Image-processor extraordinaire Kevin Gill has reached back in time to give us a new image of Neptune and its moon Triton.
When NASA’s Voyager 2 spacecraft flew past Neptune and Triton in August 1989, its cameras were very busy. Kevin has taken separate color-filtered images from that visit and calibrated and combined them to give us a new, almost haunting look at the planet and its largest moon.
It took Voyager 2 twenty years to reach Neptune, and it was the first spacecraft to ever visit. As it stands now, it’s the only spacecraft to have ever visited. It was Voyager 2’s last planetary encounter, and it approached to within 4,950 km (3,080 mi) of the planet’s north pole. Much of our knowledge of Neptune and Triton stems from that visit.
Kevin Gill is well-known in space-enthusiast circles for his images. In an email exchange with Universe Today, Kevin explained his approach to the image. As it turns out, this isn’t is first attempt to get this image.
“I’ve attempted this image before, but wasn’t super happy with it and I’ve improved a bit since then so I downloaded the data. It’s all processed using the calibrated images hosted on the NASA PDS OPUS site.”
Kevin explained that Voyager 2’s Vidicon camera wasn’t sensitive to red. As a result of that, the headline image isn’t true color; but it’s as close as he could get it. “I used the orange, green, and blue filtered images, so it’s not true color, but I did make attempts to get it as close as possible to reality.”
Gill said that this was not one of his most complicated images, and the instrument noise from the 80’s era spacecraft was one of the main impediments. “It’s not really a super complicated image, the main challenge being the ambient light and instrument noise. Looking at the timestamps on the files I used, from start to finish it probably took about 30 minutes to complete it.”
Kevin intended for the image to be of the “on this date” variety. The image date is August 31st, and Voyager 2’s closest approach to Neptune was just prior to that, on August 25th, 1989.
There are 55 images of Neptune and its moons in Gill’s Neptune album, including the one below. Like the main image, it’s also a combination of red, green, and blue color-filtered images from Voyager 2’s visit.
Kevin’s work covers other planets in the Solar System, too. NASA’s Juno mission to Jupiter carries the JunoCam, which isn’t part of the spacecraft’s scientific payload. It’s just there to take pictures for the rest of us, and NASA has invited anyone who’s interested to take the raw images and process them and share them.
Rover missions to Mars have opened up our eyes to that planet. Kevin Gill’s Mars Exploration Rovers album contains 30 images, including the one below from NASA’s Opportunity rover.
Kevin Gill is a software engineer at NASA’s JPL. He’s involved in data analysis and visualization in a professional capacity, which clearly feeds into his other work.
You can see his work on Flickr, where he currently has over 5,700 images up.