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Preview: Planetary Images From Then and Now

Planetary Images From Then and Now





Updated: 2018-02-03T07:50:32.468-08:00

 



Pioneer-11 at Saturn - 38 Years Later

2017-09-01T05:42:56.498-07:00

Today in 1979, Pioneer 11 made its historic flyby of Saturn, humanity's first.  While it got the first closeup images of the Saturnian system, it's images, such as this one showing the rings and a transiting Mimas, while interesting, were no match for the more spectacular images that the Voyagers returned of the Jovian system that year, and were quickly supplanted by the Voyager visits to Saturn in the coming years.  A close-up of Saturn, rings, and moons on encounter dayDue to trajectory constrains, Pioneer approached and receded from Saturn looking at the backlit side of the rings, something never seen from earth except briefly when the rings are nearly edge on during ring plane crossings.  Thus its view was interesting but also unfamiliar.  Approaching Saturn (with Titan)  Receding from Saturn.  Due to data rate constraints, only every other pixel was returned, hence the reduced quality. Best view of the unlit side of the rings during approach During closest approach, Pioneer briefly passed through the ring plane and back, in theory giving it a view of the sunlit side of the rings.  Given the speed at which it was traveling and that it's scanning imager, which built up images one pixel at a time using the spin of the spacecraft, took a long time to assemble pictures, not much could be done with this.  The instrument did have, however, a lower resolution mode that was for the purpose of polarization studies, which could only take very crude images (if they could be called that).  It could, however, work fast enough to capture the fleeting view.  Here is an example of one. The daylit side of the rings in front of the panet, with the limb visible behind them. These images can be built up into a pretty nifty model of the rings.  The day side of Saturn's rings using data from Pioneer 11 in polarization mode   While it is neither the view normally associated with Pioneer nor should it be, it brings us full circle, seeing a world and its rings in a more familiar way as it looked 38 years ago, the day we first stopped by its doorstep while, at the time of writing, we sit 14 days before our first long-term visitor becomes one with Saturn.  After 1981, which marked three consecutive years with an encounter, it would be another 23 years before humanity returned with Cassini.  Let's hope that our imminent absence is brief. [...]



Pre-Discovery Images of the Plumes of Enceladus

2017-02-03T12:42:23.430-08:00

LPSC 2017 Abstract 1603 Pre-Discovery Detection of the Plumes of Enceladus From the moment I first found out about the discovery of geysers erupting into space by NASA's Cassini mission, I began to wonder whether they had been detected before.  Pioneer data is of insufficient quality to detect them, but Voyager definitely could have.  I carefully examined all of the images targeting Enceladus, but the illumination angle wasn't ideal (very high phase, or backlit, images are best for this, but none of the available images were taken at such an angle).  I came up empty handed and dropped project.Flash forward to the New Horizons Pluto encounter in the summer of 2015.  I was sitting in a plenary meeting and the high phase images of Pluto's atmosphere were being discussed for the first time.  Later in the meeting, someone asked a question about serendipitous images that might contain Pluto's small moons.  The next talk was particle and fields stuff that I didn't really understand, so my mind wandered, and it clicked - maybe Enceladus made a serendipitous appearance in some high phase Saturn images.In the fall of 2016, I finally found time to work on this.  While Voyager 2 had the better camera, due to a spacecraft anomaly, it was not taking pictures during the first few days after closest approach, so after a check to see if there was anything from right after it was recovered, I moved on to Voyager 1.  I experimented with some imagery from a few days out to get familiar with its cameras under these conditions before beginning in earnest. This image of Saturn came from this effort.Saturn from the Receding Voyager 1As I searched through the dataset, a group of images stood out.  They were taken on November 13, 1980, a day after closest approach.  None of the Narrow Angle Camera images contained Enceladus, but eight of the Wide Angle Camera images did.  They showed the small crescent and night time hemisphere illuminated in Saturnshine as only a few pixels across.Cleaned raw image from the dataset usedI thoroughly calibrated, deconvolved, and stacked the images.  After combining different subsets as well as the full set, I am confident in the detection of the plumes, just where they should be.Enceladus from Voyager 1 on November 13, 1980.  The right side is illuminated by the sun, the left by reflected light from Saturn, and the plume can be seen at the bottomIn my excitement at having at last had some success with this project,I quickly wrote an Lunar and Planetary Science Conference abstract, which can be read here.  It gives more detail about how this dataset was handled.Erupting Enceladus over Saturn on November 13, 1980I plan to continue sifting through images to see if there are other datasets worth processing in that way.   I plan to do similar work with other worlds as well.  At the very least, this indicates Enceladus is indeed constantly erupting, extending the baseline back more than two decades.  [...]



