So following Rita and Emmas cue here is my reading Douglas post. In honour of the great man and towel day I bring you a passage that I think should be the opening passage in every country in the worlds constitution.
I hope you enjoy it as much as I did, it exemplifies Douglas Adams ability to make a huge amount of sense with passages that snake around back and fourth, something I will always love him and his writing for
Its the 14th of February, or at least thats what the calendar on the wall says, you have been out in deep space heading towards that new colony for so long each day pretty much blurs in to the next. Despite how cold it is outside (and believe me its cold), today is a day to get out the candles, throw a fresh table cloth over the zero g dinning table, open a fresh bottle of onboard engine fermented merlot and splash out on some really rare food cubes (the macaroni and cheese all but ran out several years ago appart from one pack you have been hoarding for a special occasion). Its valentines day and time for romance!
After your romantic meal and your partner retire for a little zero g love making with the hope of producing a little zero g baby to continue the mission (and the human race) onwards towards Earth 2.0 (Earth 1.0 being sadly decimated by giant zombie mutant howler monkeys… dont ask). However according to a new report by NASA scientists making your little bundle of joy is a bit of a longshot. The problem is that space is full of high energy protons which have respect for neither the hulls of spaceships nor human DNA. A study conducted by Dr Straume of the NASA Ames center and his team, seems to conclude that chances are that any fetus conceived in space would be irrevocably damaged by this radiation. Men dont get off any better with decreased sperm counts and generally decreased fertility.
In fact the team conclude that with todays ships, they wouldn’t rate a pregnancies chance of coming to term on a trip to Mars never mind a multi generation journey to the nearest habitable planet. The problem is that radiation like that given off by the sun and found in space can damage out DNA causing defects which in adults can lead to conditions such as cancer. In an unborn baby which is still growing and developing, where DNA is even more important, this effect can be even more catastrophic. Studies in non-human primates have found that about half of all pregnancies failed with a dose of only 0.07 Sieverts (a unit which measures radiation exposure). To put that in perspective, the dose of radiation you would receive on the surface of Mars without shielding is between 0.33 Sieverts and 0.08 Sieverts, much higher than the dangerous level. The report suggest that you might use the soil on Mars to effectively shield against this radiation but notes this level of shielding would be difficult in space.
So where does this leave our budding astro babies ? Well the report also discusses some ways in which the danger from radiation might be mitigated. These range from identifying biomarkers that would identify which astronauts would be the least susceptible to radiation damage, to using electromagnetic fields on ships (big magnets basically) to deflect the charged radiation in much the same way as Earth’s magnetic field protects us here. The problem with this last approach would be the generating the amount of energy required to produce such fields may be prohibitive.
For the new residents of Mars however the team suggest another idea: using Phobos one of Mars moons as a maternity ward. Phobos is closer to its planet than any other moon in our solar system, so much so that Mars covers 25% of the sky. The Mars side of the Phobos also happens play host to a large crater called Stickney crater. Inside this crater our mothers to be could be shielded from as much as 90% of harmful radiation. So perhaps all future Martians will in reality be Phobosians!
Its early days for this kind of research and more study has to be done. Until then space babies are strictly a bad idea and space condoms (possibly lead lined) are a must. Dont say science doenst know how to kill the mood on valentines day!
Tore Straume, Steve Blattnig, & Cary Zeitlin (210). Radiation Hazards and the Colonization of Mars:
Brain, Body, Pregnancy, In-Utero Development, Cardio, Cancer, Degeneration Journal of Cosmology, 12, 3992-4033
The internet has been abuzz this week with news of a recently discovered massive star being booted from its home cluster. I have the good fortune to know one of the scientists involved in this discovery and have asked him to give us an insight in what went in to this find.
So without further delay I introduce our first guest post from Dr Chris Evans, a researcher at the UK Astronomy Technology Center.
Pick a clear night in the southern hemisphere, get out of town, and let your eyes get night adjusted – not only are you assailed by the depth and scale of the Milky Way, but you also see the faint fuzzy patches of the Magellanic Clouds. Here’s a pretty spectacular shot from ESO, when Comet McNaught was visible.
