to the south is a nearly fifth magnitude star (ADS 3954) which will help you locate the small globular M79 to its northeast. At around magnitude 8.5, it is possible to see its very tiny form in binoculars, but M42 – the “Great Orion Nebula” is much easier. The next object, M43, is part of the Orion Nebula, and you will catch it as a small “patch” to the north-northeast. The next two objects, M78 northeast of Zeta Orionis and the M1 Crab Nebula northwest of Zeta Tauri, are both achievable in binoculars with excellent conditions, but are far more interesting to the telescope.

Now we can really relax. Take a few minutes and grab a cup of coffee or hot chocolate and get warmed up. The next several objects on our observing list for tonight are all very easy, very well positioned for early evening, and all observable in just binoculars. Are you ready? Then let’s go.

M35 is just as simple as finding the “toe” of Gemini – bright Eta. A short hop to the northwest will capture this fine open cluster. The next stop is Auriga and we’ll go directly between silicon star Theta and southern Beta. About halfway between them and slightly to the east you will find open cluster M37. This time let’s use Theta and Iota to its west. Roughly halfway between them and in the center of Auriga you will find M38 and a short hop southeast will capture M36. Now let’s get Sirius and finish this list for tonight. The open cluster M41 in Canis Major is found just as quickly as drifting south of the brightest star in the sky. The next three for tonight couldn’t be any easier – because we’ve studied them before. Go capture M93, M47 and M46 group in northern Puppis… And give yourself a well-deserved pat on the back.

You’ve just conquered 24 Messiers!

Next up will be four more binocular targets, the incredibly colorful open cluster M50 is roughly a third of the way in a line drawn between Sirius and Procyon – use binoculars. Hydra is a difficult constellation, but try dropping south-southeast of the most eastern star in Monoceros – Zeta – about half a fist’s width to discover relatively dim open cluster M48. Far brighter, and usually visible to the unaided eye is M44, better known as the Beehive Cluster, just a scant few degrees north-northwest of Delta Cancri. From Delta, go south and identify Alpha because M67 is just to its west. It will appear as a “fine haze” to binoculars, but telescopes will find a spectacular “cloud” of similar magnitude resolvable stars.

Now we really do have to use the telescope again because we’re going “lion taming” by hunting galaxies in Leo. Let’s trade one Alpha for another as we head west to Regulus. Roughly about a fist width east of this major star you will see two dim stars that may require the use of the finderscope – 52 to the north and 53 to the south. We’re heading right between them. About a degree and a half south of 52, you will discover ninth magnitude elliptical M105. Larger scopes will also show two additional faint galaxies, NGC 3384 and NGC 3389 to M105’s west. Continuing about a degree south towards star 53 you will spot the silver-gray beauty of M96 in a relatively starless field. Enjoy its bright nucleus and wispy arms.

About another degree west will bring you to M95, which is neither as bright nor as large as its Messier “neighbor.” Small scopes should show a brightening towards its center and large ones should begin to resolve out the arms of this awesome barred spiral. Our next destination is the southwestern star of the three that mark Leo’s “hips,” Theta Leonis – or more commonly called Chort. South of it you will see faint star 73 and right around one degree to its east-southeast you will locate a pair. In small scopes at low power, M65 and M66 are same field. The western M65 and eastern M66 are both beautiful spirals.

Now let’s head north for another “same field pair” of galaxies and hunt down M81 and M82 in Ursa Major. Many folks have trouble “star hopping” to these galaxies, but a very simple way of finding them is to draw a mental line between Phecda (Gamma) and Dubhe (Alpha). By extending that line beyond Dubhe almost the same distance, you’ll locate our next two “marathon” objects. At low power with a smaller scope, the southern-most and most pronounced of the two is the stunning M81 with its bright core. To the north is broken, spindle-shaped peculiar galaxy M82. Viewable in binoculars, we’ll study more about this pair later on as we head for Mirak (Beta) and our next galaxy. About a degree and a half southeast you will see a 10th magnitude “scratch” of light. This great edge-on galaxy – M108 – should show at least four brighter “patches” to the small scope and a nice dark dust-lane to larger ones. Continuing about another half degree southeast will bring you to the planetary nebula M97. Also known as the “Owl,” this 12th magnitude beauty is roughly the same diameter as Jupiter and can be spotted under optimal conditions with binoculars – but requires a large scope at high power to begin to discern its features. Let’s continue south to Phecda and less than half a degree to the east you will locate M109. In the field with Gamma, M109 will show its faded central bar and prominent nucleus to the small scope, but requires large aperture and high magnification to make out structure. The last in Ursa Major is an error on Messier’s part. Labeled as M40, this object is actually double star WNC 4, located in the same eyepiece field as 70 Ursae Majoris to the northeast.

