As the newest black and white image from New Horizons’ Long Range Reconnaissance Imager (LORRI) appeared on the morning of July 10, members of the science team reacted with joy and delight, seeing Pluto as never before. There will no doubt be many similar moments to come. New images and data are being gathered each day as New Horizons speeds closer to a July 14 flyby of Pluto, following a journey of three billion miles.
“We’re close enough now that we’re just starting to see Pluto’s geology,” said New Horizons program scientist Curt Niebur, NASA Headquarters in Washington, who’s keenly interested in the gray area just above the whale’s “tail” feature. “It’s a unique transition region with a lot of dynamic processes interacting, which makes it of particular scientific interest.”
New Horizons’ latest image of Pluto was taken on July 9, 2015 from 3.3 million miles (5.4 million kilometers) away, with a resolution of 17 miles (27 kilometers) per pixel. At this range, Pluto is beginning to reveal the first signs of discrete geologic features. This image views the side of Pluto that always faces its largest moon, Charon, and includes the so-called “tail” of the dark whale-shaped feature along its equator. (The immense, bright feature shaped like a heart had rotated from view when this image was captured.)
Tantalizing signs of geology on Pluto are revealed in this image from New Horizons taken on July 9, 2015 from 3.3 million miles (5.4 million kilometers) away.
An annotated version indicates features described in the text, and includes a reference globe showing Pluto’s orientation in the image, with the equator and central meridian in bold.
* Closest approach is at 11:50 UTC / 07:50 EDT / 04:50 PDT on Tuesday, July 14, 2015.
* New Horizons gets 1.2 million kilometers closer each day. As of today, it is 1 AU — 150 million kilometers — from Pluto.
* New Horizons has two cameras. The Long-Range Reconnaissance Imager (LORRI) has a field of view of 0.29 degrees and a pixel scale of 4.94 microradians and takes black-and-white (“panchromatic”) images. The Ralph Multispectral Visible Imaging Camera (MVIC) has a field of view 5.7 degrees wide and a pixel scale of 19.77 microradians and takes both panchromatic and color images. It has panchromatic, near-IR, red, blue, and methane filters, but no green filter.
* Through June 24, Pluto and all five of its known moons will fit comfortably within a single LORRI photo.
* Through July 12, New Horizons will take regular LORRI photos of Pluto, Charon, Nix, and Hydra, which will mostly be returned soon after acquisition because they are used for optical navigation.
* Pluto will appear larger than the LORRI field of view for less than 24 hours around closest approach.
* Since Pluto and Charon rotate slowly (once every 6.4 days), all of the best fully-lit images will show the same hemisphere.
* The other hemisphere will be imaged at a best resolution of about 38 kilometers per pixel, 3.2 days prior to closest approach.
* Only 1% of the science data from the flyby will be returned to Earth during the period around closest approach, including images that the mission has selected for their high science value as well as high public interest. They will be releasing captioned and processed versions as fast as their small team can manage.
* The rest of the image data will be downlinked beginning in September, about 2 months after encounter. It will take 10 weeks to download the full data set.
SOURCES – NASA, Planetary Society