1787 – Birth. In Bavaria, of Joseph von Fraunhofer, inventor of the spectroscope, and discoverer of the Sun’s absorption lines.
Unfortunately for the worlds of optics and astronomy, Fraunhofer died at the young age of 39 (early death was an occupational hazard for glassmakers in those days due to the poisonous heavy metal vapours associated with the craft).
1885 – Asteroid 246 Asporina discovered by Alphonse Borelly. Asporina is an R-type asteroid of about 60 km in diameter. R-types are a fairly rare group, rich in olivines and pyroxines. In the world of minor planet classifications they lie between the V-types (the vestoids) and the A-types).
Like R-type asteroids, the name Asporina (also known as Adporina )is fairly obscure. It is an appellation of either the Roman goddess Minerva, or the Phrygian goddess Cybele (or Cibele). As the name is only used in Phrygia I’m going with the latter as the most likely. Phrygia is a region of Asia Minor, in what is now Turkey. Cybele is thought to be Phrygia’s only home-grown goddess.
1965 – launch of Kosmos 59 by the USSR.
2009 – NASA launches the Kepler mission to find extrasolar planets, ideally those in the habitable zone of their parent star, using the transit method.
Finding Earth-sized planets using this technique isn’t easy. The drop in brightness of the star caused by a transit is only about 1/10,000; and the chance of the planet’s orbit being conveniently edgewise to Kepler’s view is only 1 in 200.
For this reason, Kepler has studied well over 100,000 stars with its 0.95-metre diameter photometer.
For a telescope, Kepler has an unusually large field of view of 105 square degrees (see the illustration, above). It is this wide-eyed gaze that allows Kepler to measure the brightness of so many stars at once.
As of late 2015 there had been over 1,000 confirmed Kepler planets, with 3,000 “possibles”, leading to speculation that there could be up to 40 billion Earth-sized planets in the habitable zones of Sun-like and red dwarf stars in our galaxy.
Alone? I don’t think so.