June 16 – Discovery of Neptune’s Moon, Proteus (1989)

Today’s anniversary is the discovery of Neptune‘s second largest moon, Proteus, found by analysis of Voyager 2 snapshots taken over a period of time leading up to June 16th 1989.  So, while June 16th isn’t the actual discovery date,    it’s as close as we’re likely to get.  It is thought that Proteus wasn’t formed at the same time as Neptune, but is a by-product of the capture of Triton.

Proteus is approximately 418 km in diameter (about 260 miles) and orbits Neptune close to the equatorial plane at a distance of a little over 117,000 km.  But aside from this, and the fact that it is dark and heavily cratered, almost nothing else is known about it.

Proteus (from Voyager 2). Image credit: NASA.
Proteus (from Voyager 2). Image credit: NASA.

Proteus is named after a shape-changing sea god, son of Poseidon, the Greek god whose Roman equivalent is Neptune.  Neptune’s moons are generally named after children or other associates of Poseidon (Triton, for example, was his other son).



June 15 – Launch of Soyuz 29

1973Kosmos 573 launched today.  It was an unmanned flight of the two-man Soyuz ferry, testing its ability to transport crews to Salyut space stations.

Fast forward five years, and by June 15th 1978 the Salyut program was in full swing. The launch of Vladimir Kovalyonok and Aleksandr Ivanchenkov onboard Soyuz 29 was to the Salyut 6, which had been put into orbit in September 1977, and became home to 11 crews in total.

Stamp showing the crew of Soyuz 29 and part of a Salyut Space Station

The first task for this crew was to get the station up and running again after a three-month period during which it had been vacant.  In orbit this involves more than just turning on the electricity and gas, and clearing up the junk mail.  It took about a week to get the atmosphere breathable, the temperature bearable, and the crew adjusted to weightlessness.


The Salyut 6 Station.

During their stay, the two-man crew of Salyut 6 became a four-man crew when they were visited by Soyuz 30, part of the “Intercosmos” program of flights involving cosmonauts from The allies of the USSR.  Soyuz 30 carried Pyotr Klimuk, the first Belarusian cosmonaut, and Mirosław Hermaszewski, the first from Poland.


June 13 – New Planet and NuSTAR

Exoplanet Gliese 876d was discovered on June 13th 2005 by the California and Carnegie Planet Search.  It was found by using the radial velocity method of planet detection, and at the time of discovery was among the lowest mass planets yet detected.  Because of this it was placed in the “super Earth” category.

As it has only been detected indirectly, there is little to say about Gliese 876d’s physical characteristics, apart from “it’s probably terrestrial, rather than gaseous”.  Other parameters, such as the radius one and a half times that of the Earth, and a mass of almost seven Earths, are probably good working calculations, but they rely to a certain extent on assumptions that Gliese 876d works in a similar way to models of solar systems of a similar make-up.

The host star to today’s discovery, Gliese 876, is a red dwarf, 15 light years away from us in Aquarius. It has four known planets, of which “d” is the innermost.  The first to be discovered, Gliese 876b, is a whopper, estimated at over twice the mass of Jupiter.  All four are really close to their host, with none of them any further than Mercury is from our Sun.


NuSTAR, the Nuclear Spectroscopic Telescope Array, was launched this day in 2012 as part of the NASA “Small Explorer” program, to study the high energy x-ray end of the spectrum, armed with an ingeneous 33 foot (10 metre) long extendable mast to greatly extend the focal length (longer focal lengths are necessary to focus x-rays) without having to use a monstrous rocket to get it into orbit, as had been the case with previous 10 metre tubes.

NuSTAR (artist's conception). Image: NASA / Caltech / JPL.
NuSTAR (artist’s conception). Image: NASA / Caltech / JPL.

Asteroid 132 Aethra was discovered on June 12, 1873 by James Craig Watson. Aethra is a Mars crossing main belt asteroid, the first to be identified as such. It is approximately 43 km across, and has an absolute magnitude of 9.21. It is named after Aethra, daughter of King Pitheus of Troezen (a small town in the Peloponnese) and the mother of Theseus.


June 11 – Launch of Kosmos 427

I’m never sure whether to call these things Cosmos or Kosmos.  Cosmos is probably better because I’m not trying to speak Russian; but Kosmos starts with a “k”, which the actual name does.  But then, if I’m going to do that, should I not go the whole hog and say Космос?  Anyhoo . . .

Cosmos 427 was launched from the Plesetsk or Pleseck (or even Плесе́цк, if you must) Cosmodrome on June 11th, 1971.  The aim was to insert a 4,000 kg satellite into orbit, and for this the Russians turned to the Voskhod variant of the world’s first intercontinental ballistic missile, the R-7 (or the “A-1” as it was known in the West in 1974 when my Observer’s Book of Unmanned Spaceflight was published).

