July 31 – Discovery of Asteroids 122 Gerda and 123 Brunhild (1872)

Asteroid 122 Gerda was discovered by C H F Peters on July 31st 1872, and named after the wife of 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 on this day in 1872, 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 – Launch of Kosmos 36 (1964)

The wasp’s head in today’s illustration is actually Kosmos (Cosmos, if you prefer) 36, which 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 27 – Birth of Sir George Airy (1801)

Today is the birthday of Sir George Biddell Airy, born in 1801 at Alnwick (I think you pronounce it ‘annick’, but don’t quote me) in Northumberland, England.  If you pay a visit, you’ll probably recognise Alnwick from its castle, which has starred in two Harry Potter films, Downton Abbey, Star Trek: the Next Generation and The Black Adder.

Airy shone as a student at Cambridge, probably to the annoyance of his fellows. Like Isaac Newton before him, Airy was a sizar, a class of student whose parents could not afford to pay the full fees, but who were allowed entry on the understanding that they paid their way by working as a servant at the university while studying.

A mere six years after entering Cambridge Airy was appointed Lucasian professor of mathematics, one of the most prestigious academic posts anywhere, held over the years by (among others) Charles Babbage, Paul Dirac,  Stephen Hawking, and the aforementioned fellow sizar Isaac Newton.

Airy made several important discoveries in his time, including a tiny inequality in the motions of Venus and Earth that led to an overhaul of Delambre‘s solar tables.  He also came up with a new figure for the mean density of the Earth.  This was achieved by measuring the change in gravity as one descends into the Earth by using changes in the swing rate of a pendulum at the top and bottom of a deep coal mine. It turns out that at just over 1000 feet down the pendulum ‘gains’ two and a quarter seconds a day. From this, Airy was somehow able to calculate a specific density of about 6.5. Today it is thought to be 5.5.

Today’s picture is the un-astronomical A Shell Forge, by war artist Anna Airy, George’s granddaughter.

A Shell Forge (Anna Airy).
A Shell Forge (Anna Airy).

1879  –  Discovery of C-type asteroid 200 Dynamene by C H F Peters.


July 26 – Launch of Apollo 15 (1971)

Today in 1971David ScottJames Irwin and Alfred Worden became the first philatelists in space.  Their attempt to smuggle unauthorised postage stamps to the Moon and back to be sold later did rather put a bit of a downer on the reputation of the fourth Moon landing, which was a shame, because the mission (including the first use of the lunar rover), was otherwise a great success.

Apollo 15 crew (image credit: NASA)
Apollo 15 crew (image credit: NASA)

Apollo 15 was the first manned craft to land somewhere other than a lunar mare, and was longer than previous visits, with over 18 hours spent outside the lunar module.  The landing site chosen for Apollo 15 was Hadley Rille, a valley to the southwest of Mons Hadley, a ‘massif’ in the Moon’s northern hemisphere.

It was Scott and Irwin who went to the surface with their Lunar Roving Vehicle.  This allowed them to travel much further than before and still keep in touch with Mission Control, and indirectly the command module, using the Lunar Communications Relay Unit on the front of the rover.  In total the astronauts drove for over 17 miles (27 km), reaching a distance of just over three miles from the lunar module.  Unfortunately their distance record only stood for a year and a half; Apollo 17 smashed it in their rover by traveling 22 miles (36 km), and getting to 4.7 miles (7.6 km) from their lunar module.


1958 – launch of Explorer 4. Launched this day in a blaze of secrecy, Explorer 4 spent the summer of 1958 collecting data on the Van Allen radiation belts. The Explorer family is the longest running series of spacecraft ever, from Explorer 1 in 1958 to Explorer 78 in 2000.


July 25 – Apollo 11 Splashdown (1969)

On July 21st, 1969, the Eagle ascent stage, which had brought Neil Armstrong and Buzz Aldrin back from the lunar surface to join Michael Collins in the Columbia command module, was jettisoned (it is thought to be on the surface somewhere) and the journey home began.

Apollo 11 Returns to Earth (image: NASA)

The task of picking up the crew fell to the aircraft carrier USS Hornet, which had been sailing to the splashdown site since July 12 (before Apollo 11 had even launched). At a quarter to six in the morning, Columbia landed, upside down I believe, about 13 miles from the Hornet. Flotation bags were used to bring her the right way up and aid stability, and the astronauts were winched into a helicopter.

The crew of Apollo 11 (image: NASA)

Unfortunately, it was then straight to quarantine. In total, the astronauts spent three weeks isolated from direct contact with other humans (except the mission doctor, who was allowed in, but then had to stay with them).

July 23 – Discovery of Asteroid 114 Kassandra (1871)

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 22 – Birth of Friedrich Wilhelm Bessel (1784)

Today is the anniversary of the birth, in 1784 of Friedrich Wilhelm Bessel, the German astronomer who was the first to use parallax to find the distance to a star.  The star in question was 61 Cygni, which Bessel decided was 10.3 light years away (the current measurement is 11.4 ly).  One can only marvel at Bessel’s ability, in 1838, to measure the unbelievably small angles involved.  The feat was somewhere akin to measuring the differences in direction of the left and right edges of a Brussells sprout located about three miles away.

