Wallpaper: Dione and Saturn

Dione’s most notable features are the wispy streaks which are seen here in the upper left-hand side. These have been determined to be “ice cliffs” and are now thought to reveal tectonic fractures just like those known on Earth to cause earthquakes.

IMAGE NOTE: One of the best images returned from Cassini is this one of Saturn’s moon Dione passing in front of its host. Nearly hard to believe this is an actual image and not a composite. All that was added, or altered to this image was the extension of left side Saturn’s rings as they were cropped off in the square format of the original.

Wallpaper: Hyperion Portrait

Hyperion is an irregularly shaped moon and like most of these was thought to be a “captured” moon of Saturn, which is an object that strays too close to a larger body and is pulled into its orbit. Soon other theories suggested that perhaps it was a single fragment of some larger body which was largely destroyed and perhaps is what littered Iapetus with its darker material. Now, closer observations show us that much of Hyperion’s interior is hollow space… or nothing… which could mean that Hyperion is actually a collection of smaller fragments of ice and some rock which over time pulled itself together to form Hyperion. In other words an orbiting pile of rubble.

Wallpaper: Miranda Portrait

Of the five moons of Uranus, the only one to really stand out would be Miranda. One look at the moon suggests that some kind of cataclysmic event must have taken place in its past - huge fault canyons and ridges run across its surface. However, newer theories have replaced the idea that Miranda was shattered several times and instead suggest that somehow internal heating has caused lighter materials to rise up in various locations to the surface. Internal heating in smaller objects (Miranda is about 470km wide) is no longer an unexpected thing in the outer solar system. If it is ever confirmed that Miranda does in fact experience internal heating it will join Enceladus, Io and Europa (and possibly others) in this whole new class of body to be explored in the Solar System.

Wallpaper: Sol (the sun) Portrait

I don’t mean to go over some details that many of us already know, but just in case you don’t:

1) If you consider the manner in which the planets are named in the solar system, then the sun’s name would be “Sol” which is the root of the word “solar”. 2) The sun is a star which is neither a solid or a gas but is made of something called plasma. 3) The fusion that creates the energy the sun provides takes place in the core and it takes 170 thousand years for it to make its way out and radiating into space. 4) The sun has an eleven year cycle in which all kinds of activity such as sunspots, flares and solar storms peak and can sometimes disrupt things here on Earth. 5) It is estimated that Earth has only 5 billion years left before the sun depletes its resources and turns into a red giant and fries all things on Earth to a cinder. The image was taken from the SOHO solar observatory. This is the first spacecraft to take advantage of what is called a “halo” orbit around the sun. This involves orbiting a spot called the Lagrangian point which is a spot in between the Earth and Sun where the pull on the object is equal on each side. This means that SOHO actually orbits a space occupied by nothing, and follows inside the orbit of Earth. The advantages of this position allows SOHO to observe the sun uninterrupted by not having to pass behind the Earth which has been an issue with every previous mission to observe the sun. IMAGE NOTE: What is shown in the image above is in ultraviolet light. I make an effort to not use images in false-color and favor visible light, but the sun cannot be imaged in this way for any kind of detail (other than sunspots). So, in the case of suns and stars… I make the exception.

Wallpapers: Just a Note

I am reworking the wallpapers so that the labels and info parts are smaller and intrude far less on the images on the bottom. Some have been replaced already (see Mercury, Venus and a few others).     I also expect to figure out a way to quick resize these so i can offer various monitor sizes. That might take a while though.

Wallpapers: Saturn From Above and Behind

A new image recently returned from Cassini when passing into the dark side of the ringed giant. Seen from above the rings are being lit straight on with light reflecting off of them and captured by Cassini.

IMAGE NOTE: The image has been adjusted from the original. The lower half of the disk of Saturn was copied from the top half of the globe, flipped and darkened to hint at the lower half of the globe. Only this lower half of the globe was “faked” in the image, and is barely even visible.
Here the rings of Saturn are lit from behind and take on quite a different appearance as the light is now filtered through the rings instead of reflected.

IMAGE NOTE: A considerable amount of the ring details have been fabricated in this image. Unfortunately, the original cropped about 1/3 of the right side of the image. The rings were completed by referencing pixels at the edge of the original and continuing the arc around. Where no information was available to fill the frame, other images of Saturn were referenced to guess at their appearance. Again… the left 2/3 of the image is untouched.

Wallpaper: Asteroid Eros

The NEAR spacecraft was designed to visit a few asteroids with the main target being one named Eros. This probe was meant only to orbit this object closely for a year… and it did. But as the probe ran out of feul and for lack of any reason not to, the controllers decided to attempt an impromptu landing on the surface. Even though the probe had not been designed to do this (it lacked landing gear of any kind) they managed to “rest” the probe carefully upon the surface in 2001 and it continued to transmit information back to Earth for more than 2 weeks from the surface.

Image Note: The color of the asteroid itself was enhanced to match that of the close up image included in the upper right. The original full image was black and white.

