As we anticipate the July 14 Pluto flyby - as NASA's New Horizons spacecraft zips through the dwarf planet's system of moons - in new images published by the mission team on Wednesday, the small world has revealed it has two faces.
PHOTOS: Fuzzy to Clear: Space Robots Snap Solar System Into Focus
Beginning to look like a fuzzy, slightly paler version of Mars, Pluto seems to have a huge diversity of surface features, even from a distance of over 9.5 million miles (15 million kilometers) and it's beginning to look like the dwarf planet has two very distinct hemispheres. One "face" is smooth, with large dark features; the opposite side appears to have a peculiar series of spots spanning Pluto's equator, all roughly the same size, around 300 miles (480 kilometers) in diameter.
"It's a real puzzle - we don't know what the spots are, and we can't wait to find out," said Alan Stern, New Horizons' principal investigator at the Southwest Research Institute, in Boulder, Colo. "Also puzzling is the longstanding and dramatic difference in the colors and appearance of Pluto compared to its darker and grayer moon Charon."
NEWS: Pluto and Moon Charon Not Cut From Same Cloth
Indeed, the difference in color is becoming more pronounced on every image release. Pluto has a ruddy yellow hue, whereas Charon's color appears to have more in common with our moon than Pluto. It is worth noting, however, that these images are still very early in the flyby game, so we'll need to be patient until we start drawing any conclusions about surface composition or whether Pluto possesses clouds in its thin exosphere.
In other news from the Kuiper Belt, the New Horizons infrared spectrometer is online and has detected frozen methane on Pluto's surface. Astronomers have known about the spectroscopic signature of methane on Pluto since 1976, but the mission will study the distribution of this molecule around the dwarf planet to see how it varies.
ANALYSIS: Can We Call Pluto and Charon a ‘Binary Planet' Yet?
"We already knew there was methane on Pluto, but these are our first detections," said Will Grundy, New Horizons Surface Composition team leader with the Lowell Observatory in Flagstaff, Ariz. "Soon we will know if there are differences in the presence of methane ice from one part of Pluto to another."
The study of methane on Pluto will provide us with more clues as to the composition of the nebula from which our sun and the planets were born from 4.5 billion years ago. In short, this primordial chemical is an open book from the beginning of planetary formation.
As New Horizons continues to approach Pluto, the world is getting bigger, as shown in this awesome series of images captured from May 28 to June 25, 2015: