Gas-rich dwarf galaxies appear to retain only about a tenth of the oxygen their stars have made, according to a census of 37 nearby systems using data from the NASA/ESA Hubble Space Telescope. This Hubble image shows NGC 4449, one of the dwarf galaxies in the Galaxies Losing Oxygen via Winds (GLOW) study. Image credit: NASA / ESA / Hubble Heritage-ESA / Hubble Collaboration / Alessandra Aloisi, STScI...

Teghaza 001, a meteorite found in the Sahara Desert in Mali four years ago, is a fragment of Mars’ primordial crust, formed at least 4.1 billion years ago, according to a new paper in the journal Science. The largest fragment of the Martian meteorite Teghaza 001. Image credit: Liu et al., doi: 10.1126/science.adz5646. Teghaza 001 consists of eight fragments with a total mass of 798.5 g, the largest...

Some of the oldest drawings known to humanity, made roughly 37,000 years ago in France’s Chauvet Cave, are covered by a thin, translucent film of calcite that cannot be seen with the naked eye. Scientists from Sorbonne Université and the French National Center for Scientific Research (CNRS) have now found a way to detect it from a distance, without touching the walls. The Horses panel in Chauvet...

A new species of extinct megapode bird — a ground-dwelling relative of the chicken that was several times heavier than its living cousin — has been identified from a single fragment of leg bone found in a cave on the Indonesian island of Flores. Megapodius rokusi (left) next to Megapodius reinwardt (right). Image credit: Davin Arya Nirwasita. The newly described species belongs to the...

A new study led by the University of Cambridge challenges the long-standing idea that comets helped kick-start life on our home planet, suggesting that the icy bodies were largely unable to deliver the concentrated chemical ingredients needed for prebiotic chemistry. An artist’s impression of cometary impact. Image credit: Scarlett White. “Historically, scientists thought that comets were important...

Physicists at Northwestern University have held a single positron — the antimatter twin of the electron — in a trap for months and manipulated it one quantum jump at a time. They call their setup a ‘one-positron quantum cyclotron.’ Cloud chamber photograph by the American experimental physicist Carl David Anderson of the first positron ever identified. Antimatter is hard to study...

Scientists have identified a receptor on sensory nerves that appears to detect a fatty-acid byproduct found at high levels in psoriasis skin, and blocking it eased itch and skin thickening in mice. Wheeler et al. identify a metabolic- to-sensory axis in which EKODE, an endogenous dietary linoleic acid derivative, acts as a potent ligand for the G protein-coupled receptor 35 (Gpr35) to drive chronic...

Humans and chimpanzees share more than 96% of their protein-coding DNA, yet human brains are roughly three times larger and far more complex. New research led by Lund University scientists suggests that part of the explanation may lie in a viral infection that struck chimpanzee ancestors millions of years ago and never reached ours. Gerdes et al. show that LINC00662, a human-specific transcript expressed...

Zircon crystals and impact-altered minerals show that a massive asteroid slammed into what is now the Pilbara region of Western Australia about 3 billion years ago. The North Pole Dome crater: (A) simplified map of the East Pilbara Terrane (EPT, Western Australia), showing Paleoarchean granite domes (pink) and greenstone belts (greens and blues); the North Pole Dome (NPD) lies near the terrane center;...

The fossilized remains belong to Aratasaurus museunacionali, a species of coelurosaurian theropod dinosaur that lived in what is now northeastern Brazil during the Early Cretaceous epoch, some 115 million years ago. SEM images showing red blood cell-like structures in the bone of Aratasaurus museunacionali. Image credit: Grice et al., doi: 10.1073/pnas.2614248123. “Our findings challenge longstanding...