we-are-star-stuff:

Astronomers searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that it would taste vaguely of raspberries.

The unanticipated discovery follows years of work by astronomers who trained their 30m radio telescope on the enormous ball of dust and gas in the hope of spotting complex molecules that are vital for life.

Finding amino acids in interstellar space is a Holy Grail for astrobiologists, as this would raise the possibility of life emerging on other planets after being seeded with the molecules.

In the latest survey, astronomers sifted through thousands of signals from Sagittarius B2, a vast dust cloud at the centre of our galaxy. While they failed to find evidence for amino acids, they did find a substance called ethyl formate, the chemical responsible for the flavour of raspberries.

“It does happen to give raspberries their flavour, but there are many other molecules that are needed to make space raspberries,” Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, told the Guardian.

Curiously, ethyl formate has another distinguishing characteristic: it also smells of rum.

The astronomers used the IRAM telescope in Spain to analyse electromagnetic radiation emitted by a hot and dense region of Sagittarius B2 that surrounds a newborn star.

Radiation from the star is absorbed by molecules floating around in the gas cloud, which is then re-emitted at different energies depending on the type of molecule.

While scouring their data, the team also found evidence for the lethal chemical propyl cyanide in the same cloud. The two molecules are the largest yet discovered in deep space.

Dr Belloche and his colleague Robin Garrod at Cornell University in New York have collected nearly 4,000 distinct signals from the cloud but have only analysed around half of these.

“So far we have identified around 50 molecules in our survey, and two of those had not been seen before,” said Belloche.

Last year, the team came tantalisingly close to finding amino acids in space with the discovery of a molecule that can be used to make them, called amino acetonitrile.

The latest discoveries have boosted the researchers’ morale because the molecules are as large as the simplest amino acid, glycine. Amino acids are the building blocks of proteins and are widely seen as being critical for complex life to exist anywhere in the universe.

“The difficulty in searching for complex molecules is that the best astronomical sources contain so many different molecules that their ‘fingerprints’ overlap and are difficult to disentangle,” Belloche said.

The molecules are thought to form when chemicals that already exist on some dust grains, such as ethanol, link together to make more complex chains.

“There is no apparent limit to the size of molecules that can be formed by this process, so there’s good reason to expect even more complex organic molecules to be there,” said Garrod.

this is why I fucking love space so much

(via bionicspacejelly)

we-are-star-stuff:

Was Earth’s most devastating mass extinction caused by a single microbe?

Around 251 million years ago, over 90% of the species on Earth suddenly went extinct. Their killer may not have been a devastating meteorite or a catastrophic volcanic eruption, but a humble microbe.

The prevailing theory is that the mass extinction at the end of the Permian period was triggered by volcanic eruptions over a vast area of what is now Siberia. This led, among other things, to a dramatic rise in greenhouse gas emissions.

But the scenario just doesn’t fit the facts, says Daniel Rothman of the Massachusetts Institute of Technology. From his analysis of an end-Permian sediment sample from China, Rothman says carbon levels surged much too quickly for geological processes to be at work.

Microbes can generate carbon compounds that fast, though. When Rothman’s group analysed the genome of Methanosarcina - a methanogen responsible for most of Earth’s biogenic methane today - they discovered that the microbe gained this ability about 231 million years ago. The date was close to that of the mass extinction, but not close enough to suggest a link.

But Methanosarcina needs large amounts of nickel to produce methane quickly. When the team went back to their sediment cores, they discovered that nickel levels spiked almost exactly 251 million years ago - probably because the Siberian lavas were rich in the metal. That suggests Methanosarcina did trigger the extinction, Rothman told the American Geophysical Union meeting in San Francisco last week.

Other geologists remain to be convinced. “[But] it’s a fascinating idea that the evolution of a new life form led to an extinction,” says Anthony Barnosky of the University of California, Berkeley. Today’s mass extinction of biodiversity is similar, says Barnosky, because it is largely driven by our species.

neurosciencestuff:

Bullying by childhood peers leaves a trace that can change the expression of a gene linked to mood

A recent study by a researcher at the Centre for Studies on Human Stress (CSHS) at the Hôpital Louis-H. Lafontaine and professor at the Université de Montréal suggests that bullying by peers changes the structure surrounding a gene involved in regulating mood, making victims more vulnerable to mental health problems as they age. The study published in the journal Psychological Medicine seeks to better understand the mechanisms that explain how difficult experiences disrupt our response to stressful situations. “Many people think that our genes are immutable; however this study suggests that environment, even the social environment, can affect their functioning. This is particularly the case for victimization experiences in childhood, which change not only our stress response but also the functioning of genes involved in mood regulation,” says Isabelle Ouellet-Morin, lead author of the study.

A previous study by Ouellet-Morin, conducted at the Institute of Psychiatry in London (UK), showed that bullied children secrete less cortisol—the stress hormone—but had more problems with social interaction and aggressive behaviour. The present study indicates that the reduction of cortisol, which occurs around the age of 12, is preceded two years earlier by a change in the structure surrounding a gene (SERT) that regulates serotonin, a neurotransmitter involved in mood regulation and depression.

To achieve these results, 28 pairs of identical twins with a mean age of 10 years were analyzed separately according to their experiences of bullying by peers: one twin had been bullied at school while the other had not. “Since they were identical twins living in the same conditions, changes in the chemical structure surrounding the gene cannot be explained by genetics or family environment. Our results suggest that victimization experiences are the source of these changes,” says Ouellet-Morin. According to the author, it would now be worthwhile to evaluate the possibility of reversing these psychological effects, in particular, through interventions at school and support for victims.

(Image: mentalhealthsupport.co.uk)

(via fracturedrefuge)

astrotastic:

I went on a walk this morning up the hill and on my way back down, I stopped to notice these really cool ice crystals sticking up out of the snow. I went and got my camera and took some pictures. I thought now would be a great opportunity to talk about the structure of frozen water!

Water freezes in a hexagonal shape because of where the bonds lie in the water molecule.

When water is at room temperature, or at a liquid state, all the molecules bunch up together and try to fill every crevice they can. It looks like this:

(source) 

But, when water freezes, the molecules rearrange themselves along the hydrogen atoms and bond there. This structure is more organized than liquid water is:

(source)

This accounts for why ice floats on top of water in your drinking glass - there is more space between the molecules in a solid state, which means it is less dense than water in a liquid state. The shape of this model is also hexagonal - the molecules arrange into a tetrahedral shape so every hydrogen atom is bonded to another oxygen atom via a lone pair of electrons. This naturally forms a hexagonal shape, thus the spectacular forms of snowflakes!

Yay science!

(via bouncingdodecahedrons)

unfriendlyatheist:

fwd:re:fwd:fwd:fwd

(via unfriendlyatheist-deactivated20)

ihateallyourgods:

Let’s get something straight!

(via abaldwin360)

ihateallyourgods:

-NdT

(via baconbeernboobs)

jtotheizzoe:

There’s no science in this post. I just know we’re all gonna want to save this picture for future reference.

(Source: allbrook86, via progressivegroan)