Planetary 'twins' Uranus and Neptune may have different origin stories‎

By indirectly probing the depths of Uranus and Neptune's atmospheres, an international team of scientists has revealed a significant contrast in their chemical composition. Neptune appears to be more enriched in oxygen than Uranus. These results suggest that the two ice giants may have formed in different regions of the primitive solar system before reaching their current orbits, calling into question the idea of a common origin for these two planets, often considered twins.