July 31 – 122 Gerda

Asteroid 122 Gerda was discovered by C H F Peters on July 31st 1872, and named after the Norse God Freya. It is an S-type main belt asteroid of about 81km diameter, and is a member of the Hecuba family of asteroids. Gerda takes 2112 days to orbit the Sun at 16 km/s.

Skírnir Persuades Gerðr to Follow Him. Karl Ehrenberg (1882).

Skírnir Persuades Gerðr to Follow Him. Karl Ehrenberg (1882).

The story of Freya and Gerðr is mentioned in both the Poetic and Prose Edda of Icelandic folklore, though they differ as to whether Freya had to rely on the threats of his servant Skirnir to win Gerðr as his bride.  How romantic.

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Also today, with a touch of deja vu, asteroid 123 Brunhild was also discovered by C H F Peters, and named after the famous Valkyrie of Norse mythology. IRAS observations give us a diameter of just over 48 km, somewhat smaller than Gerda, and this particular S-type main belt asteroid is a little speedier, taking 1615 days to orbit the Sun at about 18 km/s.

Siegfried awakens Brünnhilde (Arthur Rackham).

Siegfried awakens Brünnhilde (Arthur Rackham).

Brynhildr (aka Brunhild or Brunhilde) is also mentioned in the Edda (and the Völsunga Saga), but is today mostly known as a stereotypically enormous-bosommed soprano from Wagner’s Der Ring des Nibelungen.

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July 30 – Kosmos 36

Kosmos (Cosmos, if you prefer) 36 was launched by the USSR on July 30th, 1964, via a Kosmos 2I launcher from the Kasputin Yar site (now in the Russian Federation) between Volgograd and Astrakhan.  It was used as a radar calibration target during tests of a missile defence system to presumably protect the comrades from the likes of decadent me.

Kosmos 36 (image credit: KB Yuzhnoye).

Kosmos 36 (image credit: KB Yuzhnoye).

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July 23 – 114 Kassandra

Asteroid 114 Kassandra was discovered by prolific asteroid hunter Christian Heinrich Friedrich Peters on July 23rd 1871.  It is in the main belt, is about 100km in diameter, and is of spectral type “T”.  We don’t get many T-types in these pages, mainly because you don’t get many T-types anywhere.  They tend to orbit in the inner main belt, and are thought to be related to P-types, but as we don’t have any convenient examples to study, very little is known about them.

Woodcut showing Cassandra predicting the fall of Troy and her own death.

Woodcut showing Cassandra predicting the fall of Troy and her own death.

Kassandra is named after the tragic Greek prophetess of the same name but with a “C”, cursed by her spurned would-be lover Apollo to be able to foretell the future but never be believed.

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ALSO TODAY . . . .

1995  –  Today in 1995 saw the discovery of Comet Hale-Bopp by Alan Hale (New Mexico) and Thomas Bopping (Arizona). “C/1995 01” was one of the brightest comets of the 20th century, visible with the naked eye for over eighteen months around its perihelion at April 1st 1997. It became the most observed comet in history, largely due to the increase in Internet availability happening at the time, and NASA’s Hale-Bopp Web page was their first to receive over a million hits in one day. How much scrutiny Hale-Bopp receives next time around is anyone’s guess. Perihelion is expected in around 4385 AD, by which time I expect Richard Branson’s descendants to be offering cut-price round trips through the tail (with a free night on Mars if you book early).

1999  –  Launch of the CHANDRA spacecraft.

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July 02 – Hans Bethe

The happy chap in the photograph is today’s birthday boy, German-born (later American) nuclear physicist, Hans Bethe.

Hans Bethe

Hans Bethe

Born in Strasbourg in 1906, Bethe majored in chemistry at Strasbourg University for a while, but was tempted to Munich in 1926 by the superior standard of physics there. After obtaining his doctorate, Bethe took up a couple of posts in Germany, before obtaining a travelling scholarship from the Rockefeller Foundation. This enabled him to work at the Cavendish Laboratory in Cambridge, and then for Enrico Fermi in Rome. A year in Manchester was followed by Bethe taking up a post at Cornell University in 1935.

Like many eminent nuclear physicists of the 1940s, Bethe was involved in the development of the atomic bomb, and later the H-bomb (although he claimed to be opposed to it).

From our perspective, though, it is Bethe’s work on theoretical astrophysics that gets his photo at the top of this page. In 1967 he was awarded the Nobel Prize in Physics, and his work on the thorny problem of how electron neutrinos convert to muon neutrinos is remarkable, and even more so when one considers that he was in his 80′s at the time.

Basically, the so-called solar neutrino problem was a discrepancy between the number of electron neutrinos passing through the Earth and the number predicted by models of the Sun’s interior. I don’t think we need go into it too much, but the solution was that supposedly massless neutrinos aren’t massless after all, and can change from one type to another.

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