Enigmatic object baffles supernova team

An astronomical enigma has been spotted by a team hunting for very distant supernovas for their studies of the early universe.

At first glance, the object discovered on 22 February in the constellation Bootes resembled an ordinary supernova. But it kept growing brighter for much too long, and its spectrum was abnormal.

The mysterious object was spotted by the Hubble Space Telescope's Advanced Camera for Surveys and took at least 100 days to reach peak brightness, says Kyle Dawson of the Lawrence Berkeley National Laboratory in California, US, a member of the Supernova Cosmology Project. Normal supernovas reach peak brightness about 20 days after the blast.

Hubble saw nothing on 29 January at the point in the sky where the object appeared, so it must have brightened by more than a factor of 200. It has just begun to fade.

The object's spectrum is also unusual. The researchers could find no matches when they compared it with objects in the wide-ranging Sloan Digital Sky Survey. And its colour has not changed since it was first observed. Normally, temperature changes after an explosion cause colour changes.

Uncertain distance

How far away the object is, as determined by its redshift, is uncertain. If the strongest feature in the spectrum is a pair of calcium absorption lines, its red shift would be 0.54, corresponding to a distance of 5.5 billion light years.

But the object is at least one magnitude brighter than a Type 1A supernova would be at that distance, Dawson told New Scientist. And there is no sign of a host galaxy, which should be visible.

Astronomers can only speculate on what the object is. "It could be some galactic variable [star], a supernova or a quasar. But none of those makes any sense," Dawson says.

The object's behaviour doesn't match any known quasar. The team is not convinced the object is outside our galaxy, but nothing like it is known inside the galaxy. Furthermore, the region of Bootes is a largely empty area of the sky far from the plane of the Milky Way.

Intriguing object

"It's a very intriguing object," says supernova researcher Stefan Immler of the NASA Goddard Space Flight Center in Maryland, US, but he will not rule out the possibility that it might be a supernova.

If it was extremely distant, the expansion of the Universe would relativistically stretch a supernova explosion. We would see a 20-day event stretched to 100 days at a red shift of 4, corresponding to an object about 12 billion light years away seen just 1.5 billion years after the big bang.

That would require an extremely bright supernova, but Immler says that such young stars would explode differently because they contain fewer heavy elements than modern stars.

The best hope to resolve the question is to make more observations, and so Dawson has booked time for 25 June. "It's still going to be visible for another 2.5 months on the ground. We hope the spectrum will evolve and we see some features we can recognise," he says. Observations outside the visible spectrum may also provide more insights.

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'Water bears' are first animal to survive space vacuum

Tiny invertebrates called 'water bears' can survive in the vacuum of space, a European Space Agency experiment has shown. They are the first animals known to be able to survive the harsh combination of low pressure and intense radiation found in space.

Water bears, also known as tardigrades, are known for their virtual indestructibility on Earth. The creatures can survive intense pressures, huge doses of radiation, and years of being dried out.

To further test their hardiness, Ingemar Jönsson of Sweden's Kristianstad University and colleagues launched two species of dried-up tardigrades from Kazakhstan in September 2007 aboard ESA's FOTON-M3 mission, which carried a variety of experimental payloads.

After 10 days of exposure to space, the satellite returned to Earth. The tardigrades were retrieved and rehydrated to test how they reacted to the airless conditions in space, as well as ultraviolet radiation from the Sun and charged particles from space called cosmic rays.

The vacuum itself seemed to have little effect on the creatures. But ultraviolet radiation, which can damage cellular material and DNA, did take its toll.

Dried out

In one of the two species tested, 68% of specimens that were shielded from higher-energy radiation from the Sun were revived within 30 minutes of being rehydrated. Many of these tardigrades went on to lay eggs that successfully hatched.

But only a handful of animals survived full exposure to the Sun's UV light, which is more than 1000 times stronger in space than on the Earth's surface.

