Science news in brief: a new map of the Milky Way and the Humpback baby boom

A roundup of other stories from around the world

This map of the Milky Way and neighbouring galaxies, containing more than a billion stars, is the most detailed survey ever produced of our galaxy (European Space Agency)

A galaxy in a bottle

Last month, astronomers in Europe released a three-dimensional map of the Milky Way. It is the most detailed survey ever produced of our home galaxy. It contains the vital statistics of some 1.3 billion stars — about one percent of the entire cosmic panoply of which Earth and the sun are part. Not to mention measurements of almost half a million quasars, asteroids and other flecks in the night.

Analysing all these motions and distances, astronomers say, could provide clues to the nature of dark matter. The gravity of that mysterious substance is said to pervade space and sculpt the arrangements of visible matter. Gaia’s data could also reveal information about the history of other forces and influences on our neighbourhood in the void. And it could lead to a more precise measurement of a historically troublesome parameter called the Hubble constant, which describes how fast the universe is expanding.

The map is the latest result from the European Space Agency’s Gaia mission, which was launched into an orbit around the sun in December 2013. It was built by an international collaboration of European astronomers and universities as the successor to the Hipparcos satellite, which charted the positions of about two million stars. Gaia’s cameras find the distances to stars by triangulation, measuring how their images shift against background stars and quasars as the spacecraft swings from one side of its orbit to the other – a baseline of about 186 million miles. A preliminary data release, containing information on two million stars, was published in 2016.

The new data set is based on 22 months, from July 2014 to May 2016, of staring at the sky. The first sifting of these stars has led to new insights into the types and colours and ages of the stars, and has allowed astronomers to distinguish subsets of stars with different histories and origins in the galaxy, which could lead to a better account of how and when the Milky Way formed.

The mission continues. The final Gaia catalogue, expected in the early 2020s, will include positions, motions, brightnesses and other parameters of more than one billion more stars. There is Big Data and then there is Cosmic Data.

“Gaia is astronomy at its finest,” says Fred Jansen, of ESA, the mission’s manager.

Humpback whale baby boom near Antarctica

In a rare piece of good news for whales, humpbacks who live and breed in the southern oceans near Antarctica appear to be making a comeback, with females in recent years having a high pregnancy rate and giving birth to more calves Humpback whales were nearly hunted out of existence in the late 19th and most of the 20th centuries until treaties were signed to stop killing them and protections were put in place for the world’s coldest, least accessible continent.

The end of hunting has fostered the recovery of the school-bus-sized animals whose life spans are roughly comparable to ours, according to Ari Friedlaender, an associate researcher at the University of California, Santa Cruz, who led the new study The population was believed to have been reduced to less than 10 percent of its pre-whaling levels.

To determine gender, identity and pregnancy rates, the scientists, led by Logan Pallin, a doctoral student working with Friedlaender, used darts to take small skin and blubber samples from 239 males and 268 females from 2010 to 2016 around the Western Antarctic Peninsula.

Slightly more than 60 percent of the females had high progesterone levels in their blubber, indicating that they were pregnant, according to the new study, published in the journal Royal Society Open Science. There were more pregnant whales in recent years than earlier, according to the research.

Although some other whale species also appear to be rebounding in the southern oceans, humpbacks seem to be faring the best, Friedlaender says. It may have been easier for the humpbacks to recover than the bigger fin and blue whales because the humpbacks mature faster, have a short period between pregnancies, and have centralised breeding grounds.

So far, climate change around the Antarctic Peninsula has been beneficial for humpbacks, Friedlaender says, providing about 80 more ice-free days per year when these whales that prefer open water can feed on abundant stocks of tiny shrimp-like crustaceans called krill.

Whale researchers are concerned that this moment of health and easy access to food will be short-lived. Krill stock around Antarctica is being fished by some countries, and threatened by climate change.

How a rose blooms: Its genome reveals the traits for scent and colour

Researchers have now figured out precisely which genes make a rose smell so sweet, and where to tinker in the genome to enhance its distinctive scent (Pasc­al Heitz­ler)

The scent of a rose fades over time, and has for hundreds of years. For centuries, generations of breeding in the quest for longer blooms and petals in shades of nearly every hue have dulled the sweetest smells that once perfumed gardens around the world. French researchers have figured out precisely which genes make a rose smell so sweet, and where to tinker in the genome to enhance its distinctive scent.

Although the rose genome has been mapped before, a newly published version is far more complete, indicating which genes tend to travel together – scent and colour, for instance – and which genes are responsible for continuous blooming, among other traits. The study, published in the journal Nature Genetics, also reveals a detailed family tree of the rose, and how it differs from its closest cousin, the strawberry, and its more distant apple and pear relations.