Now let’s take a deep breath and move into Canes Venatici to round up a few more. This is an area of dimmer stars, but the two major stars, Alpha (it is called Cor Caroli and it is a wonderful double star) and Beta are easily recognizable to the east of the last star in the “handle” of the “Big Dipper” (Eta). The northernmost is Beta and you will find the soft-spoken spiral galaxy M106 almost midway between it and Phecda less than 2 degrees south of star 3. M94 is a much brighter, compact galaxy and is found by forming an isosceles triangle with Alpha and Beta Canum with the imaginary apex towards Eta Ursae Majoris. M63 is a very pretty, bright galaxy (often known as “the Sunflower”) that approaches magnitude 10 and is found about one-third the distance between Cor Caroli and Eta Ursae Majoris (Alkaid). Still heading towards Alkaid (Eta UM), the incomparable M51 comes next. Near Eta you will see an unmistakable visual star called 24 CnV, the “Whirlpool” is the same basic distance to the southwest. Now that we’re back into “big bear country” again, we might as well head on to the M101 “Pinwheel” galaxy which is found by following the same trajectory and distance to the other side of Alkaid. Before we head on, let’s continue north and clean up… ummm… another “messy mistake.” The accepted designation for M102 is lenticular galaxy NGC 5866, located in Draco south east of Iota.

Now let’s finish up – it’s time for a break! Our next stop will be to identify the three primary stars of Coma Berenices now high in the east above Arcturus. You will find small globular cluster M53 northeast of Alpha. One of the coolest galaxies around is M64 (known as the “Blackeye”) just a degree east-northeast of 35 Comae, which is about one-third the distance between Alpha Comae and Alkaid. The last, and most outstanding for this half of the night, is a globular cluster that can be seen in binoculars – M3. As strange as this may sound, you can find M3 easily by drawing a line between Cor Caroli and Arcturus. Starting at Arcturus, move up about one third the way until you see Beta Comae to the west of your “line”… Poof. There it is.

Awesome job. We’ve just completed another 24 objects and we’ve claimed 48 on the Messier list before midnight.

Saturday, April 5 – These next targets will be best viewed after midnight when the constellations of Coma Berenices and Virgo have well risen, providing us with the darkest sky and best position. For the large telescope, we are going to be walking into an incredibly rich galaxy field that we will touch on only briefly because they will become the object of future studies. Just keep in mind that our Messier objects are by far the brightest of the many you will see in the field. For the smaller scope? Don’t despair. These are quite easy enough for you to see as well and probably far less confusing because there won’t be so many of them visible. Now let’s identify the easternmost star in Leo – Denebola – and head about a fist width due East…

Our first will be M98, just west of star 6 Comae. It will be a nice edge-on spiral galaxy in Coma Berenices. Next return to 6 Comae and go one degree southeast to capture M99, a face-on spiral known as the “Pinwheel” that can be seen in apertures as small as 4″. Return to 6 Comae and head two degrees northeast. You will pass two fifth magnitude stars that point the way to M100 – the largest appearing galaxy in the Coma/Virgo cluster. To the average scope, it will look like a dim globular cluster with a stellar nucleus. Now let’s continue on two degrees north where you will see bright yellow 11 Comae. One degree northeast is all it takes to catch the ninth magnitude, round M85. (Ignore that barred spiral. let’s keep moving…) Now, let’s try a “trick of the trade” to locate two more. Going back to 6 Comae, relocate M99 and turn off your drive. If you are accurately aligned to the equator, you may now take a break for 14 minutes. When you return the elongated form and near stellar nucleus of M88 will have “drifted” into view. Wait another two to three minutes and the faint barred spiral M91 will have joined the show in a one degree field of view… Pretty fun, huh?