These are two irregular galaxies outside of our own, only visible from the south, with distances of 160,000 light years to the Large Magellanic Cloud (LMC), and 195,000 to the Small Magellanic Cloud. These are great laboratories for learning about how stars live their lives, from birth in beautiful nebulae, to their deaths, sometimes as spectacular supernovae explosions.
The fruits of some of our work in the Clouds came together early this year with some very cool new observations from the Hubble Space Telescope, leading to a journal paper and a press release on a so-called “runaway” star, that we think has been ejected from the centre of the largest stellar nursery in the local universe, 30 Doradus.
Astronomers often have unpublished data from projects that were incomplete due to bad weather, people leaving the subject, the onslaught of more immediate deadlines and so on. In our case, we had two observations of a bright blue star on the western edge of 30 Doradus; the much bigger project we had planned was thwarted by bad weather. Months later at a conference, Nolan Walborn, based at STScI in Baltimore, was looking through the observations and recognised the tell-tale signs of one of the most massive, rare types of stars called O2 stars. Even with all of our work over the past decades we still only know of a handful of these. A journalist once asked me if they lived fast and died young? It’s a cheesy but accurate description. After just a few million years they effectively run out of fuel in their cores, causing a fatal collapse of their atmospheres leading to a supernova explosion. Intriguingly, the speed of this O2 star (relative to the Sun) looked peculiar when compared to the rest of the LMC, but at the time we dimissed this as perhaps being a binary system.
Cut to 2009… NASA launched the fifth servicing mission to the HST which installed some new instruments, as well as giving Hubble some much needed TLC (new batteries and gyroscopes) to keep it going for a few more years. One of these new instruments was the Cosmic Origins Spectrograph, which takes spectra at ultraviolet wavelengths.
Our O2 star was used as one of the calibration targets immediately after the servicing mission, using some of the spectral lines to help focus COS. Nolan contacted me the moment he saw the data as the COS observation tells us that this star has a stellar wind that accelerates up to a velocity of 3450km/s – that’s 1% of the speed of light just from the processes in the atmosphere of the star, some acceleration!
By chance, the star was also observed as part of a new survey that over thirty of us across Europe (and beyond) are working on, the VLT-FLAMES Tarantula Survey, in which we’ve observed 1000 stars in that part of the LMC. It’s rare you have a real “eureka” moment of discovery, but this was one of them.
The new data, taken over the course of a year, show no changes in the velocity of the star, ruling out a massive binary companion. This tells us that its velocity is very different to the local gas, suggesting it was not formed locally and that it has been ejected from the dense core of 30 Dor, thought to be home of some of the most massive stars known. Theoreticians think that runaway stars like ours can either be ejected via interactions with other stars or via the kick of a supernova explosion. The key to this story is that the cluster at the centre of 30 Dor is thought to be too young to have hosted any supernovae, suggesting this as the first compelling evidence for a star booted-out by more massive stars.
C. J. Evans, N. R. Walborn, P. A. Crowther, V. Henault-Brunet, D. Massa, W. D. Taylor, I. D. Howarth, H. Sana, D. J. Lennon, & J. Th. van Loon (2010). A massive runaway star from 30 Doradus The Astrophysical Journal Letters, 715 (2) arXiv: 1004.5402v1
This morning sees the launch of the newest project from the zooniverse team, moonzoo ! Using high resolution images from the LCROSS mission, we want people to help us map craters, find unusual structures and help find lost spacecraft. Turns out we dont know where a bunch of stuff we sent to the moon is, LCROSS is the first mission with a high enough resolution to be able to see manmade objects on the surface of the moon. We covered this mission before but now its your turn to pour over the stunning images of the moons surface.
so head over to www.moonzoo.org and happy hunting.
[tweetmeme only_single=false service=”wp.me” source=”allinthegutter”]
Just a quick heads up to advertise a great project run by Greenwich Royal Observatory. The astronomy photographer of the year competition invites members of the public to submit their images of the night sky.
