Australian Science

Tag: space

  • Giant Impact: making the moon

    Giant Impact: making the moon

    It began… where it always begins — out there — in the vastness of space. What would it look like, that void of empty nothingness? So early on in the sound of creation, indescribable things all around. Not yet planets, not yet moons. Not yet defined. A titanic mass of rock. Different. Ugly and melancholic. Mischievous and cumbersome. As immediately as it’s gone, another smaller rock — about a tenth the size of its predecessor — in the other direction. We will come to realise that they are almost on the same path. A perilous planetary orbit around our sun.

    One is a destroyer. The other is to be destroyed. The larger mass continues to grow as it gobbles up remnants from a cloud of dust. A hot, violent place with molten rock mantles wrapped around a dense hot core. On the other side of our sun swings the smaller mass. Both will have the same fate. On the far side, they collide. A cataclysm of apocalyptic proportions. In the vacuum/vacuous of space not a sound is heard. The smaller rock ploughs into its destroyer, like the little man in a fight with a lot to prove. It sinks deep into its molten core. Spiralling vast amounts of debris in long arcs into orbit. Debris, drawn together by nothing more simple than gravity, clump together, forging something close to a primitive moon. And with primitive moons come primitive planets. Finally, one defines the other.

    This has always been the theory… at least, more eloquently put in the form of maths, calculations, numbers and analysis. The origin of our Moon by giant impact has always been the leading theory. Leading because it is able to explain so many features of the Earth-Moon system. From it’s current spin and angular momentum to its composition. Both Earth and Moon are very similar in their oxygen, tungsten, chromium, and titanium isotopes — leading to the logical conclusion that one was formed from the other, since these isotopes vary differently in different planetary bodies and meteorites.

    However, simulations have shown this not to be the case. It is the Moon that should have a similar isotopic composition to the smaller impactor in this scenario, but instead it is made up mostly of material from Earth. Researchers had been tinkering around with the permutations and combinations to find such a scenario of impact that could satisfy all conditions. But to date, none had come close.

    In papers published in Science by researchers from Harvard and the Southwest Research Institute, a new model is proposed. One that adequately accounts for a similarity in composition while also coming out with an appropriate mass for Earth and Moon. One paper describes two bodies of similar mass colliding slowly, while the other describes a giant erosive impact (with a small impactor) happening really fast. Both have the same solution to the problem. That is to have the Earth-Moon system losing angular momentum over time, reaching its present state through the Sun’s gravitational influence. Thereby, in the end, both coming to a compromise in explaining the physics and the overall geo-chemistry of the Earth-Moon system.

  • The nearest solar system to ours has an Earth-sized planet…

    The nearest solar system to ours has an Earth-sized planet…

    Already there’s an artist’s impression of the
    newly discovered ‘Alpha Centauri B a’

    Yes—you read right. Alpha Centauri has a planet, and it is roughly the size of Earth. And at just 4.37 light years distance, it is theoretically reachable (with a whole lot of space travel development!) despite the frustrating limitations put on us by Mr Einstein.

    In a paper appearing in the journal Nature today, lead author Xavier Dumusque (Geneva Observatory, Switzerland and Centro de Astrofisica da Universidade do Porto, Portugal) explains how they use the 3.6-metre telescope at the European Space Observatory’s La Silla Observatory in Chile to detect the tiny back-and-forth wobbles to a sun’s position that are caused by the gravitational mass of a planet revolving around it.

    BUT don’t pack your bags yet. This planet is closer to its sun than Mercury is to our Sun. So close in fact that it orbits it in just 3.2 days. So close that its surface temperature is likely to be around 1200 degrees Celsius.

    So not exactly in the much-sought-after ‘Goldilocks zone’—that orbital distance from a sun that would allow liquid water to exist on a planet, making it theoretically hospitable to life—as we know it anyway…

    And besides, while 4.37 light years sounds pretty close—that’s some 56 trillion kilometres—56,000,000,000,000 kilometres. To put that into perspective, Voyager 1 is currently 18,353,400,000 kilometres from Earth, and it was launched in 1977! How’s that in light years? Just 16 hours, 59 minutes and 38 seconds of light-travel time. So we’d probably need something like Arthur C Clarke’s Rama spaceship to make the crossing, because we’d be in there for a very long time…

    Let’s just clarify some details. Alpha Centauri isn’t one star, it’s actually three:

    • Alpha Centauri A (α Cen A)—about 110% the size of our Sun and 152% the luminosity
    • Alpha Centauri B (α Cen B)—about 91% the size of the Sun and half its luminosity
    • Proxima Centauri (α Cen C)—a red dwarf about 1/7 the size of the Sun (just 1.5 times the size of Jupiter) and less than 2% its luminosity

    Alpha Centauri A and B form a binary 4.37 light years from us. The distance they are apart varies between the distance from the Sun to Saturn, and to Pluto. Proxima is gravitationally connected to the binary, but actually slightly closer—4.24 light years away, making it the closest star to our solar system. This system is so close to ours that most of the night sky viewed from any planet there would be recognisable to us, with most constellations virtually unchanged from how they look here.

