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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March 04 – Messier 85

1781  –  Messier 85, a lenticular (elliptical if you prefer) galaxy, was discovered on this day in 1781 by Pierre Méchain.  It can be found in the constellation Coma Berenices (named after the Egyptian queen Berenice II) and is about 60 million light years away, making it the northernmost galaxy in the Virgo Cluster, a collection of somewhere between 1,200 and 2,000 galaxies, on the periphery of which is our own local group.

M85 (image credit: NOAO / AURA / NSF)

M85 (image credit: NOAO / AURA / NSF)

There are hundreds of beautiful photographs of all manner of galaxies on the internet, but M85 is very under-represented by legal entities with relaxed media sharing policies, hence the above.

1861  –  Asteroid 64 Angelina discovered from Marseilles by Ernst Tempel.  Angelina is an E-type (containing enstatite) with a very high albedo (0.28) compared to many other asteroids.  It is named after an astronomical station operated by the Hungarian astronomer Franz Xaver von Zach.  For discovering Angelina (and 65 Cybele) Tempel received the ‘Lalande Prize’ from the French Académie des sciences.

1892  –  M-type (mainly metallic) main belt asteroid 325 Heidelberga was discovered today by Max Wolf.  If you’ve been following these pages closely the choice of name should come as no surprise, being the location of most, if not all, of Wolf’s discoveries. Heidelberga is reasonably large, at approximately 75 km in diameter.  Fuller details of Heidelberga’s physical and orbital characteristics can be found in the NASA JPL Small-Body Database browser.

1904  –  Birth of George Gamow, cosmologist, and early champion of the Big Bang theory.

1923  –  Birthday of Patrick Moore, amateur astronomer extraordinaire.

This post originally appeared in 2015, and was slightly updated in 2017.


December 30 – Launch of RXTE

December 30th seems to be a thin day astronomically, but I did manage to find, in 1995, the launch of the Rossi X-Ray Timing Explorer from Cape Canaveral.  Bruno Rossi, after whom the satellite was named, was the discoverer of the first source of x-rays beyond the Sun.

Artist's Impression of RXTE

Artist’s Impression of RXTE

Over a sixteen year lifespan, RXTE did exactly what its name suggests: it timed variations in emissions from x-ray sources using three experiments (a proportional counter array, theHigh Energy X-ray Timing Experiment, and an all-sky monitor).

Also today, in 1924, Edwin Hubble announced to the world that the Milky Way is not the only galaxy.  Using the 100-inch Hooker Telescope at Mount Wilson, Hubble was able to calculate the distance to Cepheid variable stars in the Andromeda Galaxy using a technique devised by Harvard astronomer Henrietta Swan Leavitt.  At the time, “spiral nebulae” were assumed to be patches of dust or gas within the Milky Way, but calculating a distance to Andromeda of approximately 860,000 light years changed the scale of the Universe for ever.


December 27 – Johannes Kepler

Today is Johannes Kepler’s birthday.

Kepler was born in Weil der Stadt, a small town near Stuttgart, on December 27th 1571, and was introduced to astronomy from an early age, whether he liked it or not, by being taken outside to witness the Great Comet of 1577, C/1577 V1, at age 6. The comet was also seen, incidentally, by Tycho Brahe, with whom Kepler would later spend some time studying at the site of Brahe’s new observatory near Prague.

Johannes Kepler

Johannes Kepler

Kepler’s works included many revolutionary (and I mean that in several ways) publications on the behaviour of planets. His Astronomia Nova, published in 1609, contained arguments in favour of a heliocentric ‘universe’, and Harmonia Mundi (“The Harmony of the World”, 1619) was the setting for his third law of planetary motion.

As well as being an influential astronomer, Kepler was also a major influence in the field of optics (possibly because his own eyesight wasn’t the best). He was the first person to explain how a telescope works; worked out how our eyes perceive depth; investigated how a pin hole camera might be used to produce pictures, and discovered total internal reflection.

Also today, globular cluster Messier 92 was discovered in 1777 by Johann Elert Bode.

M92 (Photo courtesy of the Isaac Newton Group of Telescopes, La Palma)

M92 (Photo credit: the Isaac Newton Group of Telescopes, La Palma)

M92 is located in the constellation of Hercules. It is one of the oldest and brightest globular clusters, and is about 27,000 light years from Earth.

1968 – Splashdown, south of Hawaii, of Apollo 8, following a 6 day flight that included the first Earthrise seen by humans, and the first Christmas broadcast from a craft orbiting the Moon.


December 16 – Asteroid 351 Yrsa

Asteroid 351 Yrsa was discovered today in 1892 by Max Wolf.  There isn’t a great deal to say about it:  it’s in the main belt, and is about 40 km across.  It is thought to have been named after the wife of King Eadgils of Swedish legend.  her father, Helghe, who had only had a brief fling with her mother, visited the region where she lived years later and, not knowing she was his daughter, got her in the family way, as they say.   Unlike the average Greek god, who would have thought nothing of it, he did the decent thing and killed himself upon discovering the truth.