Reflections on a flyby: My personal journey to Pluto

2015-07-13T18:33:53.983-07:00

As a ten year old, I would take daily breaks from a long summer of yard baseball and building trails through the woods to go to the public library and that of a local college, hoping to spot the latest Voyager image of Neptune and Triton, its planet-sized moon.  I would scour every newspaper, magazine, CD-ROM – anything that came in, hoping to see a slightly sharper view of these mysterious worlds.  Of course many days ended in disappointment.  When that happened, or when I had some extra time after seeing the latest from Neptune, I would seek out what else I could find.  Via NASA publications, books, and especially back issues of periodicals, I was able to relive a whole history that I had missed.  I rode around the far side of the moon with Luna 3.  I saw our view of Mars evolve from Christian Huygens first spotting of dark markings and polar caps to our first glimpse of Martian craters from Mariner 4 (incidentally, 50 years to the day before the New Horizons Pluto flyby).  I got to ride along with Mariner 6 and 7 as they zoomed in on Mars and Mariner 9 as it watched dust clouds abate and the surface reveal itself on a global scale I would set out book and compare how worlds looked as different spacecraft approached.Mariner-10 brought us the cloud covers of Venus and the cratered surface of Mercury, and the Venera and Viking landers took us to the surfaces of Venus and Mars.  The Pioneers gave us glimpses that were enough to tell us that the Jovian and Saturnian systems were far more complex and interesting than we thought from our earthbound view, but while they were very good at studying other things such as magnetic fields, they were small spacecraft designed to pave the way for the follow on, Voyager.  While the previous missions revealed a world (or, in the case of Mariner 10, two worlds but separated by years), the Voyagers visited planets with planet-sized moons as well as a retinue of smaller companions.  From the volcanoes of Io to Titan’s thick atmosphere, from Europa the billiard ball with a hint of a global ocean to Miranda with its jigsaw puzzle surface, each encounter was a grand tour of a mini solar system. August 25 - encounter day - finally came and I was glued to the coverage on PBS.  Neptune and its great dark spot created a lot of buzz, and Triton looked like, well, a cantaloupe (at least in places).  I didn’t get to watch all the coverage – my mother made me go to bed, telling me I’d thank her for it someday (still hasn’t happened).  I remember after much arguing, responding, “OK, but I’ll be there next time.”Next time.  There was much to do about Voyager 2 reaching the edge of the solar system, exploring its most distant planet and its moons.  That was technically true at the time – from 1979 to 1989, Pluto was inside Neptune’s orbit.   But the proclamation that we had completed the initial reconnaissance of the solar system felt hollow, because there was one major world that hadn’t received a visit – Pluto.  But the Voyagers, speeding out of the solar system, could not help us anymore.  It would take great effort by people such as Principle Investigator Alan Stern, to finally get humanity on its way to filling this gap with the launch of New Horizons in 2006, 17 years after Voyager visited Neptune.  In the intervening years, three things changed our view of Pluto.  From ground based and Hubble Space Telescope observations, we produced our first crude maps, revealing Pluto to be one of the most high contrast objects in the solar system.  This indicated that it isn’t simply a carbon-copy of Triton, which is thought to be a captured satellite and is similar in size and mass to Pluto.   Second, the Kuiper Belt of distant worlds beyond Neptune, predicted a half a century earlier, became real to us, transforming Pluto from an oddball to the largest of these outer worlds that we can [...]



Kanehekili Patera from Galileo

2015-05-26T04:21:05.212-07:00

Due to the nature of its orbit, although Galileo made several close approaches to Io, some parts of its surface were never seen except from a great distance.  Some of these areas were covered by Voyager 1's close flyby, but others were not.  The are centered around Kanehekili, the volcano which can be seen erupting above the limb at about four o'clock, is one such place. A major eruption was seen here earlier this year.  Hopefully a new mission will be able to fill in this gap.



