One of my students asked me this week if it rains on the sun. The answer is a fairly surprising yes, although it is nothing like rain as we think of it. When a solar eruption occurs, the plasma ejected from the surface of the sun can cool and “rain” back down. The charged particles are captured by the magnetic “lines” and form graceful patterns as they fall back toward the surface. This process is known as coronal rain, and it is really quite beautiful.
Video credit: Solar Dynamics Observatory and NASA.
The terminator, or day/night divide on the Earth, is show here in an image taken by the crew of the ISS. The station orbits at an altitude of 233 miles. Even from this relative closeness, the atmosphere of the Earth appears as the thin film it is. Image by NASA.
Just got to 150 followers! Thank you, new followers. Have a wonderful evening, and an image of my absolute favorite animal, the tardigrade. In addition to being adorable, these little critters can survive (briefly!) in temperatures ranging from -200°C to 151°C.
This nanostructure is actually very, very thin layers of a titanium compound. Each layer is only about five atomic layers thick- so thin, in fact, that researchers are calling it one of the first truly two-dimensional structures ever created. Image captured via electron microscope by a large team at Drexel University.
These fantastical structures are the microscopic crystals that make up a sea urchin’s tooth. Each shade of blue, aqua, green, and purple—superimposed with Photoshop on a scanning electron micrograph (SEM)—highlights an individual crystal of calcite, the abundant carbonate mineral found in limestone, marble, and shells. The curved surfaces of the crystals look nothing like normal calcite crystal faces. Instead of flat sides and sharp edges, the sea urchin produces “incredibly complex, intertwined” curved plates and fibers that interlock and fill space in the tooth as they grow. Though made of a substance normally as soft as chalk, the teeth are hard enough to grind rock, gnawing holes where the sea urchins take shelter from rough seas and predators.
Photo and caption credit: Pupa U. P. A. Gilbert and Christopher E. Killian; University of Wisconsin, Madison
An onlooker witnesses the annual solar eclipse as the sun sets on May 20, 2012. Photo and caption by Colleen Pinski.
