September 20 – HEAO-3

Two and a half tonnes of HEAO-3, the last of its kind, were sent 486 kilometres in a generally upwards direction on top of an Atlas-Centaur launch vehicle on this day in 1979, on a planned 6 month mission, which eventually stretched to 21 months, to study x-rays, gamma rays and cosmic rays. HEAO stands for High Energy Astronomy Observatory.

Launch of HEAO-3 (image credit: NASA)

Launch of HEAO-3 (image credit: NASA)

HEAO-3 carried three experiments, described very briefly below:

1) The High Resolution Gamma Ray Spectrometer could have had an even longer name, as it was designed to study x-rays as well. Its purpose was to perform an all-sky survey, looking for x- and gamma-rays within a certain energy range.

2) The Cosmic Ray Isotope Experiment, whose primary purpose was to measure the isotopic composition of cosmic ray nuclei, as part of the drive to better understand the nature and propogation of cosmic rays.

3) The Heavy Nuclei Experiment did exactly what it said on the tin. It searched for heavy (and so-called super heavy) nuclei in cosmic rays.

So, here we are, 34 years later, and we still don’t quite understand how, why and where cosmic rays originate. But at least we’ve sorted one problem out: we know they’re not rays.

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ALSO TODAY . . . .

Launch of Surveyor 2 from Cape Kennedy, 1966, headed for Sinus Medii, but which crashed at or near crater Copernicus three days after launch, following a spin caused by a faulty thruster.

Model of Surveyor 2. (Photo credit: NASA.)

Model of Surveyor 2. (Photo credit: NASA.)

The purpose of Surveyor 2 was fairly simple.  It was a flying camera, designed to image the lunar surface, and possibly perform a “lunar bounce” (basically, fire up the engines to jump up and down on the Moon to test the surface consistency).

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1969  –  Discovery of comet 67P Churyumov-Gerasimenko by Kim Ivanovich Churyumov and Svetlana Ivanova Gerasimenko in the Soviet Union. “Chury” is a Jupiter-family comet with an intriguing shape. You will, of course, be familiar with it from the recent visit by the Rosetta probe. Research carried out since the discovery of the two-lobed shape of this comet by scientists at the University of Bern (Journal of Astrophysics, November 2016) has concluded that it is probably the result of a more conventionally shaped comet undergoing a gentle collision, creating two large fragments which then re-attached under their mutual gravitational attraction.

September 19 – C H F Peters

Christian Heinrich Friedrich Peters  was born in Koldenbüttel (which was in Denmark at the time) on September 19th 1813, and became a big name in asteroid spotting, finding 48 in all, which makes him second in the all-time list of visual asteroid discoveries after Johann Palisa.

Peters was a bit of a radical in his youth, and while living in Italy his attempts to avoid the attentions of the authorities ended up with his fleeing to Turkey, where he made the acquaintance of the American ambassador, and before long found himself across the Atlantic mixing with the Harvard scientific community, and speaking in front of the American Association for the Advancement of Science in Rhode Island.

C H F Peters

Peters settled down at Hamilton College in Clinton, NY, as professor of astronomy, and as we have been hearing in this blog at irregular intervals all year, he made good use of their large 13½ inch refractor, working on sunspots by day and looking for asteroids at night.  I’m not sure when he slept.

His work was greatly aided by a supplement added to his rather meagre salary by a local businessman, who had the college observatory re-named after himself in return (to the Litchfield Observatory).  

Peters discovered his last asteroid, 287 Nephthys, at the age of 76, less than a year before his death.  He died on his way to the observatory, on July 19th 1890.

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Asteroid 20 Massalia was discovered twice.  It was first spotted on September 19th 1852 by Annibale de Gasparis in Naples, and then again the following night by Jean Chacornac in Marseille.  Chacornac, despite being second, got his report of the discovery in first, so he got to choose the name.

Massalia is an S-type asteroid of about 145 km in diameter, and has a family of similar asteroids named after it, all at 1:2 resonance with Mars. Orbital resonance is something I keep saying I’m going to write about eventually (but not yet).

