A round-up of today's other stories in brief
The wind beneath their wings
CHANGES IN wind patterns appear to have given an albatross species in the Southern Ocean something of a boost, according to findings published recently in the journal
Science.
Wandering albatross (Diomeda exulans) can forage over large areas, and the wind is thought to assist their journey.
The new study combed through decades of data on foraging, breeding success and body mass of the large seabird – the information was collected by breeders from the Crozet Islands, an archipelago that lies roughly mid-way between Madagascar and Antarctica.
The data showed that the Crozet birds foraged from subtropical to Antarctic waters, with a maximum range of around 3,500km.
And as westerly winds in the Southern Ocean have increased in intensity and moved south, the foraging range of the wandering albatross has also shifted towards the south.
The endangered seabirds have been generally travelling faster, foraging more rapidly, breeding more successfully, and gaining weight in conjunction with the changes in wind pattern, note the authors.
The jump up in weight was unexpected – over the past 20 years males and females have increased in body mass by more than a kilo. The increased mass of the albatross could be due to spending less time fasting on the nest, and the higher wing loading could help the seabirds to “use dynamic soaring flight to exploit windier zones”, suggest the researchers.
However, they also note that the lift may not last: “These positive consequences of climate change may be temporary if patterns of wind in the southern westerlies follow predicted climate-change scenarios.”
A galaxy of possibilities
A NEW STUDY suggests that exoplanets could orbit around every star in our own galaxy.
Using a technique called “gravitational microlensing”, an international team of researchers surveyed millions of stars in the Milky Way. “We have searched for evidence for exoplanets in six years of microlensing observations,” says Arnaud Cassan from the Institut d’Astrophysique de Paris, lead author of the Nature paper.
“Remarkably, this data show that planets are more common than stars in our galaxy.” Astrophysicist Dr Niall Smith, head of research at Cork Institute of Technology and a founder member of Blackrock Castle Observatory, wasn’t involved in the study, but he says the results are an encouragement to continue to look for exoplanets “because now we have an estimate that the universe teems with them”.
He puts the numbers into context: “If there are roughly 1.6 planets per star [according to the microlensing results] in our galaxy, and there are 200,000 million stars in our galaxy, then there are of the order of 320 billion planets in the Milky Way.”
If that weren’t dizzying enough, he scales the estimate up for the 200,000 million or so galaxies in the observable universe, coming to 64,000 billion billion exoplanets.
With such an abundance of exoplanets, the difficulty is in selecting the interesting ones, notes Dr Smith, but he adds that having that many seems to give life a good chance of getting a foothold elsewhere.
“Listening for the telltale signs of ET might not be as thankless a task as one might think, though it could still be a search for the proverbial needle, but in a very big haystack,” he says.
“The challenge is to develop better ways to detect more planets, planets that are smaller than the ‘hot Jupiters’, but, most importantly, planets that are at the correct distance from their parent star to be capable of hosting liquid water.”