Before this experiment, only lichen and bacteria were known to be able to survive exposure to the combination of vacuum and space radiation.

"No animal has survived open space before," says developmental biologist Bob Goldstein of the University of North Carolina at Chapel Hill, who was not affiliated with the study. "The finding that animals survived rehydration after 10 days in open space – and then produced viable embryos as well – is really remarkable."

This ability to survive in extreme conditions "might be important when we consider the habitability of other bodies in our solar system or beyond," says astrobiologist Gerda Horneck of the German Aerospace Center. But the results say little about how the animals might develop and reproduce in harsh environments, Horneck says.

The authors aren't sure what causes the animals to be as resistant as they are to the effects of ultraviolet radiation. They speculate their hardiness might stem from the same adaptations that enable tardigrades to bounce back from being dried out.

Journal reference: Current Biology, vol 18, p R729

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Scientists expose mystery behind northern lights

Scientists have exposed some of the mystery behind the northern lights. On Thursday, NASA released findings that indicate magnetic explosions about one-third of the way to the moon cause the northern lights, or aurora borealis, to burst in spectacular shapes and colors, and dance across the sky.

The findings should help scientists better understand the more powerful but less common geomagnetic storms that can knock out satellites, harm astronauts in orbit and disrupt power and communications on Earth, scientists said.

A fleet of five small satellites, called Themis, observed the beginning of a geomagnetic storm in February, while ground observatories in Canada and Alaska recorded the brightening of the northern lights. The southern lights — aurora australis — also brightened and darted across the sky at the same time.

These auroral flare-ups occur every two or three days, on average.

A team led by University of California, Los Angeles, scientist Vassilis Angelopoulos confirmed that the observed storm about 80,000 miles from Earth was triggered by a phenomenon known as magnetic reconnection. Every so often, the Earth's magnetic field lines are stretched like rubber bands by solar energy, snap, are thrown back to Earth and reconnect, in effect creating a short circuit.

It's this stored-up energy that powers the northern and southern lights or, in other words, causes them to dance, according to Angelopoulos.

An opposing theory has these geomagnetic events occurring much closer to Earth, about one-sixth of the way to the moon. More Themis observations are needed to resolve the debate, said David Sibeck, NASA's project scientist.

"Finally, we have the right instruments in the right place at the right time, and it's allowed scientists to be able to make the necessary observations to settle this heated debate once and for all," said Nicola Fox, a Johns Hopkins University scientist who was not involved in the study.

At present, about 20 of these geomagnetic storms are being analyzed. Scientists hope to eventually learn, via this project, more about the bigger solar storms that occur about 10 times a year and can lead to far more expansive and prolonged northern and southern lights.

The five Themis spacecraft — a NASA acronym standing for Time History of Events and Macroscale Interations during Substorms — were launched aboard a single rocket last year.

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Could water really have a memory?

The trial appeared to back the theory of homeopathy

The news that the number of prescriptions for homeopathic medicines written by GPs in England has nearly halved in just two years coincides with the 20th anniversary of a seminal scientific paper on the subject.

Twenty years ago, in the summer of 1988, the science world was rocked by one of the most controversial research papers ever published in the highly-respected journal Nature.

According to a charismatic French scientist named Jacques Benveniste, pure water could somehow remember what it had previously contained.

Benveniste had started with a substance that caused an allergic reaction, he diluted it over and over again until there was nothing left except water, and then he observed that the pure water still managed to trigger an allergic reaction when it was added to living cells.

If the experiment was correct then it would mean rewriting the laws of physics and chemistry.

Moreover, the research would have a major impact on the credibility of homeopathy, because it is a form of alternative medicine that relies on remedies made by diluting the key curative ingredient over and over again until that ingredient has disappeared.

Even Benveniste was shocked by the implications of his own work.

"It was like shaking your car keys in the Seine at Paris and then discovering that water taken from the mouth of the river would start your car!"

