An enigmatic line across Pluto: Plutonian canali!?
Pluto and Charon are growing larger in New Horizons' forward view, beginning to develop distinct personalities. Pluto: larger, brighter, but with dark splotches on its surface. Charon: smaller, dimmer, its features still hidden. Here's the very latest from the New Horizons raw image website: the best image ever taken of Pluto and Charon.
NASA / JHUAPL / SwRI / Emily Lakdawalla
New Horizons' view of Pluto on June 9, 2015
Pluto and Charon as seen by New Horizons on June 9, 2015, from a distance of 42 million kilometers. Three 100-millisecond exposures were enlarged and then stacked to reduce JPEG artifacts, then downsampled to the original resolution.
If you're an image processing magician like Björn Jónsson, you can take several images like these and stack and sharpen them to reveal more detail than can be perceived in any single photo. Björn took four images from June 6 and produced this.
NASA / JHUAPL / SwRI / Björn Jónsson
New Horizons' view of Pluto on June 6, 2015
New Horizons captured the four images used to make this view on June 6, 2015 from a distance of 46 million kilometers. Four images have been stacked and sharpened. The dark line running across Pluto is likely a real feature, not a processing artifact. Charon is still too small for any apparent features to be definitively discerned.
See that diagonal line running across it? Björn is certain that it's an actual feature. Yay! Dark lines criscrossing a disk! It's the discovery of canali on Pluto! We have reached Schiaparelli-quality mapping of Pluto's surface!
I am not entirely joking when I evoke Martian canali here. Schiaparelli was one of the great astronomers of his day. Many of his peers also saw canali on Mars, including Percival Lowell, whose name graces the observatory that was used to discover Pluto. I find it fitting that the first new "feature" observable on Pluto is an enigmatic dark line, recapitulating the history of the exploration of Mars and Venus. Fortunately, we need only wait a few weeks more to learn whether the line is an artifact built by an alien civilization to transport valuable liquids across the Plutonian surface* -- or if it's something else entirely. My money is on the latter!
Via Sky and Telescope and Phil Stooke
Canali on Venus
Percival Lowell mapped Venus in 1896, observing the same kinds of canali on it that he saw on Mars.
* Just in case it's not painfully obvious: this is a joke!! I hate that I even have to write that, but this is the Internet, so....