Now let’s shift guidestars by locating bright Vindemiatrix (Epsilon Virginis) almost due east of Denebola. Let’s hop four and a half degrees west and a shade north of Epsilon to locate one of the largest elliptical galaxies presently known – M60. At a little brighter than magnitude 9, this galaxy could be spotted with binoculars. In the same telescopic low power field you will also note faint NGC 4647 which only appears to be interacting with M60. Also in the field is our next Messier, bright cored elliptical M59 to the west. (Yes, there’s more – but not tonight.) Moving a degree west of this group will bring you to our “galactic twin,” fainter M58. Moving about a degree north will call up face-on spiral M89, which will show a nice core region in most scopes. One half degree northeast is where you will find the delightful 9.5 magnitude M90 – whose dark dust lanes will show to larger scopes. Continue on one and a half degrees southwest for M87, one of the first radio sources discovered. This particular galaxy has shown evidence of containing a black hole and its elliptical form is surrounded by more than 4,000 globular clusters.

Just slightly more than a degree northwest is a same field pair, M84 and M86. Although large aperture scopes will see many more in the field, concentrate on the two bright cored ellipticals which are almost identical. M84 will drift out of the field first to the west and M86 is east. Next we will select a new guidestar by going to 31 Virginis to identify splendid variable R about a degree to its west. We then move two degrees northwest of R to gather in the evenly lighted oval of M49. Now shifting about three degrees southwest, you will see a handsome yellow double – 17 Virginis. Only one-half degree south is the large face-on spiral, M61. Larger scopes will see arms and dust lanes in this one. Last for this location is to head for the bright blue beauty of Spica and go just slightly more than a fist width (11 degrees) due west. M104 – the “Sombrero” galaxy – will be your reward for a job well done.

Congratulations. You’ve just seen 17 of the finest galaxies in the Coma/Virgo region and our “Marathon” total has now reached 65. We’re over halfway home…

With Corvus relatively high to the south, the next drop is about five degrees to the south-south east of Beta Corvi. Just visible to the unaided eye will be the marker star – the double A8612. Eighth magnitude M68 is a bright, compact globular cluster in Hydra that will appear as a “fuzzy star” to binoculars and a treat to the telescope. Our next is tough for far-northern observers, for the “Southern Pinwheel” – M83 – is close to ten degrees southeast of Gamma Hydrae.

Now we’re going to make a wide move across the sky and head southeast of brilliant Arcturus for Alpha Serpentis. About 8 degrees southwest you will find outstanding globular cluster M5 sharing the field with 5 Serpens. Now locate the “keystone” shape of Hercules and identify Eta in its northwest corner. About one-third of the way between it and Zeta to the south is the fantastic M13, also known as the “Great Hercules Globular Cluster.” A little more difficult to find is the small M92 because there are no stars to guide you. Try this trick – Using the two northernmost stars in the “keystone,” form an equilateral triangle in your mind with its imaginary apex to the north. Point your scope there. At sixth magnitude, this compact globular cluster has a distinct nucleus. Both are very binocular friendly.

Now we’re off to enjoy summer favorites and future studies. M57, the “Ring Nebula,” is located about halfway between Sheilak and Sulafat. You’ll find the small globular M56 residing conveniently about midpoint between Sulafat and Alberio. About 2 degrees south of Gamma Cygni is the bright open cluster M29. And equally bright M39 lays a little less than a fist width to the northeast of Deneb. If you remember the hop north of Gamma Sagitta, you’ll easily find M27, the “Dumbbell Nebula,” and the loose globular, M71, just southwest of Gamma. All of the objects in this last paragraph are viewable with binoculars (albeit some are quite small) and all are spectacular in the telescope.

