Meteor showers, which happen when our planet traverses through debris streams left behind by passing comets, are a fairly common occurrence. While the tiny rocks usually burn up when they collide with our atmosphere, resulting in what we call “shooting stars,” every so often one manages to survive the impact and land on Earth. That is precisely what appears to have happened in Costa Rica recently.
On April 23, 2019, at 9:09 pm local time, residents of San Carlos in Costa Rica’s Alajuela Province heard a loud noise, which was followed by a massive “fireball” streaking across the skies. Photos and videos of the stunning bright flashes soon went viral, with hundreds of residents reporting on the incident.
Looking for a fun Earth Day activity? You may want to try plogging, or picking up litter while jogging. Odd as it may sound, the new “sport” is becoming extremely popular with runners worldwide, many of whom are posting images of themselves and friends holding bags of trash on social media.
Derived from the word jogging and “plocka upp,” the Swedish phrase for pick up, plogging is the brainchild of Erik Alström. In 2016, after moving to Stockholm from a small ski community in northern Sweden, Alström became increasingly agitated at the amount of trash on the road during his daily bike ride to work.
When a falling liquid droplet hits a surface, like a raindrop hitting pavement, it either flattens and spreads out evenly, or produces a sharp-edged splash. Now, a team of Chinese researchers has created a surface which allows the descending liquid to rebound and swirl around like a graceful dancer.
The team, led by Huizeng Li of the Chinese Academy of Sciences, Beijing (CAS), began by coating an aluminum surface with nonstick material, like the kind used on cooking utensils. The researchers then created several designs by covering portions of the nonadhesive area so that it would act like a normal, “wettable” surface – meaning it would cause the falling droplets to spread around. An ultraviolet (UV) light shone over the entire surface completed the setup.