New Pluto images show the difference 32 million kms can make
Meteorologist/Science Writer
Wednesday, May 27, 2015, 4:37 PM - It's been nearly a month since we were treated to the most recent look at Pluto's surface, and what a difference a month and 32 million kilometres can make...
The latest images from NASA's New Horizons team are in, and Pluto is looking sharper than ever, thanks to the spacecraft closing the distance at a speed of about 1.2 million kilometres every day.
In three images (in the animation below), NASA's team presents snapshots of Pluto from May 8, 10 and 12, compared to previous images from April 12, 15 and 16, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute, compiled and edited by author.
"These new images show us that Pluto's differing faces are each distinct; likely hinting at what may be very complex surface geology or variations in surface composition from place to place," Alan Stern, the New Horizons Principal Investigator at the Southwest Research Institute in Boulder, Colorado, said in a NASA statement. "These images also continue to support the hypothesis that Pluto has a polar cap whose extent varies with longitude; we'll be able to make a definitive determination of the polar bright region's iciness when we get compositional spectroscopy of that region in July."
"By late June the image resolution will be four times better than the images made May 8-12, and by the time of closest approach, we expect to obtain images with more than 5,000 times the current resolution," added project scientist Hal Weaver, from Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.
How Do They Do It?
The spacecraft was at least 75 million kilometres away when these most-recent images were taken. So, how is the New Horizons team able to take the tiny light dot of Pluto and produce these amazing, albeit still blurry, pictures?
A technique known as image deconvolution was used - the same technique that corrected the images from the Hubble Space Telescope before it was repaired.
In this method, the image data is processed by a computer, which figures out how the light from an ideal source (typically a pinpoint) would be distorted simply by passing through a perfect instrument, thus neglecting any optical flaws or distortions due to movement of the instrument or the source. When this "ideal" distortion is determined, the computer then plots the inverse and applies that to the image data, which sharpens it as much as possible.
According to the New Horizons team: "Deconvolution can occasionally add 'false' details, so the finest details in these pictures will need to be confirmed by images taken from closer range in the next few weeks. All of the images are displayed using the same linear brightness scale."
On Schedule, With Plenty To See
With a July 14 rendezvous data between New Horizons and Pluto, we have just under 7 weeks before we get the best look at Pluto we're likely to see in some time to come.
"As New Horizons closes in on Pluto, it's transforming from a point of light to a planetary object of intense interest," said Jim Green, NASA's Director of Planetary Science. "We're in for an exciting ride for the next seven weeks."