This year they are asking guest astronomers to curate flicker galleries of their favourite entries and have asked me to take part this month. You can find my gallery and links to the flicker pool at here. I cant heap enough praise on the entries, pretty much all of the images are simply stunning and it was a hard job to pick just 18!
oops forgot to include the link
So this morning I head out to a field in Chilbolton to help build the UK node of the LOFAR radio telescope. Today we will be helping lay cabling for the scope and you can, if my iphone battery holds out and signal at the site is good, follow the effort on twitter @allinthegutter. I will have a blog post in the next few days about it as well.
Wish me luck
Happy birthday Hubble ! Thank you for many years of stunning views of the Universe.
I have to say Emma pretty much took the best image Hubble has ever taken as her favorite. Its a hard act to beat ! I am however very partial to this series of images taken by Hubble over the years.
As the glorious Hitchhikers Guide to the galaxy tells us “Space… is big. Really big. You just won’t believe how vastly hugely mindbogglingly big it is. I mean you may think it’s a long way down the road to the chemist, but that’s just peanuts to space…”. A lot of things in space are big as well and that normally means that the time scales over which they change are very long. So long in fact that its often very hard to see things changing at all, the universe appears timeless. What I love about these images of the variable star V838 Monocerotis is that over only a few years we can see the image of the star changing.
The star at the center of this image underwent a catastrophic outburst. In a short period of time it became roughly 1 million times brighter than our sun, giving out a huge amount of light in the process. The light which came directly towards us arrived first but then gradually over the years, light heading away from the star in a shell, reflected off of surrounding gas and dust eventually heading towards the earth. As we let time go on the light illuminates different regions around the star.
Despite the fact that the images look like they are showing a concave bubble around the star its actually convex with the material which appears to the the side of the bubble closer to us actually being behind the star.
I just love seeing something in the sky evolve in this way! Thanks again Hubble !
Hey everyone… I know what your thinking, who is this Stuart person, I dont remember him. Well you would be forgiven for thinking that as I have not posted here for quite a long time.
Over the past 6-7 months I have been very busy finishing up my phd, applying for jobs, accepting a job, getting worried and weepy about leaving my beloved beautiful Edinburgh and finally shipping off to Oxford where I am now. Thankfully the job I have started at Oxford and the city itsself are much more engaging than I could have hoped for and as a plus, the pubs in Oxford are almost as good as those in Edinburgh.
So what am I doing? Well I have been very fortunate to have been hired to work on a project that I have been interested in for a long time now : Galaxy Zoo and the Zooniverse. These are citizen science projects which aim to get people involved in real science!
When you think about it, its strange, almost every intrest you have allows you to do something practical involving it. If you like food you can get involved in cooking for friends, if you like watching F1 you might not be able to make yourself a formula one car but you can take an interest in restoring your own car etc etc. Astronomy is a little different, as a result of the increased size and cost of the kinds of telescopes which probe the cutting edge of our understanding, most people who are not professional astronomers have become consumers of the science. Dont get me wrong there is a large community of amateur astronomers who can and do contribute in the hunt for supernove and binary stars, but the time, dedication and money required is more than I would personally be willing to devote!
The creation of these telescopes however has presented professional astronomers with a large problem. We are faced with a deluge of information from automated telescopes which scan huge tracks of, if not the entire sky, taking images of hundreds of thousands if not millions of objects. The problem will only get worse with telescopes like Pan-STARRS and the nightmarish LSST coming online in the next few years.
For some questions we want to ask of this torrent of data, computers give us the answer. Dutifully trudging through repetitive tasks like measuring the brightness or position of objects, is a task which our silicone chums are perfectly suited to. However some tasks such as the precise shape of a galaxy, or how unusual a galaxy is, is a much harder question for a computer to answer. Humans however are ideal at this kind of task. I will show you what I mean, which one of these is a spiral galaxy and which is an elliptical
its pretty obvious right, even without training, without knowing what a spiral or elliptical galaxy actually is, you can instantly pick one our from the other. Isnt your brain awesome !
