A snowflake cannot form out of nothing. Water vapour will sit in the air quite happily, supercooled and reluctant, until it finds a speck of dust to build on and then it crystallises around it. Cosmochemists have had a version of that problem for decades. The early Solar System was a furnace of gas, and the first solid grains had to condense out of it somehow, yet condensing from a perfectly uniform gas is slow and difficult work. New research from Caltech, analysing fragments of a meteorite that fell over Mexico in 1969, suggests the seeds were already there. Buried inside the oldest solids we possess are specks of stardust from a star that lived and died before the Sun existed. from Universe Today https://ift.tt/WCxv6sj via IFTTT
Hunting for dark matter usually means building something enormous and burying it — a tank of liquid xenon in a mine, a magnet the size of a lorry, decades of engineering and a great deal of money. A team in Japan have just done it differently. They realised that the Earth's own magnetic field is larger than any magnet we could ever construct, and that the gap between the ground and the ionosphere behaves as a natural resonating cavity, ringing at around eight cycles per second. If dark matter is what some theorists suspect, it should leave a faint hum in that cavity. So they went looking, not with a new instrument, but in ten years of geomagnetic readings already recorded at a quiet observatory in Dumfriesshire in Scotland. from Universe Today https://ift.tt/BrJ2DgV via IFTTT