How many stars are there in the sky? People living in Brighton can probably count fewer stars than those living a few miles north.
A university scientist is, though, urging people to count how many stars they can see.
Dr Darren Baskill, the physics and astronomy outreach officer at Sussex University, in Falmer, wants as many people as possible to join in with the Orion Star-Count Week this week.
The Orion Star-Count Week started on Monday and is a joint initiative organised by the Campaign to Protect Rural England and the Campaign for Dark Skies.
The Campaign for Dark Skies is run by the British Astronomical Association and aims to cut light pollution in the night skies.
The count ends of Sunday (6 February).
Dr Baskill said: “A star count is a great excuse to go outside and enjoy the beautiful view of the night sky.
“But it also provides a way of assessing where the best places are to view the sky at night.”
He said that the star count involved going outdoors one night this week between 6pm and midnight and, when clear skies permitted, counting the number of stars in a particular part of the night sky.
In this case people are being asked to tally all the stars that can be seen within the four corner stars of the constellation of Orion.
Instructions on how to locate Orion, and what to do after counting the stars that can be seen with the naked eye, can be found on the Campaign for Dark Skies at www.britastro.org/dark-skies/starcount.
Dr Baskill said: “From the information provided we’ll be able to build a map of where the best places are to go star-gazing in the UK.
“Over the last 50 years, we have lost the once awe-inspiring view of a night sky full of stars simply due to excessive and inefficient lighting.
“Something that has inspired science and art for millennia is now unknown to the majority of us.
“I find that incredibly sad.
“The campaign is aiming to raise awareness of the problems caused by wasted lighting spilling into the night sky.
“Not only does such lighting prevent us from seeing a sky full of stars, but it also costs the UK an estimated £1 billion in wasted energy.
“Excessive and inefficient lighting also has a major impact on public health and well-being and on wildlife.”
Light pollution causes problems for astronomers too.
Dr Baskill had to travel to Hawaii last year to use Britain’s infrared telescope.
He said: “One reason that we have to place our telescopes in such remote areas is to get away from intrusive light pollution in the UK.”
A similar survey in 2006-07 showed that only 2 per cent of people who responded could see more than 30 stars compared with 54 per cent who saw fewer than ten stars in Orion.
The results indicated severe light pollution.
The physics and astronomy department at Sussex is ranked 5th in Great Britain and 37th in the world, according to the Times Higher Education World University Rankings (2010).