Kosmos 427 spent a fairly short time in space: 12 days.  It’s orbit decayed on June 23rd, 1971.  Not that this was anything for the ground crew to worry about; the actual payload of this particular flight was a Zenit-4MK reconnaissance satellite, all of which were given the name “Kosmos” to hide their true purpose, which would almost certainly have been to spy on the USA or one of her allies.  This being the early 1970’s, the easiest way to do this was to launch a collection of cameras into orbit, get them to take loads of photos, and then arrange for them to fall back to Earth at a place of your choosing.

A Zenit-style satellite (image credit: anybody’s guess; possibly the Energia corporation).

Today’s visual aid is almost certainly not a Zenit-4MK, but a Zenit-4MT.  But there is very little difference in the basic design: something looking like two-thirds of a vary large ant goes up, and the big sphere at the top comes back down full of pictures.

Just in case you were wondering, Kosmos satellites were launched sequentially, from “1” upwards, meaning the number 427 really does signify the 427th in a quite staggering sequence of launches.

I’ve added a page of Cosmos launches by year here.








June 09 – Johann Gottfried Galle

Johann Gottfried Galle was born in the town of Radis, Germany, on June 9th, 1812. He was the first person to observe Neptune, knowing at the time that it was a planet. If you cast your mind back to a previous blog, you will recall that two men were on the hunt for Neptune simultaneously in the 1840s: English astronomer John Couch Adams , and Urban Le Verrier of France. It was Le Verrier who called on Galle with a prediction of the location of the new Trans-uranian planet while Couch’s guy was waiting for up to date charts to arrive.

While working at Berlin Observatory, Galle also discovered a new ring around Saturn and three comets.

Galle died at the grand old age of 98, on July 10th, 1910. He now has the innermost ring of Neptune named in his honour.

J G Galle
J G Galle

June 08 – Birth of Giovanni Domenico Cassini (1625)

On this day in 1625 the Italian mathematician and astronomer Giovanni Domenico Cassini was born in the tiny municipality of Perinaldo.

Cassini (Leopold Durangel, 1879).
Cassini (Leopold Durangel, 1879).

Cassini held several important astronomical positions during his career, including professor of astronomy at Bologna University, and director of the Paris Observatory, and was responsible for the discovery of four saturnian moons: Iapetus, Rhea, Tethys and Dione. He also discovered the Great Red Spot on Jupiter (at the same time as Robert Hooke, so he only gets half a credit for that one), and the “gap” in Saturn’s rings which now bears his name, the Cassini Division. I’ve put the word “gap” in inverted commas because recent visits to the planet have found it to be actually quite busy (see below).

The Cassini Division (image credit: NASA / JPL / Space Science Institute)
The Cassini Division (image credit: NASA / JPL / Space Science Institute)

Cassini wasn’t just a gas giant geek, though, and made observations of our nearest planetary neighbour, Mars, from Paris (simultaneously with a colleague a long way away in French Guiana to make the angle as big as possible) to make the first calculation of the size of the solar system using parallax. The relative positions of all the known planets had already been calculated, so only the distance to one was needed in order to have a stab at working out how far away they all were. Mars was the obvious choice because it’s the closest, so the apparent shift would be greatest. Cassini’s measurements turned out to be not too far from the values we have now; he used his observations to calculate the Earth-Sun distance as 21,700 “Earth radii”. Today we use the accepted value of 23,455.

1873: Main belt asteroid 146 Lucina discovered by Alphonse Borrelly, and named after the Roman goddess of childbirth.

1887: Themistian asteroid 268 Adorea discovered by Alphonse Borrelly.


June 07 – Launch of Soyuz TM-5 (1988)

The Russian Soyuz program is the gift that keeps on giving.  Any date about which I’m short of something to write there’s bound to have been a Soyuz launch.

Today’s mission, from 1988, was to the MIR space station, which at the time had been in orbit for just over two years.

As with most flights to space stations, the crew launched aboard Soyuz TM-5 was different to the crew who landed three months later.   Going up were Russians Anatloy Solovyov (on the first of his five visits to Mir) and Viktor Savinykh, and Bulgarian research cosmonaut Aleksandr Aleksandrov.  Aleksandrov became the first Bulgarian in space.  Coming back down were Russian Vladimir Lyakhov, and the first Afghan in space, Abdul Ahad Mohmand.

Soyuz TM-5 Crew.

The expedition comprising the three-man “up” crew was known as Mir EP-2.  The crew docked their Soyuz to Mir’s aft port on June 9th, but moved the craft to the fore port on June 18th following the departure of Soyuz TM-4 the previous day.

Soyuz TM-5 Mission Patch


June 06 – Launch of Soyuz 11 (1971)

In the history of spaceflight, June 6th 1971 is significant for all the wrong reasons, being the launch date of Soyuz 11, the crew of which are, to date, the only astronauts or cosmonauts to die beyond the Earth’s atmosphere. Commander Georgy Dobrovolsky, and engineers Vladislav Volkov and Viktor Patsayev, docked with the Salyut 1 space station just under a day after lift-off, and spent 23 days in space, after which they made what looked like a successful re-entry. Unfortunately, on recovery of the capsule, all three were found to have asphyxiated due to a ventilation valve opening at an altitude of 168km, resulting in instant depressurization, and death within a matter of seconds.