    Comparative star sizes

    Alpha Centauri is very easy for us to find in the Southern Hemisphere. It’s the fourth-brightest star in our skies at magnitude -0.27, is in the constellation Centauri and is also one of the Pointers to the Southern Cross—the furthest one from Crux. It’s also the brightest of the two pointers and indeed the whole Centauri constellation—hence the alpha in the name. A reasonable amateur telescope or even good binoculars will resolve the binary system, with clear differences between the sizes of the two stars. You need a fair bit better telescope and very good seeing to find Proxima…

    The discovery was made using the HARPS instrument on the ESO telescope—the High Accuracy Radial Velocity Planet Searcher spectograph. Rather than detecting sideways wobbles, HARPS was able to discern variations in the star’s light due to red-shifts and blue-shifts of the forward and away aspects of the star’s wobbles! Considering that the relative velocity this movement is in the order of the speed a baby would crawl, it’s a truly remarkable achievement.

    No doubt others will be looking to verify the finding over coming months. There’s a small (10 to 25%) chance that the planet could be orbiting in an elliptical plane that has it passing in front of α Cen B from our perspective. If so, the other main way that planets are found could be used. This method detects periodic dips in the star’s brightness caused by the planet’s partial eclipse, and is the way the Kepler Space Telescope has been used to find hundreds of other exoplanets.

    Sources:

    http://www.eso.org/public/news/eso1241/

    http://www.nature.com/news/the-exoplanet-next-door-1.11605

    http://bigstory.ap.org/article/earth-sized-planet-found-just-outside-solar-system

    http://www.sciencenews.org/view/generic/id/345756/description/The_alien_next_door

    http://en.wikipedia.org/wiki/Alpha_centauri

  • What an Astronaut’s Camera Sees from ISS

    What an Astronaut’s Camera Sees from ISS

    When astronauts head to the International Space Station (ISS), Dr. Justin Wilkinson,  the chief geoscientist at NASA, asks them to snap pictures of various geographical locations. From this vantage point 250 miles above the planet’s surface, he learns many things — for example, he tells Slate, “there are a lot more examples of a geographical phenomenon called an inland delta or megafan—that is, deltas formed far from coastlines—than was once thought.

  • A flawless launch for the world’s first commercial space mission

    A flawless launch for the world’s first commercial space mission

    Photo: Ben Cooper http://www.launchphotography.com/SpX-1.html

    Elon Musk’s commercial space travel venture SpaceX has ticked off another global first – the first commercial space flight. Watch a replay of the launch first stage:

     

    The SpaceX Falcon 9 rocket roared off the launch pad at 11:35am Canberra time, boosting the robotic Dragon capsule into a three-day chase of the International Space Station, carrying a NASA-commissioned resupply cargo. The media kit includes the full cargo manifest – 905 kilograms each way.

    What it doesn’t mention is that the cargo includes a freezer with vanilla and chocolate ice cream for the crew! Special treat.

    SpaceX are switched on with their broadcasts too – they had multiple onboard cameras giving some amazing perspectives, such as this one of the second stage rocket glowing white hot.

    This one shows the solar array deployment – unfolding surprisingly quickly.

    During the broadcast, SpaceX confirmed the stories behind the naming of their craft: the Falcon 9 is named after Han Solo’s Millenium Falcon on Star Wars, and the 9 is for the nine Merlin rocket engines that power it. This screengrab shows the Falcon breaking the sound barrier.

    The capsule itself is named Dragon, after the old show Puff the Magic Dragon, following criticism back in 2002 of SpaceX’s goals. This screengrab shows Dragon docked to the ISS.

     

    Recently, SpaceX also tested their “grasshopper” configuration – a set of legs on the base of the first stage. The goal here is to retain some fuel in the booster and return the whole thing back to a gentle landing for reuse.

    This shows the shock absorbers on the grasshopper legs. It was only a short hop a few metres off the ground, but it’s a start.

    And what about this as a workplace?

    Finally, here’s the launch control room in SpaceX HQ. NASA it is not!

    The Dragon capsule looks very cylindrical there – just a wide angle lens distortion.

  • My mega grab-bag of astronomy resources for teachers, students, telescope beginners and space fans

    My mega grab-bag of astronomy resources for teachers, students, telescope beginners and space fans

    Whether you are a parent, teacher, student or simply an interested enthusiast, here are a number of interesting sites, podcasts, and social media people for you to draw on as you get going in amateur astronomy.

    Podcasts provide an amazing resource – all free. Most are available via iTunes, the original publishers’ websites, or a raft of other podcast aggregators. There are very good apps to allow you to download podcasts to your smartphone for listening when suitable – Podcruncher is my choice for the iOS platform – brilliant app and service. Just don’t bother trying to use the Apple Podcasts app – it’s a total lemon. Good podcast apps also allow you to increase the playback speed up to double normal (Podcruncher goes in quarter increments) and surprisingly you learn to follow it. In fact, it can get so listening at normal speed is far too slow!

    Many of these links also have Twitter accounts (where noted), so you can keep right up to the minute!

    Astronomy podcasts:

    In Australia there is the wonderful StarStuff, an independent project run by Stuart Gary but sponsored by the ABC, with the 30-minute podcasts at ABC. @abcstarstuff


    Canberra’s Steve Nerlich produces Cheap Astronomy, regular 10-minute shows of varying complexity. @cheapastro

    Overseas, despite a truly ugly website, the fantastic Naked Scientists from UK’s Cambridge University have a stack of brilliant podcasts on general, science, archaeology, earth sciences, oceans, Africa, great kitchen-friendly experiments, and the monthly 60-minute Naked Astronomy, steered by Ben Valsler.

