Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
Six new species of tiny frogs from Mexico
Scientists have identified six new species of frog the size of a thumbnail from the forests of Mexico, with one earning the distinction of Mexico’s smallest frog.
All six species are smaller than an Australian five cent coin, around only 15mm long when fully grown, according to a new study published in Herpetological Monographs.
The newly discovered species are known as ‘direct-developing’ frogs: rather than hatching from eggs into tadpoles like most frogs, they emerge from the eggs as perfect miniature frogs.
Researchers studied 500 frog specimens that had originally been collected in Mexico but were gathered from museums around the world.
They used DNA sequencing to sort the frogs into groups based on how similar their genes were, then CT-scans were used to create 3D models of the frogs’ skeletons, so that physical details could be compared.
The six new species are all from the same genus Craugastor.
30 exocomets discovered in a young planetary system
The star Beta Pictoris has fascinated astronomers for 30 years, because it enables them to observe a planetary system in the process of formation.
It is made up of at least two young planets, and also contains comets, which were detected as early as 1987. These were the first comets ever observed around a star other than the Sun, which are known as exocomets.
Now, an international team of astrophysicists has discovered 30 exocomets orbiting Beta Pictoris and determined the size of their nuclei – the solid central part of a comet – which vary between three and 14 kilometres in diameter.
They were also able to determine the proportion of small to large comets, finding their size distribution to be strikingly similar to that of those orbiting the Sun – indicating that they were also shaped by a series of collisions and breakups.
The research is published in Scientific Reports.
Suspended animation space travel may never be possible
How realistic is human hibernation for a hypothetical future space voyage?
Bad news for sci fi fans: the answer is not very, according to a new study by Chilean researchers published in Proceedings of the Royal Society B. We just wouldn’t save enough energy.
They calculated the actual amount of energy savings from hibernation, and its dependence on body mass, for a range of hibernating animals – from bats to bears.
They found that the daily energy expenditure of hibernation scales isometrically with mass, which means that a gram of hibernating bat has a similar metabolism to that of a gram of bear, 20,000 times larger.
Working out the likely metabolism of a hibernating human based on our own mass, they found we save more energy by sleeping than we would if hibernating.
No more nasty nanotube tangles
A new acid-based solvent has been developed to simplify the processing of carbon nanotubes, which are prone to tangle like spaghetti, according to a recent paper in the journal Science Advances.
The unique combination of acids – including methanesulfonic (MSA), toluenesulfonic, and oleum acids – helps separate carbon nanotubes in solution and turn them into films, fibres, or other materials.
Oleum and chlorosulfonic acids have long been used to dissolve nanotubes without modifying their structures, but both are highly corrosive. By combining oleum with two weaker acids in a solvent that is compatible with conventional manufacturing processes, chemical engineers have developed a process that enables new manufacturing for nanotubes products.
Study reveals Stonehenge landscape before the world-famous monument
Four thousand years before Stonehenge was constructed, land within the World Heritage site was covered by open woodland, with meadow-like clearings, inhabited by grazing animals and hunter-gatherers, according to new research published in PLoS One.
Geologists exploring Blick Mead – a Mesolithic archaeological site just over 1.5 km from the iconic standing stones – have found evidence that the land was not covered in dense, closed canopy forests during the later Mesolithic period, as had previously been thought.
The research team analysed pollen, fungal spores and traces of DNA preserved in ancient sediment (sedaDNA), combined with optically stimulated luminescence (OSL) and radiocarbon dating to produce an environmental history of the site.
Instead, they found it was partially wooded and populated by aurochs (cattle), red deer, elk, and wild boar – making it good hunting ground for humans who lived opportunistically off the land, prior to the arrival of early farmers.