By Matthew Cobb
I have been spending quite some time recently helping scientists study the spiders of Mars. Not Ziggy Stardust’s band, nor, sadly, actual spiders, but strange geological formations in the Martian Antarctic.
And above all these:
Over at planetfour.org they have put millions of these images on line, obtained from the HiRISE (High Resolution Imageing Science Experiment) camera aboard the Mars Reconnaissance Orbiter, which has been mapping the surface of Mars with a 0.3 metre resolution. That means each of those pictures is about the size of two football pitches (of whatever kind – soccer, American or rubgy).
The planetfour folk are using the power of the crowd to scan those photos in a way that computers could not do, and to track the patterns of the blotches and fans you can see in the third image, plus anything else weird and wonderful, like you can see in the first two. As I write, nearly 50,000 people have been involved since the sit went live less than a week ago, and over 2 million images have been classified.
In the winter, the icy surface of the Martian Antarctic is covered with ‘spiders’, strange wiggly channels. As the Martian spring begins, the CO2 ice over the ‘spider’ melts, and the area becomes peppered with strange dark fans and blotches. This picture shows a timelapse sequence of a spider that was initially covered with a 1 metre of CO2 ice (top left) to ice-free (lower right):
Here’s an image of some fans in the northern polar region, with useful scale bar (taken from Portyankina et al, in press).
Sometimes there can be loads of fans in a given area (in fact, that’s what you can see in the first image at the top of the page – the “quilted”, brain-like appearance is an illusion, as your brain interprets a 2-D structure in 3-D).
The team think that the fans are produced by the sudden eruption of geysers of gas bursting through the melting CO2 ice, bringing with it all sorts of debris. That’s why the fans have a clear point of origin. The wind blows the debris, which explains why in many images the fans are pointing in the same direction. If there isn’t any wind, then you get a blotch.
Here’s a series of images from the website illustrating what they think is happening.
Here’s a dramatic artist’s impression of what happens when the geysers erupt (you wouldn’t want to be wandering about on Mars when this was happening):
An Artist’s conception of sediment-laden jets that shoot into the polar sky from the south polar ice cap as southern spring begins. CREDIT: Ron Miller/Arizona State University
Here’s an image from planetfour.org which some of the people on the site think is a geyser erupting:
[EDIT: It turns out the sun is coming from the bottom right, so this is a crater, not a dome. As one of the scientists has said in a blog discussion: “sun comes from the low-low right, therefore we believe this is a negative feature (crater-like). don’t understand it yet,definit. weird”]
What the PlanetFour folk want us to do is to classify the features on these millions of images, using one of three tools (‘fan’, ‘blotch’ or ‘interesting’). Here’s a screenshot, showing a picture of massive fans on the icy surface that they just asked me to classify, along with the simple tool interface on the left.
The outcome of all this will be an accurate measure of the climate on this southern region on Mars, and an idea of how these weird formations occur during the year.
PlanetFour is just one example of the crowd-sourcing being carried out by Zooniverse – if you go to their website you can help in all sorts of project.
Finally, a lot of the impetus for the support for this came from the site’s appearance on the excellent BBC TV programme “Stargazing Live”, which went out on three successive nights on BBC2 last week from the Jodrell Bank raidio telescope at the University of Manchester, and fronted by comedian and Physics/Maths graduate Dara O Briain and by my colleague from the University of Manchester, Professor Brian Cox (I could be spotted in the audience on the first night…). Those of you in the UK can watch again on the BBC iPlayer by clicking on the link above. Episodes from previous years can be found on YouTube.
Anyway, you should all go over to planetfour.org, sign up, classify some images and DO SOME SCIENCE!
You can find out more about Martian spiders here.
Ganna Portyankinaa, Antoine Pommerola, Klaus-Michael Ayea, Candice J. Hansenb, Nicolas Thomasa (In Press) Observations of the northern seasonal polar cap on Mars II: HiRISE photometric analysis of evolution of northern polar dunes in spring. Icarus.
16 thoughts on “Spend some time with the spiders of Mars and help science!”
I’m exploring Mars! I saw this on Stargazing live, I thought I would be waiting until monday for my maths exam to finish. I can sacrifice a few hours of revision for this. This is so much more exciting than Xbox.
I saw this on Stargazing Live as well (I am in the lucky position of being able to watch the Beeb from the continent), and stumbled upon the show. I immediately went looking for my old telescope I had as a kid and went out looking at stars. I am planning to follow their/your advice and spend some time looking at Mars pictures later tonight, when my toddler (aka the diapered tyrant) is in bed.
Incidentally, does anybody know any good stargazing/astronomy apps they would recommend?
Oh, this pushes a major button for me. For ipad and iphone the ‘Redshift’ app is very good. Once it is set up by your longitude and latitude you hold the device in front of you against the sky and it shows what objects are directly in front of you. As you turn, the map turns with you, and you can zoom in with the ‘pinch’ controls. There are similar apps to this one. Other smart phones and data tablets probably have similar things. Also the web site for Sky and Telescope magazine includes a tool called the Interactive Sky Chart which also shows a ‘live’ star chart with objects labelled. This resource is totally free.
Finally, another favorite which I frequently visit is SkyWatch which shows you when to look up to see the International Space Station going over your location. If you have not seen that it is a MUST for everyone. Totally cool. The station is easily as bright as venus.
A good evening object to see now is Jupiter. Easy to spot, and very pretty even with binoculars.
Wonderful stuff! Does the “Spiders” phenomenon happen in the Martian arctic just the same?
Yes, it appears so. The middle picture is from the Arctic, and the article in the references is on the northern pole.
Liquid water on Mars!
Just tell the Republicans that those are oil geysers. We’ll have men on Mars by the end of the year.
Well if it *were* oil, I’d be first in the queue – it would definitely mean that there had been life there!
Thx Brian! I’m such a zooniverse freak! Lol. I’ve been classifying the fans and blotches for a few days. Fascinating stuff!!!
There’s a strong possibility that we will soon be able to observe a similar phenomenon on earth. The melting of permafrost releasing vast amounts of methane gas into the active layer beneath a frozen ground surface? A build up of sub surface gas pressure creating similar vents during the summer melt season?
|Its a shame that republicans don’t realise that we all live on the same planet. And extremely ironic that the human race will probably be wiped out by the American public’s desire for cheap gas.
I did galaxy classification for these guys a while back when I was a lady of leisure, it was great fun and helped provide a more accurate perspective on the size of the universe. They’re very good at making this sort of thing doable for the average person.
Interesting stuff I never heard about before. One comment, though–shouldn’t the article be saying that the carbon dioxide ice is subliming, rather than melting?
Yes you’re right.
Very nice, but I still don’t want to go there for my holidays.
Sensational images there. I can easily see hours disappearing investigating those sites to the extent they deserve.
I can’t resist – not all football pitches are rectangular. We play on ovals down here!