Science: Stars and Planets: March

OUR MILKY Way galaxy is populated not just with stars and planets made of ordinary matter, but with worlds made of a strange kind of "mirror matter" that we cannot see. This startling new theory links together experiments in particle physics and measurements of gravitational force in the Universe - and it suggests that aliens could be living much closer to us than we might suspect.

The starting point is evidence that our Galaxy has an unexpectedly strong gravitational pull - more powerful than we would expect from the visible stars and gas making up the Milky Way. It must contain some kind of "dark matter" that has a gravitational pull but is not obvious to any telescope.

Astronomers in Australia and Chile are on the track of this dark matter. They have found that the stars in a neighbouring galaxy, the Large Magellanic Cloud, sometimes seem to brighten unexpectedly. Most likely, their light is being focused by the gravity of objects in the outer part - the halo - of the Milky Way. These objects are called Machos - massive compact halo objects - and they weigh about half as much as the Sun.

Machos cannot be ordinary stars, because they don't emit any detectable amount of light. Most astronomers think that they are some kind of shrunken star - a white dwarf, a neutron star or a black hole. But Rabindra Mohapatra and Vigdor Teplitz, of the University of Maryland have a new idea, rooted in particle physics. There is now a lot of evidence that the light particles called neutrinos can change from one type into another. The results are best fitted if the neutrinos first change into a different kind of matter altogether - so-called "mirror matter" - and then back into another neutrino.

The mirror-world has a counterpart for each of the particles making up the Universe we see, such as the proton and the electron, but - the Maryland physicists calculate - the mirror-particle would weigh only one-twentieth as much. Whereas ordinary heavyweight stars in our Galaxy weigh about 10 times as much as the Sun, the heaviest "mirror stars" would weigh half of the Sun's mass.

Mohapatra and Teplitz realised that is just about the mass of the Machos in our Galaxy. Mirror-stars fit the bill for Machos in another way, too. They would not be visible, because they produce "mirror-light" that can't be detected with an ordinary telescope. .

Mohapatra believes that the mirror-stars could easily have mirror-planets and on these worlds life may have arisen. These aliens cannot see us, any more than we can see them.

What's up this month

Early March is a good time for Mercury-spotting. On March 3, it sets over an hour after sunset at about 7.30pm, before turning tail and plunging back sunwards by mid-month. Its fellow inner planet, Venus, is also visible in sunset skies, growing even brighter and setting three hours after the Sun.

Mars is beginning to put an appearance in our evening skies again, rising about 10pm mid-month. The stars now on view tell us that Spring is on the way. Replacing the winter constellations at centre-stage are the spring constellations of Cancer and Leo - the latter being one of the most ancient star-patterns of all, and one which really does resemble its namesake, the lion.

Heather Couper and

Arts and Entertainment
Emo rockers Fall Out Boy

music

Arts and Entertainment
Jamie Dornan as Christian Grey in Fifty Shades of Grey

film Sex scene trailer sees a shirtless Jamie Dornan turn up the heat

Arts and Entertainment

film

Arts and Entertainment
A sketch of Van Gogh has been discovered in the archives of Kunsthalle Bremen in Germany
arts + ents
Arts and Entertainment
Eleanor Catton has hit back after being accused of 'treachery' for criticising the government.
books
PROMOTED VIDEO
Arts and Entertainment
Taylor Swift is heading to Norwich for Radio 1's Big Weekend

music
Arts and Entertainment
Beer as folk: Vincent Franklin and Cyril Nri (centre) in ‘Cucumber’
tvReview: This slice of gay life in Manchester has universal appeal
Have you tried new the Independent Digital Edition apps?
Arts and Entertainment

ebooksNow available in paperback
Arts and Entertainment

ebooks
Arts and Entertainment
‘A Day at the Races’ still stands up well today
film
Arts and Entertainment
‘The Royals’ – a ‘twisted, soapy take on England’s first family’
tvAnd its producers have already announced a second season...
Arts and Entertainment
Kraftwerk performing at the Neue Nationalgalerie (New National Gallery) museum in Berlin earlier this month
musicWhy a bunch of academics consider German electropoppers Kraftwerk worthy of their own symposium
Arts and Entertainment
Icelandic singer Bjork has been forced to release her album early after an online leak

music
Arts and Entertainment
Colin Firth as Harry Hart in Kingsman: The Secret Service