    Tony Darnell works in the Space Telescope Science Institute and as a hobby runs Deep Astronomy, with videos and podcasts generally about 10-minutes.

    There are a stack of NASA video and audio podcasts. Of interest are the space telescope ones for Hubble, Spitzer, Chandra, plus This Week @ NASA, Universe, Earth…where to stop? You’ll be amazed at how much NASA is doing – for an agency that altogether too many people think has shut up shop!

    365 Days of Astronomy is a real mixed bag of 10-minute podcasts – one for every day of the year. And it’s well worth looking back over previous episodes. Following are some specific ones worth checking out.
    Teachers could start with four of the best called ‘Wonders From Class’ by Diane Turnshek from Carnegie Mellon Uni. Over four podcasts and with great passion, she describes how she engages and interests her students with the field of astronomy. Part 1, Part 2, Part 3, and Part 4. Some others for beginning viewing and then a bit more:
    Common Q&As about telescope use – from RapidEye Observatory
    8 Telescope Tips for Beginners – by Telescope Man
    Buying your first telescope – Telescope Man again
    Have a plan – by Ed Sunder of flinstonestargazing.com
    How to be an armchair astronaut – From Riding With Robots – now there’s a site to spend some time at!
    Armchair astronauts exploring the solar system – by Doug Ellison ofunmannedspaceflight.com @doug_ellison
    Exploring space with your computer – a guide to computer simulation tools by Bruce Irving of JPL
    Moving onto photographing what you see:
    Introduction to astrophotography – by Adam Pender
    Webcam astrophotography – by Alexander Hobson
    Amateur astrophotography for beginners – by Richard Drumm
    Astroimaging under light polluted skies – by Robert Vanderbei
    Expanding further – into spectroscopy:
    Basic spectroscopy for amateurs  and Part 2 – by Mark DeVito and Tom Field

    And if you’d like to go a bit further, you can subscribe to an entire university astronomy course via podcast – all the learning but no horrible assignments or exams! Here’s one in audio format from Ohio State Uni. There are others too, including video. Check iTunes, or iTunesU, the app for which includes study notes and the ability to record your own notes as you go along.

    Observing podcasts:

    The Sydney Observatory posts a monthly podcast summarising the night sky viewing for the month – great for Southern Hemisphere viewers and East Coast Australians in particular. They have the added benefit of a transcript so you can print and highlight the key bits as a night sky viewing plan. @sydneyobs

    NASA’s Jet Propulsion Lab has a short monthly video podcast, plus there’s a stack of related brain food on their site.

    Observing with Webb – another USA podcast by Rod Webb, but many of the sights will be visible here, just in different locations.

    Telescope Man – look for the monthly viewing summaries. No nonsense, best viewing tips, with catalogued numbers if you have a go-to scope, but based on Texas. Plenty of other good beginner podcasts too.

    Non-podcast observing resources:

    The Hayden Planetarium (part of the American Museum of Natural History and headed up by none other than Neil deGrasse Tyson @neiltyson) has a good monthly sky report. You can see a lot of what they discuss, but of course not all. You’ll also find their 3D atlas to the Universe.

    Slooh has several large telescopes around the world and you can view the feeds for free. They have guest speakers during regular events. @slooh

    Heavens Above allows you to register and enter your location, then get schedules of when key objects will pass over your patch of the sky – from GPS satellites to the International Space Station. Find out why the brightness scale goes backwards, planet and comet locations, and more.

    If you just want to focus on passes of manned vehicles like the ISS or Soyuz, then check the RSS subscription for your location at NASA Human Spaceflight.

    Stellarium – a free public domain computer planetarium. Free-standing once installed with no need of web access, so you can switch to red mode and take your notebook computer out with you.

    Celestia – another free planetarium. This one lets you explore off-planet, and even check out various space missions.

    Eyes on the Solar System – NASA’s mission tracking simulator. Go for a ride along with every NASA space mission past and present. A great way to piggy back onto the Mars Curiosity rover and relive her descent to Mars last August!

    Non-podcast astronomy resources:

    NASA’s Breaking News is a good resource, and has a useful RSS feed – check out Google Reader for how to collate key websites simply via RSS feeds, and Feedler Pro is a great app for viewing your Google Reader subscriptions on iThings. @NASA

    NASA also has a comprehensive education section, with specialist information for teachers at different levels, students and a kids club. Too much to list and it seems to grow every time you return. It’s not all about the US either – they have an international Scientist for the Day competition running right now for school students.

    It’s hard to go past Space.com for some of everything you want, and great RSS and Twitter feeds. They have a good shop too – from meteorites to kids’ spacesuits, genuine gone-to-space memorabilia to clothing. I mean, you’ve got to look the part for your classes right? @spacedotcom

    With broadband, giant televisions with network sockets, and a high definition feed from NASA TV, there’s never been a better time for live viewing rocket launches, spacewalks, and more. Keep an eye on the schedule for education shows too. Be warned though, spacewalks are REALLY long and slow-mo. Some younger viewers will have a short attention span for them. But launches…Phroar! Crank up the volume.

    The Square Kilometre Array is the project to build the world’s biggest radio telescope – right here in Australia. And in South Africa. It will be the biggest science project ever in our history. Good video clips explaining the project.

