Its eye-stache isn’t the most fascinating thing about this trilobite. It’s thought that it swam in the open waters to hunt for plankton. Due to its heavy armor, it probably swam upside down.
Quartzite stela with figures of the sculptor Bak with his wife, Taheret. Amarna Period. Bek or Bak (Egyptian for “Servant”) was the first chief royal sculptor during the reign of King Akhenaten. This is possibly the first self-portrait in history. The inscription of this stela also mentions him being taught by Akhenaten. Now in the Egyptian Museum, Berlin.
The God Horus in His form of sacred falcon spreading His wings in protection and holding the ‘shen’-ring (symbol of eternal protection). Watercolour copy by Howard Carter (1874-1939) of a painted scene from the “Temple of Millions of Years” of Hatshepsut (Deir el-Bahari)
Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy’s disturbing the primary galaxy’s spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger.
A giant galaxy interacting with its satellites is common. A satellite’s gravity could attract one of the primary’s spiral arms, or the secondary satellite’s path could coincide with the position of the primary satellite’s and so would dive into the primary galaxy (the Sagittarius Dwarf Elliptical Galaxy into the Milky Way being an example of the latter). That can possibly trigger a small amount of star formation. Such orphaned clusters of stars were sometimes referred to as “blue blobs” before they were recognized as stars.
Colliding galaxies are common during galaxy evolution. The extremely tenuous distribution of matter in galaxies means these are not collisions in the traditional sense of the word, but rather gravitational interactions.
Colliding may lead to merging if two galaxies collide and do not have enough momentum to continue traveling after the collision. In that case, they fall back into each other and eventually merge into one galaxy after many passes through each other. If one of the colliding galaxies is much larger than the other, it will remain largely intact after the merger. The larger galaxy will look much the same, while the smaller galaxy will be stripped apart and become part of the larger galaxy. When galaxies pass through each other, unlike during mergers, they largely retain their material and shape after the pass.
Galactic collisions are now frequently simulated on computers, which use realistic physics principles, including the simulation of gravitational forces, gas dissipation phenomena, star formation, and feedback. Dynamical friction slows the relative motion galaxy pairs, which may possibly merge at some point, according to the initial relative energy of the orbits.
Astronomers have estimated the Milky Way galaxy, will collide with the Andromeda galaxy in about 4.5 billion years. It is thought that the two spiral galaxies will eventually merge to become an elliptical galaxy or perhaps a large disk galaxy.
The findings come after images from NASA’s New Horizon mission have been analysed from travelling the system for nearly a decade. As well as having a diameter of only 2,377km and surface temperatures of -230C; Pluto’s atmosphere was thought to be too thin for the formation of features similar to those found in deserts on earth. The dunes formed next to a major mountain range of water ice 5km high where wind is generated as air flows downhill. It can get as high as 10m/s which is enough to carry the tiny particles. Scientists can’t see everything from the images but they were able to discern the dunes are 0.4-1km apart and the methane crystals 200-300 micrometers in diameter (roughly a grain of sand).
The grains of methane (and maybe nitrogen) are thought to be produced through a process known as sublimation. This is where a solid transitions directly to a gas skipping the liquid phase. This essentially transports it into the atmosphere where the tiny crystals form then the Pluto’s winds transport them around the dwarf planet.