Lithograph depicting Yrsa

Lithograph depicting Yrsa

Max Wolf was a great friend of today’s birthday boy, Edward Emerson (E.E.Barnard, namesake of Barnard’s Star, one of the most closely observed objects in the Galaxy.  Barnard was mainly a prolific comet finder, discovering 17 in all (15 solo, and 2 co-discoveries), but he’s always going to be associated with the one star in my mind, because it was, and indeed may still be for all I know, the intended target of Project Daedelus, the mind-bogglingly ambitious unmanned interstellar mission proposed by the British Interplanetary Society.  When I was an impressionable teenager in the 1970’s, Daedelus seemed likely to happen “any year now”.  Unfortunately, 30 years later, they still haven’t quite got around to working out how to get the necessary helium-3 fuel back from Jupiter in order to get it to work, and I suspect that the cost in today’s money of a nuclear-powered spaceship bigger than a Saturn 5 and built in orbit would be rather more expensive than gold-plating the Isle of Wight or  buying Australia and Canada back.

E E Barnard

E E Barnard



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 14 – Tycho Brahe

Tycho Brahe was born today in 1546 in Denmark. As the child of a wealthy family (he was born in a castle) he was well placed to receive a good education, and took up astronomy while studying law.

Tycho Brahe wearing the Order of the Elephant (and the Moustache of the Walrus)

Tycho Brahe wearing the Order of the Elephant (and the Moustache of the Walrus)

Tycho made several leaps of the imagination, including the development of his own model of the solar system, which he nearly got right. He correctly deduced that the Moon orbits the Earth, and that the planets orbit the Sun. unfortunately he also decided that the Sun must orbit the earth; an easy mistake to make I suppose at that time, if you spend your entire life seeing it cross the sky thousands of times in front of your very eyes.

Tycho was also the first person to decide that novae (they weren’t called that at the time) originated further away than the Moon. The popular view was that the stars were fixed and unchanging, and anything that appeared in the sky had  to be closer than them. But Tycho noticed that a bright new star in Cassiopeia (now called SN1572) did not move against the background stars, and so must be farther away than all the objects that did. It sounds fairly reasonable to us, but in the 16th century the night sky was anything but obvious.

2009 – Launch of the Wide-field Infrared Survey Explorer (WISE) by NASA, on a mission  to map 99% of the sky. So far, it has found more than 33,000 asteroids and comets, over 200 Near-Earth Asteroids (including 43 potentially hazardous ones), the most luminous galaxy in the known universe, and numerous brown dwarfs.

2013  –  the Chinese Chang’E 3 mission lands on the Moon.

The Chang'E Lunar Lander, imaged by the Yutu rover (image: China National Space Administration)

The Chang’E Lunar Lander, imaged by the Yutu rover (image: China National Space Administration)



December 09 – Patrick Moore

There’s not a lot I can say that hasn’t already been said a hundred times or more about this chap, but it’s four years today since the passing, at the age of 89, of Sir Patrick Alfred Caldwell-Moore CBE, FRS, FRAS, singleton, leg spinner, xylophonist (if that’s the right word), RAF veteran, composer, cat lover, EEC hater, star of The GoodiesThe Morecambe and Wise Show and GamesMaster, general legend, and best all-round entertainer since Daffy Duck.  And it appears from the photograph that he also may have owned a telescope.

Patrick Moore (image credit: unknown).

Patrick Moore (image credit: unknown).

I’m not sure where I got that signed photograph from, but it lives inside my copy of Mrs Moore in Space, by Patrick’s mother, Gertrude.

I briefly met him a few times, donkey’s years ago: two of these were at speeches he was giving in the environs of North Staffordshire and South Cheshire, where I was restricted to standing in line waiting for an autograph, and twice were a little more informal at book signings I was involved with in my previous life as a bookseller.  I’d like to say how many books Patrick Moore wrote, but I’m not entirely sure they can be easily counted, as they stretch over such a long period, and had such wildly varied life spans.

To end on a sour note: it’s pantomime season, so boos and hisses to Macmillan publishers, who decided in 2016 to cease publication of “Patrick Moore’s Yearbook of Astronomy”.  Remind me to never buy any of their books again.

1892  ⇒  Discovery of the large main belt asteroid 349 Dembowska by French astronomer Auguste Charlois.  It was named in honour of the Italian astronomer Baron Ercole Dembowski, a specialist in double stars (and if the name sounds less than Italian, it’s because his father was a Polish general).  349 Dembowska is about 140 km wide, and is one of the brightest of the large asteroids.  It is classified as R-type, characterised by spectral lines showing the presence of olivine and pyroxene (the main constituents of the Earth’s mantle), and possibly plagioclase feldspars.


December 08 – Asteroid 5 Astraea

Asteroid 5 Astraea was discovered on this day in 1845 by Karl Ludwig Henke, and, as it was still relatively unusual to find asteroids at that time, it won him an annual pension of 1200 Marks from the king. Astraea is S-type, in the main belt, is quite big (roughly 167 km across at its widest point) and takes just over 4 years to orbit the Sun.

