The littleBits Exoplanet Detector: A NAM 2014 Hack Day Project

June 26, 2014 — 1 Comment

Yesterday was the Hack Day at the UK National Astronomy Meeting 2014 in Portsmouth. I organised it with my good friend Arfon Smith of GitHub, formerly Zooniverse. We wanted to try and start a new NAM tradition – it went well so maybe we did. I’m psyched that .Astronomy got to help make it happen – not just through my involvement, but the many .Astronomy alumni who attended!
Some of the hack projects have already started to appear online, such as Geert Barentsen, Jeremy Harwood, and Leigh Smith (Hertfordshire) who created a Martian Nyan Cat, which is planning to fly over the entirety of ESA’s Mars Express data archive in one continuous, two-day-long, flight. You also grab the code for Duncan Forgan’s beautiful ‘Music of the Spheres’ project, which sonifies the rhythms of planetary systems. Other projects are harder to place online, such as Jane Greaves’ knitted galaxy cluster – with dark matter contributed by many people during the hack day itself.

I spent much of the day working with Edward Gomez (LCOGT) on the littleBits Space Kit. littleBits is a modular system of circuits that let anyone try their hand at something that ordinarily requires a soldering iron. littleBits components may be switches, sensors, servos, or anything really, and they connect magnetically to create deceptively simple circuits that can be quite powerful.

IMG_2359

For example you could connect an infrared sensor and an LED to make a device that flashes when you press buttons on your remote. Or you could use a microphone and a digital LCD display to create a sound meter. The littleBits components are sturdy enough to withstand being bashed about a bit, and simple, and large enough, to let you stick on cardboard, homemade figures, or anything else you find around the house. I found out about littleBits when I met their creator, Aya Bdier at TED in March. She is a fellow TED Fellow.

We decided fairly quickly to try and built an exoplanet simulator of some sort and ended up crating the littleBits Exoplanet Detector (and cup orrery). There were two parts to this: a cup-based orrery, and a transit detector.

The cup orrery consisted of a rotating ‘planetary system’ fashioned from a coffee cup mounted on a simple motor component – we only had hack day supplies to play with – and a central LED ‘star’. Some more cups and stirrers were required to scaffold the system into a stable state but it was soon working.

The transit detector used a light-sensor component that read out to both a speaker and a LCD numerical display – Ed refers to this as the laser display board. With a bit of shielding from the buffet’s handy, black, plastic plates the light sensor can easily pick up the LED and you can see the light intensity readout varying as the the paper planet passes in front of the star. It was awesome. We got very excited when it actually worked!

You might think that was geeky enough, but it gets better. I realised I could use my iPhone 5s – which has a high-frame-rate video mode – to record the model working in slow motion and allow us to better see the digital readout. We also realised that the littleBits speaker component can accept an audio jack and so could use the phone to feed in a pure tone, which made it much easier to hear the pulsing dips of the transits.

Finally, we had the idea to record this nice, tonal sound output from the detector and create waveforms to see if we could recover any properties about the exoplanets. And sure enough: we can! We built several different coffee-cup planetary systems (including a big planet, small planet, and twin planets) and their different properties are visible in their waveforms. Ed is planning a more rigorous exploration of this at a later date, but you can see and hear the large cup planet’s waveform below.

Waveform for Large Cup Planet

Waveform for Large Cup Planet

So if you want to try something like this, you only need the littleBits Space Kit. You can buy them online and I’d love to see more of these kits, and to see them in schools. I’m now totally addicted to the idea myself too!

GitHub Stickers

Thanks to Arfon for suggesting that we do this Hack Day together; to the NAM 2014 Portsmouth team for being so supportive; and to GitHub for sponsoring it – where else would we have gotten all the cups?!

Trackbacks and Pingbacks:

  1. Research data, citation and software repositories for the savvy astronomer. | chasing telescopes - July 9, 2014

    […] good example of this was the  recent UKs National Astronomy Meeting (NAM2014) hackday. Rob Simpon wrote about this on his blog, Orbiting Frog.  My advice – go and put the kettle on, make yourself a cuppa […]

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