Another Great Image: Tethys 'Eyes' Saturn

 

My first thought when seeing the image was the earlier Star Wars film where the Death Star was rounding a targeted planet.  However, this shot was taken from the Cassini spacecraft and shows the moon of Tethys.  Here is the rest of the story from NASA's Jet Propulsion Laboratory:

The two large craters on Tethys, near the line where day fades to night, almost resemble two giant eyes observing Saturn.

The location of these craters on Tethys’ terminator throws their topography into sharp relief. Both are large craters, but the larger and southernmost of the two shows a more complex structure. The angle of the lighting highlights a central peak in this crater. Central peaks are the result of the surface reacting to the violent post-impact excavation of the crater. The northern crater does not show a similar feature. Possibly the impact was too small to form a central peak, or the composition of the material in the immediate vicinity couldn’t support the formation of a central peak.

In this image Tethys is significantly closer to the camera, while the planet is in the background. Yet the moon is still utterly dwarfed by the giant Saturn.

This view looks toward the anti-Saturn side of Tethys. North on Tethys is up and rotated 42 degrees to the right. The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 11, 2015.

The view was obtained at a distance of approximately 75,000 miles (120,000 kilometers) from Tethys. Image scale at Tethys is 4 miles (7 kilometers) per pixel.

And let's not forget Mimas, another moon of Saturn, that has even greater resemblance to the Death Star up close. 

Alien Ocean: NASA's Mission to Europa

NASA's Jet Propulsion Laboratory released this video on NASA's planned mission to Jupiter's moon Europa.  It discusses the space agency's plan to send a spacecraft to conduct flybys of the moon to better understand its composition, its presumed liquid water oceans, and its potential for life.  Unlike other missions that orbit the object being observed, the radiation around the moon would soon cook any nearby spacecraft.  So instead NASA hopes that multiple flybys, and even a potential fly-through of any plumes, will provide us with the necessary information to make some solid determinations about Europa. It is an ambitious plan, but as spacecraft such as Galileo, Voyager, Cassini, New Horizons, and others have proven, we are up to the task.

Light Spots on Ceres: Is it a Shopping Center?

NASA's Jet Propulsion Laboratory (JPL) is asking for your guess about the bright spots spotted on Ceres.  JPL asks:

Can you guess what's creating those unusual bright spots on Ceres? On March 6, NASA's Dawn spacecraft began orbiting Ceres, the largest body in the main asteroid belt between Mars and Jupiter. Even before the spacecraft arrived at the dwarf planet, images revealed mysterious bright spots that captivated scientists and observers alike. Until Dawn gets a closer look over the next few months, it's anyone's guess what those spots could be. So, go ahead! Cast your vote...

The possible options are (1) volcano, (2) geyser, (3) rock, (4) ice, (5) salt deposit, and (6) other. You can see a better image below, taken on May 16th by the Dawn spacecraft.  I believe the most likely source of the light is reflection on ice, but you never know.  When I voted (no peaking), about 30 percent voted for ice, but 38 percent voted for "other."  I would like to know what some of those "other" scenarios might be, but we may not know for some time (or ever).  The mystery continues.

A Helicopter on Mars?

While rovers have been the rage up to now, it seems helicopters may have a role to play as well.  NASA's Jet Propulsion Laboratory (JPL) recently announced it is developing a 2.2 pound prototype to assist rovers with reconnaisance:

Each NASA rover has delivered a wealth of information about the history and composition of the Red Planet, but a rover's vision is limited by the view of onboard cameras, and images from spacecraft orbiting Mars are the only other clues to where to drive it. To have a better sense of where to go and what's worth studying on Mars, it could be useful to have a low-flying scout.

Being solar-powered, the little craft will be able to fly only a few minutes a day.  But that should be enough to give the rover a better idea about its surroundings.  You can watch a video from JPL discussing the testing of the helicopter given the different environment on Mars. 

Rosetta's Mission to a Comet

Above is an amazing shot of the comet being pursued by the European Space Agency's (ESA) Rosetta spacecraft.  This image was taken earlier this month from about 65 miles away.  After 10 years, the Rosetta mission is finally on target to orbit the comet before landing on it in November of this year.  This will be the first ever landing on a comet and provide all of us with a greater understanding of whether comets seeded life in our solar system. 

You can follow the mission via the ESA website or NASA's Jet Propulsion Laboratory.  ESA has also put together a fun story on its website for kids following the mission. 

Image Credits:  ESA/Rosetta/NAVCAM (coment) and ESA (cartoon)

New Impact Crater on Mars

Earlier this week NASA's Jet Propulsion Laboratory reported on a new impact crater on Mars.  The crater was spotted last November using the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera.  The impact happened sometime between July 2010 and May 2012.

About 100 feet in diameter, the crater produced a beautiful spread of colors, including an odd powder blue that you would not associate with Mars.  In the accompanying text, JPL explains "Because the terrain where the crater formed is dusty, the fresh crater appears blue in the enhanced color of the image, due to removal of the reddish dust in that area." 

2.9 Billion Miles - For Dust?

NASA's Stardust space capsule is now safely back on Earth after quite a journey. Scientists are now studying the payload (about one teaspoon of dust) that successfully landed in the Utah desert. We will now learn much more about the comets that circle our solar system and thereby more about the early foundations of our own planet some 4.5 billion years ago. Visit NASA's Jet Propulsion Laboratory for more on the progress of the research.