Koppernigk

Wrinkles: older - and higher

"Saturn's moon Titan ripples with mountains, and scientists have been trying to figure out how they form. The best explanation, it turns out, is that Titan is shrinking as it cools, wrinkling up the moon's surface like a raisin.

A new model developed by scientists working with radar data obtained by NASA's Cassini spacecraft shows that differing densities in the outermost layers of Titan can account for the unusual surface behavior. Titan is slowly cooling because it is releasing heat from its original formation and radioactive isotopes are decaying in the interior. As this happens, parts of Titan's subsurface ocean freeze over, the outermost ice crust thickens and folds, and the moon shrivels up. The model is described in an article now online in the Journal of Geophysical Research.

"Titan is the only icy body we know of in the solar system that behaves like this," said Giuseppe Mitri, the lead author of the paper and a Cassini radar associate based at the California Institute of Technology in Pasadena. "But it gives us insight into how our solar system came to be."

An example of this kind of process can also be found on Earth, where the crumpling of the outermost layer of the surface, known as the lithosphere, created the Zagros Mountains in Iran, Mitri said.

Titan's highest peaks rise up to about two kilometers (6,600 feet), comparable to the tallest summits in the Appalachian Mountains. Cassini was the first to spot Titan's mountains in radar images in 2005. Several mountain chains on Titan exist near the equator and are generally oriented west-east. The concentration of these ranges near the equator suggests a common history.

While several other icy moons in the outer solar system have peaks that reach heights similar to Titan's mountain chains, their topography comes from extensional tectonics -- forces stretching the ice shell -- or other geological processes. Until now, scientists had little evidence of contractional tectonics -- forces shortening and thickening the ice shell. Titan is the only icy satellite where the shortening and thickening are dominant.

Mitri and colleagues fed data from Cassini's radar instrument into computer models of Titan developed to describe the moon's tectonic processes and to study the interior structure and evolution of icy satellites. They also made the assumption that the moon's interior was only partially separated into a mixture of rock and ice, as suggested by data from Cassini's radio science team.

Scientists tweaked the model until they were able to build mountains on the surface similar to those Cassini had seen. They found the conditions were met when they assumed the deep interior was surrounded by a very dense layer of high-pressure water ice, then a subsurface liquid-water-and-ammonia ocean and an outer water-ice shell. So the model, Mitri explained, also supports the existence of a subsurface ocean. .." (JPL)

A fresh scar

Craters on the Moon might seem olod, but some - at least one - is at least ten years younger than yours truly. LRO's camera discovered a new crater when Lunar scientists compared Apollo 15 footage with a new pic taken by the LROC:

"The new crater was announced last week by the Lunar Science Institute at NASA Ames. The impact occurred sometime between an image of the region taken by the Apollo program in 1971 and an image recently taken by the Lunar Reconnaissance Orbiter (LRO).

The LRO is a spacecraft that is taking large amounts of data on the Moon's terrain and mineralogy, as well as taking those neat pictures of the Apollo landers and astronaut footsteps. ..." (Discovery)

(Click on the picture for a large image with captions)

Go south, go Saturn

"Looking up toward Saturn's southern hemisphere, the Cassini spacecraft pictures a pair of the planet's moons orbiting in the distance.

Tethys and Rhea orbit in the plane of the planet's rings, but from this vantage point they appear to be below the planet. Tethys (1,062 kilometers, or 660 miles across) is near the center of the image, and Rhea (1,528 kilometers, or 949 miles across) is in the lower right.

This view looks toward the southern, unilluminated side of the rings from about 12 degrees below the ringplane.

The image was taken with the Cassini spacecraft wide-angle camera on June 29, 2010 using a spectral filter sensitive to wavelengths of near-infrared light centered at 728 nanometers. The view was obtained at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 100 degrees. Image scale is 124 kilometers (77 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org ." (JPL)

A family portrait

Because I had nothing better to do, I created this picture with Celestia. It shows the eight planets (no, no, Pluto is a dwarf planet) at actual size differences. From left to right, top to bottom, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Click on the picture for a larger size. Soon we will discover truckloads of these familiies of solar systems. Count my words. Or Kepler's.

Venus recreated

"Scientists are able to learn about the atmospheres and surfaces of planets by studying their spectra - the different wavelengths of light which they reflect or absorb. However, when researchers study spectra of Venus, the hottest planet in the Solar System, they run into a problem. Its high temperatures and pressures seriously affect the data.

Venus and Earth are often described as sister worlds. However, the second planet from the Sun has obviously evolved in a very different manner from our Earth. The surface of Venus is very hot, with temperatures reaching 480 degrees Celsius, and its surface pressure is 90 times greater than on Earth. These extreme conditions cause great difficulties for scientists who are attempting to unveil the mysteries of the Venusian lower atmosphere and surface.