And now we’ve made it to 76 on our “Messier Hit List.”

So, are you having fun yet? I’m not about to let you go. We’re moving into early morning skies and looking at our own galactic halo as we track down some great globular clusters. Ophiuchus is a sprawling constellation and its many stars can sometimes be hard to identify. Let’s start first with Beta Scorpii (Graffias) and head about a fist’s width to the northeast. That’s Zeta and the marker you will need to locate M107. About one quarter the way back towards Graffias, you will see a line of three stars in the finder. Aim at the center one and you’ll find this globular in the same field. Now go back to Zeta and you will see a pair of similar magnitude dim stars higher to the northeast. The southernmost is star 30 and you will find the M10 globular cluster about one degree to its west. M12 is only about three degrees further along to the northeast. Both are wonderfully large and bright enough to be seen in binoculars.

Now we need to identify Alpha in Ophiuchus. Head toward Hercules. South of the “keystone” you will see bright Beta Hercules with Alpha Hercules to the southeast. The next bright star along the line is Alpha Ophiuchi and globular cluster M14 is approximately 16 degrees south and pretty much due east of M10. Now let’s head for bright Eta Ophiuchi (Sabik) directly between Scorpius and Sagittarius. The next globular, M9, is about three and a half degrees southeast.

Let’s move on to an easier one. If you know is Antares, you can find the globular cluster M4 in Scorpius. All you have to do is aim your binoculars at this brilliant red star, for this diffuse giant is just a little over one degree to the west. Go back to Antares and shift about four degrees to the northwest and you’ll find compact, bright globular M80. It will be very small in binoculars, but it’s quite bright. Going back to the scope is best for M19, although it’s easy to find around seven degrees due east of Antares. The last for this region is M62 about a half a fist’s width to the south.

Hey, you’re doing terrific. Some of these are tough to find unless you’ve had practice… But now we’re up to a total of 85. Now let’s dance…

The lower curve of Scorpius is quite distinctive and the unaided eye pair you see at the “stinger” is beautiful double Shaula (Lambda) and its slightly less bright neighbor Upsilon. Aim your binoculars there and head towards the northeast and you cannot miss M6, the “Butterfly Cluster.” Below it and slightly east is a hazy patch, aim there and you will find another spectacular open cluster M7, often known as “Ptolemy’s Cluster.”

Now go north and identify Lambda Aquilae and you will find M11, the “Wild Duck” open cluster just to the west. About the same distance away to the south/southwest you will spot M26, another open cluster. These are all great binocular targets, but it will take an exceptionally dark, clear sky to see the Eagle Nebula associated with the M16 easy open cluster about a fist’s width away to the southwest. Far easier to see is the “Nike Swoosh” of M17 just a little further south. Many of you know this as the “Omega” or “Swan” nebula. Keeping moving south and you will see a very small collection of stars known as M18, and a bit more south will bring up a huge cloud of stars called M24. This patch of Milky Way “stuff” will show a wonderful open cluster – NGC 6603 – to average telescopes and some great Barnard darks to larger ones.

Now we’re going to shift to the southeast just a touch and pick up the M25 open cluster and head due west about a fist’s width to capture the next open cluster – M23. From there, we are dropping south again and M21 will be your reward. Head back for your scope and remember your area, because the M20 “Triffid Nebula” is just a shade to the southwest. Small scopes will pick up on the little glowing ball, but anything from about 4″ up can see those dark dust lanes that make this nebula so special. You can go back to the binoculars again, because the M8 “Lagoon Nebula” is south again and very easy to see.

This particular star hop is very fun. If you have children who would like to see some of these riches, point out the primary stars and show them how it looks like a dot-to-dot “tea kettle.” From the kettle’s “spout” pours the “steam” of the Milky Way. If you start there, all you will need to do is follow the “steam” trail up the sky and you can see the majority of these with ease.

Our Messier temperature has now risen to 98…

OK, folks… It’s “crunch time” and the first few on this list will be fairly easy before dawn, but you won’t have long before the light steals the last few from the sky.

