Sun's protective 'bubble' is shrinking

By Richard Gray, Science Correspondent

Data has shown that the sun's heliosphere is shrinking Photo: AP

New data has revealed that the heliosphere, the protective shield of energy that surrounds our solar system, has weakened by 25 per cent over the past decade and is now at it lowest level since the space race began 50 years ago.

Scientists are baffled at what could be causing the barrier to shrink in this way and are to launch mission to study the heliosphere.

The Interstellar Boundary Explorer, or IBEX, will be launched from an aircraft on Sunday on a Pegasus rocket into an orbit 150,000 miles above the Earth where it will "listen" for the shock wave that forms as our solar system meets the interstellar radiation.

Dr Nathan Schwadron, co-investigator on the IBEX mission at Boston University, said: "The interstellar medium, which is part of the galaxy as a whole, is actually quite a harsh environment. There is a very high energy galactic radiation that is dangerous to living things.

"Around 90 per cent of the galactic cosmic radiation is deflected by our heliosphere, so the boundary protects us from this harsh galactic environment."

The heliosphere is created by the solar wind, a combination of electrically charged particles and magnetic fields that emanate a more than a million miles an hour from the sun, meet the intergalactic gas that fills the gaps in space between solar systems.

At the boundary where they meet a shock wave is formed that deflects interstellar radiation around the solar system as it travels through the galaxy.

The scientists hope the IBEX mission will allow them to gain a better understanding of what happens at this boundary and help them predict what protection it will offer in the future.

Without the heliosphere the harmful intergalactic cosmic radiation would make life on Earth almost impossible by destroying DNA and making the climate uninhabitable.

Measurements made by the Ulysses deep space probe, which was launched in 1990 to orbit the sun, have shown that the pressure created inside the heliosphere by the solar wind has been decreasing.

Dr David McComas, principal investigator on the IBEX mission, said: "It is a fascinating interaction that our sun has with the galaxy surrounding us. This million mile an hour wind inflates this protective bubble that keeps us safe from intergalactic cosmic rays.

"With less pressure on the inside, the interaction at the boundaries becomes weaker and the heliosphere as a whole gets smaller."

If the heliosphere continues to weaken, scientists fear that the amount of cosmic radiation reaching the inner parts of our solar system, including Earth, will increase.

This could result in growing levels of disruption to electrical equipment, damage satellites and potentially even harm life on Earth.

But Dr McComas added that it was still unclear exactly what would happen if the heliosphere continued to weaken or what even what the timescale for changes in the heliosphere are.

He said: “There is no imminent danger, but it is hard to know what the future holds. Certainly if the solar wind pressure was to continue to go down and the heliosphere were to almost evaporate then we would be in this sea of galactic cosmic rays. That could have some large effects.

“It is likely that there are natural variations in solar wind pressure and over time it will either stabilise or start going back up.”

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Scientist develops programme to understand alien languages

By Richard Alleyne, Science Correspondent

A computer programme which could help identify and even translate messages from aliens in outer space has been developed by a British scientist.

Even if there are extra terrestrials are one day discovered, scientists fear their alien tongue may make it impossible to understand them.

	Alien life form: the new programme would compare alien language sounds with those of 60 human languages

But John Elliott of Leeds Metropolitan University believes he has come up with software which at least will decipher the structure of their language - and be the first step in understanding what they are saying.

Dr Elliott's programme would compare an alien language to a database of 60 different languages in the world to search see if it has a similar structure.

He believes that even an alien language far removed from any on Earth is likely to have recognisable patterns that could help reveal how intelligent the life forms are.

"Language has to be structured in a certain way otherwise it will be inefficient and unwieldy," he told New Scientist magazine.

Previous research had shown that it is possible to determine whether a signal carries a language rather than an image or music.

Dr Elliott, from Leeds Metropolitan University, has gone a step further by devising a way to pick out what might be words and sentences.

All human languages have "functional terms" that bracket phrases - words like "if" and "but" in English.

According to Dr Elliott, such terms in any language, are separated by up to nine words or characters.

This limit on phrase length seems to correspond to the level of human cognition - how much information we are able to process at once.

In an alien language, analysing these phrases might make it possible to gauge how clever the authors of the message are.

If they are much smarter than us, there would a lot of words packed into the phrases.

The programme should also be able to break a language up into crucial words such as nouns and verbs, even though their meaning is unknown.

It can, for instance, locate adjectives from the fact that they are almost always next to nouns.

Because languages have different word orders, Dr Elliott is amassing a library of the syntaxes of 60 human tongues.

If a message is received from outer space, it could be compared against this database. Scientists would then be able to see if it resembled anything human, or a mix of Earthly languages.

Dr Elliott admits that in order to translate what the aliens are actually saying it may still be necessary to have a "code book" of some sort.

But US linguist Dr Sheri Wells-Jensen, from Bowling Green State University in Ohio, points out that "you have to start somewhere".

She added: "My money is on being able to understand aliens."

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The week in science: diesels go green, bananas glow blue

By John Timmer

The case for fuel- and energy-efficient vehicles gets more compelling every year, and the two most popular stories this week both focused on new ways of getting more out of existing technology. One story focused on how two companies were managing to burn less fuel with diesel engines by figuring out ways of ensuring they never get switched on in the first place.

Future vehicles may rely on plug-in hybrid or purely electric tech, meaning that battery power becomes essential. Existing lithium battery tech will operate more efficiently when metal hydrides are incorporated into the electrode design.

Planetary science took center stage in upstate New York this week, as the American Astronomical Society's Division for Planetary Sciences held its annual meeting. Ars had a correspondent on hand, and he provided reports on some of the planetary happenings, including a discussion of how gravity fuels the geysers of Enceladus, one of Saturn's moons.

Publishing drives the dissemination of scientific information, but that doesn't necessarily mean that it's a flawless system. One analysis of the publishing system, which suggested that the current system results in a systematic over-hyping of high-profile results (called a "winner's curse") appeared in the news section. Meanwhile, our own Chris Lee shared his thoughts on the scientific content of high-profile publications and concluded that, in some ways, they're less useful than their lower-profile peers.

Biology provided us with a couple of surprises this week. It turns out that ripe bananas don't only turn yellow; they glow blue. The ripening process results in a chlorophyll derivative that emits blue light when exposed to UV. Those of you with a black light are undoubtedly running off to check this.

Image © Wiley.

Deep in a South African mine, researchers have discovered what's really involved in living on the edge. So few nutrients are available that only a single species can hack it. Despite the tough environment, the organism has a large genome and a full complement of genes, simply because it needs them all to make it in the prevailing conditions.

Some of the other highlights from the week:

• Most young stars are surrounded by rings of dust. Researchers have now modeled what a planet lurking in that dust would look like.
• More gecko-tech: a carbon nanotube-based gecko mimic is so resistant to shear forces that a 4mm square patch can support a bottle of Coke.
• A new reactive metal coating will release chemicals that block corrosion when it gets damaged.
• Science sees a Japanese import: manga comics that teach math and science are being translated for sale to the US audience.

Check out Nobel Intent for your fix of the latest science news.

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