“A lot of these genes were known before, but it’s a very nice way of putting them all together and showing their history. And I think it’ll be very important for breeding,” says Rob Martienssen, a plant biologist and professor at Cold Spring Harbour Laboratory on Long Island, who was not involved in the new study. By identifying genes with great precision, the new sequence will be useful for breeding plant species other than the rose, as well, he says.

Now, to develop a new type of rose, breeders typically make thousands of hybrid offspring, looking for the combination of traits they want. Then, they have to select and identify the offspring that have the desirable trait. It’s a process that can take up to 10 years and require lots of greenhouse space and land, as well as water, says Mohammed Bendahmane, a senior author on the paper and research director at the École Normale Supérieure de Lyon, in France.

With data from the more detailed sequence of the rose genome, this process should be significantly shortened, reducing the cost and energy consumption needed to introduce new species, he says.

Gassy earthquakes near Istanbul may pose new risks to region

Istanbul – with a population of approximately 15 million – straddles one of the most active seismic fault lines on the globe. And that fault, which sits below the turquoise waters of the Sea of Marmara just south of the city, is expected to rupture in coming decades, causing a devastating earthquake.

That makes scientists eager to better understand the North Anatolian fault line. In a new study published in Scientific Reports, Louis Géli from the French Research Institute for Marine Exploitation, IFREMER, and his colleagues showed that the fault shook nearby gas reservoirs – a result that could help scientists better assess earthquake risks.

The finding follows a series of aftershocks that occurred in the weeks after an earthquake struck the western part of the Marmara Sea on 25 July, 2011. Typically, those smaller rumbles are a good omen. They suggest that the fault is releasing pent-up energy. But when a fault line is motionless, scientists have to worry because it might be locked and could rupture suddenly.

But when Géli and his colleagues analysed those aftershocks they noticed something rather odd. The tremors did not occur at the same depth as the main earthquake deep within the hard bedrock, but at shallower depths within the sea’s muddy sediment. Such a surprise could mean that a mechanism other than tectonic stress was at play.

The researchers now blame underground gases. When the larger quake hit a nearby gas reservoir, it released gases that moved upward and triggered weaker quakes. The finding suggests that the North Anatolian fault line is not directly responsible for the aftershocks, which could mean that it is far more at risk of a major quake than previously assumed, Géli says.

Tom Parsons, a geophysicist at the Pacific Coastal and Marine Science Center who has studied the North Anatolian fault but was not involved in this study, is not so sure. He argues that while the latest results can certainly be pinned on gas movement, that does not necessarily mean the fault is locked. The waters of the Marmara Sea have hindered more complete studies of the break.

Lightning struck her home – then her brain implant stopped working

Shock treatment: lightning over Ljubljana (iStock)

One stormy afternoon in Ljubljana, the capital of Slovenia, thunder rolled, a bolt of lightning streaked across the sky, and the television and air conditioner went dark in the apartment of a woman with electrodes implanted in her brain Lightning had struck the building.

After about an hour, the woman, who had had the electrodes put in five years before to help with debilitating muscle spasms in her neck, noticed her symptoms coming back. When she went to see her doctors the next day, they found that the pacemaker-like stimulator that powered the electrodes had switched itself off in response to the lightning strike.

In a study describing these events published recently in the Journal of Neurosurgery her doctors suggest that physicians and medical device companies add lightning strikes to the list of things that patients with electrodes implanted in their brains should watch out for.

Some patients with diagnoses like epilepsy, obsessive compulsive disorder and painful muscle spasms who don’t respond to other treatments have surgery to implant electrodes on either side of the brain. The electrodes are attached to wires running down to a stimulator implanted in the chest or torso. The stimulator provides electrical impulses to keep symptoms in check, using a battery that in some models can be topped up with an antenna-equipped power pack that’s charged with a wall plug.

Those with deep brain stimulation implants must be careful about getting diagnostic MRIs and spending time around devices that generate electromagnetic fields. These could set up a current in the implants and cause injury or other issues, says Dusan Flisar, a neurologist in Slovenia who is an author of the paper.

“There are also environmental causes that can affect the proper functioning of this device,” Flisar says – namely, it appears, lightning strikes The woman was lucky: She had not been charging her implanted battery at the time, nor had she had the charger pack plugged into the wall “The charger would be destroyed like other appliances and the patient injured if she was charging the stimulator during the event,” Flisar says.

Flisar and his colleagues recommend that patients plug their chargers into surge protectors, which will help protect them, and suggest that doctors tell patients to avoid charging during storms.

© New York Times