The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact ...

Even the best telescopes can’t see exoplanets. It’s all about watching for jiggly stars, blue shifts, and transits.

New high-contrast images from SPHERE show a stunning variety of debris disks shaped by collisions of tiny planet-building ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

Still, science being science, we needed proof—and we got it in 1992, when two astronomers found two planets orbiting a pulsar 2,300 light years from Earth. Since then, over 6,000 confirmed exoplanets ...

Astronomers are uncovering distant worlds beyond our solar system using ingenious indirect methods like observing stellar ...

"This is really like looking at ourselves in a funhouse mirror." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Skewed planetary pathways around ...

A new explanation for the solar system's radioactive elements suggests Earth-like planets might be found orbiting up to 50 ...

Astronomers using planet-hunting satellites have discovered a rare solar system with six planets moving completely in sync with one another, as if they were untouched by any outside force since being ...

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 ...

Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though only slightly larger than Earth’s Moon, Mercury endures some of the most ...

Seven planets are aligning in the night sky this week, creating a brief chance to see a "planetary parade." Worldwide, the best day to see the alignment is today, Feb. 28. Mercury, Venus, Mars, ...