Our directory of things of interest

University Directory

Into the dark side

The Milky Way as seen over the desert of Bardenas in Spain The Milky Way as seen over the desert of Bardenas in Spain Inigocia
11 Apr
2015
Every 30 million years or so, the Earth passes through the most crowded section of the galactic disc. Mass extinction events and radical changes to the Earth’s geology follow

New research has suggested that what the Earth encounters when it enters the Milky Way’s crowded section of the galactic disc – namely dark matter – causes changes deep within the planet’s core.

‘When the Earth passes through [that part of] the disc, it might encounter dense clumps of invisible dark matter,’ says professor Michael Rampino, a biology professor at New York University, whose research shows a correlation between mass extinctions, geological change and the Earth’s orbit.

‘Dark matter is slowed by collisions with the Earth, loses energy and spirals into the Earth’s core,’ says Rampino. ‘If the particle is its own antiparticle they will annihilate each other, giving off energy.’

As the particles annihilate each other, immense heat is created in the Earth’s core. This heat triggers volcanic eruptions, mountain building, changes sea levels and can even flip the Earth’s magnetic fields.

A passage through dark matter also changes pathways for comets orbiting far from Earth in the outer Solar System. Comets that usually take orbits far from Earth can be pushed onto a collision course.

‘As well as being important on the largest scales, dark matter may have a direct influence on life on Earth,’ says Rampino. These changes apparently take place over a long time period and the professor warns that it may not be possible to predict encounters with dense clumps of dark matter.

‘We are fortunate enough to live on a planet that is ideal for the development of complex life. But the history of Earth is punctuated by large scale extinction events, some of which we struggle to explain,’ says Rampino. We can rest easy for a while though. Earth’s last journey through the disc was three million years ago.

This article was published in the April 2015 edition of Geographical Magazine

Related items

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Oceans

Steps to regulate fisheries and protect marine reserves can be…

Wildlife

Government proposals to change conservation legislation could see vulnerable mammals…

Wildlife

New research confirms that sharks navigate using the Earth's magnetic…

Nature

The field of bioremediation involves cleaning up toxic waste products…

Wildlife

A new analysis tots up the cost of invasive species…

Climate

It’s surprisingly difficult to know why trees die, but understanding…

Nature

By the late 1980s, almost all mature specimens of the…

Oceans

Scientists are discovering that narwhal tusks reveal a great deal about…

Climate

Climate change is bringing earlier, dangerous 'false springs', longer summers…

Wildlife

A victory for conservation, South Africa has announced plans to…

Energy

The UK has made little progress decarbonising heating, but a significant source…

Nature

The concept of 'natural capital', where the value of nature…

Geophoto

Prestigious photography competition returns for a fourth year

Climate

Founded in the USA by Denis Hayes, Earth Day became…

Geophoto

Tom Goldner's project Do Brumbies Dream in Red? is an intimate portrayal…

Wildlife

Not your usual tune: translating spider's silk into sound could…

Oceans

Millions of oysters have been rescued from the struggling shellfish…

Climate

History is littered with examples of fungi helping to digest…