September 30 – Discovery of Jupiter’s Moon, Themisto (1975)

The Jovian moon Themisto, discovered on September 30th 1975 by Charles Kowal and Elizabeth Roemer, is a rather small, irregular moon, orbiting about halfway between Jupiter’s large, well known Galilean moons and the rather less famous Himalia Group of prograde irregular companions. The best photographs currently available on the Internet show Themisto as a white pinhead on a black background, so I haven’t bothered “borrowing” one.

Themisto was named after a character from Greek mythology, the subject of a tragedy by Euripides which has unfortunately been lost. In the play, Themisto accidentally kills her own children, believing them to be the offspring of her husband’s first wife. When she realises what has happened, Themisto does what the star of any tragedy would be expected to do, and kills herself as well. The Greek stage at an average drama festival was littered with more bodies than an entire season of Murder She Wrote.

Co-discoverer Elizabeth Roemer also has two asteroids to her name, the magnificently named 1930 Lucifer and 1983 Bok. Charles T Kowal does even better, with 19 minor planets discovered between 1970 and 1981, including 2060 Chiron, the first of the centaurs. His collection of astronomical trophies also boasts a few comets, and Leda, another Jovian satellite.

September 30 – Discovery of Asteroid 81 Terpsichore (1864)

Asteroid 81 Terpsichore, discovered on September 30th 1864 by Ernst Wilhelm Tempel, is a large (about 120 km diameter), dark, “C” type (carbonaceous) main-belt asteroid.  Terpsichore is named after my least favourite muse, the one in charge of dancing.  Her name means “delight in dancing“, a concept alien to myself.  According to the epic poem the Dionysica of Nonnus, she was the mother of the Sirens.

Terpsichore by Antonio Canova (Cleveland Museum of Art)
Terpsichore by Antonio Canova (Cleveland Museum of Art)


Asteroid 191 Kolga was discovered today in 1878 by C H F Peters, and named in honour of the daughter of a Norse sea God. The name means “chilling wave”.

Chilling Wave
Chilling Wave

Two years later to the day, Johann Palisa added asteroid 219 Thusnelda to his collection. Thusnelda is an S-type main belt asteroid of approximately 38 km diameter. The name comes from a Germanic princess captured in AD 15 by the Roman general Germanicus Julius Caesar , adoptive son of the Emperor Tiberius, and father of Caligula.

September 29 – Discovery of Asteroid 243 Ida (1884)

243 Ida was discovered by by the Austrian astronomer Johann Palisa on September 29th, 1884, and unlike most bodies in the main asteroid belt, this particular S-type asteroid has been studied at close quarters. Ida was visited by the Galileo spacecraft in 1993. It is one of the larger members of the Koronian family of asteroids, about 6000 strong, who orbit as a group, and are thought to be the remains of a collision involving a single, larger body. Thanks to Galileo, we have pretty good photographs of Ida, and we now know it has a small companion, Dactyl.

Ida and Dactyl, courtesy of Galileo (image: NASA/JPL)

Dactyl is pretty teeny, measuring just over a kilometre across in most directions. It is the small dot on the right side of Ida in the photograph, and was the first moon discovered orbiting an asteroid. The name comes from a race of mythical beings who inhabited Mount Ida in Crete. They are credited with discovering how to use fire to work metal.

The asteroid itself is named for the nymph who, with her sister Adrasteia, was entrusted with caring for the infant god Zeus. The name was the idea of Moriz von Kuffner, an Austrian brewer, philanthropist and astronomer, who founded the Kuffner Observatory in Vienna. Kuffner eventually got his own named asteroid, but not until 2006 (number 12568).

Also as a result of the Galileo visit, I will be abandoning my usual use of the words “about” and “approximately”, and will be stating that Ida’s principal dimensions are 59.8 km by 25.4 km by 18.6 km, with a mean radius of 15.7 km (Belton et al, 1996).

September 29 – OSO-7

The Orbiting Solar Observatory 7 (OSO-7 ) was the seventh of eight similar satellites, and was launched on September 29th 1971, straight into a drama, when a problem with the second-stage guidance system left it in an unplanned orbit, and pointing in unexpected directions. Fortunately, John Thole at NASA (who we might well come across again in connection with Echo 2) managed to get the mission back on course with a mix of skill and luck, saving the day. I can’t imagine how he must have felt, slewing this huge craft around from so far away he couldn’t even see it. It’s bad enough when your spaceship is made by Nintendo and you get to start again if you crash.

OSO-& (image credit: NASA)
OSO-& (image credit: NASA)

OSO-7, like its brethren, came in two main parts, known as the “sail” and the “wheel”. The sail faced the Sun (during the satellite’s day) and measured solar x-rays and coronal activity. The wheel, as the name suggests, rotated continuously, measuring solar x-rays and cosmic x- and gamma-rays. The spinning of the wheel, combined with the axial movements that kept the sail pointing at the Sun, allowed two of the wheel-based experiments to cover the whole sky every six months.

OSO-7 re-entered the Earth’s atmosphere on July 9th 1974.

ALSO TODAY . . . .

1884  —  Discovery of asteroid 243 Ida.

1962  —  Launch of satellite Alouette 1.

1988  —  Launch of shuttle mission STS-26 (“Discovery“).

September 28 – Discovery of Jupiter’s moon, Ananke (1951)

Ananke is one of Jupiter’s many smaller moons.  It was discovered on September 28th 1951 by Seth Barnes Nicholson at Mount Wilson Observatory.  It takes its name from the mythological personification of “Necessity” (the word means something similar in Greek).  Ananke was the mother of the Fates (also kmown as the Moirai), their father being Zeus (surprise, surprise).


