Mason bees like this one build landmarks to help them navigate as they construct a shelter for their eggs. Even hauling materials, these bees can easily stay aloft. This is in contrast to an old misconception that physics can’t explain how a bee flies. It’s true that bees don’t fly using the same mechanisms as a typical airplane — no fixed wings here! But they, like every other flyer aerodynamicists study, still produce lift and drag and thrust. The flapping of a bee’s wings generates much unsteadier quantities of these things, but at its small size, that is no hindrance to its ability to control its flight and even carry cargo. (Image credit: S. Zankl; via Wildlife POTY)
Category: Phenomena
Simeis 147
Sometimes known as the Spaghetti Nebula, Simeis 147 is the remnant of a supernova that occurred 40,000 years ago. The glowing filaments of this composite image show hydrogen and oxygen in red and blue, respectively. These are the outlines of the shock waves that blew off the outer layers of the one-time star within. What remains of that star’s core is now a pulsar, a fast-spinning neutron star with a solar wind that continues to push on the dust and gas we see here. (Image credit: S. Vetter; via APOD)
Light Pillars
These lovely pillars of light over the Mongolian grasslands are the result of tiny, suspended ice crystals. With the right weather conditions, ice crystals can align so that their largest faces are roughly parallel to the ground. In this orientation, the crystals collect and reflect artificial lights from the ground into these towering light pillars. It’s worth noting that the pillars aren’t located directly above the light source; instead, the column of crystals will lie roughly halfway between the light source and the observer. Next time you’re out on a cold winter night, see if you can find one! (Image credit: N. D. Liao; via APOD)
Sharpshooters
The sharpshooter‘s superpower is pee flinging. These insects consume nutrient-poor plant sap, so to get the calories they need, they have to drink 300 times their body weight each day. All that extra liquid has to go somewhere, so the sharpshooter evolved to be an expert excretor. Each drop gathers on their anal stylus, then gets launched with an energy-efficient flick. During that move, the sharpshooter compresses the droplet, adding a little extra energy that helps speed up the drop’s flight once launched. (Video and image credit: Deep Look)
That Drain Life
No matter your cleaning habits, it’s possible to get some unexpected roommates. This variety is the drain fly, a species well-adapted to the moist environment of our pipes. As larvae, they slither and squirm in the biofilms that form from the hair, saliva, and food that make their way down our drains. Being fully immersed is no problem for them, since they carry their own air bubble like a mini scuba tank. In adulthood, these tiny flies are incredibly hairy, all the better to escape from water. All those little hairs trap air near the fly, making it hydrophobic so that water just slides off. It takes a serious dowsing to immerse them enough to drown. (Image and video credit: Deep Look)
Farewell, Saffire!
After eight years and six flight tests, NASA said a fiery farewell to the Spacecraft Fire Safety Experiment, or Saffire, mission. Each Saffire test took place on an uncrewed Cygnus supply vehicle after undocking from the space station. Cygnus craft burn up during atmospheric re-entry, so using them as a platform guaranteed safety for the station’s crew.
A Plexiglass sample burns as part of Saffire-V’s experiments. In this experiment, researchers found that flames grew and spread faster on thin ribs of Plexiglass (left) than on thicker samples (right). Saffire itself used a small wind tunnel to push air past its burning materials. The tests included materials like plexiglass, cotton, Nomex, and other fabrics that might be found on a spacecraft or its occupants. The goal, of course, is to understand how fires grow and spread in a spacecraft in order to protect the crew. To that end, Saffire experiments recorded not only what went on inside their test unit, but also what the conditions were in the spacecraft as Saffire burned. (Image and video credit: NASA; via Gizmodo and NASA Glenn)
Langebaan Lagoon
Strands of green and brown mix in Langebaan Lagoon on the South African coast in this astronaut photograph. The shallow tidal estuary has a sandy floor and, since no river flows into it, the deeper green sections seen here are channels carved solely by the back-and-forth flow of the tides. To the north of the lagoon, Saldanha Bay is a busy hub for fishing and industry. The long reddish line extending into the water is a railroad pier responsible for loading 96 percent of South Africa’s iron ore gets loaded onto ships. (Image credit: NASA; via NASA Earth Observatory)
Convection in Action
We’re surrounded daily by convection — a buoyancy-driven flow — but most of the time it’s invisible to us. In this video, Steve Mould shows off what convection really looks like with some of his excellent tabletop demos. The first half of the video gives profile views of turbulent convection, with chaotic and unsteady patterns. When he switches to oil instead of water, the higher viscosity (and lower Reynolds number) offer a more structured, laminar look. And finally, he shows a little non-temperature-dependent convection with a mixture of Tia Maria and cream, which convects due to evaporation changing the density. (Image and video credit: S. Mould; submitted by Eric W.)
Saharan Dust
In late January, dust from the Sahara blew westward toward the Cabo Verde archipelago before turning northward toward Europe. During winter and spring, Saharan dust tends to stay at lower altitudes, where it can be carried by the northeast trade winds. In contrast, from late spring to early fall, dust rises higher, carried westward by the Saharan Air Layer; there, the dust can help suppress both the formation and intensity of the Atlantic’s hurricanes.
On the left side of the image scant clouds trace von Karman vortex streets behind the archipelago, marking the atmospheric disruption caused by the rocky islands. (Image credit: L. Dauphin; via NASA Earth Observatory)
Moths in Flight
Moths and butterflies are such unique fliers among insects. Compared to their bodies, their wings are often enormous. High-speed video reveals the complex motions of their wing strokes. Some species have wings that flex dramatically, bringing sections of the opposite wing close enough to clap together. Other species, like the plume moth, have porous wings that resemble feathers. For these fliers, viscosity provides some resistance to keep air from simply flowing through the wing. But the little bit of air that does get through may help the moth aerodynamically. (Image and video credit: A. Smith/Ant Lab)
