December 15 – Janus

J R Hind discovered today’s main belt asteroid, 23 Thalia, from Hyde Park, London, on December 15th, 1852 (I’d like to see him try that nowadays). Thalia is an S-type asteroid of about 107 km diameter, located between the 3:1 and 5:2 Kirkwood gaps.

In Greek mythology, Thalia, daughter of Zeus and Mnemosyne, with a name derived from the verb “to flourish”, was the muse of comedy and pastoral poetry. She may or may not (depending on which source you believe) have been the mother of the Corybantes, attendants to the Great Mother of the Gods, and associated with particularly orgiastic rites.

We also have a moon today.  The discovery of Janus, one of the inner Saturnian satellites, is attributed to Audouin Dollfus, who first observed it on December 15th 1966. Three days later, Richard Walker also observed an object in the right place but at the wrong time, which caused confusion for a while, but was eventually found to be another moon, Epimetheus, which shares an orbit with Janus.

Janus, photographed by the Cassini probe (image credit: NASA / JPL / SSI)

Janus, photographed by the Cassini probe (image credit: NASA / JPL / SSI)

Janus is the two-faced Roman god of beginnings, entrances, gates, doors, etc. You should thank him the next time an automatic door opens for you. Janus is also one of the select group of deities after whom a month (January) is named, and strangely he has no Greek counterpart.

1965  –  launch of San Marco 1 by Italy. Being their first satellite, the Italians wisely did not fill it with lots of expensive equipment. It did, though, contain a couple of experiments to study the ionosphere, the layer of the atmosphere stretching from about 60 km to 1,000 km, a region you need to know about if you’re planning to become a space-faring nation, needing to send radio messages over great distances.

2000  –  Death of George Alcock, aged 88, hunter of novae and comets. I believe he found five of each (remarkable for south-eastern England), some of them from indoors using binoculars, and even occasionally through double glazing1!  His eyesight must have been unbelievable.

2014  –  Voyager 1 crossed the termination shock.


2015  –  Launch of Expedition 46 to the International Space Station.  This caused considerable press interest in my homeland (in fact I’m going to call it a frenzy) because in addition to Russian cosmonaut Yuri Malenchenko and American astronaut Tim Kopra, the three-man crew contained Tim Peake, the first Briton to float into the ISS (I was going to say “set foot aboard” the ISS, but I’ve seen the footage, and feet don’t feature much).  Because of the  numbering system they use at the ISS when crews overlap, these three also formed part of Expedition 47.

ISS Expedition 46 Patch

ISS Expedition 46 Patch

As a supporter of Port Vale FC, I was distraught to discover that one of Tim Peake’s tasks whilst on this mission was to unveil a flag featuring the name of our local rivals, Stoke City.  I’ve gone off him a little.


1   Journal of the British Astronomical Association, vol.111, no.2, p.64-66

December 10 – Asteroid 211 Isolda

Asteroid 211 Isolda, discovered on December 10th 1879 by Johann Palisa, is about as average as asteroids get.  It’s dark, in the main belt, C-type, 150-ish km across, and has an orbital period of 5.3 years.

So today, as well as mentioning those orbital characteristics of Isolda with which we all should now be familiar from previous posts (aphelion – 3.53 AU; perihelion – 2.54 AU; semi-major axis – 3.04 AU, and longitude of ascending node – 263.8°) I’m going to say that Isolda has an eccentricity of about 0.16.

Eccentricity is another fairly simple concept: it’s got very little to do with the behaviour of the English upper classes (you shouldn’t confuse eccentricity with lunacy) but a lot to do with the orbit of almost everything in the solar system being non-circular.  Eccentricity, if we’re talking about planets, moons, asteroids and most known comets, will be measured on a scale somewhere between zero (completely circular) and one (an “escape” orbit).  Planets have a fairly low eccentricities (Earth = about 0.017); asteroids are a bit more wayward (their average is ten times greater, at 0.17), and comets can be anything, with values near to, or even in excess of, 1.0 (eccentricities of more than 1 are reserved for comets that are being flung out of the solar system following their solar fly-by).  Neptune’s moon Triton has the lowest known eccentricity, at 0.000016.  This is about as circular as can be accurately measured.

Isolda, of course, is named after Isolde, (or Iseult of Ireland) the lover of Sir Tristan of Arthurian legend and Wagnerian opera.