"Remote observation of the surface and atmosphere, particularly at infrared wavelengths, enables us to probe the deepest regions of the atmosphere and surface of Venus," explained Håkan Svedhem, Venus Express Project Scientist.

"On Earth, we understand the spectral absorption lines in the atmosphere, so we can calculate their effects. However, the high temperatures and pressures on Venus make observations much more complex. We don't know precisely how they modify the spectra, so it is impossible to interpret the data accurately."

In an effort to overcome this problem of interpretation, teams of scientists in several countries are attempting to reproduce the extreme environment of Venus and discover how it affects the data sent back by instruments such as the Visible InfraRed Thermal Imaging Spectrometer (VIRTIS) on board ESA's Venus Express orbiter. ... " (ESA)

First a wipe, then a devil

"n its six-and-a-half years on Mars, NASA's Mars Exploration Rover Opportunity had never seen a dust devil before this month, despite some systematic searches in past years and the fact that its twin rover, Spirit, has seen dozens of dust devils at its location halfway around the planet.

A tall column of swirling dust appears in a routine image that Opportunity took with its panoramic camera on July 15. The rover took the image in the drive direction, east-southeastward, right after a drive of about 70 meters (230 feet). The image was taken for use in planning the next drive.

"This is the first dust devil seen by Opportunity," said Mark Lemmon of Texas A&M University, College Station, a member of the rover science team. ..." (JPL)

Bhabha on display

This beautiful picture was taken by the LROC and depicts Bhabha Crater in the Aitkin Basin near the Lunar south pole. Click on the picture to see a bigger version of this intriguing play of light and dark. (LROC)

Neptune playing comet catcher

"Neptune was struck by a giant comet about two centuries ago, according to new research. The find adds to a growing body of evidence that cometary collisions with gas giant planets may be more common than astronomers thought.

On rocky planets with thin atmospheres, such as Mercury (pictures) and Mars, it's easy to count the craters made by impacts dating back millions of years, giving scientists a rough estimate of how frequently space rocks collide with other worlds.

But the gas giants—Jupiter, Saturn, Uranus, and Neptune—are planets that are almost all roiling atmosphere with just tiny cores of rock, making it much harder to find evidence of past impacts.

In 1994 the comet Shoemaker-Levy 9 broke apart and smashed into Jupiter, and several space probes, including Voyager 2, Galileo, and the Hubble Space Telescope, were able to document the rare event.

Using what they'd learned about chemicals left in Jupiter's atmosphere after the comet crash, scientists from the French observatory LESIA and the Max Planck Institutes in Germany analyzed the composition of Neptune's atmosphere with the European research satellite Herschel.

The data show that the amount of carbon monoxide in Neptune's upper atmosphere is higher than in the planet's lower atmosphere. Since gas would normally thin out as it reaches higher atmospheric layers, the extra gas had to come from some outside source, the scientists say.

A comet, which carries carbon monoxide in its icy tail, is the "main explanation," said study co-author Paul Hartogh of the Max Planck Institute for Solar System Research. ..." (NGC)

Ready for a real big snowfight

"While orbiting Saturn for the last six years, NASA’s Cassini spacecraft has kept a close eye on the collisions and disturbances in the gas giant’s rings. They provide the only nearby natural laboratory for scientists to see the processes that must have occurred in our early solar system, as planets and moons coalesced out of disks of debris.

New images from Cassini show icy particles in Saturn’s F ring clumping into giant snowballs as the moon Prometheus makes multiple swings by the ring. The gravitational pull of the moon sloshes ring material around, creating wake channels that trigger the formation of objects as large as 20 kilometers (12 miles) in diameter.

“Scientists have never seen objects actually form before,” said Carl Murray, a Cassini imaging team member based at Queen Mary, University of London. “We now have direct evidence of that process and the rowdy dance between the moons and bits of space debris.”

Murray discussed the findings today (July 20, 2010) at the Committee on Space Research meeting in Bremen, Germany, and they are published online by the journal Astrophysical Journal Letters on July 14, 2010. A new animation based on imaging data shows how one of the moons interacts with the F ring and creates dense, sticky areas of ring material. ..." (JPL)

Mercury's exosphere scrutinized

"Analysis of data from MESSENGER’s third and final flyby of Mercury in September 2009 has revealed the first observations of emission from an ionized species in Mercury’s exosphere, new information about magnetic substorms, and evidence of younger volcanism on the innermost planet than previously recognized. The results are reported in three papers published online on July 15 in the Science Express section of the website of Science magazine.