    Bad Astronomy blogger Phil Plait sorts the facts from the nonsense. @BadAstronomer

    Universe Today by Fraser Cain, who also does weekly virtual star parties with Dr Pamela Gay via Google+, YouTube and Cosmoquest. Also does the Astronomy Cast podcast.

    The Space Tweep Society has great articles, photos and videos from spacefans on Twitter who travel the world to attend Tweetups – key space events like launches – and hang out with other fans who use Twitter to share their experiences with their followers. The travels to Russia are brilliantly recounted.

    Registax allows you to stack multiple photos or frames from a video clip to produce a single sharp picture. Free!

    Galaxy Zoo is a citizen science website that allows anyone to help the scientists categorise galaxies as seen by Hubble. There have been a number of people credited on scientific journals for the new wonders they discovered on Galaxy Zoo! And now on a spin-off you might help find exoplanets…

    Tweeps you should follow:

    @NASAKepler – the search for exoplanets
    @SpaceflightNow – space news up to the moment, from Florida
    @Nightskyonline – Australian amateur astronomer, alerts to sights
    @SpaceX – the future of manned missions
    @elonmusk – the boss of SpaceX – a real-life Tony Stark
    @MarsRovers – updates from Opportunity on Mars
    @MarsCuriosity – updates from the Mars Science Laboratory herself
    @matt_heverley – lead Mars Curiosity rover driver
    @marsroverdriver – Scott Maxwell, formerly driving Opportunity, now Curiosity
    @spaceroboticist – Vandi Thomas – there are women driving Curiosity too
    @NASAWebbTelescp – the future of space telescopes, being built now
    @twisst – alerts of ISS passes over your location
    @Aussie_Starman – Mark Rigby, head of the Brisbane Planetarium
    @NASAJuno – Juno is heading to Jupiter
    @carolynporco – the wonderful head of the Cassini mission around Saturn
    @PULSEatParkes – high school students taking over The Dish at Parkes!
    And all the other ones named earlier.
    Apps:

    Lastly, iPhone and iPad apps are simply brilliant for finding out exactly what you are looking at in the sky.
    Star Walk – virtual planetarium, my favourite, $3 – worth every cent!
    Distant Suns – virtual planetarium, free
    SkyOrb – virtual planetarium, free
    Pocket Universe – first off the line with this whole virtual planetarium approach, $2
    3D Sun – know about and watch solar flares before anyone else, free
    Cassini – find out what this probe is doing around Saturn, free
    APOD – astronomy picture of the day – website and iPhone app, free
    Exoplanet – the latest on every exoplanet discovered, free
    NASA – their own app, and simple access to NASA TV – never miss another launch! Free
    Mars Images – what it says on the box, free
    ISS Spotter –  brilliant way to make sure you don’t miss passes of the Space Station – live maps and smart alarms, free
    Mission Clock – don’t miss your dose of roar, $5
    Meteor Counter – help scientists monitor meteor density, free, great activity for families.

    Anyway, that’s enough for now. But rest assured, it is only scratching the surface. There’s a whole world of astronomy resources out there online for you.

  • Hubble goes to the eXtreme to assemble the deepest ever view of the Universe

    Hubble goes to the eXtreme to assemble the deepest ever view of the Universe

    Like photographers assembling a portfolio of their best shots, astronomers have assembled a new, improved portrait of our deepest-ever view of the Universe. Called the eXtreme Deep Field, or XDF, the photo was assembled by combining ten years of NASA/ESA Hubble Space Telescope observations taken of a patch of sky within the original Hubble Ultra Deep Field. The XDF is a small fraction of the angular diameter of the full Moon.

     

    The Hubble eXtreme Deep Field (XDF)

    The Hubble Ultra Deep Field is an image of a small area of space in the constellation of Fornax (The Furnace), created using Hubble Space Telescope data from 2003 and 2004. By collecting faint light over one million seconds of observation, the resulting image revealed thousands of galaxies, both nearby and very distant, making it the deepest image of the Universe ever taken at that time.

    The new full-colour XDF image is even more sensitive than the original Hubble Ultra Deep Field image, thanks to the additional observations, and contains about 5500 galaxies, even within its smaller field of view. The faintest galaxies are one ten-billionth the brightness that the unaided human eye can see [1].

    Magnificent spiral galaxies similar in shape to the Milky Way and its neighbour the Andromeda galaxy appear in this image, as do large, fuzzy red galaxies in which the formation of new stars has ceased. These red galaxies are the remnants of dramatic collisions between galaxies and are in their declining years as the stars within them age.

    Peppered across the field are tiny, faint, and yet more distant galaxies that are like the seedlings from which today’s magnificent galaxies grew. The history of galaxies – from soon after the first galaxies were born to the great galaxies of today, like the Milky Way – is laid out in this one remarkable image.

    Hubble pointed at a tiny patch of southern sky in repeat visits made over the past decade with a total exposure time of two million seconds [2]. More than 2000 images of the same field were taken with Hubble’s two primary cameras: the Advanced Camera for Surveys and the Wide Field Camera 3, which extends Hubble’s vision into near-infrared light. These were then combined to form the XDF.

    “The XDF is the deepest image of the sky ever obtained and reveals the faintest and most distant galaxies ever seen. XDF allows us to explore further back in time than ever before,” said Garth Illingworth of the University of California at Santa Cruz, principal investigator of the Hubble Ultra Deep Field 2009 (HUDF09) programme.

