How to Be an Armchair Planetary Scientist
A brief guide to online image data from planetary missions Emily Lakdawalla The Planetary Society
Image: NASA / JPL / Ted Stryk
It’s a great time to be an armchair space explorer
• Rapid release of “raw” image data is now norm • High-speed Internet common • Digital cameras mainstream
– More people have image processing skills
• Forums, blogs, YouTube, etc. facilitate sharing
Image: NASA / JPL / SSI / Emily Lakdawalla
Where can amateurs get data?
• Many missions have special raw image websites
– Current missions include: Mars Exploration Rovers, Cassini, and Phoenix
• Data release is automated
– After being received on Earth, data is usually contrast-enhanced and converted to JPEG format
• These allow amateurs to follow missions in “real time,” along with science teams
What can you do with raw images?
• Answer “What is Cassini (or Phoenix) doing today?” • Crop, play with brightness/contrast to make pretty pictures • Make animations • Make mosaics • Make color images out of three separate images taken through different filters
Three Cassini images taken on Saturday, May 30
• Tiny little moons in great big frame, overexposed • Crop and adjust levels to bring out detail
Images: NASA / JPL / SSI
Three Cassini images, made prettier
Images: NASA / JPL / SSI / Emily Lakdawalla
Making animations
• Many spacecraft take time-series of images, usually separated in time by one or more minutes:
– Cassini: Saturn cloud motions, F ring patterns, moons passing each other, moon flybys – Rovers: Hazcams and Navcams take images during drives and during arm operations – Phoenix: many images of arm motions and motion of wind vane
• These don’t make smooth movies. • They do make neat animations.
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 1 / 6)
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 2 / 6)
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 3 / 6)
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 4 / 6)
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 5 / 6)
Do-it-yourself animation in Powerpoint: Phoenix arm deployment (frame 6 / 6)
Phoenix sol 3 arm deployment animation
• 6 frames • Assembled into an animated GIF using Photoshop
Image: NASA / JPL / UA / Emily Lakdawalla
Hyperion rotation animation
• Cassini, 500,000-km flyby • 6 frames
Image: NASA / JPL / SSI / Justin Phillips
Titan, Dione, and Saturn
• 16 frames, artificially colorized
Image: NASA / JPL / SSI / Gordan Ugarkovic
Making Mosaics
• When things don’t fit into one picture, they take several for later assembly
Images: NASA / JPL / SSI
Making Mosaics
Making Mosaics
Making Mosaics
Making Mosaics
Making Color Images
• Spacecraft do not carry color cameras. • Spacecraft camera detectors detect a broad range of wavelengths of light. • To get color information, a filter is placed in front of the camera that only lets in photons of a narrow color range. • To make a color picture, you need three such images, taken through different filters. • Red, green, and blue filter images give you approximate true color.
Making color images
• Phoenix calibration target • Each chip a different color or gray • Left: red filter; middle: green; right: blue
Making color images
Phoenix Sol 2 postcard
• Assembled from raw images taken in red, green, and blue filters
Image: NASA / JPL / UA / James Canvin
Go out and play with pictures!
• • • • Phoenix: http://phoenix.lpl.arizona.edu Cassini: http://saturn.jpl.nasa.gov Rovers: http://marsrovers.jpl.nasa.gov For the rovers, get the Midnight Mars Browser auto-downloader and virtual reality panorama builder: http://midnightmarsbrowser.blogspot.com • To share images and ask for tips, go to http://unmannedpaceflight.com