In the science news this week, a water-rich asteroid being pulled apart by a white dwarf, elephants have an innate ability to understand human gestures, jaundice babies in developing countries have new hope for treatment, and finally…the Nobel prize winners for 2013 are announced.
Dead star eats water-rich asteroid
The Hubble telescope has spotted a distant asteroid that is being pulled apart by its host star, a white dwarf called GD 61. What makes this find so exciting though, is that the asteroid appears to be rich in water – potentially 26% of its mass as water.
The chemical signatures observed in the star’s atmosphere point to the asteroid containing a lot of water, the researchers explained in the paper published in Science .
This is the first time that both a rocky surface and the existence of water have been seen together on an object outside of our solar system, reported Jonathan Amos for the BBC .
The white dwarf, GD 61, has long since burnt through its nuclear fuel and is now a dim point in the night sky. However, it still has a strong gravitational pull on the objects around it, including this asteroid, which it is pulling apart.
The asteroid has a very similar water content to Ceres, the largest asteroid in the main belt in our Solar System, determined the astronomers from the universities of Cambridge and Warwick, in the UK, and from Kiel in Germany.
The Earth, in comparison, has just 0.02% mass from water, most of which is likely to have arrived from comets and asteroids bombarding the planet in the past.
They have speculated that the GD 61 was likely to have had rocky planets similar to the ones in our own solar system when the star was still burning its fuel.
Lead author Dr Jay Farihi told the BBC's Science In Action programme: "The reason that we can say that is that the planet-formation process starts with things as small as dust grains. They grow into things as big as pebbles and boulders and then as large as asteroids. Once you get to things as big as asteroids, planets are essentially inevitable - it's a runaway process; you simply cannot stop it.
"Having asteroids and no planets is logically possible but it's very likely physically implausible. So, we know there were rocky planets [in GD 61] because we can see the rocky building blocks; and we know there was the potential to deliver water to their surfaces because we've seen at least one very water-rich and large asteroid."
It gives a hint at the Sun’s own future, which will eventually become a white dwarf once it uses up its nuclear fuel.
"I think alien astronomers would then be getting pretty similar information to what we're getting on GD 61," Dr Farihi, from the Cambridge Institute of Astronomy, explained.
"I guess it would depend on what time they looked and which asteroid they were lucky enough to catch. But we know of water-rich asteroids in the outer main belt and I think there would be a good chance that they would see a signature of something like the asteroid Ceres. And in that case, if the alien astronomers speculated about habitable planets - well, if they're looking back at our system, in that case they'd be correct."
Elephants instinctively understand human gestures
African elephants have shown what appears to be an instinctive understanding of human gestures, such as pointing, according to researchers from the University of St Andrews, reported the BBC news website .
Ann Smet, one of the study’s authors, offered the elephants a choice between two identical buckets, only one of which contained a hidden treat. She then pointed to the bucket with the treat, and from the very first trial the elephants went to the bucket she pointed at first.
The research was carried out with a group of captive elepghants at a lodge in Zimbabwe, who had been rescued from culling operations and trained for riding.
"They specifically train the elephants to respond to vocal cues. They don't use any gestures at all," said Professor Richard Byrne, co-author of the study.
"The idea is that the handler can walk behind the elephant and just tell it what to do with words."
However, the animals seemed to understand the meaning of pointing from the outset, not needing any training at all.
This makes them the only non-human animals to understand the gesture without being trained to do so.
"Of course we had hoped that the elephants would be able to learn to follow human pointing, or we wouldn't have done the experiment in the first place," Ann Smet said.
"But it was really surprising that they didn't seem to have to learn anything.
"It seems that understanding pointing is an ability elephants just possess naturally and they are cognitively much more like us than has been realised."
Pop-up huts could save jaundiced infants
Nearly 80% of premature babies suffer from jaundice due to underdeveloped livers. The build-up of blood pigment that turns their eyes, and sometimes skin, yellow can also become toxic in the brain. If left untreated, this can result in cerebral palsy, blindness, deafness, cognitive damage, or even death.
The simple treatment – bathing the infant in blue light – isn’t offered by many hospitals in developing countries because there isn’t a steady electricity supply.
However, Donna Brezinski, a paediatrician based in Boston, has come up with a possible solution, reports New Scientist .
She has built a portable, battery-operated device, which costs just $400 per unit – a price that could reduce even further – and can run on a 12-volt car battery for up to a month straight.
The 460 nanometre wavelength of the blue light triggers a chemical reaction that makes the toxic blood pigment, bilirubin, water-soluble, allowing it to filter out naturally in the baby’s urine. If the infant is bathed in the light continuously, they can often be cured in just a few days.
The first pilot study of the “Bili-Hut” will start this month at St Boniface Hospital in Fond-des-Blancs, Haiti – a hospital that suffers frequent power outages.
The Nobel prize winners 2013 are announced
Last week saw the announcement of this year’s Nobel prize winners , and you can see the full list below:
Physiology or Medicine – James E. Rothman, Randy W. Schekman and Thomas C. Südhof 
Physics – François Englert and Peter Higgs 
Chemistry – Martin Karplus, Michael Levitt and Arieh Warshel 
Economic Sciences – Eugene F. Fama, Lars Peter Hansen and Robert J. Shiller 
Peace – Organisation for the Prohibition of Chemical Weapons 
Literature – Alice Munro