Portrait of Bessel by the Danish artist C A Jensen
Portrait of Bessel by the Danish artist C A Jensen

Asteroid 30 Urania was discovered on July 22nd 1854 by John Russell Hind.  It is a main belt S-type asteroid of about 100km diameter at its widest point.

Urania
Urania

Urania is the Greek muse of astronomy, a daughter of Zeus, and great-granddaughter of Uranus.  She is usually represented wearing a cloak embroidered with stars.  The allegorical representation above is by the French portrait painter Jean Louis Tocqué.


July 21 – Small Step; Big day

July 21st 1969 is going to take some beating as far as big days go.  I’ve been thinking about it, and it’s just really obvious that nobody has ever done anything even remotely as impressive as walking on the Moon.  The more one thinks about it, the less likely it seems that it was even possible with 1960′s technology (don’t forget that the processors used in the guidance system were smaller than the ones available in home computers just a decade later, and my android phone is obviously from a different planet).

Pretty big shoes to fill (image credit: NASA)
Pretty big shoes to fill (image credit: NASA)

Maybe something to top it will come along eventually (the first gay pope to visit  Mars, maybe?) but in the meantime, here are a couple of other events being commemorated and largely forgotten in the enormous shadow thrown by Neil Armstrong’s boots.


1914  –  Discovery of Jupiter’s moon Sinope by S B Nicholsonwhile he was working as a summer assistant at Lick Observatory.  The ninth satellite of Jupiter to be spotted, Sinope was, as I say, discovered in 1914, but didn’t receive a proper name until 1975; until then it was simply “Jupiter IX”.  It was named, along with eight other moons, “on the recommendation of the Working Group for Planetary System Nomenclature” of the IAC.  Nicholson’s discovery was slightly serendipitous, as he was actually photographing “Jupiter VIII” at the time with the 36-inch British-built Crossley Reflector, a device the observatory had bought from it’s previous owner when it became obvious that the skies above Halifax, England, were a waste of a large telescope.


1998  –  RIP Alan Shepard.  Shepard (another of the Mercury Seven) was, as commander of Apollo 14, the fifth man on the Moon, and the first to play golf there.  It’s perhaps just as well that the Americans conquered the Moon.  I doubt the effect would have been quite the same when the first Briton on the surface got his dartboard out.


1961  – Launch of MR-1, the first unmanned spacecraft of the Mercury project.  A spectacular failure, it managed to attain an altitude of four inches in a flight lasting 2 seconds.


2006  –  Discovery of Actaea, the satellite of trans-Neptunian object  120347 Salacia.


July 20 – Sea of Activity (1969)

Today was a very big day in 1969, as it was the day on which, at 17 minutes past 8 in the evening, Neil Armstrong and Buzz Aldrin (but not Michael Collins) landed their lunar module in the Sea of Tranquility, becoming the first humans in a short line of white, American males to land on the surface of the Moon.

Apollo 11 Crew (image credit: NASA)
Apollo 11 Crew (image credit: NASA)

There has been a great deal written and said about this event, and even more than usual in this 50th anniversary year, with which I won’t attempt to compete. I will just say that although the intrepid moon men brought back 21.5 kg of lunar material, the main impact of their visit from the Moon’s perspective was to leave behind several tonnes of extremely expensive scrap metal.

Tranquility from the window of the Lunar Module (image credit: NASA)
Tranquility from the window of the Lunar Module (image credit: NASA)

The Sea of  Tranquility (Mare Tranquillitatis), once thought to be an ocean on the Moon, is a large basalt basin, probably produced by a lava flow following the impact of something quite large, at the time of the Pre-Nectarian epoch, meaning it was formed before the Mare Nectaris.  The Pre-Nectarian doesn’t really have an equivalent epoch on Earth, because any rocks of a similar age down here would long ago have been sucked back below the surface to be recycled.

Looking towards home from Apollo 11 landing site (image credit: NASA)
Looking towards home from Apollo 11 landing site (image credit: NASA)

 

 

July 19 – Discovery of Asteroid 226 Weringia (1882)

Main belt asteroid 226 Weringia was discovered on July 19, 1882 by the great Austrian asteroid hunter, Johann Palisa.  In under 50 years Palisa identified 122 asteroids, Weringia being one of nine he found in 1882.

Weringia is a fairly bright body of 34 km diameter, but little more is known of it, except that photometric observations from 2008 made by Kingsgrove Observatory in New South Wales, Australia, give it a rotation period (day) of 11.4 hours (Minor Planet Bulletin, Vol. 36, No. 4).   It is named after the district of  Währing in Vienna.

Wahring
Wahring

Today’s artistic offering shows the church of St Gertude in Währing, about 1850, by an unknown artist.

Palisa’s home town (called Troppau then, now Opava) is these days located in the Czech Republic, and the local university at Ostrava thought highly enough of their local hero to re-name their observatory and planetarium after him in 2000.