May 28 – Discovery of Asteroid 99 Dike

Asteroid 99 Dike was the first of many asteroids (and the occasional comet) to be discovered by Alphonse Borrelly (1842-1926) from his Marseilles observatory. This one was spotted on May 28th 1868.  I have very little to say about it, except that I think it should be pronounced die-kee rather than dyke or decay.

99 Dike has been shown, like three-quarters of all known asteroids, to be a carbonaceous “C-type”, meaning it has a high carbon content, which also means it is dark in colour.  According to the JPL Small Body Database, Dike is about 67km across, takes 1,589 days to orbit the Sun, and has an absolute magnitude of 9.43.

Dike Astrea was a daughter of Zeus and Themis, and was the goddess in charge of justice and fair judgement in the mortal world (her mother had the same responsibility over the immortals).

Dike Astrea (credit : GearedBull at Wikipedia)

May 25 – Launch of Skylab 2 (SL-2)

Skylab 2, launched today in 1973, was the first manned mission to NASA’s orbiting Skylab space station, prior to setting a new record of 28 days for the longest time spent in space (back in those days it was a lot more about setting records to get one over on the Russians than it is now). The actual Skylab station had already been launched, unmanned, on May 14th, in what was to be the final mission of the gigantic Saturn V rocket.

The Skylab Orbiting Space Station (image credit: NASA).

The crew comprised three astronauts; a famous veteran and two rookies. Flight commander, Charles “Pete” Conrad, third man on the Moon, was on his fourth mission, pilot Paul Weitz was making the first of his two (the other would be on the maiden voyage of the shuttle Challenger), and Joseph Kerwin was on his only venture beyond the atmosphere (which made him the first physician in space).

The crew of SL-2 (image credit: NASA).Fb

Following their launch atop a Saturn 1B, at 13:00 UTC, the crew took less than a day to reach Skylab, after which they set about trying to minimise the impact of the damage the staion had sustained at launch. It was missing its micrometeorite shield and part of the solar power array. Also, the remaining solar panel was jammed by a strap, possibly from the meteorite shield.

A partially deployed solar array, and the errant strap preventing it from unfurling (image credit: NASA)

Fortunately, it was known there would be a few issues before the crew lifted-off, so launch was delayed by ten days to allow for training on how to conduct repairs in orbit. It took some doing (they almost reached double figures in docking attempts, and had to use a foldable parasol to protect parts of the already blistered station from overheating) but eventually Skylab was brought up to a level that would allow future mission to be less stressful.

Skylab 2 Mission Patch. Spot the not-so-deliberate mistake? (Image credit: NASA)

May 08 – Look What I Found

This isn’t actually anything to do with May 8th, but I’m off work following an operation, and the day has no previous blog entry.

My Dad moved house recently (long story, but I’m blaming it for the hernia that put me in front of this keyboard today). In amongst the dusty, massive pile of junk he deposited in the middle of my Mum’s garage floor was a toffee tin full of cigarette cards. And in that I found a small, yellowing notebook containing a series issued by the company W.D. & H.O. Wills called “Romance of the Heavens”, which I now know were issued in 1928.

Unfortunately the cover is missing, and my Dad hasn’t got a clue who was responsible for the book, which was obviously created with some care, and probably with the use of a razor blade by someone who these days would be deemed far too young to have access to one, but is now showing it’s age. All he knows is it wasn’t him, which I already guessed, because there are no steam engines in it.

The author has also decided to add dates to the sides of certain cards showing when various phenomena were observed (they were all in January 1949, suggesting the creator of the book was not the smoker of the cigarettes from 1928).

The later pages of the book have some basic seasonal maps of the sky cut from a magazine or book and pasted in, and brief writings about each of the eight (including Pluto, excluding Earth) planets, in the slightly quirky order Mercury, Mars, Jupiter, Saturn, Venus, Uranus, Neptune, Pluto. I like to think that at some point in the winter of 1948-49, the phrase “Sh*t, I forgot Venus!” could be heard in the North Staffordshire countryside.

I’ll end with a short, badly drawn table to show how much has changed since as recently as 1949. For some reason our writer doesn’t mention any moons of Neptune, even though one was already known (the second, Nereid, would be discovered just four months after the latest known date written in the book). here’s a summary of then and now:

Planet Known Moons
1949 2019
Jupiter 9 79
Saturn 10 62
Uranus 4 27
Neptune 1 14
Pluto 0 5

Not forgetting, of course, that Jupiter, Uranus and Neptune have also been shown to possess ring systems.

