The space probe began making discoveries even before today's flyby. — -- Three billion miles and nearly ten years of travel led up to the moment NASA's New Horizons probe zoomed past Pluto ...

Today, the dwarf planet Pluto orbits the sun from the edge of our solar system and its surface temperature is an inhospitable negative 378 to negative 396 degrees Fahrenheit. But a new study ...

We still don't know for sure if there's a ninth planet in our solar system, but a new discovery could help to prove that Planet Nine doesn't exist.

Pluto’s mysterious far side may conceal towering ice formations, according to research offering clues about the dwarf ...

The science community may be ecstatic over the discovery of a ninth planet, but the former planet "Pluto" had a totally different reaction. Hours after scientists announced there's solid evidence ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...