Over at CNN’s Opinion Page, science dude (senior scientist at Fermi National Accelerator Laboratory, to be specific) Don Lincoln wrote a fascinating article about a “hurricane” of 100+ stars and a LOT of dark matter. To a pitiful laymen like me, it sounds like an apocalypse scenario, but apparently it’s a good thing?
In short, the Gaia telescope had released its data to the public last April and scientist found evidence that stars were moving (I know, I always thought of stars as fixed points myself) around the Milky Way. The stellar streams and full of dark matter, a mysterious type of matter that only exists gravitationally. Having it come close allows scientists to study it.
While dark matter has not yet been observed, hypothesizing its existence is the simplest and most economical explanation for myriad astronomical mysteries. Averaged over the entire universe, dark matter is thought to be five times more prevalent than the ordinary mass of stars and gas and planets.
In dwarf galaxies, the fraction of dark matter is often higher. In Fornax, a well-studied dwarf galaxy orbiting the Milky Way, researchers estimate that the dark matter is between 10 and 100 times greater than the mass found in its stars.
If that number holds for S1, the dark matter of the S1 stream is passing through the Earth at a much higher velocity than the more ordinary dark matter that orbits the Milky Way -- about twice as fast. It is thought that S1 dark matter is flying through the solar system at a speed of about 550 km/s, or about 1.2 million mph. While these numbers are impressive, they are misleading. Dark matter, if it exists, is extremely diffuse and it will have no discernible effect on the solar system.
Read the rest of the article here. In the meantime, check out the video below on CNN.