May 18 – Launch of Apollo 10 (1969)

Apollo 10 was the fourth of the crewed flights in the NASA Apollo program, launched this day in 1969.

As usual there was a three man crew: Tom Stafford and John Young got to try out the lunar module, while Eugene Cernan stayed in the command module.

(Image credit: NASA)

Apollo 10 was a dress rehearsal for the big one: landing men on the Moon.  As such, it was a great success.  Stafford and Young in the lunar  module were successfully separated, and got to within 9 miles (~16 km) of the surface. The “descent stage” of the lunar module was then jettisoned,  just as it would if they had actually landed (I’m not sure if anyone knows whether it’s still in orbit?) and the crew used the “ascent stage” to get back to Cernan.

The three then jettisoned the ascent stage and successfully made it back to the Pacific Ocean (setting a new space speed record for a crewed vehicle along the way), where they were met by the USS Princeton.

There are those who say that the ascent stage of “Snoopy” (the nickname given to the lunar module) is still up there going round the Sun.  A British search has decided that they are 98% certain that the Earth-crossing asteroid 2018 AV2 is in fact the only crewed space vehicle to still be in orbit without its crew.




May 07 – Launch of STS-49 (Space Shuttle Endeavour) 1992

Today marks the launch the shuttle Endeavour in 1992 on mission STS-49 to retrieve and relaunch the intelsat 603 satellite.

This was the maiden voyage of Endeavour, lasting 9 days.  The crew (left to right in the photo below) were Kathryn C Thornton, Bruce E Melnick, Pierre J Thuot, Daniel C Brandenstein (mission commander), Kevin P Chilton (pilot), Richard J Hieb and Thomas D Akers.

Crew of Endeavour mission STS-49 (image credit: NASA)
Crew of Endeavour mission STS-49 (image credit: NASA)

The mission was a success, and included the first ever 3-astronaut EVA (spacewalk).  Four EVA’s were carried out in total (another first), but only one of them involved three crew members. The need for so many EVA’s was the result of the first two attempts to catch the Intelsat not going according to plan.  That was also the reasoning behind sending three of them outside for the third EVA.  It’s understandable when you see the size of the fish they were trying to reel in (below):

Catch of the day (Image credit: NASA)

May 04 – Launch of “Magellan” on Shuttle Mission STS-30

Happy Star Wars Day.

1886  – on May 4th 1866, asteroid 258 Tyche was discovered by Robert Luther. It is a 650m wide “S” type main belt asteroid, and is possibly a member of the Eunomia family. It was named after the Greek goddess whose Roman equivalent was Fortuna. Her main responsibility was to decide how prosperous a city should be.

1896  –  Asteroid 416 Vaticana was discovered on May 4th, 1896, by Auguste Charlois. It is an S-type main belt asteroid, about 85 km across, and was named after the Vatican Hill (Mons Vaticanvs) in Rome.

1989 – Launch of shuttle mission STS-30 carrying the Magellan probe, aka the Venus Radar Mapper, to be sent on its way to Venus. This was the first ever launch of a spacecraft from a shuttle. Magenta arrived at Venus on August 8th, 1990, and used a high-gain parabolic antenna to allow it to map the Surface through the opaque Venusian atmosphere. The probe burned up in this atmosphere on October 13th, 1994. Being mostly composed of carbon dioxide (96.5%) and nitrogen (3.5%), both of which are colourless, you might think that seeing the surface from orbit would be a doddle, but it is the presence of clouds of sulphuric acid, blowing around the planet at over 200 mph (about 300 km/h) that pose the problem.


The photograph shows the Venusian volcano Sapas Mons, a monster by Earth standards at over 240 miles wide and nearly a mile high.


April 28 – Oorter Space

We have two birthdays today.

Johann Oskar Backlund was born on April 28th 1846 in Länghem, Sweden, but after university spent his career in firstly Tartu, Estonia (part of Imperial Russia at the time) and then Pulkovi (also Russia). He was a dab hand at celestial mechanics, and became so well known in Russian astronomical circles for his work on comet 2P/Encke that Russian sources sometimes refer to it as Encke-Backlund.

Oskar Backlund
Oskar Backlund


2P/Encke is believed to be the source of the Taurid meteor shower, but Backlund was more interested in the effect it might be having on Mercury, and used the perturbations produced by the motion of the comet to predict the mass of the planet. If I had a copy of the 1961 journal Soviet Physics I might be able to share his results with you (unless they were in Russian, which seems likely).

Jan Oort was also born on this day, in 1900, in Franaker, Friesland (the Netherlands). He was mostly drawn to radio astronomy, and his day job was as a professor at the University of Lieden, under Director Ejnar Hertzsprung. Among Oort’s many career highlights were the discovery of a group of stars outside the Milky Way (the galactic halo), the calculation of how far away and in what direction lies the centre of the galaxy, and of course the idea that comets originate in what is now commonly known as the Oort Cloud, a roughly spherical region of icy planetesimals surrounding the Sun at distances of up to an almost unbelievable 50,000 AU (defining the limits of our home star’s gravitational supremacy).

Jan Oort (image: Nationaal Archief NL Fotocollectie Anefo)
Jan Oort (image: Nationaal Archief NL Fotocollectie Anefo)

1903  –  Discovery of asteroid 509 Iolanda (a.k.a. 190LR) by Max Wolf. Iolanda is an S-type main belt asteroid, and the NASA JPL Small-Body Database Browser gives it a diameter of just under 53km, an absolute magnitude of 8.40, and a rotation period (day) of 12.306 hours.

1928  –  Birth of Eugene Shoemaker, a leading light in the development of astrogeology, but mostly remembered these days as co-discoverer of comet Shoemaker-Levy 9, which famously collided with Jupiter in 1994.

