What's worse than one asteroid hitting Earth? Scientists identify double impact crater

Binary asteroid systems create 'doublets' - twinned impact craters

Imagine Bruce Willis at the end of Armageddon, riding an Earth-bound asteroid wired with dynamite and preparing to blow the charges and save the planet. He turns around, only to see – another asteroid. Also headed for Earth. Without explosives.

It sounds improbable even by Hollywood standards, but according to a recent investigation by a team of scientist such a double impact rocked the Earth 458 million years ago.

Dr Jens Ormo and his team from the Centre for Astrobiology in Madrid, Spain analysed tiny, plankton-like fossils in two neighbouring craters in Sweden, coming to the conclusion that the pair were formed by a binary asteroid strike some time in the Ordovician Period.

The site in Sweden is one of several proposed double impact craters, but other scientists have warned that although the two may seem contemporary, they could have been created years apart and that our current methods of dating these impacts is simply not precise enough.

Despite this, astronomers say that binary asteroids are actually quite common and that nearly 15 per cent of near-Earth asteroids have twins. These pairs are thought to form when a type of asteroid known as a “rubble pile” (one consisting of numerous lumps of rock drawn together by gravity) begin to spin quickly as they’re warmed by the Sun, eventually throwing off a piece of rock to form a tiny moon.

Clearwater Lakes in the US - believed to have been created by a double asteroid impact 290 million years ago.

However, not every asteroid pair forms a double crater as it hits the Earth, as the objects are often too close together to form distinct indentations. Because of this, scientists calculate that only 3 per cent of impact craters are so-called doublets.

Dr Ormo has suggested that the pair of Swedish craters known as Lockne and Malingen are a possible double impact, after drilling down into the formations to retrieve tiny fossilised sea creatures known as chitinozoans and dating them to the same general time period.

The space between the two craters also suggests that they were the result of a double impact.  The 16 kilometre distance is close enough that the two asteroids would have been pulled together by gravity, but far enough for the craters to not have overlapped.

However, it remains impossible to say for certain. Dr Garteh Collins, who studies impact craters at Imperial College London but was not involved with the research, told the BBC: "Short of witnessing the impacts, it is impossible to prove that two closely separated craters were formed simultaneously.

"But the evidence in this case is very compelling. Their proximity in space and consistent age estimates makes a binary-impact cause likely."

The research by Dr Ormo will be presented at the 45th Lunar and Planetary Science Conference in The Woodlands, Texas, with the findings to be published in the Meteoritics and Planetary Science journal.

Start your day with The Independent, sign up for daily news emails
News
people

Harry Potter actor suffered 'severe flu-like symptoms' on a flight from London to Orlando

Arts and Entertainment
Legendary Star Wars filmmaker George Lucas
film
News
news
Arts and Entertainment
tv

First full-length look is finally here

PROMOTED VIDEO
ebooks
ebooksA special investigation by Andy McSmith
Arts and Entertainment
Frank Turner performing at 93 Feet East
musicReview: 93 Feet East, London
News
Toronto tops the charts across a range of indexes
news

World cities ranked in terms of safety, food security and 'liveability'

Extras
indybest
Voices
A mother and her child
voices
Voices
The veterans Mark Hayward, Hugh Thompson and Sean Staines (back) with Grayson Perry (front left) and Evgeny Lebedev
charity appealMaverick artist Grayson Perry backs our campaign
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: Digital Content Manager

£26000 - £31000 per annum: Recruitment Genius: A Digital Content Manager is re...

Recruitment Genius: Senior .Net Application Developer

£40000 - £60000 per annum: Recruitment Genius: This is a fantastic opportunity...

Recruitment Genius: Office Administrator

£14000 - £17500 per annum: Recruitment Genius: The successful applicant will b...

Recruitment Genius: Continuous Improvement Manager

£41500 per annum: Recruitment Genius: This company is going through a period o...

Day In a Page

Isis hostage crisis: The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power

Isis hostage crisis

The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power, says Robert Fisk
Missing salvage expert who found $50m of sunken treasure before disappearing, tracked down at last

The runaway buccaneers and the ship full of gold

Salvage expert Tommy Thompson found sunken treasure worth millions. Then he vanished... until now
Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Maverick artist Grayson Perry backs our campaign
Assisted Dying Bill: I want to be able to decide about my own death - I want to have control of my life

Assisted Dying Bill: 'I want control of my life'

This week the Assisted Dying Bill is debated in the Lords. Virginia Ironside, who has already made plans for her own self-deliverance, argues that it's time we allowed people a humane, compassionate death
Move over, kale - cabbage is the new rising star

Cabbage is king again

Sophie Morris banishes thoughts of soggy school dinners and turns over a new leaf
11 best winter skin treats

Give your moisturiser a helping hand: 11 best winter skin treats

Get an extra boost of nourishment from one of these hard-working products
Paul Scholes column: The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him

Paul Scholes column

The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him
Frank Warren column: No cigar, but pots of money: here come the Cubans

Frank Warren's Ringside

No cigar, but pots of money: here come the Cubans
Isis hostage crisis: Militant group stands strong as its numerous enemies fail to find a common plan to defeat it

Isis stands strong as its numerous enemies fail to find a common plan to defeat it

The jihadis are being squeezed militarily and economically, but there is no sign of an implosion, says Patrick Cockburn
Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action

Virtual reality: Seeing is believing

Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action
Homeless Veterans appeal: MP says Coalition ‘not doing enough’

Homeless Veterans appeal

MP says Coalition ‘not doing enough’ to help
Larry David, Steve Coogan and other comedians share stories of depression in new documentary

Comedians share stories of depression

The director of the new documentary, Kevin Pollak, tells Jessica Barrett how he got them to talk
Has The Archers lost the plot with it's spicy storylines?

Has The Archers lost the plot?

A growing number of listeners are voicing their discontent over the rural soap's spicy storylines; so loudly that even the BBC's director-general seems worried, says Simon Kelner
English Heritage adds 14 post-war office buildings to its protected lists

14 office buildings added to protected lists

Christopher Beanland explores the underrated appeal of these palaces of pen-pushing
Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Scientists unearthed the cranial fragments from Manot Cave in West Galilee