A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system?

Since Pluto was relegated to dwarf planet status, almost everyone has agreed that there are eight planets in our solar system ...

A low-density, puffy planet orbiting relatively far from a young star in a nearly perpendicular orbit. What's going on?

Astronomers are investigating a strange class of exoplanets known as eccentric warm Jupiters — massive gas giants that orbit their stars in unexpected, elongated paths. Unlike their close-orbiting ...

We're just weeks away from this interstellar visitor reaching its brightest in Earth's night skies. Will we see it?

KENNEDY SPACE CENTER — SpaceX’s Falcon 9 rocket pierced the Wednesday morning sky as it launched three spacecraft from NASA and NOAA that will study the solar system’s “bubble,” collect information on ...

Planets that orbit white dwarf stars should be too hot to host alien life, theories suggest. But a new study accounting for ...

Astronomers believe they may have uncovered evidence of a hidden Earth -size planet lurking in the outer solar system. Dubbed “Planet Y”, the proposed world could be nearly twice as close to Earth as ...