So how do we utilize the millions of brains out there, idling away thinking about puppies or candy-floss or penguins or candy-floss penguins or what it would be like if we could make a pengin puppy hybrid (which would be called a pupegin obviously) and if that would be the cutest sight in the world… the intrinsic cuteness of a puppy with the mass huddling instinct of penguins, to make a massive quivering stack of furry awwwwwww….. see in the few seconds it took you to read that (and the subsequent minute worrying about the mental health of the author) your brain could have been put to a higher good classifying galaxies. What we need is some system where by humans can donate their free thought cycles to doing the tasks that computers struggle with.
The internet is great at this kind of thing, people already donate their free brain cycles to kittens with bad grammer, annoying facebook games and arguing about what is better: puppies or penguins (penguins obviously). So why not some real science? The galaxy zoo and related projects seek to do just that, if you are board or are just trying to avoid work, you can sign on and help find supernove, classify galaxies, detect solar storms and help us figure out how galaxies smash together .
This is really really useful data which is thoroughly welcomed by real scientists who use it to make real discoveries. I am aware this post is getting pretty long so let me leave it just now and talk about some of the really great science the team have done with the project so far and what the future will bring in two follow up posts. Until then stop “browsing” the interent and start doing our work for us !
[tweetmeme only_single=false service=”wp.me” source=”allinthegutter”]
As stunning as an eclipse is to see from the Earth it’s not the only vantage point we have on the event. Having sent probes in to space now for a number of years we can look back on the Earth to witness this event from the outside in. During the last major eclipse astronauts on board the ISS turned their cameras back to the earth and recorded these frankly terrifying images:
You can clearly see the ominous shadow that the Moon is casting on the Earth. In the center of that dark spot many onlookers are experiencing a total eclipse while around the periphery where the shadow is not so deep will be a partial eclipse. This shadow slowly makes its way across the face of the Earth. It’s a stunning and largely foreign perspective on an already amazing event.
As Emma discussed last post we are pretty much just lucky that the Sun and Moon appear to be the same size in the sky but one place in the Solar system in which this is obviously not the case is our own Moon. On the Moon the Earth appears in the sky much as the Moon does in ours and can on occasion eclipse the sun as well. Solar eclipses on the Moon though are a little different form here on Earth, for a start the Earth moves across the sky much slower on the Moon: a lunar day is about as long as our month meaning the Earth moves across the sky roughly 29 times slower than the Moon moves in our skies. The Earth also appears much larger in the sky both of which mean that Eclipses on the Moon last much longer than ours.
We don’t just have to imagine what an eclipse on the moon would like: there have been two Solar eclipses observed from the Moon over the years, one by human eyes and one by robotic. The first was witnessed by the Apollo 12 crew on their way home from the moon and snapped this image:
The small slither of light still visible is filtering through the Earth’s atmosphere, where if you just squint you might be able to make out some details of clouds. This is something we are generally unaccustomed to seeing in an eclipse as the Moon has no atmosphere.
The second eclipse in which the shadow is cast by us was recorded in wonderful HD by the Japanese Kaguya probe which is currently orbiting the Moon. To check out the full HD video of the eclipse you can here.
It’s hopeful to think that with our return to the Moon that such sights might become much more common.
Join us tomorrow when Niall will be talking about what eclipses have meant to people down through the years.
[tweetmeme only_single=false service=”wp.me” source=”allinthegutter”]
Harbingers of death and destruction? A neat way to test how gravity works? A good opportunity to wear silly glasses and crowd around strange looking devices? Yes eclipses are all of these things and more… apart from the harbinger of death thing I just stuck that in there to scare you.
This week India will be treated to a spectacle which will see people flocking from around the world to witness. Taregna a small town in the Indian state of Bihar will be the epicenter for this event seeing the Sun completely covered by the moon. In honor of this event we here at weareallinthegutter have decided to have an eclipse week celebrating all astronomical based shadows.
To start with I want to talk about what eclipses are, how they occur and how we predict when the next one will be. At this point I feel like I have to make a confession: to a professional astronomer there is nothing more terrifying than being asked a question about what actually goes on in the sky. Ask most of us to point a constellation or why planets move the way they do and you will get an answer which will be right eventually, but to get there you will experience a lot of hand waving and muddled sentences. It turns out when you study objects many many times larger than our galaxy which contains all the stuff you normally see in the sky it’s not really that useful to know in depth details of the motion of our little rock and its closest buddies.
