One of the things that always strikes me about Enceladus is the differences in terrain. Look at the terrain in the lower right side of the picture and how the crater is cut cleanly in half as is the whole side of the moon.
Here’s the Cassini description:
This half-lit view of Enceladus bears a passing resemblance to similar views of Earth’s own natural satellite, but the similarities end there. Earth’s rocky moon is covered in dark, volcanic basins and brighter, mountainous highlands — both exceedingly ancient. The surface of icy Enceladus is uniformly bright, far brighter than Earth’s moon. Large areas of Enceladus’ surface are characterized by youthful (on geologic timescales), wrinkled terrains.
Although the north pole of Enceladus (313 miles or 504 kilometers across) was dark when Cassini arrived at Saturn, the march of the seasons at Saturn have brought sunlight to the north and taken it from the south.
This view looks toward the leading hemisphere of Enceladus. North on Enceladus is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 8, 2015.
The view was acquired at a distance of approximately 80,000 miles (129,000 kilometers) from Enceladus. Image scale is 2,530 feet (772 meters) per pixel.
There is more to the Planet Nine story: “A predicted consequence of Planet Nine is that a second set of confined objects should also exist. These objects are forced into positions at right angles to Planet Nine and into orbits that are perpendicular to the plane of the solar system. Five known objects (blue) fit this prediction precisely.” – Source: Caltech/R. Hurt (IPAC)/NASA website
The diagram was created using WorldWide Telescope.
Note: I meant for this to publish yesterday but I messed it up.
Expedition 46 Commander Scott Kelly of NASA and Flight Engineer Mikhail Kornienko of Roscosmos will be ending a year-long mission aboard the ISS.
How they adapted to the weightless environment after a the year in space will be of great interest as well as how they re-adjust to gravity. The findings will assist with any future long duration missions, say to Mars.
One day our Milky Way will be in the midst of a similar merger, ours with Andromeda.
The ESA description: The subject of this NASA/ESA Hubble Space Telescope image is known as NGC 3597. It is the product of a collision between two good-sized galaxies, and is slowly evolving to become a giant elliptical galaxy. This type of galaxy has grown more and more common as the Universe has evolved, with initially small galaxies merging and progressively building up into larger galactic structures over time.
NGC 3597 is located approximately 150 million light-years away in the constellation of Crater (The Cup). Astronomers study NGC 3597 to learn more about how elliptical galaxies form — many ellipticals began their lives far earlier in the history of the Universe. Older ellipticals are nicknamed “red and dead” by astronomers because these bloated galaxies are not anymore producing new, bluer, stars in ages, and are thus packed full of old and redder stellar populations.
Before infirmity sets in, some freshly formed elliptical galaxies experience a final flush of youth, as is the case with NGC 3597. Galaxies smashing together pool their available gas and dust, triggering new rounds of star birth. Some of this material ends up in dense pockets initially called proto-globular clusters, dozens of which festoon NGC 3597. These pockets will go on to collapse and form fully-fledged globular clusters, large spheres that orbit the centres of galaxies like satellites, packed tightly full of millions of stars.
ISRO PSLV-C31 launched the fifth satellite of the Indian Regional Navigation Satellite System IRNSS-1E from Sriharikota on 19 January 2016 at 09:30 local time. This was the 33rd flight of PSLV launch vehicle. IRNSS-1E is the fifth navigation satellite in the IRNSS space system, comprising seven satellites.