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Asteroid 48 Doris is a large main belt asteroid, and one of two to be spotted on September 19th 1857 by Hermann Goldschmidt.

The Doris after whom the asteroid was named was an Oceanid (a daughter of Oceanus and Tethys).  She had one son and fifty daughters, collectively known as the Nereids after their father Nereus.  She was Achilles’ grandmother.

Doris and Hippocamp

Doris and Hippocamp

Today’s accompanying visual aid shows a rather sour-looking Doris riding a hippocamp (literally “horse monster” in Greek).

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Asteroid 49 Pales was the second asteroid to be discovered on September 19th 1857 by Hermann Goldschmidt. It’s a C-type, about 150 km in diameter, and completes an orbit of the Sun every 5.44 Earth years.  There is also a certain amount of light curve evidence to suggest it may be a binary system.

Pales was the Roman god or goddess (the gender is uncertain) of shepherds and livestock.  He/She had a festival on April 21st, probably approached with dread by shepherds, who were expected to symbolically purify their flocks by dragging a sheep through a bonfire.

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The winner of the “all-time shortest name for an asteroid” award goes to 85 Io, discovered by the birthday-boy himself, C H F Peters, on September 19th 1865.  It is mostly a fairly unremarkable C-type body of about 170 to 180 km wide, orbiting the Sun at about 40,500 miles per hour, in the midst of the Eunomia asteroid family, to which, by the way, it is unrelated.

Io  was a nymph and priestess of Hera, who was turned into a heifer by Zeus to hide her from his wife (unsuccessfully).  I may well talk more about her on January 8th, anniversary of the discovery of the more famous Jovian moon of the same name.

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112 Iphigenia is another large and dark C-type asteroid, with a longer rotation period than most (over 31 hours) discovered by C H F Peters on his 57th birthday, September 19th 1870.  Does anybody else get the impression he didn’t spend too much time celebrating his birthday?

Iphigenia was the daughter of Agamemnon and Clytemnestra, who may have been sacrificed to Artemis by her father in order to expedite safe passage to the Trojan War for his fleet.  Then again, if you’ve ever read “Iphigenia in Tauris” by Euripides, she may not.

Iphigenia

Iphigenia

The final accompanying artwork today is entitled Iphigenie.  It is by the German classicist painter Anselm Feuerbach (1829 – 1880), and is one of two studies of the subject by him.  This one is from 1862.

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September 18 – 375 Ursula / 1965 S1 Ikeya-Seki

Asteroid 375 Ursula is a fairly bulky main belt asteroid (approx 216 km diameter) discovered by Auguste Charlois on September 18th 1893. Ursula is another one of his finds with no readily apparent reasoning behind the name (you may recall 298 Baptistina from September 9th). If I could only find out on what date the naming happened, and maybe who came up with “Ursula” (it isn’t always the discoverer) I might get somewhere.

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Comet C 1965 S1 Ikeya-Seki was first spotted on September 18th 1965 by Kaoru Ikeya and Tsutomu Seki, observing independently of one another. Ikeya-Seki performed in 1965 in the manner we are hoping for from ISON later this year. At magnitude -10 it was visible in daylight, and has earned the name The Great Comet of 1965.

Ikeya-Seki (photograph by Maynard Pittendreigh)

Ikeya-Seki (photograph by Maynard Pittendreigh)

Ikeya-Seki is one of a group of over-performers known as the Kreutz Sungrazers. The group also contains the Great Comets of 1843 and 1882, and is thought to comprise fragments of a huge parent comet that broke up in 1106.

The photograph above by Carolina astronomer (and Presbytarian minister) Maynard Pittendreigh might look a little dated to the Hubble generation, but to me it’s just fabulous.  It was probably all accidental, and he might have been going for a perfect shot, but I love the star trails, the scratches, the unidentified smear in the centre, and the telegraph wires.   It wouldn’t look out of place in a futuristic film from the early twentieth century, or a Bogus Blimp video.

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ALSO TODAY . . .

