Astronomers shed light on mystery of 'dark matter'

British astronomers have come a step closer to understanding one of the most mysterious substances in the universe - the "dark matter" which acts as a kind of cosmic glue, holding galaxies together.

New research into dark matter, believed to make up 23 per cent of the cosmos compared to the 4 per cent of "normal matter" that can be seen and felt, has for the first time pinned down its behaviour and properties, which are essential to anchoring an ordered universe.

Scientists assumed the existence of dark matter in the 1930s after "weighing" galaxies and finding that the sum of each galaxy's parts was much less than its total mass.

They have speculated ever since on what the "missing mass" might be. A team led by Professor Gerry Gilmore from Cambridge University's Institute of Astronomy began the latest experiment three years ago in northern Chile's spectacular Atacama desert - a place with "no birds, no animals, just sad little astronomers", he said.

Using the Very Large Telescope, the real name for an array of interconnected 26ft-wide telescopes, to look at a dozen "dwarf" galaxies that hang on to the coat-tails of our own galaxy, the Milky Way, the astronomers claim to have achieved astonishing results.

"We've got the first clue as to what dark matter is," Professor Gilmore. "Which is that you only find this stuff in big, magical, rather dilute lumps, about 1,000 light years across, 40 million times the mass of the Sun." However, he admitted: "We don't know how to interpret this clue yet."

Dark matter does not give off any light, hence its name. Scientists had always assumed that because it couldn't be seen it was "cold" - a sort of dead, sluggish cosmic sludge. But there were two further unexpected findings from the Cambridge research. The first showed that dark matter actually has a "temperature" higher than that of the surface of the Sun.

If it was made of hydrogen atoms, dark matter would be 10,000C and appear as a blinding light. Yet, confusingly, it does not give off any heat.

The second surprise was that particles of dark matter zip about at 9km per second and are loosely packed.

They are transparent to light, and unlike most particles of ordinary matter, have no electric charge. But they are weighty enough to exert a gravitational pull that prevents the stars in galaxies from flying apart.

A paper on the research is in the final drafting stage and should appear in a scientific journal soon.

It is not time for astrophysicists to relax quite yet, however. Once the question of dark matter is resolved, there is the question of the remaining 73 per cent of the cosmos - made up of something even more mysterious called dark energy, which is forcing galaxies apart at increasing speed.

"It's fair to say there is more work to do," said Professor Gilmore.

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksA special investigation by Andy McSmith
  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Photographer / Floorplanner / Domestic Energy Assessor

£16000 - £25000 per annum: Recruitment Genius: A Photographer/ Floor planner /...

Ashdown Group: Front-End Developer - Surrey - £40,000

£30000 - £40000 per annum: Ashdown Group: Front-End Developer - Guildford/Craw...

Recruitment Genius: Customer Service Assistant

£13500 - £15000 per annum: Recruitment Genius: A Customer Service Assistant is...

Recruitment Genius: Sales Executive - OTE £35,000

£16000 - £35000 per annum: Recruitment Genius: An ambitious and motivated Sale...

Day In a Page

Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

How a costume drama became a Sunday night staple
Miliband promises no stamp duty for first-time buyers as he pushes Tories on housing

Miliband promises no stamp duty for first-time buyers

Labour leader pushes Tories on housing
Aviation history is littered with grand failures - from the the Bristol Brabazon to Concorde - but what went wrong with the SuperJumbo?

Aviation history is littered with grand failures

But what went wrong with the SuperJumbo?
Fear of Putin, Islamists and immigration is giving rise to a new generation of Soviet-style 'iron curtains' right across Europe

Fortress Europe?

Fear of Putin, Islamists and immigration is giving rise to a new generation of 'iron curtains'
Never mind what you're wearing, it's what you're reclining on

Never mind what you're wearing

It's what you're reclining on that matters
General Election 2015: Chuka Umunna on the benefits of immigration, humility – and his leader Ed Miliband

Chuka Umunna: A virus of racism runs through Ukip

The shadow business secretary on the benefits of immigration, humility – and his leader Ed Miliband
Yemen crisis: This exotic war will soon become Europe's problem

Yemen's exotic war will soon affect Europe

Terrorism and boatloads of desperate migrants will be the outcome of the Saudi air campaign, says Patrick Cockburn
Marginal Streets project aims to document voters in the run-up to the General Election

Marginal Streets project documents voters

Independent photographers Joseph Fox and Orlando Gili are uploading two portraits of constituents to their website for each day of the campaign
Game of Thrones: Visit the real-life kingdom of Westeros to see where violent history ends and telly tourism begins

The real-life kingdom of Westeros

Is there something a little uncomfortable about Game of Thrones shooting in Northern Ireland?
How to survive a social-media mauling, by the tough women of Twitter

How to survive a Twitter mauling

Mary Beard, Caroline Criado-Perez, Louise Mensch, Bunny La Roche and Courtney Barrasford reveal how to trounce the trolls
Gallipoli centenary: At dawn, the young remember the young who perished in one of the First World War's bloodiest battles

At dawn, the young remember the young

A century ago, soldiers of the Empire – many no more than boys – spilt on to Gallipoli’s beaches. On this 100th Anzac Day, there are personal, poetic tributes to their sacrifice
Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves

Follow the money as never before

Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves, reports Rupert Cornwell
Samuel West interview: The actor and director on austerity, unionisation, and not mentioning his famous parents

Samuel West interview

The actor and director on austerity, unionisation, and not mentioning his famous parents
General Election 2015: Imagine if the leading political parties were fashion labels

Imagine if the leading political parties were fashion labels

Fashion editor, Alexander Fury, on what the leaders' appearances tell us about them
Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

The architect of the HeForShe movement and head of UN Women on the world's failure to combat domestic violence