As New Horizons continues to close the gap between itself and Pluto more details are being revealed in images of the planet and its (comparatively) giant moon. Some of the latest images are showing some particularly intriguing features just below Pluto’s equator: a row of somewhat evenly-spaced dark spots, each about 300 miles (480 km) wide.
The New Horizons team combined 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 the image above.
This is the first time these dark spots have been observed and scientists aren’t sure what to make of them.
“It’s a real puzzle – we don’t know what the spots are, and we can’t wait to find out,” said New Horizons principal investigator Alan Stern of the Southwest Research Institute in Boulder, CO. “Also puzzling is the longstanding and dramatic difference in the colors and appearance of Pluto compared to its darker and grayer moon Charon.”
New Horizons will perform its closest pass of Pluto and Charon on July 14.