“Cool Jovian-mass” extrasolar planet MOA-2007-BLG-400Lb discovered today in 2008 in Sagittarius by Subo Dong and others.

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September 17 – Enterprise vs The Death Star

Not really, but it’s a good headline.

Mimas, or Saturn I, (sometimes known as the “Death Star” for reasons obvious to anyone who’s ever seen one of the original Star Wars films) was discovered on September 17th 1789 by William Herschel. It’s a heavily cratered, 396 km wide, low density moon with one really obvious surface feature: the 130 mile wide crater Herschel. It’s hard to imagine how Mimas managed to survive the impact of a body capable of forming such a gigantic hole, and there are fractures on the opposite side of the moon that may indicate it nearly didn’t.

Mimas from Cassini. (Image credit: NASA / JPL)

Mimas from Cassini. (Image credit: NASA / JPL)

Mimas has proved irresistible to a succession of spacecraft visiting Saturn and its environs. Pioneer 11, Voyager 1 and Voyager 2 all flew past, and Cassini has taken some very close shots from less than 10,000 km away.

Mimas, like the other six satellites of Saturn known at the time, was named after one of the Gigantes (giants) of Greek mythology. The names were suggested by John Herschel, son of William.

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ALSO TODAY . . . .

 Space Shuttle Enterprise (OV-101), the first of her kind, was rolled out of her construction plant for a photo opportunity with Gene Roddenberry and the cast of Star Trek. The phrase “roll out” is particularly apt in this case, as Enterprise was intended for testing in Earth’s atmosphere only, and so was built without engines.

1930 – Birth of Thomas P Stafford, veteran of Gemini and Apollo missions (21 days in space), commander of the second manned mission to orbit the Moon.

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September 16 – Hyperion

Hyperion is an unusual moon of Saturn.  It was discovered on September 16th 1848 by three astronomers: William Lassell of Liverpool (on his own), and Americans William Cranch Bond and his son George Phillips Bond (together).  The Bonds spotted the moon first, but Lassell got published first, so all three are credited.  They are honored together in the form of the only named feature on Hyperion, a prominent ridge called the Bond-Lassell Dorsum.

Hyperion (image credit: NASA/JPL/Space Science Institute)

Hyperion (image credit: NASA/JPL/Space Science Institute)

It’s an odd place, Hyperion.  You can tell from the photograph that it isn’t a regular shape, suggesting it may be the remnant of a larger body destroyed by an impact at some point long ago, and appears to be a bit like a bath sponge (i.e. mostly holes) or the papery wasp’s nest I extracted from our bird box last autumn following a Summer spent creeping up to it with an insect spray and running away as fast as possible after giving them a quick blast in the entrance.  Latest calculations suggest that as much as 40% of the moon’s volume is empty space, and what solids there are may turn out on closer inspection to be mostly water ice, with a sprinkling of frozen methane and carbon dioxide, and only a small percentage of rock.  Hyperion is the second largest moon in the Solar System to have an irregular shape, and is the largest with a “chaotic” (wobbly) rotation.

Hyperion was first visited by Voyager 2 in August 1981, where its odd shape and rotation were the subject of much head-scratching.  Voyager only got to within about 300,000 miles though, so it was left to the Cassini mission to reveal the full oddness of the moon’s surface when it got to a mere 628 miles (1010 km) in September 2005.  Cassini took today’s  first photograph.

In Greek mythology, Hyperion was a Titan.  There were twelve of them, children of Gaia and Uranus.  Hyperion married Theia, his sister (as usual) and had three children with her: Helios (the Sun), Selene (the Moon) and Eos (the Dawn).  So today’s second photograph (aren’t you lucky?) is the Horse of Selene from the east pediment of the Parthenon (now in the British Museum).  I first saw this sculpture when I was seventeen, on a sixth form trip to London.  If I’d paid more attention to my teacher, Mr Perry, at the time I could probably tell you all sorts about it, but alas.

The Horse of Selene.

The Horse of Selene.

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ALSO TODAY  . . . . 