film
Arts and Entertainment
Brian Blessed as King Lear in the Guildford Shakespeare Company's performance of the play

theatre
Arts and Entertainment
In the picture: Anthony LaPaglia and Martin Freeman in 'The Eichmann Show'

tv
Arts and Entertainment
Anne Kirkbride and Bill Roache as Deirdre and Ken Barlow in Coronation Street

tvThe actress has died aged 60
Arts and Entertainment
Marianne Jean-Baptiste defends Joe Miller in Broadchurch series two

tv
Arts and Entertainment
The frill of it all: Hattie Morahan in 'The Changeling'

theatre
Arts and Entertainment
Gillian Anderson and David Duchovny may reunite for The X Files

tv
Arts and Entertainment
Jeremy Clarkson, left, and Richard Hammond upset the locals in South America
TV
News
A young woman punched a police officer after attending a gig by US rapper Snoop Dogg
people
Arts and Entertainment
Reese Witherspoon starring in 'Wild'

It's hard not to warm to Reese Witherspoon's heroismfilm
Arts and Entertainment
Word up: Robbie Coltrane as dictionary guru Doctor Johnson in the classic sitcom Blackadder the Third
books

Arts and Entertainment
The Oscar nominations are due to be announced today

Oscars 2015
Arts and Entertainment
Hacked off: Maisie Williams in ‘Cyberbully’

Maisie Williams single-handedly rises to the challenge

TV
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

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

    As in 1942, Germany must show restraint over Greece

    As in 1942, Germany must show restraint over Greece

    Mussolini tried to warn his ally of the danger of bringing the country to its knees. So should we, says Patrick Cockburn
    Britain's widening poverty gap should be causing outrage at the start of the election campaign

    The short stroll that should be our walk of shame

    Courting the global elite has failed to benefit Britain, as the vast disparity in wealth on display in the capital shows
    Homeless Veterans appeal: The rise of the working poor: when having a job cannot prevent poverty

    Homeless Veterans appeal

    The rise of the working poor: when having a job cannot prevent poverty
    Prince Charles the saviour of the nation? A new book highlights concerns about how political he will be when he eventually becomes king

    Prince Charles the saviour of the nation?

    A new book highlights concerns about how political he will be when he eventually becomes king
    How books can defeat Isis: Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad

    How books can defeat Isis

    Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad
    Judith Hackitt: The myths of elf 'n' safety

    Judith Hackitt: The myths of elf 'n' safety

    She may be in charge of minimising our risks of injury, but the chair of the Health and Safety Executive still wants children to be able to hurt themselves
    The open loathing between Barack Obama and Benjamin Netanyahu just got worse

    The open loathing between Obama and Netanyahu just got worse

    The Israeli PM's relationship with the Obama has always been chilly, but going over the President's head on Iran will do him no favours, says Rupert Cornwell
    French chefs get 'le huff' as nation slips down global cuisine rankings

    French chefs get 'le huff' as nation slips down global cuisine rankings

    Fury at British best restaurants survey sees French magazine produce a rival list
    Star choreographer Matthew Bourne gives young carers a chance to perform at Sadler's Wells

    Young carers to make dance debut

    What happened when superstar choreographer Matthew Bourne encouraged 27 teenage carers to think about themselves for once?
    Design Council's 70th anniversary: Four of the most intriguing prototypes from Ones to Watch

    Design Council's 70th anniversary

    Four of the most intriguing prototypes from Ones to Watch
    Dame Harriet Walter: The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment

    Dame Harriet Walter interview

    The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment
    Art should not be a slave to the ideas driving it

    Art should not be a slave to the ideas driving it

    Critics of Tom Stoppard's new play seem to agree that cerebral can never trump character, says DJ Taylor
    Bill Granger recipes: Our chef's winter salads will make you feel energised through February

    Bill Granger's winter salads

    Salads aren't just a bit on the side, says our chef - their crunch, colour and natural goodness are perfect for a midwinter pick-me-up
    England vs Wales: Cool head George Ford ready to put out dragon fire

    George Ford: Cool head ready to put out dragon fire

    No 10’s calmness under pressure will be key for England in Cardiff
    Michael Calvin: Time for Old Firm to put aside bigotry and forge new links

    Michael Calvin's Last Word

    Time for Old Firm to put aside bigotry and forge new links