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Getting the lowdown on LOFAR

Published Wednesday, 9 June, 2010 astronomy 1 Comment
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Me standing next to one of the LOFAR antennas. Credit: WillGater.com

Today Sky at Night Magazine’s editor Graham, and I, visited the Chilbolton Observatory in Hampshire to see the UK’s contribution to the LOFAR project now entering its final stages of construction. LOFAR (the LOw Frequency ARray) is a radio telescope which will observe the Universe at wavelengths between 1.2 and 30 metres. It’s going to work by combining the observations of several separate arrays of antennas across Europe, a process known as interferometry, to create one enormous ‘virtual’ radio telescope.

Work will soon be completed on the low-band array at Chilbolton, which is what we saw being built today. As you can see from this panorama I made (click the image below for a bigger version) there are quite a few antennas already in place; they’re the brown metal lattices with vertical poles on them. There’ll be another array (the high-band array) constructed on a similar plot, right next to the low-band array, very soon.

A panorama of the LOFAR UK low-band array under construction. Credit: WillGater.com

LOFAR will create high-resolution views of the radio sky and will study, amongst other things, transient objects (such as black holes gorging on matter and supernovae) and what the Universe was like when it was just 400 million years old (the time when the first stars were born). There’s a much more in-depth run down on what the project will be studying on the LOFAR site here.

Whilst the individual antennas themselves may seem relatively simple, the science they’ll produce when the whole project comes online promises to be hugely impressive. I can’t wait to see the first results!

To keep up with developments at the Chilbolton site be sure to read the excellent LOFAR UK blog here.

A murky moonrise (and why it appears red)

Published Friday, 28 May, 2010 astronomy Leave a Comment
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Moonrise over Bristol 27 May 2010. [Click for full size] Credit: Will Gater

Last night there was a lovely moonrise (image above) over Bristol. The conditions were relatively good for viewing it too, as there was only a small amount of low-level haze and not too much cloud around.

It appears that wonderful orange/red colour because, when the Moon is low, it is shining through more of the Earth’s atmosphere. The gases in our atmosphere are particularly good at scattering blue light (which is why our sunny skies are blue). This means that, as the light from the Moon travels through a thick slice of the atmosphere, the bluer wavelengths of light are essentially ‘filtered’ out. The end result…predominantly redder light reaching us watching on the ground and so we see a gorgeous red/orange Moon.

You’ll also notice that the effect gradually wears off as the Moon rises, with the Moon becoming less and less red the higher in the sky it climbs. That’s simply because the amount of the atmosphere that the light is travelling through, with respect to us observing on the ground, gets smaller. So as the amount of atmosphere that the moonlight has to pass through to get to our eyes reduces, there’s less ‘filtering’ of the bluer wavelengths. Here’s a short time-lapse I made of the Moon as it rose above the horizon last night:


Credit: Will Gater

Radio 4 takes a shine to noctilucent clouds

Published Tuesday, 18 May, 2010 astronomy Leave a Comment
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A stunning noctilucent cloud display seen in the summer of 2009. Credit: Will Gater

It’s approaching that time of year when the skies of the northern hemisphere are graced by an ethereal phenomenon known as noctilucent clouds (or NLCs). These high altitude clouds of ice crystals shine long after the Sun has set and are visible from latitudes of around 50 to 60 degrees north during the summer months. They are beautiful to look at, glowing a bright blue/white colour against the reds and oranges of the twilight. We had some wonderful displays last summer and I’m hoping that this year they’ll put on a good show too.

Late last year BBC Radio 4 announced that they would be holding a new competition ‘So You Want To Be A Scientist?’ to find the BBC’s Amateur Scientist of the Year. People from around the UK submitted their ideas for scientific experiments they’d like to carry out, with the four best now being put into practice with the assistance of professional scientists. The finalists will be judged later this year at the British Science Festival to see who wins the coveted title.

I mention this because one of the finalists, aerial photographer John Rowlands, will be studying noctilucent clouds for his experiment, with the help of Professor Nick Mitchell from the University of Bath. You can read (and hear) more about John’s idea and the science behind noctilucent clouds on the Radio 4 website here. There’s also a Facebook page where John and the Radio 4 team are keeping everyone up-to-date with how the project is progressing. It should be a really interesting experiment to follow over the next few months, not least because the subjects of the study are so fun to look at and photograph.