This image was taken on May 6, 1997, during Galileo's eighth orbit around Jupiter.

Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Nereid from Voyager

2015-05-26T04:12:46.224-07:00

When planning began for Voyager 2's 1989 encounter with Neptune, the planet had two known moons - Triton and little Nereid, a small, distant moon that, like Triton, is likely captured.  The flyby didn't go well for little Nereid.  First, it takes nearly 360 days to orbit Neptune - almost a year! - and was not in a convenient place for Voyager to meet it (unless Neptune itself and Triton were sacrificed).  Second, it would be dethroned as Neptune's second largest moon by Proteus, a newly discovered moon that would receive much better coverage. 

Voyager 2 came no closer than 4.7 million kilometers from Nereid.  All that could be made out is that it is a somewhat spherical (if a bit lumpy), 340-km in diameter little world with a relatively low albedo -15%.  It rotates in 11 hours, as determined by light curve data, further supporting the idea that it is captured (not being tidally locked is unusual for a moon). 

Here are Voyager 2's two best views.  The first shows the lumpy little world in a gibbous phase as Voyager approached on August 21, 1989, and the second shows a crescent on August 24 - Nereid was "in front" of Neptune, so closest approach was earlier than the August 25 closest approach of Neptune.
 

Yet another world cries out for exploration!

Processed images Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Looking Down On Jupiter's North Pole.

2015-04-28T15:09:51.443-07:00

In December 1974, Pioneer 11 became the second emissary of humanity to visit Jupiter.   Being a spin stabilized spacecraft with essentially no onboard memory and only able to transmit at 2048 bits per second, it carried no real camera, but it did carry the Imaging Photopolarimeter, basically a scanning one-pixel photometer which scanned along with the spacecraft's spin.  By doing this, it could, over time, develop crude pictures.  In high resolution mode, the images were at most 14 degrees wide and 466 pixels across (although in practice most were much smaller.  And given that the spacecraft was moving quickly and these scans took around half an hour, the ones near closest approach are, in addition to being frustratingly small, badly distorted.  Although attempts were made to correct for this, they were made with 1970s computing power, so they are limited, and since the digital data is missing (perhaps forever), all we have to work with are scans of these attempts. 

Pioneer 11's dataset is unique in that after passing Jupiter, it looked down on its north pole as it headed off across the solar system toward Saturn.  No other spacecraft has gotten such a direct angle on a Jovian pole (although Juno will do so next year), but the global images are frustratingly small.  In this view, I have combined the best six pictures (12 if you count the color pairs as individual pictures) to make a mosaic of Jupiter looking down on the pole soon after closest approach.  I think I can improve on it, but having tinkered with it a year, I am ready to share the image as it stands now.


Processed Image Copyright Ted Stryk, Data Courtesy NASA/Ames Research Center.  A special thanks to the Ames Research Center history office for helping me find the data used in making this. 



Venus from 33 years ago, and why we need to explore.

