The Planetary Society Blog
By Emily Lakdawalla
Jupiter as seen from Mars
Jan. 31, 2007 | 10:11 EST | 15:11 UTC
Every Wednesday the Mars Reconnaissance Orbiter HiRISE camera team posts a new set of images from Mars. I'm overwhelmed by the detail in these pictures; there is so much to look at that I hardly know where to begin, and the images are so big that it's tough to work with them, with the result that I don't post HiRISE pictures nearly as often as I should. But they made picking an image easy for me this week: they've released a photo taken by HiRISE, from Mars orbit, of Jupiter -- a photo that compares favorably with the images being taken by LORRI on New Horizons as it approaches for its flyby next month. In fact, the sheer number of pixels that HiRISE can acquire in one swath puts a framing camera like LORRI to shame; HiRISE managed to get Jupiter and all its satellites in one enormous picture. (You probably won't be able to see the moons without enlarging the picture.) Jupiter and its moons as seen from Mars Reconnaissance OrbiterMars Reconnaissance Orbiter turned toward Jupiter on January 11, 2007 to capture this view of Jupiter and all four of its large moons: from left, Callisto, Io, Europa, and Ganymede. Jupiter was 580 million kilometers (360 million miles) from Mars when this photo was taken. Credit: NASA / JPL / U. Arizona |
A detail they mentioned in the caption was that "This image of Jupiter and its major satellites was acquired to calibrate the pointing and color response of the camera. An oversight in planning this unusual observation put the focus mechanism in the wrong location, blurring the image. This does not detract from the calibration objectives, but makes the raw image less esthetic." The HiRISE chief optical designer Dennis Gallagher sharpened the image, producing the version below:Jupiter as seen from Mars Reconnaissance Orbiter (sharpened)
Credit: NASA / JPL / U. Arizona |
Just for fun, compare that one to one of the most recent views from New Horizons LORRI:Jupiter and Io as seen from New HorizonsNew Horizons captured this image of Jupiter and Io on January 21, 2007 from a distance of 61.5 million kilometers (38 million miles). Credit: NASA / JHUAPL / SwRI |
When it took this image, New Horizons was 9.4 times closer to Jupiter than Mars Reconnaissance Orbiter was when it took the Jupiter photo above. This shows you the incredible resolving power of HiRISE. I mean no disrespect to LORRI, which actually has the sharpest vision of any camera ever sent beyond Mars' orbit; this is just the difference between a framing camera and a pushbroom camera, not to mention the difference between the economical design of New Horizons and that of Mars Reconnaissance Orbiter, which is, by comparison, a luxury model spacecraft.
On a different topic, I just want to say welcome to anyone who's visiting here for the first time because the Cassini ring plane crossing animation that Gordan Ugarkovic and I put together was posted as today's Astronomy Picture of the Day! If you'd like to read more about what's going on in that animation, please see my earlier post about it.Credit: NASA / JPL / SSI / Gordan Ugarkovic |
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