Supernatural powers

John Maddox, editor of Nature, realised that Benveniste's research would be controversial, so it was accompanied by a disclaimer similar to one that had been run when he published research about Uri Geller's supposed supernatural powers.

It said: "Editorial reservation: Readers of this article may share the incredulity of the many referees ... Nature has therefore arranged for independent investigators to observe repetitions of the experiments."

The investigation team was led by Maddox himself, and he was joined by chemist Walter Stewart and James Randi, a magician, who had a reputation for debunking extraordinary claims.

Unfortunately for Benveniste, the investigators soon discovered that the results in his laboratory were unreliable.

The three of them went on to publish a report explaining how Benveniste's assistants were being subconsciously selective in the way that they interpreted their data.

They said: "We believe that experimental data have been uncritically assessed and their imperfections inadequately reported."

Benvensiste gradually moved out of academia as a result of the Nature debacle, but right up to his death in 2004 he maintained that his research was valid and that he was being ignored by a blinkered scientific establishment.

Twenty years after his research was published, perhaps now is the ideal time to asses his long-term impact on the debate surrounding ultra-dilute solutions and homeopathy.

Was he an unrecognized genius who was ahead of his time or was he a deluded scientist who failed to see that his research deeply flawed?

First of all, it is worth noting that there have been many attempts to reproduce Benveniste's experiments - occasionally there are positive results, but they are neither consistent nor convincing, and in any case these are countered by several negative results.

For example, the BBC science series Horizon attempted to test Benveniste's claims in 2002, and the conclusion was announced by Professor Martin Bland, of St George's Hospital Medical School.

He said: "There's absolutely no evidence at all to say that there is any difference between the solution that started off as pure water and the solution that started off with the histamine [an allergen]."

Phenomenon

Similarly, Benveniste started a spin-off company called DigiBio, which claimed that water could not only have a memory, but that this memory could be digitized, transmitted via email and reintroduced into another sample of water, which in turn could have an impact on living cells.

The US Defense Advanced Research Projects Agency (DARPA) tested DigiBio's claim and came to the following conclusion: "Our team found no replicable effects from digital signals."

Nevertheless, Benveniste's research continues to be very influential among many homeopaths, such as Alex Tournier, the founding director of the Homeopathy Research Institute.

He said: "Benveniste was a very inspiring and dedicated scientist, who at the very apogee of his career at the French National Institute for Health and Medical Research, was ready to put his reputation on the line to report a phenomenon he didn't understand: homeopathic dilutions.

"Homeopathy is still not understood, however his efforts started a new era of rigorous scientific investigation of the field."

Other homeopaths are convinced by Benveniste's idea of digital homeopathy and are even willing to sell such remedies over the internet.

The vast majority of scientists would argue that, because there is still no convincing evidence that homeopathy is effective after 200 clinical trials, the idea that digitized homeopathy can help patients is fanciful.

But for $1,000 you could go online and buy yourself a digital homeopathy software kit and start treating yourself and others today.

Serious question marks remain over the Benveniste paper, but what is not in doubt is that its influence among homeopaths is still powerful and profound 20 years on.

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Unique Habitat Found Inside Earth

Researchers studying life in the deep subsurface of our planet have discovered a unique bacterium living 1 mile (1.7 km) below the Earth's surface. The tiny bacteria live in a community of subsurface microbes inhabiting a South African platinum mine.

The deep subsurface of Earth harbors many unique microbes that are only accessible through large scale drilling projects or mining. By trekking into the ultra-deep mines of South Africa, researchers are getting a rare glimpse into this unique habitat. In the depths of South Africa's Northam Platinum mine, scientists from the University of Western Ontario and Princeton University have gained access to many previously undiscovered microbial communities.

While mining and drilling allow scientists to sample the unique environment below the Earth's soil, these activities obviously disturb the subsurface of the planet. Digging into the ground disrupts the microbial communities that live there. When people enter mines and caves, they bring with them a massive number of non-native microbes. Because of this, it's difficult to get uncontaminated samples.