    The Universe is 13.7 billion years old, and the XDF reveals galaxies that span back 13.2 billion years in time. Most of the galaxies in the XDF are seen when they were young, small, and growing, often violently as they collided and merged together. The early Universe was a time of dramatic birth for galaxies containing brilliant blue stars far brighter than our Sun. The light from those past events is just arriving at Earth now, and so the XDF is a time tunnel into the distant past when the Universe was just a fraction of its current age. The youngest galaxy found in the XDF existed just 450 million years after the Universe’s birth in the Big Bang.

    Before Hubble was launched in 1990, astronomers were able to see galaxies up to about seven billion light-years away, half way back to the Big Bang. Observations with telescopes on the ground were not able to establish how galaxies formed and evolved in the early Universe.

    Hubble gave astronomers their first view of the actual forms of galaxies when they were young. This provided compelling, direct visual evidence that the Universe is truly changing as it ages. Like watching individual frames of a motion picture, the Hubble deep surveys reveal the emergence of structure in the infant Universe and the subsequent dynamic stages of galaxy evolution.

    The planned NASA/ESA/CSA James Webb Space Telescope (Webb telescope) will be aimed at the XDF, and will study it with its infrared vision. The Webb telescope will find even fainter galaxies that existed when the Universe was just a few hundred million years old. Because of the expansion of the Universe, light from the distant past is stretched into longer, infrared wavelengths. The Webb telescope’s infrared vision is ideally suited to push the XDF even deeper, into a time when the first stars and galaxies formed and filled the early “dark ages” of the Universe with light.

    Notes

    The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

    The HUDF09 team members are G. Illingworth (University of California, Santa Cruz), R. Bouwens (Leiden University), M. Carollo (Swiss Federal Institute of Technology, Zurich (ETH)), M. Franx (Leiden University), I. Labbe (Leiden University), D. Magee and P. Oesch (University of California, Santa Cruz), M. Stiavelli (Space Telescope Science Institute), M. Trenti (University of Cambridge), P. van Dokkum (Yale University), and V. Gonzalez (University of California Observatories/Lick Observatory).

    [1] The faintest objects detected in the XDF are 31st magnitude.

    [2] The total exposure time is approximately two million seconds, or 23 days. Because Hubble can only observe for about 45 minutes of every 97-minute orbit, the observations that make up the XDF represent 50 days of telescope time.

    Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team
    Links

    Source: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50874

  • A long time ago in a galaxy far, far away

    A long time ago in a galaxy far, far away

    Feast your eyes on this image…

    Image credit: The CLASH team/Space Telescope Science Institute

    The tiny object in that inset may not look like much. A blurry smudge of red pixels. Not nearly as dramatic as the stunning bouquet of galaxies all around it. But in astronomy, not everything is quite so straightforward. That small red smudge is probably the most exciting thing in this whole image. You see, it too is a galaxy. An unimaginably ancient one.

    An ultraviolet image of the nearby Andromeda Galaxy – possibly similar to what we might see of MACS 1149-JD if we could get a more detailed view… Credit: NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)

    The light that made this unassuming red dot left its source less than 500 million years after the Big Bang and the birth of the Universe. The photons that make up that light have been travelling for over 13.2 billion years. This galaxy was blazing brightly as the oldest known stars in our own galaxy, the Milky Way, were just starting to shine. Back when the gas which would one day become the Sun was still drifting silently amongst stars which are now long dead, and before planet Earth was even a whisper of interstellar dust. Before a massive star forged the iron atoms in your blood, and before a supernova scattered those atoms into space. Before anything we know from the world around us existed, even the stars we see as we look up to the night sky, this galaxy was shining in the dark.

    The Universe was a much smaller place back then. Over the billions of years these photons have been travelling, the Universe itself has expanded with them in the midst of it – stretching them out, redshifting them to longer and longer wavelengths. The light we see here as red was probably ultraviolet once, when it left the galaxy which created it.

    Ancient galaxies like these are difficult to see, purely because they’re so distant. So few photons make it this far that only the most sensitive telescopes can make them out, and even then they need a helping hand. The bloom of galaxies in this image is a massive galaxy cluster called MACS J1149+2223. A collection of galaxies bound together by gravity, clusters like these are some of the largest and most massive objects in the Universe. With that much mass gathered together, gravity starts to do some interesting things, and one of the most interesting is gravitational lensing. Because the gravity of all of those galaxies distorts spacetime, it actually causes the space around the galaxies to act like a titanic lens. A gravitational lens. The ancient red galaxy in this image is only visible because it’s magnified, not only by the Hubble Space Telescope, but by that gravitational lens too.

    It would be naive to assume that this galaxy, dubbed MACS 1149-JD, is special somehow. Instead, it’s most likely to be one of a huge number of primordial galaxies. Except that this one just happened to be in the right place at the right time. A whole population of these ancient galaxies were likely shining brightly at the time, full of hot stars which were driving the reionisation epoch – the time when the Universe went from being an opaque, dark fog, to a clear place where photons could travel long distances. The photons in this image may well have been some of the first photons to have travelled through that ancient and newly transparent Universe.

    The scientific paper is available from Nature – DOI: 10.1038/nature11446

  • Weekly Science Picks

    Weekly Science Picks

    It’s been an interesting week for science news, and I’ve been lucky enough to be asked to give this week’s science picks! This made me spend a little while sipping contemplatively on a cup of vanilla iced coffee and wondering where to even start…

    The articles I’ve selected are, of course, slanted towards my own (rather geeky) interests, but all the same I hope you find them all as fascinating as I did!

