Blood groups are complex. The two best known blood group systems are ABO and Rh. Within each blood group, red cells can carry surface markers called antigens. For example, within the ABO blood group system, there are the A and B antigens — people with A have the A antigen, people with B have the

Using images from the JunoCam instrument aboard NASA’s Juno spacecraft, planetary scientists have spotted a fresh volcano with multiple lava flows and volcanic deposits covering an area about 180 x 180 km. A comparison of the JunoCam image from February 2024 with Galileo spacecraft imagery of the same area in November 1997 (grayscale insert) reveals

Chemists at the Leibniz Institute for Tropospheric Research have provided experimental evidence that sulfurous acid (H2SO3), once formed in the gas phase, is kinetically stable enough to allow its characterization and subsequent reactions. In the gas phase, if once formed, sulfurous acid shows a certain kinetic stability with an estimated lifetime of at least one

The images in the Martian Cloud Atlas have been captured by the High Resolution Stereo Camera (HRSC) instrument on ESA’s Mars Express spacecraft. Lee waves on Mars are created by the wind encountering obstacles and build up on the ‘leeward’ or downwind side. Image credit: ESA / DLR / FU Berlin. Due to the elliptical

Paleontologists have found the fossilized seeds of gymnosperm trees — relatives of today’s conifers and ginkgos — in stomachs of two specimens of Longipteryx chaoyangensis, one of the earliest known birds and one of the strangest. The discovery shows that these birds were eating fruits, despite a long-standing hypothesis that they feasted on fish, and

The newly-discovered footprints of theropod and ornithopod dinosaurs date back to the Early Cretaceous epoch, over 120 million years ago, when Australia was still connected to Antarctica. Melissa Lowery and Anthony Martin examine a dinosaur track. Image credit: Ruth Schowalter. The Early Cretaceous dinosaur footprints were discovered in the Wonthaggi Formation south of Melbourne, Australia.

At least 140 million Sun-like stars in our Milky Way Galaxy are likely to have experienced a similar stellar flyby, according to new research by a team of astrophysicists from the Forschungszentrum Jülich and Leiden University. Snapshot of the ancient stellar flyby. The turquoise particles indicate the TNOs injected into the planet region by the

Archaeologists have identified a 2.7-km- (1.7-mile) long Roman defensive wall and ditch — initially constructed by the Roman general Marcus Licinius Crassus to contain the Thracian gladiator and slave revolt leader Spartacus and his forces — in Calabria, southern Italy. The 2,070-year-old Roman wall in the Dossone della Melia forest in south-central Calabria, Italy. Image