C-type main belt asteroid 105 Artemis was discovered on September 16th 1868 by J C Watson, and named after the Greek goddess of the hunt.

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September 15 – 47 Aglaja

47 Aglaja (the “aja” is pronounced like the “iar” in “friar”) is a C-type main belt asteroid, about 140 km (80 miles) wide, following a fairly average path around the Sun at a fairly average speed of about 17.5 km/s.  It was discovered on September 15th 1857 by one of our regular contributors, Robert Luther, and  was named after one of the Charites of Greek mythology (who have become more famous under their Roman name of the Graces).  Aglaia (or Aglaea) was responsible for splendour.  We have already encountered another of the trio, Euphrosyne, (“mirth”) on September 1st, but we won’t be coming across the third, Thalia (“good cheer”), because she shares her name with the more popularMuse of Comedy, who we will probably meet on December 15th.

The Three Graces

The Three Graces

Today’s accompanying artwork is by the German artist  and former student of Albrecht Dürer, Hans Baldung (c. 1484 to 1545).  In this painting I have no idea which Grace is which.

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September 14 – Echo and Erato

60 Echo is an S-type asteroid, discovered September 14th 1860, fairly large at about 60 km in diameter, with a day lasting 25 hours and a year equivalent to 3.7 of our own.  It was the third and final asteroid to be found by American astronomer James Ferguson, working out of the US Naval Observatory. He named it Echo when his first choice, Titania, turned out to have already been taken.

Echo and Narcissus

Echo and Narcissus

Echo, a mountain nymph, was punished in a peculiar and inventive way by Hera, who was annoyed at being distracted by Echo’s stories while her husband Zeus was off ravishing other nymphs. The punishment was to make Echo unable to speak except to repeat the words of others. Today’s painting of Echo and Narcissus, is in my local art gallery: the Walker (Liverpool). It is by John W Waterhouse.

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Asteroid 62 Erato is our second Themistian asteroid in a week.  This one, a C-type of about 65 km wide, was the first asteroid to have two credited discoverers.  They were Otto Lesser and Wilhelm Foerster, and the discovery was made on September 14th 1860.  Erato was named after the Greek muse of lyric and love poetry, often portrayed holding a lyre or kithara ( a lyre for professionals).

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September 13 – Babcock

Horace Welcome Babcock (fantastic name), astronomer and inventor, was born today in 1912, son of solar specialist Harold D Babcock.  Babcock junior was the chap who realised that changing the shape of mirrors can be used to reduce the distorting effect of turbulence in the Earth’s atmosphere on light from distant objects (called adaptive optics). Unfortunately he made this discovery in the 1950s, roughly 40 years before the technology to actually do it became available.

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Asteroid 12 Victoria, named after the Roman goddess of Victory (and possibly the queen of the same name) was spotted by John Russell Hind on September 13th 1850.  It’s an S-type, which you will recall are the stony asteroids, the second most common group, most of whom are congregated in the inner main belt.  Victoria has an apparent magnitude varying between 8.7 and 12.8, suggesting she is either elongated or binary.

Victoria the goddess was very important to the Romans (much more than her predecessor Nike had been to the Greeks).  I’m guessing this had something to do with her rôle in deciding who would be victorious in battle.

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Asteroid 104 Klymene is a Themistian asteroid, discovered by J C Watson on September 13th 1868. The Themistians are a family of C-type asteroids, named after 24 Themis (and including 62 Erato, coming up tomorrow).

Klymene and Hera

Klymene and Hera

The name Klymene (or Clymene) crops up quite a few times in Greek mythology, but one of them, an attendant to Hera, stands out in my mind as being the most likely candidate for today’s rock, when you consider that the asteroid named immediately before this one was 103 Hera. This particular Klymene was an Oceanid (daughter of Oceanus) and you can see her, with Hera, in today’s picture, a detail of a depiction of the Judgement of Paris from the Badisches Landesmuseum, Karlsruhle.

