A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is hidden in our solar system.

The lawnmower's wheels and handle made the telescope easy to maneuver. My dad lived for another seven years after this photo was taken, passing on in 1997 at the age of 90. Pluto becomes a dwarf ...

It was October 2001, and a leaky Lindley Hall roof and Lawrence light pollution had rendered the 1929 telescope — which had been refurbished by Pluto discoverer Clyde Tombaugh — nearly useless.

To mark the 35th anniversary of the Hubble Space Telescope, Space.com looks at some of the most scientifically significant images that have emerged from the observatory's lens.

Pluto will mark a birthday of sorts on March ... Not long before coming to work at the observatory, Tombaugh had built his ...

Two NASA spacecraft have teamed up to capture direct images of Uranus. The Hubble Space Telescope and the New Horizons Pluto probe formed a cool tag team to investigate the mysterious seventh ...

Comet SWAN, hailing from the Oort Cloud beyond Pluto, may not have survived its recent trip past the sun and is fading fast.

Before New Horizons, the best images of Pluto revealed nothing more than a few light and dark patches. The best Hubble Telescope images were only 150 pixels across. The new pictures show much more ...

"The telescope itself is a big telescope ... Can you recite the names of all the planets in our solar system? Well, ever since Pluto got demoted, schools today have kids memorizing eight major ...