Wallpaper: Comet Wild 2

When the Stardust spacecraft passed nearby the comet Wild 2, it opened up a container that held a material called aerogel exposing it to high velocity particle impacts originating from the surface of Wild 2. You can see the haze and jet streams of these particles flowing from various points on Wild 2 and creating what is known as the coma around the comet nucleus. Once the encounter was completed, the Stardust spacecraft returned the samples captured to Earth, in 2006, and successfully completed one of the very few robotic sample return missions ever attempted.

WALLPAPER NOTE: The wallpaper image itself has been greatly reverse manipulated. The most common image from this mission to be found in any publication, or by doing a Google search, is the one seen at left. This image is obviously enhanced and most notably in the edges on the upper left, look absolutely fake. However, what looks like glowing light around this image is based upon data actually captured by the Stardust cameras of dust and gas flowing from Wild 2’s surface. So it was possible to go back to the original nucleus image, re-mask it and then re-apply the jet streams and coma information in a more realistic way… which is what I did. An image is also provided in the wallpaper of what a small segment of the aerogel and a small cometary dust particle looks like. This aerogel is the lightest solid ever created and its invention is what made the Stardust mission even possible. The blast markings are, for the most part, only impact marks left in the aerogel. Look carefully and you will see tiny white particles at the far end of these blast marks which are pieces of comet Wild 2 itself returned to us here on Earth. Probably the most pristine bits of material ever obtained by mankind from what is considered to be left overs from the earliest days of the formation of the solar system.

Wallpaper: Comet Halley

When comet Halley last swung into the vecinity of the inner solar system, it was one of the lesser impressive apparitions in probably hundreds of years. In previous visits, the Halley either fascinated or horrified people everywhere. It was, as I would imagine, an object one could not ignore hanging in the sky above. Instead of a glorious vision in the sky, 4 independent probes were launched for the historic event to see what Halley was really all about. The one that returned the best images was the European Giotto probe which got in pretty close and returned the above image.

IMAGE NOTE: The image above is one rarely posted and may be a more recent “clean-up” version of the one more commonly seen when doing a google search for comet halley (seen at left here). The only alterations I made to this was to extend the slight haze beyond the tail so that it runs off the upper left hand side of the cropping. Color is ever so slightly enhanced from the original. Now whether or not the original was enhanced… that I don’t know.

The Surface of Venus Revealed

During the cold-war between America and the Soviets the real race was to the moon, but once that race was won a lesser race began to see who would master Mars exploration. After an unbelievably long series of failed Soviet missions to Mars — America managed to take the lead position in Mars exploration as well, with the Mariner and Viking missions. So the Soviets turned their eyes to our other neighbor, Venus, which seemed to garner very little attention from America apart from a few flyby missions. The Russians had Venus all to themselves and really didn't have to be too concerned with anyone beating them to the punch.

So during the early 70’s the Soviets managed to be quite successful with multiple Venera missions to Venus which included various flybys, orbiters, radar mapping of the surface and even multiple landings on the surface. Some of the missions had failed, but most completed their missions and we have the above color images to prove it. Recently though, I stumbled across these projections of the above images which I have never seen before.

Someone who knows about such things, Don P. Mitchell (see more on his blog mentallandscape.com) had returned to the original data sent to us by the Venera spacecraft from over 30 years ago and with new computing techniques, managed to reveal to us Venus anew. Instead of just looking at some stones and tiny hints at what a Venusian sky might look like, these projections show what it might actually look like walking on the surface of Venus. The main part of the image above is a composite from spherical projections, which are seen at the top-right, remapped to perspective projections. The way the projection works is the closer you get to the very center of the image, the less accurate the representation may be. However, there is evidence in the data to assume most of what you see here even at the very center where the data was at most thin, is still fairly accurate.

Unfortunately the new projection images were only in black and white and i really missed what seemed to be really fascinating color from the original Venera images… so I tried to colorize it to match the originals.

This interpretation is artistic and not based upon any data other than looking at the original images and trying to assume some of those colors back into Don’s black and white image.

Wallpaper: Triton Portrait

Another big surprise of the Voyager mission was the discovery that the coldest place in the solar system is also home to a considerable amount of geological activity. The moon appears to be widely populated by a large amount of cryovolcanos which were observed directly by Voyager in 1989. These volcanos can be seen in this image as small black smudges mostly located running across the center of the disk. It also has a tenuous atmosphere almost entirely composed of nitrogen.

One of the most interesting bits of information about Triton to me is that the orbit runs in the opposite direction of Neptune’s rotation. This suggests that at one time, Triton may have been a dwarf planet captured by Neptune’s pull. This would also explain the lack of numerous moons which we see at many of the other gas giant planets. Triton would have swept through the Neptune system and probably either collided with or ejected whatever moons may have existed in the system. Triton also has a very slowly decaying orbit and will likely collide with Neptune or shatter into pieces to form a new ring system in 3.6 billion years.

Image Note: This is the orignal Triton portrait image that was posted to this site. The newer and improved main top image was recently generated by Ted Stryk and posted to unmannedspaceflight.com.