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September 12 – Gemini XI

Gemini XI was the 17th manned US spaceflight, and the 9th manned flight of the Gemini programme. It was crewed by Charles “Pete” Conrad and Richard “Dick” Gordon. The main aim of the mission was to rendezvous with an Agena Target Vehicle, to simulate the return of a Lunar Module to the Command/Service Module following a landing. Several such rendezvous were performed successfully, as well as two periods of extra-vehicular activity (that’s space walks to you and me).

The Crew of Gemini XI

The Crew of Gemini XI (image credit: NASA)

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Asteroid 59 Elpis  is a rather large, dark (albedo 0.04) C-type asteroid in the main belt. It has a diameter of 165 km.

Elpis was discovered by Jean Chacornac on September 12th 1860 (it was his last find). The name Elpis was chosen by Karl L Lithow, director of the Vienna Observatory. Elpis is the personification of ‘hope’ in Greek mythology, and was supposedly the only item left in Pandora’s pithos (jar) after she had emptied it.

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ALSO TODAY . . . 

Firstly, asteroid 117 Lomia was discovered by Alphonse Borrelly on September 12th 1871 from Marseilles. It has a nearly circular orbit, and in composition is somewhere between a C-type and an X-type. The origin of the name is unknown.

And secondly, asteroid 241 Germania (C-type, main belt) was discovered today in 1884 by Robert Luther in Düsseldorf. He named it, obviously, after his homeland.  I was tempted here to insert a photograph of a moustachioed general in a uniform and spiky helmet, but I resisted. No racial stereotypes here.

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September 11 – Messier 2

M2, or NGC 7089, is a globular cluster of about 150,000 stars in Aquarius. It was discovered twice: firstly by Jean-Dominique Maraldi on September 11th 1746, and again on the same date 14 years later (1760) by Charles Messier.

Messier 2 (aka NGC 7089)

Messier 2 (aka NGC 7089)

M2 is fairly large, as globular clusters go, at 175 light years across, a little more elliptical in shape than most, and quite elderly (13 billion years old). It is also heading slowly in our direction, at 5.3 km/second. ‘Slowly’, of course, is relative to other intra-galactic speeds. Travelling at three miles a second would be plenty fast enough to get you a speeding ticket down here, but up there it’s nothing special.

(image from freestarcharts.com)

(image from freestarcharts.com)

Theoretically, M2 is a naked eye object if the sky is dark enough, but in practice that doesn’t apply round here in the land of the midnight security lamp. I need at least the small ‘scope to see anything.


Asteroid 125 Liberatrix, discovered by Prosper Henry (or possibly Paul Henry: you can never be sure) on September 11th 1872. It appears to be an M-type, and is possibly the biggest remnant of a larger body.

As for the name, the theory is that it honours Adolphe Thiers, president of the French Republic and suppressor of the Commune, who had recently been instrumental in extracting France from the Franco-Prussian War, in which they were doing none too well.


Asteroid 202 Chryseïs was discovered on this very day in 1879 by C F H Peters. It is about 86 km in diameter, and completes one full rotation every 16 hours as it travels at 17 km/second on its 5.4 year journey around the Sun.

Chryses visit to Agamemnon to ransom his daughter Chryseis (Image: Habib M’henni / Wikimedia Commons)

Chryses visit to Agamemnon to ransom his daughter Chryseis (Image: Habib M’henni / Wikimedia Commons)

In Greek mythology, Chryseïs (also known as Astynome) is indirectly the cause of most of the action in the Iliad. She is captured and enslaved by Agamemnon in Book One, and his refusal to allow her to be ransomed by her father, a priest of Apollo, eventually leads to all sorts of issues.


And while we’re talking of Apollo, asteroid 101955 Bennu was discovered on September 11th 1999 by the LINEAR project.  It’s an Apollo, which means it has an orbit that brings it close to Earth, but in the case of Bennu not close enough to hit us (not yet, anyway).  This proximity to Earth has led to Bennu being chosen as the target of the Osiris-REX “sample return” mission, due to depart planet Earth in September 2016, and return in 2023.