At the top of the “tea kettle” is Lambda. This is our marker for two easy binocular objects. The small M28 globular cluster is quite easily found just a breath to the north/northwest. The larger, brighter and quite wonderful globular cluster M22 is also very easily found to Lambda’s northeast. Now we’re roaming into “binocular possible” but better with the telescope objects. The southeastern corner of the “tea kettle” is Zeta, and we’re going to hop across the bottom to the west. Starting at Zeta, slide southwest to capture globular cluster M54. Keep heading another three degrees southwest and you will see the fuzzy ball of M70. Just around two degrees more to the west is another globular that looks like M70’s twin. Say good morning to M69.

Now it’s really going to get tough. The small globular M55 is out there in “No Man’s Land” about a fist’s width away east/south east of Zeta and the dawn is coming. It’s going to be even harder to find the equally small globular M75, but if you can see Beta Capricorn it will be about a fist’s width southwest. Look for a “V” pattern of stars in the finder and go to the northeastern star of this trio. You should be able to put it in the same low power field. Without the “square” of Pegasus to guide us, look low to the east and identify Enif by its reddish color. (Delphinus above it should help you.) Power punch globular M15 is to Enif’s northwest and you should be able to see the star on its border in the finderscope. Let’s be thankful that M2 is such a fine, large globular cluster. The hop is two thirds of the way between Enif and Beta Aquarius, or just a little less than a fist’s width due west of Alpha.

Let’s hope that Beta is still shining bright, because we’ll need to head about a fist’s width away again to the southwest to snag what will now be two very dim ones – the M72 globular cluster and M73 open cluster just west of Nu Aquarius. We’re now dancing just ahead of the light of dawn and the M30 globular cluster is our last object. Hang on Delta Capricornus and show us the way south/southwest to star 41. If you can find that? You’ve got the very last one…

We’ve done the Messier Catalog of all 110 objects in just one night.

Is this a perfect list with perfect instructions? No way. Just like the sky, things aren’t always perfect. This is just a general guideline to helping you find the Messier objects for yourself. Unless you are using a computer-guided scope, it truly takes a lot of practice to find all the Messiers with ease, so don’t be discouraged if they just don’t fall from the sky. You might find all of these in one year or one week – and you just might find all of them in one good night. Regardless of how long it takes you – or when the skies cooperate – the beauty, joy and reward is the peace and pleasure it brings.

Clear skies!

National Astronomical Meeting 2008 Coverage

You’re going to see a flurry of astronomy news this week. That’s because it’s time for the UK’s National Astronomical Meeting, or NAM 2008. We couldn’t get to this one, but our friends across the ocean have it covered. Chris Lintott and Orbiting Frog team are going to be live blogging the conference.

Click here to read the NAM 2008 live coverage.

Early Universe Had Burst of Star Formation

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Just as humans develop and grow the fastest when we are young, it also appears our universe grew and developed stars at an incredibly fast rate when it was young, too. New measurements from some of the most distant galaxies helps support evidence that the strongest burst of star formation in the history of the universe occurred about two billion years after the Big Bang. An international team of astronomers from the UK, France, Germany and the USA have found evidence for a dramatic surge in star birth in a newly discovered population of massive galaxies. The astronomers have been studying five specific galaxies that are forming stars at an incredible rate. The galaxies also have large reservoirs of gas to power star formation for hundreds of millions of years. These galaxies are so distant that the light we detect from them has been travelling for more than 10 billion years, meaning we see them as they were about a three billion years after the Big Bang.

The recent discovery of a new type of extremely luminous galaxy during this early epoch of the universe – one that is very faint in visible light, but much brighter at longer, radio wavelengths – is the key to the new results. Using a new and much more sensitive camera that detects radiation emitted at sub-millimeter wavelengths (longer than the wavelengths of visible light that we see with but somewhat shorter than radio waves), astronomers first found this type of galaxy in 1997. In 2004 a group of astronomers proposed that these distant “submillimetre-galaxies” might only represent half of the picture of rapid star formation in the early Universe. They suggested that a population of similar galaxies with slightly hotter temperatures could exist but have gone largely unnoticed.