The Gadget Show looks to the stars

Published Sunday, 9 May, 2010 astronomy Leave a Comment
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Just a very quick post to say that, for anyone in the UK, I’ll be on Channel Five’s The Gadget Show tomorrow night (Monday 10th May) talking telescopes with presenter Jon Bentley. The programme starts at 8pm but I don’t know what time the section we filmed will be shown. The show has over 2.5 million viewers, so I’m hoping that there’ll be loads of people whose interest has been sufficiently piqued to find out what this astronomy lark is all about!

Update 11.05.10: The section of the show where we looked at telescopes is now online on The Gadget Show’s website here.

New article – “Enceladus: water world”

Published Saturday, 24 April, 2010 astronomy 1 Comment
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Enceladus as seen by Cassini. Credit: NASA/JPL/Space Science Institute

Saturn’s moon Enceladus is a mysterious world. Measuring just 512km in diameter it should be a cold lifeless body, practically unchanged since its formation. Yet it isn’t. It’s very much alive. NASA’s Cassini spacecraft has shown that this remarkable moon’s surface has, in parts, been smoothed and altered in the geologically recent past. Images sent back by the probe show great fissures on its surface and, most spectacularly, vast plumes of icy material erupting from its southern hemisphere.

Now scientists studying Enceladus have come to some fascinating conclusions about what could lie beneath its icy crust. In a new article for Sky at Night Magazine I talk to the scientists working on the data from Cassini. I explore their findings which, incredibly, seem to point to a liquid ocean of water under the ice at Enceladus. The article also discusses the various mechanisms which could be creating the plumes. You can read the full story, “Enceladus: water world”, starting on page 68 of the May issue.

Hubble IMAX 3D at the Science Museum, London

Published Friday, 9 April, 2010 astronomy Leave a Comment
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Whilst visiting London on Thursday I popped into the Science Museum to see the new IMAX film Hubble 3D. After buying my ticket I wandered amongst throngs of people looking at everything from the Apollo 10 Command Module to Stephenson’s Rocket. It was good to see the place heaving with people, hopefully learning about science and clearly having fun. I thought their presence even more remarkable considering it was a glorious sunny day outside! Great, I thought, these people clearly want to be here.

Yet I did wonder to myself whether any of them were a) interested in astronomy and b) sufficiently interested to buy a ticket to see a movie that is essentially about a telescope. Is Hubble really so well-known that it might draw crowds to the box office? Or has its magic only rubbed off on those of us who live and breathe astronomy, I thought? The answer came a little over half an hour before the film was supposed to start.

I had just passed the Apollo 10 command module when I looked to where the IMAX cinema entrance was. Snaking away from it was a rapidly growing line of perhaps fifty people or more. It was the queue for the Hubble IMAX show. Not wanting to miss the chance of a good seat I jumped in line. And still more and more people joined the queue until it had stretched right around the corner out of sight. Before long we were let in and the film started.

So what was it like? Well, frankly, it was stunning – visually, aurally, emotionally. Epic is the word that actually came to my mind as the lights came up.

When writing about science I’ve learnt it’s great if you can capture some essence of the character of a scientist or their own personal story and weave it in and around the hard facts and discoveries you’re trying to discuss. Sometimes that can be difficult, sometimes it comes easily. What struck me about this film is how naturally Hubble’s ‘personality’ leaps out of the screen. It’s every bit as arresting as the 3D effects, even to a hardened space nut like me.

There are some beautiful pieces of CGI which I’ll let you discover for yourselves. Though I shall say that there’s one zoom onto the Orion Nebula that, for me, was worth the ticket price alone. There are also some wonderful scenes which superbly convey why Hubble’s multi-wavelength observing capability makes it such a powerful instrument.

I tried to write down a few notes as I was watching. But in the darkness they just became random scrawled words. One simply says “Launch!!!!”. I’ll admit I had a tear in my eye at that point. It’s an incredible moment of cinematography coupled with a chest rattling crackle like nothing I’ve ever heard.

Do go and see the film if you get a chance. It’s running at the Science Museum until 28 May from what I can tell. I really don’t think you’ll be disappointed.

Hubble image credit: NASA/ESA

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