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The e-MERLIN Roadtrip

On a sunny day day in August 2010, some of the Jodcast team embarked on an epic mission to visit all seven of the telescopes in the e-MERLIN array in a day. This video documents their caffeine-fuelled journey!

To follow the progress of the roadtrip crew as they posted live videos during the e-MERLIN expedition, see the Jodcast YouTube channel (the videos are labelled as parts 1-6).

Please note that no-one is allowed onto the sites of the e-MERLIN telescopes outside of Jodrell Bank without the express permission of the University of Manchester.

This video was created by SEE TV for The Jodcast.


Jen (): Well it's quarter past six in the morning, and we're here at the Jodrell Bank Centre for Astrophysics ready to go on our e-MERLIN trip. Google Maps says it's going to take nine-and-a-half hours, so I guess we'd better get going.

Jen (): It's about ten past eight in the morning, and we've stopped here at the Blyth Services on the A1(M). We've come across the Peak District and apparently we've still got 180 kilometres to go.

Jen (): The e-MERLIN network of telescopes has its origins back in the 1970s. At the time, the telescopes at Jodrell Bank were being linked up with what was the Mark III at Wardle, which doesn't exist anymore, and the Defford telescope, which we'll see later. And that formed an interferometer going pretty much from north to south - which is good, but not ideal, because you want to have telescopes spread out all around, not just going in one line. So they came up with an idea to add more telescopes going east to west and build a Multi-Telescope Radio-Linked Interferometer, or the MTRLI - which is a bit of mouthful, so it quickly got renamed to MERLIN. Money for this was given in 1975, and the first images were made in December 1980; at the time there were six telescopes linked into this network. The original MERLIN network only extended down to Defford, so the longest baseline was 134 kilometres. In 1990, the 32-metre telescope at Cambridge was added, extending the longest baseline down to 217 kilometres, and that's the telescope we're on our way to see now.

Jen (): It's 10:45 and we just arrived here in Cambridge, so let's go inside the telescope and have a look around.

Jen (): Now we're here inside the 32-metre telescope at Cambridge, and, as you can see from how bright it is from the sunglight, it's a very reflective surface. The waves come down, hit the dish, and then are reflected up to a secondary reflector, and then down into the receivers. The receivers' being in the centre means that it's a lot easier for engineers to access them when they need to change them or fix them.

Jen (): So we're now here inside the dish, and once the radio waves are reflected off the secondary reflector, they come in through here, and these are the three receivers that the telescope is currently operating. So here you can see, from the different sizes, the wavelengths of radio waves that are coming in. This is the 1.4-Gigahertz receiver; this is 5 Gigahertz; and the small one here is 22 Gigahertz.

Jen (): In the background here, you can see two of the dishes from the Cambridge One-Mile Telescope.

Jen (): So it's now quarter to one, and we've just finished having lunch. We're stopped off somewhere here - we're not quite sure where - and we're still on the way to Defford. We're about 100 miles away, so we should get there in about an hour and a half.

Jen (): Now as we said at the Cambridge site, the addition of the Cambridge telescope increased the longest baseline of MERLIN to 217 kilometres And we've been going on a lot about longest baselines, and the reason of that is because the longer the baseline the better the resolution of the telescope, so the finer the detail it can resolve. And adding the Cambridge telescope to MERLIN actually increased the resolution to be comparable to the Hubble Space Telescope.

Jen (): So it's five to four, and we've finally made it to Defford. We got to the village of Defford about an hour ago and we've been driving around. You can see the telescope but you can't get to it, so one of the MERLIN engineers actually had to come out and rescue us, and we followed him here. We're on an old airbase here, and the telescope - you can see it's quite different to the other telescopes in MERLIN - and it was actually a radar tracking system way back in the Cold War. It was turned into a telescope for astronomical reasons in 1965, and has been used with the Jodrell Bank telescope since about then.

Jen (): It's 6pm, so nearly 12 hours since we left Manchester, and we've still only managed to get to two of the seven MERLIN telescopes We're about half an hour away from Knockin, and Knockin was the first telescope that was purpose-built for the MERLIN array. It's of a similar design to the VLA antennas in Socorro in New Mexico, and it's also identical to the other two MERLIN telescopes at Darnhall and Pickmere.

Jen (): Knockin here was the first telescope to actually be purpose-built for the MERLIN array, and, prior to this, the land around here was actually an ammunition dump back in World War II.

Jen (): The Sun is setting: it's 8:30 in the evening and we finally made it to Darnhall. This is the fourth out of the seven telescopes, but the last two are in the same place so we've done a lot of the journey. There's not really much to say about this telescope - it's identical to Knockin - but we're only 18 kilometres away from Jodrell now, so it's quite a short baseline. Anyway, it's really cold so we're going to get on to Pickmere.

Stuart (): Quasar to Pulsar: come in, Pulsar; over.

Mark (): Yeah, Quasar, this is Pulsar, we copy you; over.

Stuart (): Pulsar, we were wondering: what's our ETA at Pickmere? Over.

Mark (): 12 more minutes, Quasar; over. 12 minutes.

Stuart (): Do you know what the ETA at Jodrell Bank is? Over.

Mike (): Late.

Mark (): Yeah, late, apparently; over.

Stuart (): Oh well. The Sun has gone down.

Jen (): So it's getting a bit late now - the Sun is setting - and we've got sick of Mike's sat-nav not taking us to the right places, so my car has rebelled against the sat-nav and we are actually following signs for Pickmere instead of driving past them, which is what Mike and co seem to be doing. Unfortunately this seems to be the extent of the walkie-talkie range, so we have no idea where they are or who's going to get there first. Let's see.

Jen (): Well it's nine o'clock and we've finally made it here to Pickmere, the last of the remote stations on our tour. The dish, again, is the same as Knockin and Darnhall - not much to say - we're 11 kilometres from Jodrell Bank now. The other team arrived here before us - we took different routes to Pickmere. So our final stop is going to be Jodrell Bank.

Jen (): Well we've made it to Jodrell Bank. The rest of the team are busy looking at stars, but behind me - behind the trees - is the Mark II telescope, and on the other side of the control building is the Lovell. And these two telescopes can be used in MERLIN to form the very short baseline that is sometimes needed in your observations. Let's go inside and have a look at the control room.

Jen (): It's 9:30 in the evening - it's been the longest day ever - but you can see the Lovell Telescope in the background. So this is the room where all the MERLIN telescopes are controlled from, and this is where all the signals from all those telescopes come back in and are received here at Jodrell Bank.

Show Credits

Roadtrip Crew:Jen Gupta, Libby Jones, Derek Leather, Stuart Lowe, Pete Martin, Mike Peel & Mark Purver
Presenter:Jen Gupta
Camera:Pete Martin
Sound:Derek Leather
Animation:Arek Tomaszewski & Dan Fox
Additional Post-production:Stuart Lowe & Tim O'Brien
Producer:Lee Ackerley
Executive Producers:Jen Gupta & Stuart Lowe
Special thanks to:Dave Clarke, Simon Garrington, Frank Manning & Alan Williams, University of Manchester; Wilfred Darlington & Kate Corbin, University of Salford
Website:Mark Purver & Stuart Lowe
Cover art:The e-MERLIN telescope at Darnhall. CREDIT: The Jodcast/Mark Purver

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