New Speckly Image Shows Non-Planet Pluto In the Sharpest Detail Yet

Pluto and Charon This speckle image reconstruction of Pluto and Charon was obtained in visible light with the Gemini North 8-meter telescope using the Differential Speckle Survey Instrument (DSSI). Resolution of the image is about 20 milliarcseconds rms (root mean square). North is up, east is to the left, and the image section shown here is 1.39 arcseconds across. Gemini Observatory

This blurry image of Pluto and Charon may not seem that impressive at first glance, but consider this: The resolution here is equivalent to separating a pair of car headlights in Providence, Rhode Island, from a viewing spot in San Francisco. This is the clearest image ever taken in visible light of our favorite dwarf planet and its largest companion.

Scientists using the Gemini Observatory used the “speckle method” to obtain this image, which involves taking a lot of snapshots and then stitching them together. Each picture was a 60 millisecond exposure, or about 1/20th of a second. Instead of using adaptive optics to cancel out Earth’s atmospheric turbulence and other artifacts, the speckle method combines the light from each object in each picture, which remains constant.

The result is a clear image (for astronomers, anyway) that shows the precise diameters of each celestial body and how they interact with one another. This will help the upcoming New Horizons mission, which is en route to Pluto for a 2015 arrival. Along with improving our understanding of Pluto, it could also help verify the Kepler Space Telescope’s search for dim exoplanets around other stars.

[Gemini Observatory]