The team of scientists searched for the missing galaxies using observatories around the world: the MERLIN array in the UK, the Very Large Array (VLA) in the US (both radio observatories), the Keck optical telescope on Hawaii and the Plateau de Bure submillimetre observatory in France. The instruments found and pinpointed the galaxies, measured their distances and then confirmed their star-forming nature through the detection of the vastly extended gas and dust.

Click here for more images and a movie of the Sub-millimeter Star Forming Galaxies.

The new galaxies have extremely high rates of star formation, far higher than anything seen in the present-day universe. They probably developed after the first stars and galaxies had already formed in what would have been a perfectly smooth Universe. Studying these new objects gives astronomers an insight into the earliest epochs of star formation after the Big Bang.

This information was presented by Dr. Scott Chapman from the Institute of Astronomy in Cambridge at the Royal Astronomy Society’s National Astronomy Meeting on April 1, 2008. Chapman’s work is supported by a parallel study made by PhD student Caitlin Casey.

Original News Source: Royal Astronomy Society Press Release

Supernova Alert: Supernova Factories Discovered

Two “supernova factories,” rare clusters of Red Supergiant (RSG) stars, have recently been discovered. Together they contain 40 RSGs, which is nearly 20% of all the known RSGs in the Milky Way, and all 40 are on the brink of going supernova. “RSGs represent the final brief stage in a massive star’s lifecycle before it goes supernova,” said Dr. Ben Davies of the Rochester (New York) Institute of Technology. “They are very rare objects, so to find this many in the same place is remarkable.”


The two clusters are located next to each other on the edge of the central galactic bar, a long bar of stars within the central bulge of our Milky Way Galaxy. This galactic bar is believed to be made up of about 30 million stars, most of them older, red stars, and stretches 27,000 light-years from end to end. The bar is plowing through the disc of the Milky Way, and astronomers believe the interaction between the bar and the disc triggered the star formation event, creating the uncommon clusters.

The clusters are about 20,000 light years from Earth and about 800 light years from each other. Cluster 1 contains 14 RSGs and is 12 million years old; Cluster 2 contains 26 RSGs and is 17 million years old. Massive stars are rarely observed because they burn their fuel up very quickly. RSGs are doubly rare because they are only a brief period of that short life cycle.

Dr. Davies said, “The next supernova could go off in one of these clusters at any time. We estimate that it’s about 5000 years between explosions for these clusters and we can see the remnants of a supernova that went off around 5000 years ago. That means that the next one could be any time between today and 7008 AD.”

Red Supergiant Stars.  Image Credit:  Rochester Institute of Technology
The team identified the clusters initially using the mid-infrared Galactic Plane survey (GLIMPSE), a huge database of images taken by the Spitzer Space Telescope. They found two distinct groupings of bright stars very close to one another in the constellation of Scutum. Using the Keck Telescope in Mauna Kea, Hawaii, they were then able to pin-point the exact distance from Earth of each star in each group. These observations showed that, in each group, large numbers of stars were at exactly the same distance from Earth, and therefore were members of the same cluster.

“The discovery of these clusters gives us a great opportunity to answer some long-standing questions in astrophysics,” said Davies, “such as exact mechanisms of how massive stars evolve toward supernovae, and how the Galactic Bar can trigger huge starburst events in the Milky Way.”
Davies presented his findings at the Royal Astronomy Society’s National Astronomy Meeting in Belfast on April 1, 2008.

Original News Source: Royal Astronomy Society Press Release

Solar Corona Revealed by Medical X-Ray Techniques

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For several decades solar scientists have been hard at work trying to unravel the mysteries of the solar corona. Thanks to a medical x-ray technique known as tomography, scientists are able resolve solar activity in greater detail. By using a new way of processing images, active regions now take on dimensions never foreseen by computer models.

Today Dr. Huw Morgan presented his results to the Royal Astronomical Society National Meeting in Belfast. Using an adapted medical X-ray technique, scientists have produced the first detailed map of the structure of the Sun’s outermost layer, the corona. The application known as tomography uses a series of images taken from many different angles to reconstruct a 3-dimensional map created from direct solar observations.

