A head-on collision with another galaxy billions of years ago may have dramatically reoriented the Milky Way’s disk, according to new supercomputer simulations that reveal how violent mergers can leave spiral galaxies looking surprisingly normal today. Using supercomputer simulations of galaxies like the Milky Way, Batrakov et al. found that galaxies with slowly rotating stellar haloes are more...

New data from NASA’s Juno spacecraft show temperatures spike more than 20 degrees Celsius just a few meters under Io’s surface, providing the first look at what’s happening below the crust of the Solar System’s most volcanic world. The north polar region of Io was captured by NASA’s Juno spacecraft on December 30, 2023. Image credit: NASA / JPL-Caltech / SwRI / MSSS / Gerald Eichstädt. Jupiter’s...

Ararat-1, a modest limestone cave that lies at an elevation of 1,034 m on the eastern flanks of the Ararat Depression in central Armenia, has yielded a striking puzzle about how Middle Paleolithic humans moved across their landscape. A look at Ararat-1 Cave from the bottom of the Ararat Depression. Image credit: Ariel Malinsky Buller. “The Caucasus is a geographically and ecologically diverse region...

A 201-million-year-old climate catastrophe turned Europe into a landscape of fern savannahs that repeatedly caught fire, according to new research published in the journal Nature Geoscience. An artist’s impression of the end-Triassic fern spike interval. Image credit: Mark Garlick. “Ferns are truly remarkable plants that have withstood many crises throughout Earth history, and some species can...

In a new study of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), scientists found that embraces, touches and other reassuring gestures before competition for food were linked to more peaceful sharing, suggesting the roots of human social touch stretch back at least six million years. Examples of bonobo and chimpanzee reassurance behaviors. Image credit: Z. Clay / J.S. Brooker. “Social...

Using the largest sample yet of particles called beauty mesons, physicists with the CMS Collaboration at CERN’s Large Hadron Collider (LHC) refined a decades-old test of the subtle imbalance that let our Universe exist at all. Neutral beauty mesons can turn into their own antimatter opposite and back again. Image credit: Ansar Iqbal / CMS. One of the greatest mysteries in physics is why the Universe...

In a new review paper, Dr. Gregory Marcus from the University of California, San Francisco and colleagues analyzed decades of research on how caffeine — most often consumed as coffee — affects the heart and its risk factors. They defined moderate intake as up to about 400 mg of caffeine a day, roughly three to five 8-ounce cups (a fluid ounce is 30 ml) of coffee. Marcus et al. conclude...

In an analysis of 390 traditionally cultivated cacao trees representing traditional Amazonian varieties, researchers identified four previously unknown genetic lineages, with two showing ancestry linked to exceptional flavor potential and offering new opportunities for growers and chocolate makers. Motilal et al. collected cacao samples from eight departments of Peru. Image credit: Fernando Graniel. Cacao...

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;...

In a new review paper, Dr. Gregory Marcus from the University of California, San Francisco and colleagues analyzed decades of research on how caffeine — most often consumed as coffee — affects the heart and its risk factors. They defined moderate intake as up to about 400 mg of caffeine a day, roughly three to five 8-ounce cups (a fluid ounce is 30 ml) of coffee. Marcus et al. conclude...