Fourteen years later, on June 6th 1985, a more successful voyage in the series, Soyuz T-13, became the first mission to bring a previously “dead” space station, Salyut 7, back to life. Power had been lost on the station in February, and it was basically just drifting through space. The story of the mission was made into a film in Russia in 2017, but I’m not sure it’s been released over here yet.


2017: The 2-3kg Mukundpura meteorite lands in a farmer’s field near Jaipur in India (the weight can only be estimated because not all of it was necessarily found) . It was less spectacular than the 2002 explosion mentioned below, leaving a crater just 15cm deep and about 40cm wide. This was the second large Indian meteorite in under a day: the previous evening another weighing around 3kg had fallen in the Assam region.

2002: The “Eastern Mediterranean Event“. A meteorite explodes over the Mediterranean Sea with a force equivalent to 26 kilotons of TNT. I don’t blame you if you never heard of this one, because it was over water. Had it landed 200 miles away on Cyprus, I’m sure it would be a lot more famous. Don’t forget, #AsteroidDay is coming soon.

1924: Discovery of asteroid 1031 Arctica.

1931: Discovery of 1210 Morosovia.

1978: Discovery of asteroid 3369 Treshnikov.

1979: Launch of Soyuz 34.

2018: Launch of Soyuz MS-09.

June 05 – John Couch Adams

English mathematician and theoretical astronomer John Couch Adams was born on June 5th, 1819, near Launceston, in Cornwall. Under the guidance of his maternal uncle, the Rev. John Couch Grylls, and using the facilities of the Mechanics’ Institute, Devonport, to further his studies privately, at the age of 2o he entered St. John’s College, Cambridge. He excelled at mathematics to the point of achieving the exalted position of Senior Wrangler (nothing to do with cows or denim, it’s the top scoring maths graduate of the year) in 1843.

Two years previously he had already begun to be intrigued by the possibility of a planet beyond Uranus, as the following nineteenth century “note to self” shows:

“Formed a design . . . of investigating . . . the irregularities in the motion of Uranus, . . . in order to find whether they may be attributed to the action of an undiscovered planet beyond it . . . “

Adams’ study of the perturbations of Uranus’ motion first led him to conclude that an unknown planet beyond Uranus, located at double the distance from the Sun, might exert the necessary influence on Uranus if it was big enough, and in the right place. Following his obtaining more precise observations from the Astronomer Royal, a more refined prediction of how to locate the eighth planet was made, which Adams took to Greenwich Observatory and left for the attention of the aforementioned Astronomer Royal.

John Couch Adams
John Couch Adams

At the same time, Urban Le Verrier had also been on Neptune’s trail, and had predicted a location within one degree of that determined by Adams. Unfortunately for the reputation of British astronomy, the lack of accurate star charts meant that looking for an object moving against the background involved a painstaking wait for two lots of observations to be undertaken, recorded and compared. But Le Verrier’s calculations were in the hands of Dr Johann Galle at the Berlin Observatory and, despite beginning his search two months later than the British team (led by James Challis), with typical German efficiency he discovered the planet on the first night of observation, through the rather obvious method of having accurate star charts to hand.

2002 – Discovery of trans-Neptunian object 50000 Quaoar. Potentially a dwarf planet (it has a diameter of about 1000 km, but more information on its mass is needed before a decision can be made) I’m mentioning it mainly because 50000 is a nice round number, and partly because Quaoar was the first TNO to be detected directly from Hubble Space Telescope images.

1980 – Launch of Soyuz T-2.

June 04 – 456 Abnoba

Main belt asteroid 456 Abnoba was discovered on June 4th, 1900, by Max Wolf and F K A Schwassmann. It is an S-type asteroid of approximately 400m diameter,  and the JPL Small Body Database tells me it has an absolute magnitude of 9.1 and a rotation period of 18.281 hours.

Max Wolf
Arnold Schwassmann

Abnoba was a Celtic / Gaulish (I had to override the spellchecker here, to remove the word ‘goulash’) goddess of the hunt, worshipped principally in the Black Forest area, and associated with the Roman goddess Diana. She was also a goddess of waterways, and it is probable that her name is derived from the same Celtic root, abon, as the Welsh word for river, afon, and the name of a famous English river, the Avon.

Today’s final image shows an altar dedicated to Diana Abnoba from the Badenweiler Roman Baths, Germany. (Image: Wikimedia Commons).  The popular spa resort of Badenweiler was where the playwright Anton Chekhov arrived in June 1903 to help ease the symptoms of his tuberculosis.  He died there on July 15th 1904.

If you’re now in the mood for a goulash goddess, there’s a recipe on Nigella Lawson‘s website.