    First up, the news that Star Trek style warp drives may actually be possible, at least in theory, made me exclaim “Oh wow!” out loud. Fortunately, people who spend any time with me are generally used to me talking to myself while staring at a computer screen…

    Warp Drive May be More Feasible than Thought

    “Everything within space is restricted by the speed of light. But the really cool thing is space-time, the fabric of space, is not limited by the speed of light.”
    – Richard Obousy, president of Icarus Interstellar

     

    Artists impression of Mimivirus, the first giant virus to be discovered. Image Credit: InvaderXan/Wikimedia Commons

    From the vastness of space to life under the microscope, biologists have been debating for years whether or not viruses qualify as a form of life. The latest evidence is that they may indeed be a life form in their own right, and an old one at that!

    Giant Viruses are Ancient Living Organisms

    They found that many of the most ancient protein folds in living organisms were present in the giant viruses, which “offers more evidence that viruses are embedded in the fabric of life,” Caetano-Anollés said.

     

    Heritage Daily had a fascinating article about the archaeology of the future, and what precisely our distant descendents may one day think of us and the way we lived…

    The Archaeology of the Future

    The point is that most of what survives will not be determined by conscious decisions on our part. This may not be for want of trying, as shown by the current popularity of time capsules. The most impressive of these must be the KEO satellite, due to be launched in 2014 and to return to Earth 50,000 years later.

     

    And speaking of what we know of the past, it’s been shown again and again that our primitive relatives, the neanderthals, were likely not the brainless savages they’re often depicted to be. Evidence suggests that neanderthals liked to collect bird feathers as ornaments.

    Neanderthals Used Feathers as ‘Personal Ornaments’

    “I think this is the tip of the iceberg,” said Prof Finlayson: “It is showing that Neanderthals simply expressed themselves in media other than cave walls. The last bastion of defence in favour of our superiority was cognition.” Neanderthals, he said, may have been “different”, but “their processes of thinking were obviously very similar”.

     

    Curiosity self-portrait. Image Credit: NASA/JPL-Caltech/Malin Space Science Systems

    As the Curiosity rover settles into its new home in Gale Crater on our neighbouring planet, one small worry is growing in the backs of the minds of certain NASA scientists. Could a blunder on the part of some engineers lead to Curiosity contaminating the surface of Mars with Earth life?

    Drill Bits on Rover Could Contaminate Mars

    John D. Rummel, a professor of biology at East Carolina University, said, partly in jest: “It will be a sad day for NASA if they do detect ice or water. That’s because the Curiosity project will most likely be told, ‘Gee, that’s nice. Now turn around.’ “

     

    And finally, planet hunters are scouring the sky for exoplanets. Astrobiologists are hoping to soon be able to look into the atmospheres of those planets in search of life signs, in the form of certain molecules created by living organisms. But could they be fooled by those molecules coming from somewhere else?

    Meteors Might Add Methane to Exoplanet Atmospheres

    One key gas astrobiologists looking for extraterrestrial life would concentrate on would be oxygen […] Another possibility would be methane, a colorless, odorless, flammable organic gas that microbes on Earth produce. Seeing both together in an exoplanet’s atmosphere might be an especially significant sign of life, since they would both ordinarily remove each other from the atmosphere without something like life to constantly replenish them.

     

    Have a good weekend!

  • Science or fringe science? Removing the ‘giggle factor’ from Near Earth Object impacts

    Science or fringe science? Removing the ‘giggle factor’ from Near Earth Object impacts

    On June 30, 7.17am in a remote, sparsely inhabited area in Siberia, Russia, near the Podkamennaya Tunguska River, occurred an event of enormous devastation. An asteroid or comet estimated to be 40-50 meters in diameter, exploded at low altitude with an energy almost 200 times that of the atom bomb dropped on Hiroshima. Trees where knocked down over an area of two thousand square kilometres, hundreds of reindeer where killed and the seismic shock from the airborne explosion was registered on barometers in England. Eyewitnesses 60km away, reported seeing the northern sky covered with fire, followed by an enormous bang, though thankfully no human deaths were recorded.

    Fallen trees at the Tunguska impact site

    Dan Yeoman from NASA’s Jet Propulsion Laboratory stated in an interview in 2008, “the Tunguska event is of great importance not only because of the devastation caused to a thankfully remote area, but also as it is the only modern era event of this type where we actually have first-hand accounts.

  • Weekly Science Picks

    Weekly Science Picks

    “La rentrée!

  • Alien encounters and the man from Grenada

    Alien encounters and the man from Grenada

    The month of August indeed belonged to the tiny rover that could — Curiosity. We were all hooked right from the landing and until those first images of the red planet were beamed back. Not even Will.i.am could spoil it for us. We revelled in everything in between, from the missed high-fives, peanuts, Neil deGrasse Tyson’s conversation with the rover, to — yes, unfortunately — Will.i.am’s new single being broadcast from the surface. Curiosity even spawned this generation’s cultural hallmark that is the fake twitter account. If there is any one milestone that denotes you’ve reached a certain level of cultural status… it’s the fake twitter account. From Mrs Rupert Murdoch to dead literary figures, the fake twiteratti are just as important as the real ones.