In Greek mythology, Astraea is the celestial virgin, and her name means just that (“star maiden”). She was a personification of justice, innocence and purity, and was the last of the immortals to live down here among us humans. Upon leaving Earth she became the constellation Virgo.


Yesterday we met the concept of the semi-major axis, and if you were paying attention you will know what I mean when I say that Astraea’s is 2.57 AU.  Today I’m attacking you with another position-related phrase, the longitude of the ascending node.  Like yesterday’s, it sounds more complicated than it is.  But unlike yesterday’s, it needs a really long rambling explanation, so here goes.

It’s an unwieldy phrase, isn’t it? So I’ll break it down into small parts. Firstly, if I tell you that for Astraea it is 141.7°, you’ll already know that it’s some sort of direction.  Longitude, as you know, is a coordinate showing the east-west position of something.  It tells you how many degrees you have to turn in an anti-clockwise direction from some point of reference in order to end up pointing at the place you want to be.  For example, your directions might tell you that if you’re standing in the car park looking at the church (point of reference) you need to turn 141.7° to see the pub (or just follow the smell of the beer).

Next, a node is the point at which an inclined (i.e. not horizontal) orbit crosses the horizontal plane on which your reference point lies.  For objects in the solar system we use the ecliptic(the plane marked out by the Sun’s apparent path across the sky) as the plane, and the First Point of Aries (ask me later – just accept it as a direction in the sky) as the point of reference.  There will be two occasions in each orbit when a body such as Astraea crosses this plane: one when it goes down below it, and another when it comes back above it. This second one is the ascending node.

So, the longitude of the ascending node is the direction you would need to be looking in order to see Astraea, if you knew precisely when it was about to start heading upwards above the ecliptic. Does that make sense?

A poem from Emerson to finish (“cap-a-pie” means from head to foot):


Each the herald is who wrote
His rank, and quartered his own coat.
There is no king nor sovereign state
That can fix a hero’s rate;
Each to all is vulnerable,
Cap-a-pie invulnerable,
Until he write, where all eyes rest,
Slave or master on his breast,

I saw men go up and down,
In the country and the town,
With this tablet on their neck,—
‘Judgement and a judge we seek.’
Not to monarchs they repair,
Nor to learned jurist’s chair;
But they hurry to their peers,
To their kinsfolk and their dears;
Louder than with speech they pray,—
‘What am I? companion, say.’
And the friend not hesitates
To assign just place and mates;
Answers not in word or letter,
Yet is understood the better;
Each to each a looking-glass,
Reflects his figure that doth pass.
Every wayfarer he meets
What himself declared repeats,
What himself confessed records,
Sentences him in his words;
The form is his own corporal form,
And his thought the penal worm.

Yet shine forever virgin minds,
Loved by stars and the purest winds,
Which, o’er passion throned sedate,
Have not hazarded their state;
Disconcert the searching spy,
Rendering to a curious eye
The durance of a granite ledge
To those who gaze from the sea’s edge.
It is there for benefit;
It is there for purging light;
There for purifying storms;
And its depths reflect all forms;
It cannot parley with the mean,—
Pure by impure is not seen.
For there’s no sequestered grot,
Lone mountain tarn, or isle forgot,
But Justice, journeying in the sphere,
Daily stoops to harbour there.

Ralph Waldo Emerson (1847)

1842    Birth of Alphonse Louis Nicolas Borrelly, the French astronomer who crops up in these pages every few weeks as a discoverer of asteroids.  He found 18 in all, and discovered or co-discovered six comets.


December 06 – Pioneer 3

Launched from Cape Canaveral on December 6th 1958, Pioneer 3 was supposed to be a lunar flyby. Unfortunately that didn’t happen, but the craft did manage to reach a distance from Earth of about 63,000 miles, and used its Geiger-Müller tubes to gather useful information about the Van Allen radiation belt.

Pioneer 3 (image: NASA / JPL)

Pioneer 3 (image: NASA / JPL)

Pioneer 3 ended its one day flight by burning up over Africa.

1888   –   Birth of comedian and astronomer Will Hay in Stockton-on-Tees, North East England.  In 1933 he discovered a Great White Spot on Saturn in August 1933 (note: it’s “a” not “the” Great White Spot, as there have been several observed over the past century).  At his home in Norbury, South London, Hay built his own observatory to house his 1895-vintage 12.5 inch Newtonian reflector and the 6-inch refractor he used to discover the white spot.

1893   –   Discovery of asteroid 378 Holmia by Auguste Charlois (the name is the Latin for Stockholm).

1998   –   Launch of the Submillimeter Wave Astronomy Satellite (SWAS).  One of NASA’s SMEX (Small Explorer) missions, SWAS was intended to have an operational life of two years, but managed to stretch to six, studying the cores of interstellar clouds to help our understanding of what they are composed of, and how they cool and collapse to form stars.