2015-03-05T10:13:42.654-08:00

Thirty-three years ago today, Venera 14 plunged down through the thick Venusian atmosphere to the surface, where it successfully operated for 57 minutes.  Like the three imaging landers before it, its cameras scanned back and forth across the surface while other instruments took measurements.  The cameras would touch the horizon at either end of the panorama and dip down to the foot of the lander in the middle, a compromise which allowed images to be returned showing both the foreground and the horizon while having adequate resolution to be interpretable and to still be returnable during the short surface mission.  Venera 14, as it happened, landed a very rocky site.  Being tipped a bit, one of its cameras barely touched the horizon, while one side of the other camera gave the most sweeping view of the Venusian horizon we have.  On the opposite side, the landing managed to dislodge a piece of the rocky surface.Venera 14 showed a rocky, harsh surface with little regolith/soil compared to the other landing sites.  This brought to mind a talk I heard last fall, in which Victor Baker criticized the vain attempts to find a single site to send a rover where it could tell the whole story of Mars.  As Baker said, imagine finding a site where the story of Earth could be told by roving a few kilometers!  The Martian three sites we've sent stationary landers and four sites we've sent rovers are grossly inadequate.  That despite the fact that we have sub 10-meter coverage of nearly the whole planet and resolution of a few tens of centimeters over great swaths of the planet.Venus is much larger than Mars - nearly the size of earth! Yet we have only landed in four places and done very limited imaging and surface science at those sites.  We have, granted, landed at four more sites where imagery was not taken, but less than half a day, collectively, has been spent operating on the surface, while the shortest-lived Mars landers had lifespans measured in months, most lasted years, and one has lasted more than a decade.  And many of them roved the surface, covering multiple terrain types.  Beyond the four Venera sites that were imaged, the next best images we have are radar images taken at a scale of 70-100 meters per pixel, the size of a football field!   And despite the fact that all four landers landed in roughly the same area of the planet, the terrain at each site was markedly different.  The above images were balanced to better bring out detail, these balanced (or in some cases colorized)to be more along the lines of how I think the surface might actually look.(Clockwise from the upper left:  Venera 13, Venera 10, Venera 14, Venera 9 - order chosen for aesthetic purposes)  Here is the same set, tipped upright:  This is the tip of the iceberg when ti comes to terrain types, and even these landscapes were barely touched.  Below is the widest panorama that can be made by combining the panoramas, and even it is patchy and of poor resolution.Sadly, other than orbiters that primarily studied the atmosphere, Venus has been left alone since the end of the Magellan radar mapping mission in the early 90s.  The final lander accomplished its mission, albeit with no camera, on June 15, 1985.  We need to go back!Around 6:00 UTC on March 5, 1984, this picture was being returned by Venera 14 as it fell silent forever.  It remains humanity's last view from the surface of Venus. ________________________ Edit:  Here is a second interpretation of the color for the combined set, with an attempt to improve the balance. I can't decide which one i think is more accurate.Data Courtesy the Russian Academy of Sciences, Processed Images Copyright Ted Stryk[...]



Some Recent Views of Mars from Hubble

2014-11-23T19:51:45.757-08:00

During the 1990s and the early 2000s, the Hubble Space Telescope served in some respects as a Mars mission, checking in frequently to monitor seasonal changes and to study the surface at wavelengths unavailable from earth and/or with higher spatial resolution than could be obtained from earth's surface.  After 2003, when Mars received a lot of attention due to the unusually close approach, priorities changed.   Mars had and has a flotilla of spacecraft studying it that leave a lot of what Hubble used to do redundant, or at least relatively redundant.  After all, there are four planets in our solar system without a spacecraft currently present, not to mention countless other worlds, plus three with only one spacecraft present. So Hubble, for the most part, has focused its time elsewhere.The exception is in the ultraviolet.  At least until MAVEN's arrival, the ultraviolet capabilities of the fleet at Mars were very limited.  Thus Hubble periodically checks in with the Space Telescope Imaging Spectrograph (STIS) and with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC). Below is the most recent view available from STIS, taken on April 26, 2012.  Several observations have been taken this year but  none have yet been released.This year, ACS/SBC has also had some looks, some of which have been released.  One dataset was obtained on May 30, 2014, for the purpose of preparing for MAVEN, providing a baseline for its observations to be compared with Hubble's past observations.Hubble was again called into service when Comet C/2013 A1 Siding Spring flew by Mars on October 19.  Hubble of course looked on with the STIS and ACS/SBC, and one of the SBC datasets has been released.  I have no idea if it shows any effects of the comet, but it definitely show the atmosphere.Hubble also took a look with its Wide Field Camera 3 (WFC3), the successor to its old workhorse, the Wide Field/Planetary Camera 2 (WFPC2). This was during the closest approach, when the orbiters were hiding behind Mars relative to the comet.  The primary purpose was to provide a picture for posterity, covering closest approach, but given that many of the exposures overexposed much of the disk, I do wonder if they were trying to study the terminator region.  However, Mars was quite distant during the comet flyby.  As a result, its apparent diameter was less than six arc seconds, much farther away than it has been during most previous Hubble observations.  For a comparison, I have put a WFPC2 image of Mars from the 2003 close approach next to an image from October 19, 2014.  And, given that the pixel scale was somewhat coarser on WFPC2 compared to WFC3, the actual apparent size different is slightly greater.  A rough RGB process didn't offer much.   I stacked all available frames and produced the best image I could.  I even mixed in the ACS/SBC image which had higher spacial resolution, then combining it with a color overlay.  The result gives us a good idea of what Mars looked like as the orbiters were hiding behind it for protection from the comet and many around the world were trying to catch a glimpse of this historic event (well, those of us not clouded out, sniff sniff). Processed Images Copyright Ted StrykRaw Hubble Data Courtesy NASA/STScI [...]