    In an odd roundabout way, all of this got me thinking about a bizarre event that happened in 1977.

    The United Nations debating such topics as aliens and extra-terrestrial encounters of any kind seems like something confined to the annals of science fiction. And yet, the most significant debate any international body has had on the prospect of alien encounter happened at the 32nd session of the United Nations General Assembly, for reasons unbeknown to me and probably many at the committee.

    Member nations and delegations convened at the 32nd session of the General Assembly to listen to the man from Grenada, Sir Eric M. Gairy, the Prime Minister and Minister for External Affairs of Grenada (evidently taking his title to its farthest logic conclusion — what could be more external than space?).

    He began with a reading from the Bible — Psalm 100, then launching into an engaging speech that touched on freedom and independence of nations, human rights, wars and conflicts. It quickly took on another flavour. The smallest nation in the UN (at the time) had centre stage and was determined to make the most of it. Mr. Gairy began to speak of unidentified flying objects (UFOs) with the same unabashed enthusiasm he was getting a reputation for.

    He concluded by recommending that not only the UN take it seriously but they should set up a department to study UFOs. The UN already had a space outfit — the Of

  • The whole Earth-side of the Moon should be protected forever

    The whole Earth-side of the Moon should be protected forever

    Apollo 12 landing site, taken from NASA's Lunar Reconnaissance Orbiter in 2011

    Earlier this year, the New York Times had an interesting piece about museums seeking to protect small areas of the Moon around the Apollo landing sites. And a good thing too: “…the next generation of people visiting the moon might carelessly obliterate the site of one of humanity’s greatest accomplishments.”

    More recently, NASA has released draft guidelines around protecting the landing sites from damage.

    But isn’t that a bit like how Cairo almost swallows the Pyramids?

    Surely we need to go further? Much further?

    For thousands of years, all of Earth-bound humanity will gaze up on the Earth side of the Moon. And it’s exactly the same view looked upon by all of humanity throughout history.

    Surely that whole view is worthy of protection? After all, any changes made that are visible from Earth will be visible forever. There’s no atmosphere or weather to sweep away our transgressions over time. What is done on the Moon stays done…

    I raised these concerns with a NASA engineer a couple of years ago after his presentation at the Questacon national science museum about the (now ill-fated) Constellation project to return to the Moon.

    It seemed to me that the American disposable society mantra was writ large in their plans, with leftover bits free to crashland wherever once done with. It’s that sort of mentality that’s got us into a spacejunk problem in Earth orbit.

    I have no doubt that there will come a day – possibly while I’m still alive – that we are strip-mining parts of the Moon for minerals to build spaceships and Moonbase buildings and to fuel them.

    But surely there should be a commitment from all nations for this sort of permanent scarring to be limited to the far side (the incorrectly named dark side!) of the Moon only. And for communications facilities and potentially colonies to be positioned around the Earthside perimeter for minimal visual impact, while maintaining direct communications.

    There should also be strict controls on escape of artificial light. Surely the sort of light pollution that we spew pointlessly upwards from our Earth should not be shining back at us one day from the Moon?

    We owe our future generations that much, I believe.

    And while looking back – enjoy this handheld footage of the Earthrise, from Apollo 10, right out at the Moon, to very fitting music:

  • Mysterious Mars

    Mysterious Mars

    Mars is full of secrets and mysteries. The classic definition of a desert world, our planet’s arid sibling is a parched wilderness of dunes and planetwide dust storms. With a thin carbon dioxide atmosphere and only 38% the gravitational pull of Earth, there are a lot of puzzles about this cold and frosty little planet, and a lot of scientists who are longing to solve them.

    El Dorado, Gusev Crater. Mars is a world of dust and dunes…

    By now, anyone keeping up with the news is bound to have heard that NASA’s Curiosity rover made a flawless descent through the atmosphere of Mars and is now busy eyeing up its new home in the Gale Crater. As was discussed previously here on Australian Science, a big question still on everyone’s mind is the same one which David Bowie sang about back in 1971. Is there life on Mars? However, it seems that NASA’s plans are not to answer this question directly. John Grotzinger, project scientist for the Curiosity mission, is quoted as saying; “Curiosity is not a life detection mission. We’re not actually looking for life; we don’t have the ability to detect life if it was there.” Instead, the main objective of Curiosity is to look for signs of life.

    The trouble is that looking for life directly is a difficult task. Back here on Earth, new discoveries are still being made frequently, with life being found in environments and habitats where no one was expecting. There’s a lot which we still don’t fully understand about life here on our own world. When we’re talking about another planet, it’s safe to say that all bets are off. As a result, Curiosity’s goal is to look for the various elements and chemical compounds which life might use – or might have used once upon a time when the planet may have been more hospitable. The focus has shifted from the search for life on Mars right now, to life which may once have lived there.

    Arabia Terra – one of the three locations on Mars where methane plumes have been spotted.

    One point which is worth remembering right now, however, is that there’s one big unsolved mystery about Mars. A gaseous mystery. Large quantities of methane have been detected in the martian atmosphere, which gives rise to a real puzzle. Methane is destroyed by sunlight, and with the thin atmosphere found on Mars, any methane should be rapidly broken apart by solar ultraviolet. The only possible conclusion is that the methane seen on Mars is being replenished somehow. There are only really two possibilities for how this might happen.

