Jodrell Bank at risk... from lawnmowers: Observatory's experts say proposed housing estate two miles from the site will play havoc with their instruments 

It is Britain’s most famous observatory, searching for signals from outer space.

But now Jodrell Bank’s experts fear their place at the frontier of astrophysics could be jeopardised – by lawnmowers.

They say a proposed housing development less than two miles from the observatory will mean radio interference from household appliances playing havoc with their instruments.

Experts say a proposed housing development less than two miles from the Jodrell Bank observatory will mean radio interference from household appliances playing havoc with their instruments

Along with residents cutting the grass, the scientists say activities such as using power tools, microwaving meals and even doing laundry could produce sufficient electromagnetic radiation to drown out faint signals from beyond planet Earth.

The proposal for 119 new homes was initially rejected by Cheshire East Council, but the developers have now appealed.

While best-known for its popular visitor centre, Jodrell Bank – credited with the discovery of many of the first pulsars in the 1970s - is still at the cutting edge of science.

Currently its astronomers are engaged in projects including studying fluctuations in the cosmic microwave background in a bid to probe the earliest moments of the universe.

As a radio telescope, it is highly susceptible to levels of interference produced by electrical appliances – indeed the observatory was set up in rural Cheshire by scientists from Manchester University because the city’s trams proved too disruptive.

Jodrell Bank director Prof Simon Garrington said in a submission to the council: ‘Interference is correlated with human activity, whether due to intentional transmissions or unintentional leakage from a wide range of electrical and electronic devices.

‘The proposed development itself is likely to generate interference which exceeds the internationally agreed threshold for what constitutes “detrimental interference” to radio astronomy observations.’

Appliances with electric motors such as lawn mowers, hedge trimmers, power tools and washing machines are regarded as particularly problematic, while tiny amounts of radiation from microwave ovens can also drown out the scientists’ observations.

Associate director Prof Tim O’Brien said: ‘The electrical and electronic devices in houses can produce radio waves that basically mask our view of the distant universe.

‘This is one of the world’s most powerful and sensitive telescopes and these sort of signals are basically wiping out the data that we’re picking up. It’s already difficult for us, this is only going to make things worse.’

Jodrell Bank has already had to stop searching for new pulsars due to the existing level of interference, which it says has been proven to come from nearby houses, rather than cities such as Manchester.

Currently Jodrell Bank astronomers are engaged in projects including studying fluctuations in the cosmic microwave background in a bid to probe the earliest moments of the univers

The housing proposal, on a field outside the village of Goostrey, was last year rejected by Cheshire East council on the grounds it would ‘result in impairment to the efficiency of the Jodrell Bank Radio Telescope’.

Local resident Ken Morris added: ‘Cheshire East is a borough of a quarter of a million acres, so why build on this particular unique spot, damaging the telescope?

‘We do feel that building on this particular unique location is not the right and proper thing to do.’

However, the applicants, Gladman Developments, appealed, and this week a hearing began to determine whether it should go ahead.

Christopher Katkowski, representing the council, told the inquiry the protection of Jodrell Bank was ‘a matter of global significance’ because the telescope’s work is ‘internationally important’, the BBC reported.

But Gladman Developments argued that Jodrell Bank had failed to give details of the evidence it cites for the disruption.

It also pointed out that the village already has 950 properties and claimed there would therefore be no significant increase in radio interference.

In a statement to the council, the company said it would ‘consider any reasonable mitigation measures’ that would alleviate Jodrell Bank’s concerns.

The government planning inspector will make recommendations to Communities Secretary Greg Clark, who will make a final adjudication.

Scientists say radio signals from items such as wireless internet routers and cordless doorbells are less of a problem as they operate on agreed frequencies which astronomers can avoid.

By contrast, many electrical appliances create ‘chaotic’ radio interference while being operated, drowning out faint signals from outer space.