Planetary systems in the Milky Way galaxy tend to follow a particular pattern: rocky planets toward the center, closest to the host star, and gas planets toward the exterior. That’s how planets are organized around our sun, with rocky Mercury, Venus, Earth and Mars first in the lineup, followed by the gaseous Jupiter, Saturn, Uranus and Neptune.

An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how planets form. Across our galaxy, astronomers routinely observe a characteristic pattern in planetary systems: rocky planets orbiting close to their host star with gas giants farther away.

One of the coolest celestial events is happening this week, where six planets will be visible in the night sky at the same time. This phenomenon, known as a planet parade, occurs only a few times each year with varying numbers of planets. This particular ...

Astronomers have uncovered a distant planetary system that flips a long-standing rule of planet formation on its head. Around the small red dwarf star LHS 1903, scientists expected to find rocky planets close in and gas giants farther out — the same pattern seen in our own Solar System and hundreds of others.

About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong gravitational pull took shape, kick-starting the birth of the sun. But after that, the details leave more room for debate ...