Tristan and Isolde

Tristan and Isolde

Today’s photograph shows husband and wife team Ludwig and Malvina Schnorr von Carolsfeld, Wagner’s original 1865 Tristan and Isolde.  Ludwig was a heldentonor, the dramatic tenor typical of Wagnerian  protagonists. Soprano Malvina was the daughter of the Portuguese consul in Copenhagen, and was a great-grand-neice of David Garrick, giant of the English theatre.

1999  ⇒  Launch of ESA’s XMM-Newton (it stands for X-ray Multi Mirror Mission), the largest satellite to date to be launched by the European Space Agency (4 tonnes in weight and 10 meters long).

December 02 – SOHO / BBXRT

Built in Europe, the Solar and Heliospheric Observatory (SOHO) was launched on December 2nd, 1995 (and is still going, despite being planned as a two year mission).  It is a joint project between ESA and NASA, designed to provide data to help predict solar weather, and answer questions about the solar interior and corona.  The mission has been a great success, providing significant insights into such areas as the structure of sunspots, the flow of gases inside the Sun, and the dynamics of the solar wind.

Prominence spotted by SOHO (image: ESA / NASA)

Prominence spotted by SOHO (image: ESA / NASA)

In addition to all this, SOHO has still found time to become history’s greatest ever discoverer of comets, with the total ticking over to an astonishing 3000 on September 13th 2015.  Comet number 3000 was spotted by Thai astronomer Worachate Boonplod, part of an amateur army of spotters who betwen them have been responsible for the majority of SOHO discoveries.

The Broad Band X-ray Telescope (BBXRT) was launched today (1990) on board shuttle Columbia flight STS-35. It formed part of the partly-successful “ASTRO-1” payload of four instruments.


In-flight view of BBXRT (image: NASA)

In-flight view of BBXRT (image: NASA)

The mission was somewhat shorter than the previously-mentioned SOHO, as the telescope was attached to the shuttle, and had to go wherever it went (back to Earth).

November 09 – Apollo 4 / Venus Express

Today I have a good excuse (as if one were needed) to show a photograph of a Saturn V, as it marks the anniversary of the launch by NASA, in 1967, of Apollo 4, the first “all-up” (everything in working condition) test of the Saturn V launch vehicle.  Launch was at 7am, and the business end of the 363 foot (110 m) miracle of 1960’s engineering was parked into a 100 mile high orbit for two trips around the Earth, before the command module was splashed down into the Pacific Ocean, close to Midway Island.

Apollo 4 launch (image credit: NASA)

Apollo 4 launch (image credit: NASA)

The unmanned mission was deemed to have been successful, and involved placing the third stage, the S-IVB (pronounced “ess four bee”) and the CSM (Command/Service Module) into orbit, and simulating a return to Earth from a Moon mission.

Venus Express was the first mission to Venus by the European Space Agency.  It used the same basic platform used for the Mars Express mission of 2003, keeping costs down, and allowing rather a swifter progression than normal from the proposal of the mission to the actual launch.

The launch, on November 9th 2005, was from the Baikonur Cosmodrome, which by that time was no longer behind the Iron Curtain, and available to rent.  I’m not sure how much it costs to launch from Baikonur, but the Russians are currently paying the Kazakh government $115m (US) a year for the privilege.

After a voyage of just over 5 months, Venus Express parked in a near-polar orbit, chosen to give it the best view possible of most of the planet.  Obviously most of the focus was on studying the structure and composition of the extremely thick Venusian atmosphere, but observations of the surface have also been made possible by use of the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS).  This has helped support the theory that Venus has recently seen volcanic activity.

Venus Express (image copyright ESA)

Venus Express (image copyright ESA)

You can see VIRTIS on the above image.  Also indicated are the magnetometer (MAG), the Fourier spectrometer (PFS) and the camera (VMC).

October 17 – Asteroid 207 Hedda

Medium-sized (approx 60km diameter) C-type, main belt asteroid 207 Hedda was discovered on October 17th 1879 by Johann Palisa, and was his 20th discovery.

It was named after the wife of the German astronomer Friedrich August Theodor Winnecke, whose name was Hedwig.  The change to the nordic version of her name, Hedda, was suggested by J Gylden at the meeting of the Astronomische Gesellschaft in September 1881.

