The Other Red Planet

nh-7-2-15_pluto_globesMars is red because of iron oxide in the planet’s soil. Why is Pluto red? We don’t know yet, but the best guess is that it’s the result of UV light and cosmic rays interacting with hydrocarbons on the Pluto’s surface. We’ll learn more about the planet as the New Horizons spacecraft flies by on 14 July.

Image Credit: NASA

More Pluto

nh-7-1-15_pluto_charonNew color images from the New Horizons spacecraft show two very different sides of the Pluto. One has a series of evenly spaced spots along the equator, each about the size of the state of Missouri. While the origin of the spots is a mystery for now, the answer may be revealed as the spacecraft continues its approach to the dwarf planet.

The pictures above were generated by combining black-and-white images of Pluto and Charon from the spacecraft’s Long-Range Reconnaissance Imager (LORRI) with lower-resolution color data from the Ralph instrument to produce these views. The planet and its largest moon are shown in approximately true color as they would appear to someone riding on the spacecraft.

Image Credit: NASA

Triple Crescent

Triple CrescentSaturn has many moons. The three shown here—Titan, Mimas, and Rhea—show marked contrasts in their surface features. Titan, Saturn’s largest moon and the largest moon in this image, appears fuzzy because we only see its clouds. Because Titan’s atmosphere refracts light around the moon, its crescent is wrapped just a little further around the moon than it would on an airless body. Rhea (upper left) appears rough because its icy surface is heavily cratered. A close inspection of Mimas, though difficult to see at this scale, would show surface irregularities because of its violent history.

Image Credit: NASA

One more thing … If it’s clear where you are this evening, go outside and look up in the western sky just after sunset. There’s a conjunction of Venus and Jupiter tonight. They will be separated by less than half the diameter of the Full Moon.

NGC 6153

A nitrogen-rich nebula This is NGC 6153. The faint blue haze is what remains of a star like the sun after it had depleted most of its fuel. When that happened, the outer layers of the star were ejected and then ionized by the ultraviolet light from hot core of the star, forming the nebula.

NGC 6153 is a planetary nebula which contains large amounts of neon, argon, oxygen, carbon and chlorine—up to three times more than can be found in our solar system. It contains five times more nitrogen than our sun! It could be that the star developed higher levels of these elements as it grew and evolved, but it is more likely that the star originally formed from a cloud of material that already contained an abundance of those elements.

Image Credit: ESA / NASA