The team from the recent study decided to test samples from mines in order to determine just how contaminated they really are. They collected samples from slime, or biofilm, growing on the walls of the Northam mine in South Africa. An explosion of life occurs where subsurface water leaks out of the mine walls and meets with oxygen, leading to films of microscopic organisms.

Previously, researchers overlooked these biofilms because they thought the films would be too heavily contaminated. To test this theory, the team determined whether or not their biofilms were formed by contaminant organisms from the surface, or by unique subsurface organisms.

The study, by Greg Wanger, Tullis Onstott and Gordon Southam, was published in a recent edition of the journal Geobiology.

The authors showed that the biofilms contained a number of unique organisms associated with the deep subsurface, and therefore such films might be an excellent place to search for new and unusual species of microbes. In fact, in their study the team came across one particularly strange microbe shaped like a tiny, microscopic star.

Shaping up bacteria

Microbes come in a number of shapes and sizes, but most of these shapes are rather uncomplicated. The easiest shape for a microbe to make is a sphere. Like a soap bubble, the cell membranes of microbes tend to naturally form this simple structure due to forces such as surface tension.

According to the research team, "the diversity of all bacterial shapes is more difficult to explain." Other shapes often seen in microbes include rods and spirals, but these take a bit of extra work on the part of the microbe. To make more complicated shapes, microbes have to use extra energy to fight against the natural forces that favor the sphere. According to the research team, the biofilms from Northam mine "contained a morphologically diverse assortment of bacteria."

Some rare microbes go beyond the common and form radically unique shapes. The microbe discovered in the depths of the Northam mine is one such microbe. Using high-powered microscopes, the team captured images that show star-shaped cells with four to nine points. It's a unique structure for a microbe and one that has not been witnessed before.

So why would a microbe want to take the shape of a star?

As living organisms, every microbe needs food. When we need food, we can simply pick it up and put it in our mouths. That's not the case for most microbes. Many microbes simply float about in their environment in the hope that they'll be able to absorb the nutrients they need to survive

Many microbes "eat" by letting nutrients diffuse through their cell membrane. A sphere may be easy to form, but it doesn't provide the largest surface area for a cell. By forming a more complicated shape, with a cell wall that folds and bends, the surface area of the cell is increased in relation to its interior volume. This means there's more cell wall through with the microbe can absorb its food.

The new microbe discovered by the researchers in South Africa has likely developed its unique shape in response to its unique environment. The deep subsurface of the planet is thought to be quite "nutrient poor" — there's not a lot of food to go around. Microbes need to develop clever strategies to out-compete their neighbors. The surface-area-to-volume ratio for the star-shaped cells is thought to be as much as ten times better than common bacteria like e. coli. This advantage may help the stars survive amidst a neighborhood of microbes competing for the same food.

Inside planets

Scientists are just beginning to understand the unique types of life beneath the surface of our planet. Astrobiologists are particularly interested in the subsurface because it can help them understand how microbes might survive deep beneath the topsoil of other planets.

Upcoming and current missions to search for signs of past or present life on Mars are focusing on life beneath the martian soil. Right now, NASA's Phoenix Lander is using a scoop to dig on Mars. Recent images returned from Phoenix are already revealing clues about subsurface ice on the red planet.

The European Space Agency's ExoMars rover may take the exploration of Mars' subsurface one step further. Current plans are to place a drill on ExoMars that could allow the rover to dig up to 12 feet.

NASA has also been developing prototype drills for use by human explorers on Mars. Drilling technologies have already been tested by NASA researchers in extreme environments on Earth, including the Canadian high arctic.

Microbes use many methods to survive in the nutrient-poor, oxygen-free, pitch-black world deep beneath our feet. Studying these microbes might provide clues about how organisms could live in harsh environments on other planets like Mars. Because of this, unique microbes like the "stars" of Northam mine may shed a bit of light on the future of planetary exploration.

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