Mariner 10 at 40

2014-09-22T19:19:46.555-07:00

Forty years ago, Mariner 10 flew by Mercury for the second time.  I don't have anything new to post from that flyby now, but here is a more recent crack at an image from Mariner 10's first flyby, taken several days after closest approach and showing more of the Caloris Basin and the crater Mozart than could be seen during closest approach. 


Data Courtesy NASA/JPL, Processed Image Copyright Ted Stryk



Triton again

2014-08-26T19:39:23.962-07:00


Here is an area of Triton on the hemisphere seen close up but not very well imaged.  Two intersecting tectonic features can be seen. Triton is the largest known KBO (albeit a captured one) and while it is better known than any others (at least until next year), it begs for further exploration. 

(image)

Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Latest reworking of the best Triton mosaic...

2014-08-25T04:20:35.150-07:00

I am still working with this dataset.  I have an idea for some "grand" mosaics combining more image data and hopefully doing better with the terminator.  I have, however, fixed the unnatural limb, and some hazes are visible.   I am posting this today in honor of the 25th anniversary of Voyager 2's flyby of Neptune and Triton.


Here is an enlargement showing some of the atmospheric features visible.


Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



A full Titania

2014-08-20T19:25:29.354-07:00

As Voyager 2 approached the Uranian system in 1986, it focused primarily on Titania, the largest moon, until closest approach.  One of the most interesting of the more distant approach shots is this one, Titania at "full" phase.  It shows largely uniform moon with the exception of the effects of impact craters. 


Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Another crescent view of Triton

2014-07-30T12:42:12.463-07:00

Two years ago, I posted these views of Triton.  They represent two of the best global color views.  The bottom one is one of the first image sets taken (but with the wide angle camera), and shows an extremely slender crescent.  The upper image shows the first (and best) global color set taken with the narrow angle camera.  The image I am posting here was taken about three hours later.  This was the last view of Triton taken on encounter day and shows it from a slightly different angle...essentially Triton's last closeup from Voyager. 


Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



A Voyager 2 View of Europa

2014-07-22T20:05:43.788-07:00

As Voyager 2 approached Europa, this was the highest resolution global view it obtained before Europa filled more than the entire frame.  Europa was still quite small in the field of view at this point (the time in between this and the global mosaics it would later take was spent studying other targets), and, given the intricate, low contrast nature of its surface, this made this dataset very hard to work with.  It was taken on July 8, 1979, from a range of about 1.2 million kilometers. 


Raw data courtesy NASA/JPL, Processed images Copyright Ted Stryk



Standing on Venus in 1975

2014-07-20T18:20:30.997-07:00

Getting the thrill of seeing what it would be like to stand on another planet is one of the big thrills of planetary exploration.  This year, we have gotten to stand on the Moon thanks to Chang'e 3 and the short trek of the Yutu rover.  We have also gotten to ride along and tour Mars with Curiosity and Opportunity.  Later this year, the Philae lander will allow us to stand on a comet.  This August, it will be 44 years since the first probe to send data from the surface of another planet (ignoring atmospheric probes and failed landers - key word is "surface") plunked down on the surface of Venus. Venera 7 did not function well after landing, sending back only temperature and pressure data. It was followed in 1972 by Mars 3, which briefly sent a signal from the surface of Mars before failing, and Venera 8, a highly successful Venus lander but one that did not carry a camera. Veneras 7 and 8 informed us, but they didn't allow us the feeling of being there. In 1975, Veneras 9 and 10 became the first landers to image the surface of another planet, scanning 180-degree panoramas during the ~ hour that each lander functioned on the surface.  Stacking available data, this is what Venera 9 saw when, on October 22 1975, it landed (I've posted this previously, but am posting it again for context).On October 25, Venera 10 followed.The cameras scanned the scene one pixel at a time.  Given the rate at which the image could be taken and transmitted and the available amount of time, the images had to be of low resolution, even for the time. Given these limits, there were several options.  One would have been to image a very narrow area at high resolution from the lander base to the horizon, but that would have been hard to interpret.  Scanning from surface to horizon over a large area would have been so coarse that again, it would have had limited value.  The compromise worked out was that the camera would scan in a U-shape, meaning that the tips of the panorama would look at the horizon, while the middle would look down ant the base of the lander. For science, this worked well. Visually, however, they are unnatural.  Of course these panoramas can be rectified to show the surface at a more natural angle.  Still, this leaves the center, the focal area of the images, as a gaping hole, and is thus visually unsatisfying. In the past, I tried to make views out out of corrected corners of the images, but these proved too small to do much with and were still very awkward.  After seeing Don Mitchell's excellent work on Venera 13 and 14 data, I got the idea of creating an image for both landers created by sampling each image at different distances from the lander to create a "proper" picture.  The objects in the image would be real, though the arrangement would not.  However, given that the original images are only 128x512 pixels (and not all of that shows the surface), making this convincing was very difficult (Venera 13 and 14 took panoramas on both sides of the lander and at much higher resolution, allowing much more image data to sample).  The first attempt was a failure.I recently tried again.  This time, I accepted the fact that, in the case of Venera 9, I would have to use somewhat distorted versions of the same rocks at times to make a sufficiently big image.  I still don't love the result, but given the limited data and the complexity of the landscape, it is the best I've been able to do. The fact that the illumination is clearly different on the left-hand side and the right hand side of the panorama exacerbates the problems.  Still, it makes for a neat view.   An[...]



