The presence of deuterium, an isotope of hydrogen, in 3I/ATLAS suggests the interstellar comet formed in a much colder place ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

Scientists are grappling with a cosmic mystery: why does the Universe behave differently on massive scales compared to our ...

Gravity, electromagnetism, the strong nuclear force, the weak nuclear force. For decades, physicists have recognized exactly ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

Thanks to the sheer mass of Jupiter and fellow gas giant Saturn, the Solar System barycenter is rarely in the center of the ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

Rather than slowly condensing over millions of years, the first building blocks of Earth and other planets may have formed ...

The sun is an incomprehensibly gigantic, constantly roiling nuclear furnace—but some days are even busier than others. Based ...