The boundary of a solar system is not defined by planets, but by gravity. Beyond Pluto and the Kuiper Belt lies the Oort ...

At the ragged frontier where the Sun’s influence gives way to the galaxy, a decades‑old spacecraft has stumbled into a ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

The upcoming year will offer a blood-red moon, spectacular meteor showers and the first glimpse of the sun’s corona since ...

Super-Earths and sub-Neptunes, planets with sizes between Earth and Neptune, constitute approximately one-third of known exoplanets but are absent in our solar system. Their prevalence elsewhere and ...

Scientists have long puzzled over why all of the planets in Earth’s solar system have slightly slanted orbits around the sun. But a new, Yale-led study suggests this phenomenon may not be so unusual ...

So what is your favorite planet?” As museum educator Melissa Moeller opened up her presentation on the solar system Saturday ...

Short-lived radioisotopes such as aluminum-26 influenced early solar system heat, water retention and the formation of Earth-like rocky planets, according to meteorite analyses and models.

The International Astronomical Union (IAU) defines a planet as a celestial body orbiting the Sun, possessing sufficient mass for a nearly spherical shape, and having cleared its orbital neighborhood ...

NASA’s Hubble Space Telescope has captured infant planets colliding around Fomalhaut, one of the brightest stars in the night ...

Jupiter is the largest planet in the solar system, known for its massive size, strong gravity, powerful storms and many moons ...