Busy Week in Astro-News
Apr 4 at 6:06pm by Aileen
The annual meeting of the UK’s Royal Astronomical Society’s National Astronomy Meeting in Belfast this week has produced some cool news items on the astronomical discoveries of the past year. First up, we have some interesting findings in our own neighborhood with research focusing on our sun. An international team announced that they’d discovered the source of the solar wind.
The solar wind consists of electrically charged particles that flow away from the sun in all directions. The scientists working with the Hinode mission and the UK’s Extreme Ultraviolet imaging Spectrometer to determine that the sun’s magnetic fields create bright regions of activity on the solar surface. The edges of these bright regions emit hot gas at high speeds. The magnetic fields connect even in separated regions, and this connection (or collision) allows hot gas to escape from the sun’s gravitational field as solar wind.
Our Universe: Missing, Found, Then Missing Again
Nov 8 at 10:10pm by Aileen
Keeping Up With Astronomy’s Game of Hide-and-Seek
Big astrophysics science news this week that a Big Chunk of the Universe Is Missing - Again. This requires a little background for understanding how it is our universe can be so adept at playing hide-and-seek.
As much as 96% of the mass necessary to account for how our universe is observed to be has been missing for a long time. The mass is necessary to explain the gravity that holds galaxies together, but all the atomic matter we can see in planets, comets, asteroids, assorted space junk, stars and galaxies accounts for just 4% of it. In 1974 astronomer Vera Rubin discovered that instead of following a Newtonian scheme where Mercury travels faster around the sun than Neptune does, almost all stars rotating around a galaxy’s center - at any distance - all travel at the same speed.
There had to be some ‘extra’ source of gravity working in galaxies, but there wasn’t nearly enough mass to account for this anomaly. The choice was between gravity being variable (unthinkable!) or the existence of a great deal of extra mass that we couldn’t see. Scientists jumped on that answer in defense of Newtonian/Einsteinian gravity and gifted us with “Dark Matter.”
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