Created May 07, 2019.

May 03 – Messier 3

Messier 3, a globular cluster in the constellation Canes Venatici (the hunting dogs) was discovered by Charles Messier on May 3rd, 1764, but was not actually resolved into a collection of stars for another 20 years (by William Herschel).

Messier 3. Image credit: Hewholooks (Hunter Wilson).
Messier 3. Image credit: Hewholooks (Hunter Wilson).

As one of the brightest clusters (apparent magnitude 6.2) it is a popular target for amateur observers. Messier 3 contains about 500,000 stars, and is approximately 33,900 light years from Earth. Over 270 of those stars are variables, a much higher number than the average cluster; and of those, 133 are RR Lyrae variables: old, small-mass stars (about half the size of the Sun) which can be used to measure astronomical distances using the inverse square law.

1888  –  Main belt asteroid 277 Elvira was discovered by Auguste Charlois on May 3rd, 1888. It is approximately 27 km in diameter (not that I’m suggesting we are talking about a perfect sphere here) and is a member of the Koronis family. The origin of the name Elvira is not certain, but might have been inspired by a character in the Méditations poétiques of Alphonse de Lamartime, written in 1820.
The Koronis family comprises at least 300 members, mostly under 20 km wide, all following each other around in a similar orbit, and thought to exist as a result of some massive collision over two billion years ago.


May 01 – Nereid

Neptune’s third largest moon, Nereid, was discovered on May 1st, 1939, by Gerard P Kuiper, using the 83-inch Otto Struve Telescope at Mcdonald Observatory, Texas. It is about 170 km in diameter, and has a day lasting just 11.5 hours, but a year almost identical to ours, at 360 days.

Not Voyager 2's greatest photograph, but the best we have of Nereid (image: NASA).
Not Voyager 2’s greatest photograph, but the best we have of Nereid (image: NASA).

Nereid has a prograde rotation, and a very eccentric orbit, which takes it from 853,000 miles at periapsis to 5,999,000 miles at apoapsis. This has led astronomers to believe it is either a captive asteroid (or Kuiper Belt Object) or has had a previously more normal orbit changed by the capture of Triton.

The Nereids after whom this moon is named were the fifty daughters of Nereus and Doris. They were sea nymphs who attended Neptune (he married one of them, Amphitrite, who bore his son Triton.


April 29 – 68 Leto

Asteroid 68 Leto was discovered by Robert Luther on April 29th 1861.  It’s a fairly big main belt asteroid (about 125km diameter) with an absolute magnitude of 6.78, and an apparent magnitude from down here of 9.56 when at its brightest.

Leto was the daughter of the Titans Coeus and Phoebe, and mother (by Zeus, of course) of Apollo and Artemis.  She was thought to have been born on the island of Kos.  Apart from her role in bearing two important gods, Leto is hardly heard about in Greek writing and seems to have been content to remain in the Olympian background.  This fits in with her being generally portrayed as a demure woman, modestly lifting her veil.  The word letho means “to move unseen”, which may explain it.  Perhaps she’s hiding from Hera, Zeus’ wife.

Latona and the Lycian Peasants, by Jan Brueghel the Elder (about 1605).
Latona and the Lycian Peasants, by Jan Brueghel the Elder (about 1605).

The oil painting above, by Jan Brueghel the Elder, shows another incident from Leto’s life, also concerning Hera.  In a foul mood at discovering that Leto was to bear children to Zeus, Hera cursed her to be shunned everywhere she went.  In the painting, she is attempting to drink from a pond in Lycia (southern Turkey), but is being prevented from so doing by the locals, who are stirring up the mud from the bottom of the pond.  She responded by turning them into frogs.

Also today, it now transpires that in 1801 main belt asteroid 69 Hesperia was discovered by Italian astronomer Giovanni Schiaparelli from Milan.  Previously the discovery date had been thought to be April 26, but in an editorial notice of August 29th 2015 the Minor Planet Center announced that an examination of the literature of the time of the discovery shows that the date should in fact be pushed back three days.

Being a patriotic kinda guy, Schiaparelli had named his new discovery in honour of his home country, but for some reason used the Greek name for Italy rather than the Latin (or Italian) one.  The M-type Hesperia is a fairly chunky size, and would be about 130 km in diameter, if it were a sphere (which it isn’t).  I use the word “diameter” a lot in this blog to describe asteroids, but it just means “wide in no particular direction”.

