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The Planetary Society Blog
By Emily Lakdawalla
Release of the science data from Hayabusa
May. 2, 2007 | 11:40 PDT | 18:40 UTC
Last week, the Hayabusa science team released a preliminary version of all of the science images and other data taken by the spacecraft throughout its mission! The data is split up into several phases as follows:
| Cruise | May 19, 2003 - September 11, 2005 | |
| Earth Swingby | May 16-19, 2004 | Gate Position
20 kilometers above Itokawa | September 12-29, 2005 | Home Position
~7 kilometers above Itokawa | September 30 - October 7, 2005 | Home Position
Tours to various altitudes,
different solar phase angles,
and polar observing | October 8-28, 2005 | | Descent and touchdown | October 30 - November 19, 2005
Touchdowns on November 19 and 25 |
I'm still working on downloading all the images, but I can tell you now that there are more than a thousand images available. Of particular interest are lengthy sequences taken during the Gate and early Home position phases, when Hayabusa took photo after photo as Itokawa rotated underneath it. I received an email out of the blue from Øyvind Guldbrandsen of the Norwegian Astronautical Society, who saved me a lot of work by assembling 169 images (169!!) into an animation showing a complete rotation of the asteroid. He actually took images from three separate rotations over the first two days of the "Home Position" phase, September 30 and October 1, 2005, and lined them all up and sorted them in to sequence to create this animation. The one shown below just has 57 frames -- to see the full animation in all its glory, follow the link to the 4-Megabyte AVI version. Many thanks to Øyvind for his hard work on this!Itokawa rotates under HyabusaThis animation consists of 57 separate images captured by the Hayabusa spacecraft as the tiny asteroid Itokawa (535 by 294 by 209 meters in size) rotated underneath it. The images are actually from three separate rotations; they were sorted and lined up into this animation by Øyvind Guldbrandsen of the Norwegian Astronautical Society. Click here for a full-resolution movie containing 169 frames (AVI format, 3.8 MB) Credit: ISAS / JAXA / Øyvind Guldbrandsen |
It's very interesting to compare Øyvind's animation to one that the Hayabusa team posted on their website (Quicktime format, 11.4 MB), which was made not from AMICA images but instead from a 3-D shape model derived from the AMICA images. This one is fantastic -- you'll need your 3-D (red-cyan, red over the left eye) glasses in order to see the full effect.
Some other gems from the Hayabusa AMICA data release include lovely color images from the Earth-Moon flyby in May 2004. Here are the two best ones:The Moon from HayabusaHayabusa snapped this photo of the Moon during its gravity assist flyby of Earth on May 17, 2004 at 11:02 UTC. The image has been enlarged by a factor of two. Credit: ISAS / JAXA / Emily Lakdawalla | Earth from HayabusaHayabusa snapped this image of Earth during its flyby on May 18, 2004 at 15:00 UTC. Four of Earth's continents are clearly visible -- North America at left, South America at the bottom, Africa on the right, and eastern Europe above it. Credit: ISAS / JAXA / Emily Lakdawalla |
This data release is a preliminary one, and there's more to come. For one thing, while they released a table of information with the images with such useful data as the date and time the images were taken, through what filters and at what targets, the table is lacking key information about the geometry of the images -- in particular, there's no information about the distance between the spacecraft and Itokawa, or, equivalently, the pixel resolution of each image. For the closeup images of Itokawa, it is very difficult to figure out how much of the asteroid Hayabusa was looking at; and some of the images have resolutions going down to millimeters per pixel!
The other thing that this release lacks is all the images taken for navigation, not science, purposes. Among the navigation images are most of the pictures taken during the two descents, and all of the images showing Hayabusa's shadow cast on Itokawa. So we'll have to wait for a future release to see those; but in the meantime, there's a thousand images and more to play with!Itokawa as Hayabusa descends, November 19, 2005 at 19:58 UTCThis image, and others like it, were not part of the April 24 data release from the Hayabusa science team. Credit: ISAS / JAXA |
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