Planet Nine May Have Once Been an Exoplanet

It hasn’t even been found yet (they’re still working on that) but the recently-announced Planet Nine is already spurring discussion amongst the world’s astronomers. One of the recent topics surrounding this alleged new planet is (again, besides where it’s hiding) how it formed and how it got into the incredibly distant orbit it’s thought to be…

Pluto’s Frozen Lake Hints at a Warmer Past

Hockey fans take note: future visitors to Pluto may want to bring along their sticks and skates—the distant planet may harbor some pristine ice in the form of frozen ponds and lakes! (NASA might have to work on a lightweight, collapsible Zamboni first though.)

Pencil This In: Mercury’s Surface is Darkened by Graphite

Monochromatic and covered in craters, Mercury may outwardly resemble our Moon but the similarities abruptly end there. Ever since the MESSENGER spacecraft entered orbit around Mercury in 2011, and indeed even since Mariner 10‘s flyby in 1974, peculiar “dark spots” observed on the planet’s surface have intrigued scientists as to their composition and origin. Now, thanks to high-resolution spectral…

Pale Blue Dot: Our Valentine from Voyager 1

If you’re in love with space exploration then you’ll fall for this: a picture of Earth (and five other planets) taken from the Voyager 1 spacecraft after it passed the orbit of Pluto in 1990, 26 years ago today. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his…

Why Are Pluto’s Moons So Weird?

Whether you call it a planet, a dwarf planet, or a Kuiper Belt or Trans-Neptunian Object—or all of the above—there’s no denying that Pluto and its family of moons are true curiosities in the Solar System. Not only does little Pluto have one moon, Charon, that’s so massive in comparison that they both orbit each other…

Planetkiller Presents New Evidence for “Planet X”

A planet-killing astronomer is now attempting to introduce a new world into the Solar System. Self-professed “Pluto killer” Mike Brown — the Caltech professor and astronomer whose discovery of Eris in 2005 prompted the reclassification of what constitutes a full-fledged planet, thus knocking Pluto from the list a year later — is now offering up evidence for the existence of a “real” ninth…

Cassini Has Made Its Last Pass by Enceladus. Here Are the Pictures.

After nearly eleven and a half years in orbit around Saturn the Cassini spacecraft has made its last-ever targeted flyby of Enceladus, the 320-mile-wide moon of Saturn that has intrigued scientists and the public alike with its active water ice geysers for more than a decade since their discovery. On Saturday Dec. 19, 2015, Cassini performed its E-22…

Pluto Is the New Science Star of the Solar System

Now over four months after the historic and long-awaited flyby of Pluto by New Horizons, planetary scientists have had a steady stream of unprecedented data arriving on Earth from the outwardly-speeding spacecraft. We’ve learned more about Pluto in the past few months than we had over the decades before and the information is still being analyzed…

Pics Are In from Cassini’s Flyby Through Enceladus’ Plumes!

On Wed. Oct. 28 Cassini performed its lowest-altitude dive yet through the icy plumes of Enceladus, coming just 30 miles from the moon’s surface — that’s only about 6 times higher than a commercial airliner at cruising altitude. But, traveling over 19,000 mph relative to Enceladus (which is 38 times faster than a jet plane!) the pass was…