The lost meteorites of Antarctica

February 17, 2016
The Almahata Sitta meteorite number 15 in-situ on the desert floor during its find on 2008 December 8, much as it fell on October 7 earlier that year. Credit: P. Jenniskens, SETI Institute

A hidden reserve of iron-rich meteorites which could hold secrets to the formation of the solar system may be hidden beneath the surface of the Antarctic ice sheet, according to a study by a team from The University of Manchester.

Their paper, published in Nature Communications this week, suggests that these meteorites could be just 10-50cm from the surface, making their retrieval tantalisingly possible.

Although meteorites fall evenly across the Earth's surface, over two thirds of the total number of collected meteorites has been recovered in Antarctica, partly due to the contrast between the white Antarctic surface and the dark meteorites resting on top. However, it is primarily because of ice flow dynamics, which transport and concentrate meteorites buried in the ice for hundreds of years up to localised regions at the surface known as meteorite stranding zones (MSZs). This has enabled highly fruitful meteorite collection missions from the MSZ surfaces since the 1970s, which have provided colossal insights for planetary scientists, and yielded many lunar and Martian meteorite samples.

However, far fewer iron-rich meteorites are found in Antarctica than anywhere else on Earth. The reason behind their scarcity has remained a mystery until now, but Dr Geoff Evatt and his team appear to have found the solution. They propose that the meteorites are missing as a result of the Sun's rays penetrating the clear ice in MSZs and warming the iron-rich rocks more than non-metallic ones. Such warming melts the ice surrounding the , causing it to sink and offset all annual ice upwelling - this permanently traps the meteorites just below the surface.

The authors have combined laboratory experiments with mathematical models to show that typical thawing and freezing processes will cancel out the upward transportation of meteorites with (e.g. containing iron), allowing those with lower conductivities to emerge from the ice.

The filtering mechanism identified by The University of Manchester team indicates that sub-layers of ice, tens of centimetres beneath the surface of a MSZ, potentially contain iron-rich meteorites that have been kept in a preserved state for thousands of years. The accessing of this layer could significantly increase our knowledge of the early Solar system, as iron-rich meteorites invariably originate from deep inside large planetary bodies which subsequently broke apart.

"With the strong possibility that a hidden reserve of meteorites lies just below the of localised areas of Antarctica, finding conclusive evidence of its existence is imperative to our understanding of the solar system's formation," says Dr Evatt. "The challenge is now set: to be the first team to locate this reserve of meteorites and retrieve samples from it."

Explore further: 20,000 meteorites and counting: New book details productive collection program

More information: G. W. Evatt et al. A potential hidden layer of meteorites below the ice surface of Antarctica, Nature Communications (2016). DOI: 10.1038/ncomms10679

Related Stories

Meteorite search about to begin

October 6, 2015

Geological relics from the far reaches of the solar system are the focus of a quest by the fireball hunting team at Curtin University.

Recommended for you

Solar eruptions could electrify Martian moons

October 18, 2017

Powerful solar eruptions could electrically charge areas of the Martian moon Phobos to hundreds of volts, presenting a complex electrical environment that could possibly affect sensitive electronics carried by future robotic ...

Potential human habitat located on the moon

October 18, 2017

A study published in Geophysical Research Letters confirms the existence of a large open lava tube in the Marius Hills region of the moon, which could be used to protect astronauts from hazardous conditions on the surface.

A solar-powered asteroid nursery at the orbit of Mars

October 18, 2017

The planet Mars shares its orbit with a handful of small asteroids, the so-called Trojans. Among them, one finds a unique group, all moving in very similar orbits, suggesting that they originated from the same object. But ...

Scientists dig into the origin of organics on Ceres

October 18, 2017

Since NASA's Dawn spacecraft detected localized organic-rich material on Ceres, Southwest Research Institute (SwRI) has been digging into the data to explore different scenarios for its origin. After considering the viability ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

hemitite
5 / 5 (3) Feb 17, 2016
They should show up nicely on radar.

Captain Stumpy
5 / 5 (3) Feb 18, 2016
i see a potential incursion of the cruise ship industry taking all those tourist beach-combers with metal detectors seeking their fortune in the near future

we could get in on the rush and get some PO folk together to buy a ship and build our fortunes!

[hyperbole]

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.