Thirty-eight years ago today: Viking 1 lands on Mars.

2014-07-20T13:03:21.707-07:00

In recognition of the first successful Mars lander, I am posting two views from Viking 1 that I have processed.


Raw data courtesy NASA/JPL, Processed images Copyright Ted Stryk



40 Years Ago: Pioneer 10 Flies By Jupiter

2013-12-03T11:57:11.795-08:00

In the last entry, I posted a crescent view of Jupiter from Pioneer 10, on this, the 40th anniversary of the closest approach (December 3, 1973), I decided to share this view of Jupiter from the approach phase.  As time permits, I hope to do more with this dataset.

Processed Image Copyright Ted Stryk, Data Courtesy NASA/Ames Research Center.  A special thanks to the Ames Research Center history office for helping me find the data used in making this. 




Jupiter and Io from Pioneer 10

2013-08-02T13:44:59.865-07:00

This is a parting shot of Jupiter and Io, taken December 5, 1973, by the Pioneer 10 spacecraft, the first to see either world as a crescent.  This image was generated with red and blue channel data from the spacecraft's imaging photopolarimeter (image set B26, for anyone wondering), which scanned the planet as the spacecraft rotated.  The maximum scan length was only 466 pixels, leading to postage-stamp sized images that are often blown up to ridiculous sizes.  This image is shown at a significantly larger scale than its original size for clarity, and extra black sky has been added for effect.  The data for this image was of rather poor quality, especially on the red channel.   Still, it is a nice reminder of one of the most overlook "firsts" in solar system exploration.


 Processed Image Copyright Ted Stryk, Data Courtesy NASA/Ames Research Center.  A special thanks to the Ames Research Center history office for helping me find the data used in making this. 



The Land Between Triton's Frozen Lakes

2013-04-05T13:42:20.884-07:00

One of the biggest discoveries of the last decade has been the discovery of unfrozen lakes on Saturn's moon Titan.  This was the last good chance we had at finding standing liquid and non-transient streams and rivers on the surface of any extraterrestrial world in in our solar system, Io's lakes of magma nonwithstanding.  Such things had clearly existed in the past, but were either dried up or frozen over.  Back in 1989, there were hopes that we would find lakes of liquid nitrogen on on Neptune's moon Triton.   And indeed, it had produced such lakes, but they have since frozen over.   Fortunately, a pair of these lakes were in the area that received the best coverage from Voyager.   This included a narrow "bridge" that separated the pair, which was included in four of the highest resolution images of Triton obtained. This allowed me to stack them to reduce noise and improve clarity (although not all of them include the whole area covered here).  I wasn't able to get (or expecting to get) a great improvement over my previous processing efforts or those of others, but there is a moderate gain in clarity.  To be honest, I took this on for an April Fools prank, but I couldn't decide on how to approach that on time.   Still, since I went to the trouble of doing the processing work, I figured I'd share the result. It is shown at ~375 m/pixel.