Ananke is an irregular retrograde satellite, and lends its name to the Ananke group  of similarly inclined moons, as at 14km in diameter it is the largest of the type (the other members being Praxidike, Iocaste, Harpalyke, ThyoneEuanthe, and Europie).  The retrograde motion and eccentric orbits of the group lend credence to the theory that they may all be the remains of asteroids captured by Jupiter.

As far as I am aware there are no photographs of Ananke that show it as anything more than a faint grey spot.

 ALSO TODAY . . . .

1852  —  Birth of Elizabeth Isis Pogson, the first woman to attempt to gain membership of the Royal Astronomical Society (it took five years for her to succeed).

1876  —  Discovery of asteroids 168 Sibylla (by J C Watson) and 169 Zelia by Paul and Prosper Henry (a rarity, classified as “O-type” in the SMASS-based system devised by Bus and Binzel).

September 27 – Launch of SMART 1 (2003)

2003  —  Launch of SMART 1 (Small Missions for Advanced Research in Technology) by ESA.  SMART 1 was the first ESA probe to the Moon, and set a couple of unusual records.  It became the first mission to leave Earth orbit using just solar power, and the slowest ever to the Moon, taking 13 months.  It also holds the record for the lowest fuel consumption on an Earth to Moon journey.  As well as testing new power sources, SMART 1 did carry imaging equipment, and identified this location . . . .

Shackleton Crater viewed by SMART 1 (image credit: ESA)

. . . . as the best place to site solar panels for a future lunar base.

September 27 – Launch of “DAWN” (2007)

DAWN was launched on Sept 27th, 2007 to rendezvous with Vesta and Ceres.  Vesta was visited in July 2011, resulting in this fabulous photograph, below.

Composite image of Vesta from the DAWN spacecraft (image credit: NASA)

Ceres was reached in March 2015, and DAWN is currently (September 2016) orbiting at a height of just over 900 miles, and has been busy sending back excitingly detailed shots like this one . . .

Ceres from DAWN (image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

. . .  and this one:

Ceres: the area around Gerber Catena (Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

September 27 – Discovery of Asteroid 134 Sophrosyne (1873)

Asteroid 134 Sophrosyne was discovered on September 27th 1873 by Robert Luther. Its a dark, C-type, main belt asteroid, with an estimated diameter, derived from occultation observations, of 110 km (68 miles).

Sophrosyne was one of the many spirits to escape from Pandora’s jar. As a goddess she represents a concept almost completely alien today in the westernised world, that of enlightenment and happiness achieved through harmonious living, restraint, patience and self-knowledge (rather than through the acquisiton of 4x4s and HD-TVs).

There are very few representations of today’s goddess floating around, and to be honest I could have shown you a shot of almost any classically dressed woman looking a bit thoughtful and passed her off as Sophrosyne, but I haven’t.

Instead, here is Dutch/British artist Lawrence Alma-Tadema’s depiction of Pandora, looking like she’s about to do something she might later regret.

ALSO TODAY . . . .
1814 — Birth of American astronomer, Daniel Kirkwood, the man who noticed the gaps in the asteroid belt which now bear his name. I look forward to receiving hits from Evertonians (another Dan Kirkwood was a player and director there).

2003 — Launch of Kaistsat 4 (Korea Advanced Institute of Science and Technology SATellite), aka STSAT-1, with the primary mission of studying galactic hot plasma.

September 26 – Discovery of Asteroid 610 Valeska (1906)

Asteroid 610 Valeska was discovered on September 26th, 1906, by Max Wolf at Heidelberg.

The JPL Small Body Database Browser gives a diameter of 19.153 km (I’m happy with “just under 20”).

Now, Lutz D Schmadel’s Dictionary of Minor Planet Names has this one listed in the appendix of bodies for which the origin of the name is unknown, although it points out that the provisional discovery designation was “1906 VK”, and the letters v and k are prominent in the chosen name. There was actually a fairly famous Valeska around at the time of the discovery and naming, but I’m not sure whether she was big enough to impress the astronomers of Heidelberg.

Valeska Suratt
Valeska Suratt

Valeska Suratt was born on June 28th, 1882, in Owensville, Indianna, and began an acting career in Vaudeville at the turn of the 20th century. She moved onto Broadway in 1906, and began a film career in 1915. Unfortunately Max Wolf, though he did visit the USA, did so way before Suratt became famous.

But a minor detail like that isn’t going to stop me from adding her photograph to today’s blog.

September 25 – Launch of Shenzhou 7 (2008)

A lot of people in the west don’t even know the Chinese have put people in space, but they have. And they’re going to catch up. Shenzhou 7 was launched on September 25th, 2008, from the Jiuquan Satellite Launch Centre in Mongolia, and the three-man crew (a first for China) of Zhai Zhigang, Liu Boming and Jing Haipeng spent just under three days in orbit. Commander Zhai became the first Chinese astronaut to perform a spacewalk.

The mission ended with a successful landing, also in Mongolia.

The Chinese have a very long name for their astronauts, “Navigating Outer-Space Personnel”, although if you put the Chinese characters 航天员 into Google Translate it throws “astronaut” back. My Chinese reading skills leave a lot to be desired, but I can tell you that the second character means “sky”or” heaven”. The press seem to have adopted the word “taikonaut”. Apparently, the word tàikōng means “space”.