the-BA : the BA Science News Digest

In the news this week: scientists believe the North pole ice may disappear completely, why Mars is a two-faced planet, ‘crocodile language’ is translated and a new use for stink bomb gas is discovered.

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Dramatic new evidence indicates that for the first time in human history, ice is on course to disappear entirely from the North Pole this year. If the ice completely disappears this will make it possible to reach the Pole by sailing in a boat through open water. This will be one of the most dramatic examples of the impact of global warming.

According to scientists the chances of the ice completely disappearing at the North Pole are 50:50. Normally thick ice formed over many years at the Pole has been blown away and replaced by huge areas of thinner ice formed over a single year. Scientists predict that at least 70 per cent of this single-year ice – and perhaps all of it – will melt completely this summer.

(Read more in the Independent)

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It was discovered in the 1970’s during Nasa’s Viking Missions that Mars is a planet of two distinct halves. In the North, there are relatively young, smooth, low-lying plains and in the south, relatively old, heavily cratered highlands. The Mars Global Surveyor probe sent in the 1990’s also indicated that the crust of the planet is much thicker in the south and revealed magnetic anomalies in the southern hemisphere but not in the north.

There have always been two main theories why Mars is a two-faced planet. It is either due to some internal process related to the planet’s structure or an ancient impact.

New research and computer simulations now support the theory that a cataclysmic collision between 3.9 and 4.5 billion years ago altered the shape of the planet. If this is true, it is by far the largest impact scar found in our solar system.

"It’s a very old idea, but nobody had done the numerical calculations to see what would happen when a big asteroid hits Mars," said Dr Francis Nimmo, the author of this new research, as reported in the Telegraph. "The impact would have to be big enough to blast the crust off half of the planet, but not so big that it melts everything."

If this is true, the impact would have been a million-billion times more energetic than the atom bomb that exploded over Nagasaki.

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“umph umph umph” is what humans hear coming from the egg of an un-hatched baby Nile crocodile, but to the mother crocodile and to other un-hatched crocodile siblings these calls mean something.

This sound, a bit like a small starter motor, has now been translated by scientists. Amélie Vergne and Nicolas Mathevon of Université Jean Monnet in Saint-Etienne, France, have found that the calls serve the essential function of telling others in the nest that it is time to hatch, as well as warning their mother to protect them.

Scientists believe this behaviour has a long history. Birds are also known to produce "embryonic vocalisations" and this early communication could be a shared behavioural feature of past and present members of the Archosaurs, an ancient group of reptiles now represented by modern birds and crocodiles.

(Read more in the Independent)

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One million years before the dinosaurs began to roam the earth, Ventastega curonica lived in the shallow waters and tidal estuaries of modern day Latvia. This creature has a fish-like body with four primitive flippers with a high number of digits (estimated to be 8 or 9) and the head of an animal more suited to land than water.

Scientists indicate the discovery of its fossil has shed new light on important evolutionary stages. It shows an important step in the evolutionary journey that led creatures from the sea to the land. Scientists once believed that these early amphibious animals descended in a linear fashion, but this discovery instead confirms these creatures diversified into different branches along the way.

(Read more on BBC online)

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Bumblebees are being forced to seek out alternative sugary food sources due to a lack of suitable flowers. The Bumblebee Conservation Trust (BCT) said bumblebees are increasingly seeking out the sugary secretions of aphids on the leaves of trees. These secretions offer a substitute for nectar but do not contain the protein bees need to stay healthy.

There have been a number of warnings that bumblebee and wild bee populations around the UK are experiencing extremely serious declines. Bees are important part of the ecosystem and are pollinators of flowers and crops. The bumblebees' behaviour of feeding on secretions from aphids could be a further sign of the problems facing the insects.

(Read more on BBC online)

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And finally...

Hydrogen sulphide - the source of rotten eggs' unpleasant odour - is corrosive, foul-smelling, flammable and deadly in sufficient concentrations – and even a single breath can kill in high concentrations. But research into medical use of this gas is now being backed by the US military, who believe it could help their surgeons cope with injuries suffered by soldiers in battle.

Hydrogen sulphide, which gives stink bombs their revolting smell, could play a significant role in influencing some chemical pathways in the body, providing doctors with new treatments for conditions ranging from stroke to chronic arthritis. Some researchers are even trying to use hydrogen sulphide to put patients with strokes or serious injuries into a form of suspended animation to help them survive severe traumas.

'Hydrogen sulphide is made in very low doses in the body and, far from doing harm, it has become clear that it can do a great deal of good,' said Dr John Wallace, a pharmacologist at the University of Calgary in Canada, as reported in the Observer. 'It is found in the brain and is also thought to control blood pressure. It is quite pervasive, in fact.'

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