Mercury’s exosphere is a tenuous atmosphere of atoms and ions derived from the planet’s surface and from the solar wind. Observations of the exosphere provide a window into the extensive interactions between Mercury’s surface and its space environment. The insights such observations provide into surface composition, transport of material about the planet, and loss of material to interplanetary space improve our understanding not only of the current state of Mercury but also of its evolution.

The spacecraft’s observations of Mercury’s exosphere indicate remarkably different spatial distributions among the neutral and ionized elements in the exosphere. The third flyby produced the first detailed altitude profiles of exospheric species over the north and south poles of the planet. “These profiles showed considerable variability among the sodium, calcium, and magnesium distributions, indicating that several processes are at work and that a given process may affect each element quite differently,” says MESSENGER participating scientist and lead author Ron Vervack, of the Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md. ..." (NASA)

Venus, a hot and interesting place

When the Venus Express scanned Venus with UV-light, it got a good look of the top layer of Venuses impressive cloud cover. It observed dark patches in the clouds that absorbed more UV light than other clouds. What could be the cause of that?

Maybe these patches are a result of convection. Heated by the Sun enormous convection bubbles mix the upper and lower clouds, resulting in a thicker and more absorbing patch. The explanation can be much more exciting as well. In the upper atmosphere probes have found hydrogen sulfide and sulfur dioxide which react together, so there must be an external source creating them, otherwise they would be depleted by now, and it also found carbonyl sulfide which is difficult to create by anorganic means.

It might well be that extremophiles, life forms well adapted to the conditions in Venusian clouds, are creating these gases. We know extremophiles flourish on Earth in extreme conditions, both cold and hot, both base and extreme acid (up to pH 0).

Venus Express also determined that the atmosphere of Venus is losing two hydrogen atoms for each oxigen atom. Slowly all the water on Venus is dissipating and lost in space. Together with rock obviously originating from a wet environment, it hints at a past with much more water.

Venus is a fascinating planet that can us learn a lot more about the processes on our own planet. Venus Express is a great resource, circling the planet for years by now at low altitude. Let's hope there's still a lot to come.

Curious for Curiosity

"NASA's next Mars rover, Curiosity, is sitting pretty on a set of spiffy new wheels that would be the envy of any car show on Earth.

The wheels and a suspension system were added this week by spacecraft technicians and engineers. These new and important touches are a key step in assembling and testing the flight system in advance of a planned 2011 launch.

Curiosity, centerpiece of NASA's Mars Science Laboratory mission, is a six-wheeler and uses a rocker-bogie suspension system like its smaller predecessors: Spirit, Opportunity and Sojourner. Each wheel has its own drive motor, and the corner wheels also have independent steering motors. Unlike earlier Mars rovers, Curiosity will also use its mobility system as a landing gear when the mission's rocket-powered descent stage lowers the rover directly onto the Martian surface on a tether in August 2012. ..."

See black hopping Mars Bunnies

In the category "Have A Look Around" Mars Rover Opportunity sent us a panoramic view of multiple places it still wants to visit. If you follow this link you can see a big version of it.

As you can see there are multiple black Mars Bunnies hopping around; JPL will have to process this picture vigorouslyto cover up that there's life on Mars and that there are idiots on Earth - a fact they frantically try to hide from the general public. Job well done, NASA.

Oh well, on a more serious note.

"Since the summer of 2008, when NASA's Mars Exploration Rover Opportunity finished two years of studying Victoria Crater, the rover's long-term destination has been the much larger Endeavour Crater to the southeast. By the spring of 2010, Opportunity had covered more than a third of the charted, 19-kilometer (12-mile) route from Victoria to Endeavour and reached an area with a gradual, southward slope offering a view of Endeavour's elevated rim.

On the 2,239th Martian day, or sol, of Opportunity's mission on Mars (May 12, 2010), the rover used its panoramic camera (Pancam) to take multiple exposures of the horizon toward the southeast. The Pancam team combined these images into this super-resolution view showing details of a portion of the rim of Endeavour about 13 kilometers (8 miles) away plus more-distant features. Super-resolution is an imaging technique combining information from multiple pictures of the same target in order to generate an image with a higher resolution than any of the individual images.

Above the dark plains in the lower portion of the view, the horizon in the left half is mostly a portion of Endeavour's western rim. The paler-looking terrain on the horizon beyond Endeavour in the right half of the image is part of a thick deposit of material ejected by the impact that excavated Iazu Crater, south of Endeavour. The observed increase in brightness of Iazu's ejecta relative to Endeavour's features is consistent with modeling by science team members Michael Wolff, of the Space Science Institute, and Ray Arvidson, of Washington University in St. Louis, applying optical characteristics Opportunity has measured in the Martian atmosphere. ..." (JPL)

Swing Low, Titan

"This (past, JIMvD) weekend, Cassini will embark on an exciting mission: trying to establish if Titan, Saturn’s largest moon, possesses a magnetic field of its own. This is important for understanding the moon’s interior and geochemical evolution.

