If you drive from Cambridge (UK) to Wimpole, you'll see some impressively large radio telescopes that belong to the Mullard Radio Astronomy Observatory (MRAO).

However, there's much more that's not visible from the road. Hidden behind the trees, MRAO has a prototype SKA-Low array (from before the full installation in Australia), and three dishes from a HERA prototype.

The MRAO itself has a fascinating history, notably including the discovery of the first pulsar by Jocelyn Bell using the wonderfully named Interplanetary Scintillation Array, which consisted of over four thousand dipole antennas spread across nine acres. In WWI the site was a mustard gas factory, with train station and sidings. The train tracks have long since gone, but the station building remains. Inside hangs a large, coloured but faded image titled "GALACTIC RADIO EMISSION AT 38 Mc/s". This appears to be a coloured visualisation based upon the black & white figure in pages 654-655 of a 1957 paper [0].

The above 1957 paper illustrates a survey of half the celestial sphere at 38 MHz. In comparison, this specific MeerKAT image from the article [1] appears to be a 1.28 GHz measurement focusing on the galactic center (6.5 square degrees) [2]. So it's not a 100% like-for-like comparison, but interesting nonetheless to see how much the detail has improved in the past ~70 years!

[0] https://adsabs.harvard.edu/pdf/1957MNRAS.117..652B ("RESULTS OF A SURVEY OF GALACTIC RADIATION AT 38 Mc/s")

[1] https://physicsworld.com/wp-content/uploads/2025/03/2025-02-...

[2] https://arxiv.org/pdf/2201.10541 ("The 1.28 GHz MeerKAT Galactic Center Mosaic")

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timthorn 2 hours ago | parent [-]

The MRAO is a fascinating place, with things left as they were the last time an instrument was used. The floor of the hut where the array cables were aggregated for connection to the cable back to the Cavendish is covered in little plastic caps from the connectors, discarded as the instrument was being set up.

The article talks about HERA; MRAO hosts the prototype for that. IIRC, they experimented with methods to build the dishes with off-the-shelf parts - such as drainpipes to build the ring.

	▲	metalman an hour ago \| parent [-]
		there is an antena farm on the way from the city to my place that I use as a reference land mark for new visitors, which I call "area 52", which also serves as a kind of personality test, where most will laugh and say they know where it is, but some few who are uncomfortable as it's a long wave sigint base, marked on all the flight maps, that they are clearly wishing not to have seen or looked at, be in a conversation referencing, and now marked for life grimly waiting for a knock on the door.