Friedrich August Theodor Winnecke

Friedrich August Theodor Winnecke

Hedwig Winnecke (née Dell) was a niece of the Russian astronomer Otto Struve, who we will almost certainly meet again.  Struve was director of the observatory at Pulkovo in Russia in the 1850s and persuaded August Winnecke to take up a post there.  That, presumably, was how he met his future wife.

1962  –  Kosmos 10 (aka Zenit-2 #5) was launched, using a Vostok 2 rocket, on October 17th, 1962, from Baikonur Cosmodrome, into a low-Earth orbit with a perigee of about 178 kilometres (111 miles). It was primarily a reconnaissance mission, and was landed by parachute four days after launch, but, as it was derived from the manned Vostok launch vehicle, it was also used to research radiation as part of the Soviet Union’s manned space programme.

2002  –  Launch of the International Gamma Ray Physics Laboratory (INTEGRAL) by the European Space Agency. 2002 was quite a while ago in spacecraft life-spans, but INTEGRAL is still going strong, and has recently been used, in conjunction with the Fermi and Swift space observatories, to observe gamma ray jets near a supermassive black hole using gravitational microlensing.

Artist's Impression of INTEGRAL (image: ESA–Medialab)

Artist’s Impression of INTEGRAL (image: ESA–Medialab)

Also today we have a small batch of main belt asteroids, all discovered in 193p by Karl Reinmuth. They are 1172 Äneas, 1173 Archiestown, 1174 Marmara, and 1175 Margo.


October 06 – 51 Pegasi b

October 6th 1995 was a significant day in the hunt for extrasolar planets, with the discovery, in the constellation of Pegasus (the winged horse), of the first one found to be orbiting a main sequence, Sun-like star. That star was 51 Pegasi, and the planet is known as 51 Pegasi b, shortened to 51 Peg b if you’re in a hurry, and lengthened (unofficially) to Bellerophon if you’re not. Bellerophon was the Greek character who tamed Pegasus, so you can see what they did there. The “b”, by the way, indicates that this was the first planet discovered around 51 Peg. There is no “a”, as that letter would be used, in uppercase, to denote the star itself, and would only be needed if the star had a companion (“B”).

Count them if you like.

Count them if you like.

The discovery of 51 Peg b was made using the radial velocity method, and announced by Michael Mayor and Didier Queloz. It was later confirmed by other observers (always important).

Despite orbiting a Sun-like star, 51 Peg b was still nothing like the type of place planet hunters were looking for (they all wanted to find an Earth-like planet at about the same orbit as ours). 51 Peg b is about 150 times the mass of the Earth, wider than Jupiter, is closer to 51 Peg than Mercury is to the sun, giving it a mean temperature of around 1,000°C, and has a year lasting about 4 Earth days. All of which has made me decide not to move there (my border perennials wouldn’t like it one bit).

Smallish asteroid 299 Thora is a fairly typical main belter, discovered on October 6th 1890 by Johann Palisa. It is about 17 km wide, and zooms around the Sun every 1,387 days at 19 km/second.

Thor wades through a river while the æsir take the bridge, by Lorenz Frølich

Thor wades through a river while the æsir take the bridge, by Lorenz Frølich

The name Thora was chosen by a Professor Schlieber of Berlin, after the Germanic and Norse god of thunder and lightning, Thor. According to Norse legend, Thor was the son of Odin, and husband of Sif (although, as with the Greek gods, this didn’t stop him fathering children by other women). Thor, as you probably aware, carried a hammer capable of flattening mountains, and had Thursday named in his honour.

So, if you know anyone named Thora, tell them they can blame it on their pagan Viking parents.

1964  –  The Soviet Union launches Kosmos 47, an unmanned Voskhod test flight.

1990  –  Launch of the NASA / ESA Ulysses probe to study the Sun.

September 27 – 134 Sophrosyne / DAWN

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.

 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.

2003  —  Launch of SMART 1 (Small Missions for Advanced Research in Technology) by ESA.  SMART 1 was the first ESA 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)

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

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

2007  —  Launch of DAWN, to rendezvous with Vesta and Ceres.  Vesta was visited in July 2011, resulting in this fabulous photograph, below.

Image of Vesta, by DAWN (image credit: NASA)

Image of Vesta, by DAWN (image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

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)

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

. . .  and this one:

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/ID

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/ID