For Titan scientists, this is one of the most anticipated flybys of the whole mission. We want to get as close to the surface with our magnetometer as possible for a one-of-a-kind scan of the moon. Magnetometer team scientists (including me) have a reputation for pushing the lower limits. In a world of infinite possibilities, we would have liked many flybys at 800 kilometers. But we went back and forth a lot with the engineers, who have to ensure the safety of the spacecraft and fuel reserves. We agreed on one flyby at 880 kilometers (547 miles) and both sides were happy. ..." (JPL Blog)

The most beautiful desert in the Solar system

Read more about this part real, part simulated image on Mars (large!). The prespective is fantastic. And there might have been .... water .... in the past too... a recent stunning discovery..... again. :)

Bright KBO

"How do you study an extremely small planetary body in the dim outer reaches of our solar system? Get all your friends from around the world to wait for a very elusive – if not short-lived – special event. And in doing so, you may find something completely unexpected. Enter James Elliot from MIT. Elliot and astronomers from observatories across the globe teamed up to make observations of the Kuiper Belt Object 55636, a small body orbiting beyond Neptune. Since the KBO is too small and distant for direct observations of its surface, Elliot tracked and plotted its course, figuring out when it would pass in front of a distant star. "For several years, we've been accurately measuring the position of the KBO," Elliot said in an article in BBC. "With an accurate orbit, we just projected where it was going to be in the sky and looked for stars that it might occult."

The KBO occulted, or passed in front of a bright background star, an event which lasted only 10 seconds. But this was enough time to determine the object's size and albedo. And both of these results were surprising. ..." (Universe Today)

A skylight on Mars

"They went looking for lava tubes on Mars — and found what may be a hole in the roof of a Martian cave.

The 16 students in Dennis Mitchell's 7th-grade science class at Evergreen Middle School in Cottonwood, Calif., chose to study lava tubes, a common volcanic feature on Earth and Mars. It was their class project for the Mars Student Imaging Program (MSIP), a component of ASU's Mars Education Program, which is run out of the Mars Space Flight Facility on the Tempe campus.

The imaging program involves upper elementary to college students in Mars research by having them develop a geological question to answer about Mars. Then the students actually command a Mars-orbiting camera to take an image to answer their question. Since MSIP began in 2004, more than 50,000 students have participated to varying extents.

"The students developed a research project focused on finding the most common locations of lava tubes on Mars," Mitchell said. "Do they occur most often near the summit of a volcano, on its flanks, or the plains surrounding it?" ..." (ASU News)

Hayabusa burning up in close up; capsule found and secured

Here are some pictures of the retrieval of the capsule ejected by Hayabusa that landed in the Australian outback. De container will be transferred to Japan and opened in a clean room for inspection - to see if it contains dust particles or more from the asteroid Itokawa. SPACE.com has more on the story here.

The photo below is quite supercool: you see debri of Hayabusa - may it rest in peace - burning up in the atmosphere and to the right below the debri you actually see the ejected capsule moving off. Cooool. No fireworks are as cool as the fireworks Mother Nature can create for us.

Moon maker

"Saturn is perhaps best known for its intricate ring system, but the giant planet also boasts a collection of moons, numbering in the dozens, that is nothing to sniff at. The largest, Titan, has helped draw a bit more attention to the Saturnian satellites in recent days, following an announcement that various chemical abundances on Titan were consistent with but not necessarily indicative of the presence of methane-dwelling, hydrogen-breathing life.

Now, research in the June 10 issue of Nature deals with a population of smaller Saturnian satellites—Atlas, Prometheus, Pandora, Janus and Epimetheus—linking the origin of those so-called moonlets to the celebrated rings themselves. The study presents the result of a computer simulation of Saturn's dynamic environment, demonstrating how the moonlets, which dwell just beyond the planet's famed main rings, could have formed from material oozing out of the rings and accreting into clumps. (Scientific American is part of Nature Publishing Group.) What is more, the moonlets appear to have coagulated in recent astronomical time, implying that more moonlets may be forthcoming. .." (SciAm)

Either life - ummmm - or no life at all

"Two new papers based on data from NASA's Cassini spacecraft scrutinize the complex chemical activity on the surface of Saturn's moon Titan. While non-biological chemistry offers one possible explanation, some scientists believe these chemical signatures bolster the argument for a primitive, exotic form of life or precursor to life on Titan's surface. According to one theory put forth by astrobiologists, the signatures fulfill two important conditions necessary for a hypothesized "methane-based life." ..." (ScienceDaily)