April 22 – PSR B1257 12A

Extra-solar planet PSR B1257+12A was discovered on April 22nd 1994 by Aleksander Wolszczan and Maciej Konacki.

As exoplanets go it’s quite small.  Somehow it has been determined that this 500 parsec distant object that nobody can see is just twice the size of the Moon.  Only Kepler-37b (slightly better name) is smaller, while at the same time still managing to retain the description “planet”.  If it were much smaller it would probably not be called a planet.  The “PSR” in the same lets you know that this planet is orbiting a pulsar, a rotating neutron star, formed during the collapse of a massive star during a supernova.  This particular pulsar has a rotation period measured at a staggering 6.22 milliseconds, which, for the older readers among you, is 123 times faster than a 78rpm record player.

Three planets have so far been discovered around pulsar PSR 1257+12 by the Arecibo telescope in Puerto Rico.  All three have tight orbits, and would fit within the orbit of Mercury.  They were the first extra-solar planets to be discovered, with “B” and “C” being found first, followed by a third which, because it was closer to the star, became “A”.

April 21 – 137 Meliboea and 162 Laurentia

Asteroid 137 Meliboea was discovered by Johann Palisa on April 21st 1874.  It is the largest of a family of similar asteroids, which includes the wonderfully named 2829 Bobhope, discovered by E L Johnson in 1948 and named after the legendary comedian.

Meliboea is a C-type asteroid of about 145 km (90 miles) wide, with an absolute magnitude of 8.1.  There are several Maliboea’s in Greek mythology, and it isn’t known after which one this particular discovery was named.

Two years later, on April 21st 1876, French astronomer brothers Paul and Prosper Henry spotted their ninth asteroid, 162 Laurentia, with credit for the discovery being attributed to Prosper, in line with their habit of taking one each alternately.  The name they chose was a tribute to another French astronomer, A. Laurent, discoverer of asteroid 51 Nemausa in 1858.  Laurentia is another C type, with a diameter of approximately 99 km (61 miles).

Our third and final asteroid of the day is 470 Kilia, discovered by Italian astronomer Luigi Carnera on this day in 1901.  Kilia is fairly small, at 26 km across (16 miles), and according to the JPL Small-Body Database, it is a stony “S-type”, and has been named in honour of the German town of Kiel, on the Jutland peninsula.

Luigi Carnera
Luigi Carnera

Carnera was always going to find an asteroid or two, as he had worked for Max Wolf, German asteroid-bagger extraordinaire.

1972  –  At 02:23 UT, John Young and Charles Duke, in the lunar module of Apollo 16, touched down on the Moon.  Pilot Ken Mattingly II had to stay behind to ensure the command module didn’t escape while they were down there.

April 16 – Robert Luther: Asteroid Hunter

Today is the birthday of Karl Theodor Robert Luther, born in 1822 in the town of Schweidnitz, which is now in Poland, but at the time was in Germany (where it remained until the end of WWII).

Luther discovered 24 asteroids between April 1852 and February 1890.  He died on February 15, 1900.  Like several other asteroid hunters, he is now honoured with a lunar crater and his own asteroid, 1303 Luthera (discovered March 16, 1928 by A. Schwassmann).

One of his asteroids, 90 Antiope, is very interesting (as asteroids go) because it consists of two almost identically sized bodies.  There’ll be more about that on October 1st.

1756  –  Death of Jacques Cassini.

1972  –  Launch of Apollo 16.

April 03 – 119 Althaea

119 Althaea is a 57km wide main belt asteroid discovered in 1872 by James Craig Watson and named after the mother of Meleager, who killed him by setting alight a particular firebrand that had been kept safely hidden since the fates had prophesied it would one day kill him.

Althaea (illustration by by Johann Wilhelm Baur).
Althaea (illustration by by Johann Wilhelm Baur).

Asteroid 256 Walpurga was discovered by Johann Palisa on April 3rd, 1886.  It is about 63 km across.  Bucking the prevailing trend of naming asteroids after assorted pre-Christian and pagan deities, Walpurga refers to a saint, born in Devon in 710 BC.

1888  –  Asteroid 274 Philagoria discovered.

1905  –  Asteroid 562 Salome discovered.

1926  –  Astronaut Gus Grissom born.