    One scenario sees the martian methane caused by a geological process called serpentinisation. This is where a type of mineral known as olivine (more familiar to us as the gemstone peridot) chemically reacts with water and carbon dioxide. The reaction creates methane and a green mineral called serpentine (commonly found in certain parts of Western Australia and Tasmania), and releases methane gas. If this is the process which is occurring, it would mean that not only is there a suitable amount of water somewhere under the surface of Mars, but there must also be geological activity for that water to continue being brought into contact with further olivine to react with. This would suggest that there are things which we don’t know about current geological processes on Mars.

    The other possibility, more radically, is that this methane is being produced by life. Here on Earth, bacteria known as methanogens are responsible for most of the methane present in Earth’s atmosphere. In fact, on Earth, methane is so regularly produced by living organisms that it can used as an indicator of biological activity.

    When three distinct plumes of methane were discovered on Mars in 2009, it was noted that there was an equal probability of either of those two scenarios being the source of the methane – and that both would be huge revelations in our understanding of our neighbouring world. So maybe the Curiosity rover isn’t set up to hunt for life, and maybe it won’t be directly looking for it. But I, for one, do hope it finds some clues about the origin of the mysterious martian methane. Just as any scientist should, I love a good mystery!

    The three methane plumes seen on Mars at South-East Syrtis Major, Nili Fossae and Arabia Terra.

    Image credits:
    Top – NASA JPL/Cornell
    Middle – ESA/DLR/FU Berlin (G. Neukum)
    Bottom – NASA

  • Radio quiet, please!

    Radio quiet, please!

    Originally conceived over 20 years ago, there’s a project being undertaken by scientists and engineers across the whole world to help us all better understand the mysteries of the galaxy and the very beginnings of the Universe. It’s estimated to be completed by around 2024,costing $1.85 billion AUS (€1.5 billion). Once completed, it’s set to be the most complex and technologically advanced machine ever built by humanity. It will use enough optic fibre to wrap twice around the Earth and will need a computer capable of performing 10^18 operations per second – about three million times the number of stars in our galaxy. It will produce over 980 Exabytes of data every day (equivalent to about 15 million 64GB iPods) and to cope with that, it will need to handle data transfer rates over 10 times as high as the current global internet traffic. No, it isn’t a starship. But it might just be the next best thing.

    One of the first components of the SKA, constructed in Western Australia. Credit: Dave DeBoer, CSIRO.

    The Square Kilometre Array (SKA) is one of the most ambitious scientific projects ever devised, and when completed it will comprise a huge number of telescope antennae which will work as one to form a single radio telescope so powerful that it could detect an airport radar on a planet 50 light years away. The sensitivity of any telescope is defined by the area it uses to collect data. With optical telescopes, this is the size of the mirror, and with radio telescopes it’s typically the size of the dish. The SKA gets its name because when fully constructed, all of the detectors and antennae that make it up will have a combined area of one square kilometre, or one million square metres. To put that properly into perspective, the Green Bank Telescope is currently the largest steerable single dish radio telescope, and its area is just under 8000 square metres.

    Being astronomy’s answer to the large hadron collider, the SKA is a staggeringly large international collaboration. I was lucky enough to attend a major meeting regarding the planning of the SKA (the headquarters are to be based here in the UK in Manchester), and the myriad different languages and nationalities represented was impressive to say the least. Over 24 major organisations from countries spanning 5 continents are involved in the project, ranging from universities to industrial engineering companies. New technologies, both software and hardware, are still being developed as a result of this project. Based on the huge data storage and transfer requirements of a machine as complex as the SKA, many of those new technologies are likely to feed straight back into society by offering profound improvements to computing resources like the internet. In fact, as the world’s largest project for sorting and storing data, the SKA is expected to be literally bigger than Google!

    The Warkworth antenna in New Zealand – an important part of early SKA science. Credit: Alex Wallace.

    The most difficult decision, understandably, has been where precisely to build it. Humanity has an unfortunate tendancy to fill the atmosphere of our planet with noise, bouncing radio waves to and fro and filling the air with radio frequency chatter. A radio telescope array this sensitive needs to be placed somewhere quiet to gain the full benefits, and the most recent decision has been to effectively split the SKA into two components, to be built in Southern Africa and Australia. While this may seem like an odd thing to do, it actually makes perfect sense. The SKA actually has three types of antenna operating at different frequencies. Intended to cover a huge range of radio frequencies (from 70 to 100000 MHz), three types of antenna are needed, because no single technology can actually operate across such a wide range. So the decision was made to build the lowest frequency detectors across Australia, centred at Murchison in outback Western Australia. Murchison is blessed with being one of the few places on our planet which isn’t flooded with FM radio at the low end of the frequency scale. From a radio astronomer’s point of view, it’s the quietest place on Earth.

    This is set to be complemented by the higher frequency steerable dishes which are set to be constructed across Africa. Both South Africa and Australia have put extensive efforts into developing the SKA, and Australian-developed technology is still set to be implemented in the African telescopes. This will mean a huge influx to the African astronomical community and numerous African nations won’t lose out on the economic boost from contributing to such a prestigious project. It’s an ideal situation where everyone wins.

    All in all, it’s an exciting time to be an astronomer. An epic project like this is likely to attract all manner of researchers from across the world to both continents. Just maybe, it could also finally help us to answer the really big questions, like how the galaxy formed, how the Universe began, and whether or not there’s anyone else out there.

    A map of prospective SKA sites. Credit: anzska