“This is a breakthrough for scientists trying to understand the corona and the solar wind. We’ve been attempting to apply tomography to the solar corona for more than 30 years but it’s proved very difficult and very inaccurate until now. The new technique that I’ve developed is only in its infancy but shows great potential for areas of research like space weather,” said Dr Morgan, of the University of Aberystwyth.

The process has not been as easy one, nor is it a new idea. Without images of the coronal far side, researchers were left with only half the data. The near side produces its own difficulties as well, since the outermost areas of the corona are more than a thousand times fainter than the regions near the Sun. This factor introduces huge potential errors to observations. Thanks to Dr. Morgan, his new way of processing coronal images, called Qualitative Solar Rotational Tomography (QSRT), eliminates the steep drop in brightness and associated errors. With the help of SOHO’s LASCO instrument, Dr. Morgan applied the technique to a series of images taken as the Sun’s rotation brings the ‘missing’ areas into view. The result? Full coronal maps that are at least 5 times more detailed than previous tomographical studies of the Sun. And the future may hold far more. Says Morgan:

“I’ve now produced maps of the corona over almost a whole cycle of solar activity, so we can now see in unprecedented detail how structures develop and evolve in three-dimensions. The maps have produced some interesting results: for instance we’ve observed large areas of dense structures when the Sun is most active that are not predicted by current computer models. We’ve also found evidence that inner regions of the corona rotate at different speeds.”

According to the RAS press release, the technique is already being used by scientists at the Institute of Maths and Physics at Aberystwyth University to interpret their radio-wave observations of the solar wind. Dr. Morgan, together with colleagues at the Institute of Astronomy at the University of Hawaii, is also using the maps to interpret ultraviolet observations of the corona. Says Dr. Morgan:

“These maps will also prove useful in the important field of space weather. Explosions at the Sun travel through space and often hit the Earth. These energetic magnetic clouds can disrupt communication, power supplies and be a major health hazard for astronauts and airline pilots. Understanding and predicting these storms is a major goal of solar science. The ability to map the whole 3D structure of the corona is a critical step towards achieving this goal.”

Old Galaxies Stick Together In A Young Universe

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Can appearances be deceiving? According to the United Kingdom Infra-Red Telescope (UKIRT), galaxies that appear old in our Universe’s early history are positioned in huge clouds of dark matter. Using the most sensitive images ever taken, UKIRT scientists believe these galaxies will evolve into the most massive yet known.

Today University of Nottingham PhD student Will Hartley is speaking to the Royal Astronomical Society’s National Astronomy Meeting in Belfast. As the leader of the study, Hartley proposes the distant galaxies identified in the UKIRT images are considered elderly from their content of old, red stars. Because these systems are nearly 10 billion light years distant, the images are as the galaxies appeared about 4 billion years after the Big Bang. Fully evolved galaxies at that point in time are hard to explain and the answer has been puzzling astronomers who study galactic formation and evolution.

Hartley and his team used the deep UKIRT images to estimate the mass of the dark matter formed in a halo surrounding the old galaxies – a halo which collapses under its own gravity to form a even distribution of matter. By measuring their ability to form galactic clusters, astronomers can get a better sense of what causes older galaxies to stick together.

Hartley explains “Luckily, even if we don’t know what dark matter is, we can understand how gravity will affect it and make it clump together. We can see that the old, red galaxies clump together far more strongly than the young, blue galaxies, so we know that their invisible dark matter halos must be more massive.

The halos of dark matter surrounding the old galaxies in the early Universe are found to be extremely massive, containing material which is one hundred thousand billion times the mass of our Sun. In the nearby Universe, halos of this size are known to contain giant elliptical galaxies, the largest galaxies known.

“This provides a direct link to the present day Universe,” says Hartley, “and tell us that these distant old galaxies must evolve into the most massive but more familiar elliptical-shaped galaxies we see around us today. Understanding how these enormous elliptical galaxies formed is one of the biggest open questions in modern astronomy and this is an important step in comprehending their history.”