Wallpaper: Titan Portrait

Titan is without a doubt, not only one of the most interesting moons, but it is easily one of the most interesting places in all the solar system. It has been determined that Titan is host to the only other lakes ever to be discovered off Earth! Data also supports the idea that Titan has rain and other kinds of weather as well as cryovolcanism (a type of cold volcano). Even with all this, it is near impossible to eek out an interesting image of the place as its thick atmosphere hides everything taking place on the surface. Additionally, similar to Venus and Uranus, the clouds fail to show much in the way of structure or detail as well.

Wallpaper: Titan Eclipse

Titan passed in between Cassini and the sun giving us this opportunity to see the haze of the atmosphere lit from behind.

WALLPAPER NOTE: The original image only revealed half the disc. To complete the full image the top half was taken, flipped and overlapped with another lesser impressive eclipse image to avoid obvious repeat. So, in reality, the lower half of the image is “faked” but it is composed entirely of real references.

Wallpaper: Enceladus Portrait

During my run through posting images of the major moons of the solar system, I felt compelled to include this tiny 600km moon in the mix as it has suprised most scientists to be quite an active little place. Usually any body as small as Enceladus would fail to have any geological activity, but in 2006 the Cassini spacecraft discovered that there are several active geysers spewing water and ice into the space around it. These geysers have even established a tenuous atmosphere of mostly water vapor at the southern poles where the geysers are located.

WALLPAPER NOTE: I have to be honest… those stripes in the southern region with the geysers… they aren’t really blue. They would be bright gray like all the rest. Its just irresistable to use the blueish tones because they outline where all this geological activity is going on. I usually don’t use false-color.

Wallpaper: Callisto

With 3 other facinating large moons in orbit around Jupiter, asking for yet another in Callisto would have been expecting too much. This body is one of the most heavily cratered bodies we have yet seen. The heavy cratering record tells us that little has changed here on Callisto since early in the solar system’s history. So, not unlike our moon, not very much happens here… ever.

Although there are some theories being floated that Europa may not be alone in its candidacy for an internal ocean of water. Some think that Ganymede and even Callisto may also host such environments but to a lesser degree.

Wallpaper: Ganymede Portrait

The largest of all the moons in the solar system is actually larger than the planet Mercury. The moon also shows evidence to tectonic plates (the same process that causes earthquakes on Earth) and there may even be some underground ocean as on Europa though it is less likely to be nearly as extensive. Recent observations from the Hubble Space Telescope suggest that there may be a tenuously thin atmosphere of pure oxygen at Ganymede due to the radiating of water ice into oxygen and hydrogen. In this scenario the hydrogen is lost to space while the oxygen (being a heavier element) is retained at the surface.

Wallpapers: Ganymede at Half Phase

Ganymede in the best “disk” detail I have ever seen. There are some great close up images of Ganymede, but for some reason most of the images that show the moon from a distance are usually blurry and lack the detail you see here. This composite is by Ted Stryk but the trick is that his original was only in black and white, so I ham-handedly used other images of Ganymede to colorize it. So… the color here is interpretive and not based upon actual data.

Wallpaper: Europa Portrait

Europa has become a focal point of interest in our solar system. Subject to the same tidal forces that tear Io apart, Europa is less severely effected by this and here the stress takes the form of internal heating which keeps the moon from being frozen throughout. It has more-or-less been confirmed that below its icy crust lies an almost global ocean of 100% water. Considering that the center of the moon is quite warm and the icy shell is of course frozen rock-solid, somewhere in between must lie a zone with temperatures similar to that of earth deep within this watery underground ocean. As any marine biologist will tell you, the Earth's oceans are riddled with life. Even in places of extreme heat and cold, life still somehow has survived the ages and has adapted to such extreme environments. Leading to conjecture that no-matter the obstacles to life ever developing on the surface of such a place… the mere presence of earth-like conditions deep within Europa's dark underground water ocean may have been just enough for some if not many forms of life to evolve and survive to this day. There are many missions on the drawing board right now to find out more answers including a Europa orbiter, various landers and one truly aggressive mission that would involve melting through the crust and “injecting” a submersible probe into the watery core. For a new and improved portrait image of Europa see here.

Wallpaper: Europa at Half Phase

Awesome detail of Europa on this half phase image by Ted Stryk. The cracks and ridges which suggest the internal watery ocean are clearly evident and are Europa’s most notable features.

Wallpaper: Io Portrait

Io is the first large moon of Jupiter and is the most geologically active body in the solar system. Its close proximity to Jupiter and tidal forces from the giant and its 3 other giant moons push and pull the moon apart internally. This causes Io to turn itself inside out and fuels its many active volcanos. Due to this constant volcanic activity the surface of Io is quite young, continually being reshaped with not a crater to be found.

Image Note: The image itself is largely original and complete. I added the "dark side" details and completed disk. The the two plumes showing at the edges of the dark side of the disk are also additions. The plumes are taken from other real images and they do appear in true scale, however some brightening of these plumes were likely applied to these original images to show detail, so I darkend them a bit and reduced the color saturation that usually results from these manipulations.