With that disclaimer out of the way lets get in to the heart of the matter: an eclipse is the mother of all shadows. When the sun and the moon happen to be located in the same place in the sky the light from the sun is blocked ether in part (a partial eclipse) or fully (a total eclipse) by the moon. To get an eclipse we need to have an alignment of the sun and moon and so their paths have to cross in the sky. The path of the sun across the sky is called the ecliptic: a line which passes through all the signs of the zodiac (and in no way determines how lucky you will be in love or business thank you very much!). So why don’t we get an eclipse every month? Every time there is a new moon the Sun and Moon are very close to each other, so why is it that the vast majority of new Moons dont have an accompanying eclipse? Well it turns out that the moon does not travel along the ecliptic like the Sun does but rather a line which is slightly inclined to the ecliptic by about 5 degrees or so. If they lay along the same line then eclipses would be much more regular but as it stands we get at max about 2 a year. This small inclination means that the Moon is normally a little way above or bellow the Sun. The only time we get an eclipse then is when a new moon happens to occur at the point where the path of the Sun and the Moon also cross. Following me cause I am not sure if I am at this point.
Ok so now things get complicated as the orientation of the tilt in the moons orbit also changes over time. The Sun’s gravity pulls on the moon a little bit in its orbit and the orbit changing its orientation. Its sort of like what a penny does at the end of a good spin. As it slows down it does that little funny dance where the way the face of the penny is pointing moves around. The technical word it precession but that’s not too important, what is important is that it changes the two points at which the moon’s path crosses the ecliptic and so affects when we can have an eclipse.
The third and final effect is that the moon’s orbit is not completely circular but rather elliptical which means that at some points in its orbit the moon is further from the earth than at others and so will appear smaller in the sky. Obviously this has an affect on the type of eclipse we could see. If the moon is just about the right distance from us it fully covers the sun giving a total eclipse but if it is that little further away from us then it leaves a small ring of light around the outside of the Sun which we call an annular eclipse. Simple right? Only the point on its orbit when the moon is the furthest from us also changes with time which we also have to factor into our model.
So for a total eclipse like the one this week we need to have three different cycles all matching up at the same time, we need it to be a new moon, we need that new moon to occur when the paths of the Sun and the Moon are crossing and we need the Moon to be at the right point on its orbit so that its not too far away from us. You begin to understand why events such as this are so rare and attract such large crowds
Given the fact that there are three cycles involved which after different periods of time which eventually repeat, it is interesting to ask if the pattern of eclipses also repeats. Well we have three cycles to consider: the times between new Moons which is roughly every 29.53 days, the time between the moon passing the same point on the ecliptic which happens every 27.21 days and finally the time between the the moon being at the same distance from the earth must be the same which happens every 27.55 days. To get an identical eclipse we have to have a length of time in which a whole number of each of these periods will fit. It turns out that happens only after 18.031 years which is known as a Saros cycle. This basically means that 18.031 years after this weeks eclipse another eclipse will happen which looks pretty much identical in the sky. The only difference will be that it will be visible from a different part of the Earth. In fact it has been estimated that it takes 370 years for an eclipse to occur at the same place on Earth.
As you can imagine this makes the event in Taregna all the more special for its residents as it is truly a once in many lifetimes event which they are witnessing. I for one wish I was there to see it.
Phew ok I think I got through most of that. If any of it is still unclear (which I am sure it is) the best procedure to find out more is to find your local amateur astronomy society, find out which pub they frequent, go there on a Friday night buy a round and casually bring up the topic of eclipses. In no time at all beer glasses, salt shakers and beer mats will be transformed in to a mini solar system to help you visualise what is going on. By the end of the night you will ether be an expert on eclipses or be so drunk that you don’t really care any more so its win win really.
Join us tomorrow when Emma will be talking more about why eclipses look the way they do and why Earth is lucky to have total eclipses at all.