 Processed Image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Mysterious Umbriel

2013-01-09T20:33:58.052-08:00

Umbriel, a moon of Uranus, is about 1200 km across, is less reflective than the planet's other moons, except for mysterious bright features seen on the rim of what appears to be a crater and the central peak of another.   It was imaged by Voyager 2 in January of 1986, at 10 km per pixel in the two images snapped at closest approach.  Unfortunately, one was underexposed and slightly smeared, and the other was properly exposed but very smeared.  My processing of the images a few years ago, which can be seen here, was focused around desmearing and bring out detail.  This is all well and good, but the artifacts from such processing made it, well, ugly.  While there are other views that include more images and were less smeared/underexposed, they were much more distant, making them frustratingly small.   I decided to start from scratch, reprocessing the two highest resolution frames, combining them at 125% of their original size, and create a color overlay from more distant images.  Having refined some of the techniques I used in 2009 and trying to avoid overextending the processing, I have created a version that is much more beautiful and perhaps gives us an idea what Umbriel really looks like.  Since it will be at least another decade, and probably much more, before we see Umbriel close up again, it is unlikely to give up its secrets any time soon.
 Processed Image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL




The 400th Anniversary of the discovery of the Galilean moons of Jupiter

2013-01-07T09:59:17.397-08:00

In honor of the 400th anniversary of the discovery of the Galilean moons of Jupiter (from largest to smallest - Ganymede, Callisto, Io, Europa), here they are to scale from NASA's Galileo spacecraft (with the exception of a tiny bit of Voyager-derived gap-fill for Callisto).
Processed Images Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Mars from Mariner 4

2012-12-11T19:51:51.853-08:00

This week, Emily Lakdawalla posted a blog post about Mariner 4, the first spacecraft to photograph another planet,  using my catalog of reprocessed Mariner 4 image mosaics, combining the best analog data I could find combined with digital fragments. 

To add to it, here are the first four images as one mosaic.  The gap between the mosaics of frames 1-2 and 3-4 isn't much more than some of the calibration marks on the individual frames, so interpolation was used to connect them .
Processed Images Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



The Twin Peaks - low sun

2012-10-19T06:04:05.096-07:00

Shadows have a dramatic effect on landscapes.   These low sun elevation images, taken as part of the "insurance panorama" shortly after landing, demonstrate this.  Additionally, because these images were taken before the camera mast was deployed, in effect the photographer is crouching down, getting a better angle.



And with a slight bit of vertical exaggeration...


Processed Images Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



The Twin Peaks

2012-10-14T11:57:13.698-07:00

Mars Pathfinder images are some of the most frustrating to work with.  At only 256 pixels across, they are like postage stamps.  It means one has to work with a lot of them to make anything big enough to look good.  Limited by not having an orbiter to relay its data, Pathfinder couldn't have made use of a better CCD chip.  Because its optics were far better than the resolution of the chip, and, as a stationary lander as opposed to a spacecraft flying through space, are jitter free, and because it took the same picture from the same angle so many times, it is one of the most productive data-sets for teasing out super-resolution information.  Here is one of the best sets showing the twin peaks, the little hills that were the signature of the landing site.




Processed Images Copyright Ted Stryk, Raw Data Courtesy NASA/JPL



Ganymede from New Horizons

2012-06-15T09:01:55.137-07:00

On it's way to Pluto, the New Horizons spacecraft made a distant flyby of Jupiter in 2007.  It didn't get close enough to match Voyager and Galileo views of the Jovian moons.  It took a lot of images of Io to monitor its volcanoes, but it took very few images of the other moons, since there was little its monochrome high resolution images could do in terms of science from that distance that wasn't done by previous missions or from Earth.  Still, the few images taken of the three icy Galilean moons are worth taking a look at, given that they show somewhat different angles/regions than most good Voyager and Galileo images.   Perhaps the best is this exquisite little image of Ganymede, taken on February 27, 2007.   Ganymede's large size and contrasty surface somewhat make up for the 3.5 million miles between it and the spacecraft.  The color information is taken from Galileo data.
 Processed Image Copyright Ted Stryk,  Raw Data Courtesy NASA/JHU/APL (New Horizons data) and NASA/JPL (Galileo color data)