Scientists are grappling with a cosmic mystery: why does the Universe behave differently on massive scales compared to our own solar system? While distant galaxies reveal clear signs of something ...

Illustration comparing the planets of the Solar System and the Sun on the same scale. The planets are shown to scale relative to each other but their distances are not. From left to right the bodies ...

A mysterious comet from beyond our solar system is giving astronomers a rare glimpse into alien worlds — and it may have formed in a place far colder and stranger than anything around our Sun. The ...