On Feb. 15, 2013, an asteroid estimated to be the size of a six-story building shot through Earth’s atmosphere at around 43,200 miles per hour. Dragging through the air at such speed caused the object to heat, and it eventually exploded over Chelyabinsk, Russia.
The airburst released energy equal to 500,000 tons of TNT—30 times more powerful than the Hiroshima nuclear bomb—sending a pressure wave to the ground that damaged buildings and resulted in more than 100 hospitalizations. Researchers using Sandia National Lab’s Red Sky supercomputer reconstructed the path and explosion of the asteroid to improve models for future trajectories and impacts.
Images courtesy Sandia National Lab. Gif courtesy Sandia/Nature.
According to the laws of physics, a planet in the shape of a doughnut (toroid) could exist. Physicist Anders Sandberg says that such planets would have very short nights and days, an arid outer equator, twilight polar regions, moons in strange orbits and regions with very different gravity and seasons.
Canada is having a cold snap at the moment. This week, in Southern Manitoba, the temperature reached a blisteringly frigid -31 degrees Celsius, or nearly -24 Fahrenheit. (Wind chill values in Winnipeg—in case you were curious and/or in need of some meteorological schadenfreude—dipped to -58 Fahrenheit.) Which is crazy, and which makes for, as Yahoo’s Geekquinox blog puts it, “the coldest afternoon temperatures the area has seen in several years.”
The cold spell also puts Canada into some rarified company. Because you know what other place has recently registered a temperature of -31 degrees Celsius? Mars.
This is a concept video by NASA’s Goddard Space Flight Center in Maryland of how the Martian atmosphere and landscape may have changed in the past 4 billion years.
All going to plan, NASA will launch MAVEN this Monday, to find out whether the theories of change are correct. MAVEN will orbit Mars with a suite of instruments that will scan the upper atmosphere for proof of the existence of a much richer ancient atmosphere above the Red Planet.
The spacecraft will arrive at the Red Planet on Sept. 22, 2014, and slip into an elliptical orbit ranging from a low of 93 miles above the surface to a high of 3,728 miles. It also will take five “deep dips” during the course of the mission, flying as low as 77 miles in altitude and providing a cross-section of the top of the atmosphere