The Cassini spacecraft took these intriguing images. What are those red arcs on Saturns moon Tethys? Keep in mind these are color enhanced and taken through four different filters, including infrared and ultraviolet. Still they are pretty surprising. The press release explains the image and shares a couple of possible explanations. It seems like it could also be a combination of two of the ideas below, ices being contaminated by outgassing.
Unusual arc-shaped, reddish streaks cut across the surface of Saturn’s ice-rich moon Tethys in this enhanced-color mosaic. The red streaks are narrow, curved lines on the moon’s surface, only a few miles (or kilometers) wide but several hundred miles (or kilometers) long. The red streaks are among the most unusual color features on Saturn’s moons to be revealed by Cassini’s cameras.
From JPL: The color scale extends 3.7 miles (6 kilometers) below the surface in purple to 3.7 miles (6 kilometers) above the surface in brown. The brightest features (those appearing nearly white) — including the well-known bright spots within a crater in the northern hemisphere — are simply reflective areas, and do not represent elevation.
There is an animated version of the image and links to beautiful wallpaper versions for your computer – at the Dawn website
In June we saw a nice image of crater Odysseus a huge crater compared the the size of the Saturn moon Tethys – see here.
This image is from almost from the opposite direction and the impact crater seems a different color than the surrounding terrain.
Image Credit: NASA/JPL-Caltech/Space Science Institute
From the Cassini site (click for more image options): With the expanded range of colors visible to Cassini’s cameras, differences in materials and their textures become apparent that are subtle or unseen in natural color views. Here, the giant impact basin Odysseus on Saturn’s moon Tethys stands out brightly from the rest of the illuminated icy crescent. This distinct coloration may result from differences in either the composition or structure of the terrain exposed by the giant impact. Odysseus (280 miles, or 450 kilometers, across) is one of the largest impact craters on Saturn’s icy moons, and may have significantly altered the geologic history of Tethys.
Tethys’ dark side (at right) is faintly illuminated by reflected light from Saturn.
Images taken using ultraviolet, green and infrared spectral filters were combined to create this color view. North on Tethys (660 miles or 1,062 kilometers across) is up in this view.
The view was acquired on May 9, 2015 at a distance of approximately 186,000 miles (300,000 kilometers) from Tethys. Image scale is 1.1 mile (1.8 kilometers) per pixel.
ESA and NASA are both at Mars. Russia launched an ambitious mission to return a sample from the Martian moon Phobos, but a problem with the Phobos-Grunt spacecraft after launch ended the attempt and they sadly have not tried again.
The MOM mission reached Mars and is exploring and observing Mars surface features, morphology, mineralogy and the Martian atmosphere. The mission is also looking for methane in the atmosphere. Methane can be a marker of the existence of life in the right conditions.
MOM is also returning images from the Mars Color Camera (MCC), one of my favorites is Tyrrhenus Mons is shown here from an altitude of 3192 km / 1983 miles.
MOM has been quiet because of the conjunction (as was the Curiosity rover) and has started sending data back.
A replay of the 23 July docking of the Expedition 44 Soyuz spacecraft with the International Space Station.
The Soyuz spacecraft ferried Soyuz Commander Oleg Kononenko and flight engineers Kjell Lindgren and Kimiya Yui to the ISS in just six hours after being launched from the Baikonur Cosmodrome in Kazakhstan.
Here is a great video about the newly announced Kepler 452b with SETI scientists: Douglas Caldwell, Jeffrey Coughlin, Joseph Twicken. and hosted by Seth Shostak.
The Hangout fills in a lot of the blanks from the news reports. As I expected we don’t yet have a mass or density on this planet. Once we get at least a good estimate on these numbers for 452b then we will be able to make better guesses on its composition.
We have an estimate of the diameter so that’s a start, but it’s only one bit of the equation that defines the balance the must exist. If for example, 452b has the density of Earth, we might expect an atmosphere to be much different than we have, ranging up to perhaps even Neptune-like. On the other hand the mass could be much less and the weaker gravity could allow more of the lighter gasses to be lost to space.
I am bound to guess we are very close to finding a real Earth analog. It is astounding how quickly the search is progressing.