Brightest gamma-ray burst ever detected defies explanation

The brightest γ-ray burst ever detected is defying theoretical expectations. Since the blast of radiation was first spotted in October 2022, astronomers have been studying its afterglow to learn more about the mechanisms behind it. In two new studies, researchers report that the evolution of the radio waves emitted by the enormous burst was much slower than models predicted.

Best view yet of planet in hotly pursued star system

The exoplanet TRAPPIST-1b — one of seven roughly Earth-sized planets in the TRAPPIST-1 system — probably doesn’t have an atmosphere. It’s not surprising: TRAPPIST-1b is the closest to its star and is blasted by four times as much radiation as Earth receives from the Sun. But the work shows the transformational power of the James Webb Space Telescope (JWST) to observe the system, which offers a unique laboratory for studying planetary environments and how they might become suitable for life.

Brain prosthesis improves memory

A ‘memory prosthesis’ seems to boost people’s ability to remember new information. It consists of a deep-brain electrode that records and then mimics the electrical activity pattern of the hippocampus, a brain region that has a crucial role in memory. Twenty-four people, who had already had electrodes implanted to study their epilepsy, volunteered to try the device: it improved their performance in short- and long-term memory tests by up to 54%.

A fish can sense another’s fear

Zebrafish (Danio rerio) become afraid when they see other members of their species in distress. This fear mirroring is regulated by oxytocin: fish that lack the genes to produce and absorb the hormone fail to detect others’ anxiety but regain the ability when they receive an oxytocin injection. Oxytocin has the same effect in mice, and is known to affect humans’ social responses, meaning it’s likely that this empathy mechanism evolved many millions of years ago, before fish and mammals diverged on the tree of life.

Mathematicians have finally discovered an elusive ‘einstein’ tile

Researchers have discovered the first example of a single shape that can cover a surface with an infinite pattern that never repeats. The shape is surprisingly simple: a 13-sided polykite that the team has dubbed ‘the hat’. The hat’s sides can vary in length without it losing the ability to create ‘aperiodic tiling’. Previous examples of aperiodic tilings, such as Penrose tiles, required two or more shapes.

Fruit flies are first known animals that can taste alkaline foods

Fruit flies (Drosophila melanogaster) have surprised researchers with an entirely new taste receptor that allows them to detect alkaline — or basic — substances and avoid toxic meals and surfaces. The flies have an unusual mechanism: a receptor protein that, in the presence of a base, opens a cell-membrane channel through which negatively charged chloride ions escape the neuron. Most sensory receptors involve channels that let positively charged ions flow into the cell. Some studies in people and cats suggest that they, too, experience alkaline as a type of taste.

How humans settled the roof of the world

Modern inhabitants of the Tibetan Plateau are descendants of people who have lived there for 5,000 years. In the biggest study of its kind, researchers sequenced ancient genomes from the remains of 89 individuals unearthed from 29 archæological sites. The genomes suggest that Tibet’s first settlers arrived from the east — in contrast to the rest of South and Central Asia. And researchers saw the increasing prevalence of a variant of the EPAS1 gene that allows people to thrive at high altitudes.

How stem cells make a human brain

Scientists have followed the developmental destiny of individual human brain cells as they progress from stem cells to specialised structures in the brain. In a technical “tour de force”, the team painstakingly purified and classified undifferentiated brain cells from human fœtuses. The cells were injected into mouse brains, and, six months later, the researchers analysed the cellular identities that the cells’ progeny had taken.

Volcano eruption spotted on Venus

Scientists think they’ve spotted a volcano erupting on Venus. Radar images taken 8 months apart by NASA’s Magellan spacecraft in the early 1990s show changes to a volcanic vent that suggest an eruption or magma flow. Venus is covered in volcanoes, and this is some of the strongest evidence yet that at least one of them is still active. Venus doesn’t have plate tectonics that could drive volcanic activity, so it could be caused by heat released from radioactive elements.

Heartbeat May Shape Our Perception of Time, Study Shows

Our perception of time might be in part driven by heartbeats. When 45 students were asked to estimate the length of audio tones, the people with long intervals between their heartbeats perceived the tone as longer, whereas the people with shorter intervals thought it was shorter.

First full brain map of a complex animal

Scientists have mapped all 3,016 neurons and 548,000 connecting synapses in a young fruit fly’s (Drosophila melanogaster) brain. It’s the first complete brain map of a complex animal that can learn, and weigh the risks and benefits of its actions. The only other animals whose brains have been completely mapped are two worm species and the larva of a sea squirt. The neural circuit diagram will help researchers to study how the brain works and neurological diseases.

Asteroid lost 1 million kilograms after collision with DART spacecraft

The asteroid that was deliberately hit with NASA’s Double Asteroid Redirection Test (DART) spacecraft last September lost one million kilograms of rock, gained a 1,000-kilometre-long debris tail and now completes its orbit 33 minutes faster than before the collision. A detailed analysis of what happened when DART smashed into the Great-Pyramid-sized asteroid Dimorphos has revealed how successful this first test of planetary defence really was. The spacecraft hit a spot close to the asteroid’s centre and caused a large spray of rubble to fly outwards, which maximised the impact’s force and added momentum.

Ancient genomes show how humans escaped Europe’s last ice age

European hunter-gatherers holed up in what is now Spain to escape the last ice age, which covered large parts of the continent with glaciers for several millennia. Researchers analysed DNA from 356 individuals who lived in Europe and western Asia between 35,000 and 5,000 years ago. The humans who had sought out the warmer climate on the Iberian Peninsula repopulated Western Europe after the deep freeze ended. This explains how a genetic signature that first showed up in 35,000-year-old remains popped up again in populations tens of thousands of years later — a fact that had remained a mystery until now.

The molecule that kickstarted life

For more than 15 years, scientists have been on a quest: create a functional ‘protoribosome’, a reconstructed version of the protein-building machine that many think might have helped to kickstart life on Earth. The modern ribosome is a key ingredient of life as we know it because it translates genetic information into proteins. At its heart sits a small RNA pocket that some think might be closest to what the very first ribosome looked like. Now, there’s proof that some reconstructed protoribosome-like RNAs can link amino acids — the first step to making proteins. Some scientists say there are other ways for proteins to emerge, without a ribosome. But others are already thinking about repurposing these simple machines to manufacture new kinds of biomolecule.