1999  –  Launch of the ABRIXAS X-Ray Telescope by the German Deutsches Zentrum für Luft und Raumfahrt from the Kapustin Yar facility in Russia. The mission lasted approximately three days, thanks to an accident involving an overcharged battery.

2003  –  Galaxy Evolution Explorer (GALEX) launched.

April 27 – Apollo 16 Returns Home (1972)

We have two spaceflight-related events today. The first is the splashdown of Apollo 16, about which I have written elsewhere. I’m mentioning it mainly to get this brilliant photograph in.

Apollo 16 Arrives (image: NASA)
Apollo 16 Arrives (image: NASA)

The second is from the other side of the iron curtain . . .

We have a birthday boy today, and it’s the man who has spent more time away from Earth on a single trip than anyone else in history. From 1994 to 1995 Valeri Vladimirovich Polyakov stayed aboard the Mir space station continuously for 437 days, completing over 7,000 orbits of the Earth.

Polyakov (born Korshunov – he changed his name when he was adopted by his stepfather) was born in Tula, Russia, on April 27th 1942, and studied at the I M Sechenov Medical Institute in Moscow, specialising in space medicine. This helped get him selected as a cosmonaut in 1972, although he didn’t get his first flight until 1988, a brief (by his standards) 240 days.

The main event, in 1994, also gave him the record for the longest total time spent in space, though this has since been broken. The purpose of such a long stint was to see how astronauts would react physically and mentally to a long-duration flight to Mars, and whether they would be capable of doing any decent work when they arrived. The results were promising, with no evidence of long-term performance problems following his return to Earth.

Polyakov retired from cosmonauting in 1995, and became deputy director of the Ministry of Public Health in Moscow.


April 21 – Discovrry of Asteroids 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 17 – Discovery of Asteroid 17 Thetis (1852)

Today’s lump of rock, asteroid 17 Thetis, was discovered in 1852 by yesterday’s birthday boy, Robert Luther.  It was the first asteroid he discovered.

Thetis is a main belt asteroid approximately 90 km across, with an absolute magnitude of 7.76 (apparent magnitude from 9.9 to 13.5).

Not a great deal is known about Thetis, but it is thought to be an “S-type” asteroid (the S stands for stony).   S-types are the second most common asteroids after “C-types” (C = carbonaceous).

Black figure hydria showing Thetis and the Nereids mourning Achilles
Black figure hydria showing Thetis and the Nereids mourning Achilles

Most references to Thetis (goddess of water)  in Greek literature relate in some way to her role as mother of Achilles, the greatest warrior of the Trojan Wars, but she did have some adventures of her own, most notably protecting Zeus from a plot to overthrow him by summoning Briarius, a friendly “Hekatonkheire”, Greek for “hundred-handed one” (and just in case that wasn’t frightening enough, they had fifty heads as well).

2014  –  NASA announced the discovery of Kepler-186F by the Kepler mission, which is using the “transit” method to discover exoplanets.   Kepler had already discovered hundreds of planets, but this was the first Earth-sized planet, orbiting a red dwarf, to be spotted.  The Kepler team believes that red dwarf stars could provide the majority of “habitable zone” planets, and Kepler-186F is on the edge of the host star’s habitable zone, in an orbit similar to that of Mercury.

Kepler-186F, is, unsurprisingly, orbiting a star known as Kepler-186.  This is an “M dwarf” (the Sun is a “G dwarf”) about 500 light years away.  M dwarfs are the most populous type of star in the known universe (7 out of 10 stars fall into this category, even though they can’t be seen by the naked eye). M dwarf stars are much dimmer than the Sun, and smaller, some being only 8% the mass of our star.

Comparison graphic for Kepler-186F (image: NASA)
Comparison graphic for Kepler-186F (image: NASA)

We should probably resist the temptation to get too excited about the possibility of life on Kepler-186F.  It is not known whether it has an atmosphere, and NASA are uncertain as to whether the planet is “tidally locked”, which would be unhelpful to life, or subject to flares from the parent star, which would be fatal.   However, NASA say that the differences between the conditions on Earth and K-186F don’t rule out the possibility of life.

1861  –  Asteroid 67 Asia discovered by Norman Robert Pogson.

1888  –  Asteroid 276 Adelheid discovered by Johann Palisa.  The origin of the name is not known.  There were probably a few Adelheids (and Adelaides) around at the time, but the most high-profile was Princess Adelheid of Hohenlohe-Langenburg, a niece of Queen Victoria.  Unfortunately I can’t find anything spectacular happening in her life in 1888.  Another posibility though, is Princess Helena Adelaide of Schleswig-Holstein-Sonderburg-Glücksburg, born in 1888 (the name Helena had already been taken for an asteroid discovered by  J C Watson in 1868).  Who can say?

1970  –  Splashdown of Apollo 13, following the scariest mission of the entire manned Apollo program.

View of the Moon from Apollo 13 (image credit: NASA).
View of the Moon from Apollo 13 (image credit: NASA).

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.  I have been completely unable to find any picture or photograph of Luther, which is annoying.

1756  –  Death of Jacques Cassini.

1972  –  Launch of Apollo 16.

April 13 – Launch of Discoverer 2 (1959)

Discoverer 2 was launched on April 13th, 1959 from Vandenberg Air Force Base into a 239 x 346 km polar orbit via a Thor-Agena booster. It was a large cylindrical satellite, 1.5 metres in diameter, 5.85 metres long, and a hefty 3800 kg, designed to gather data for use in future missions, and to attempt ejection of an instrument package from orbit for recovery back down here.  This part of the plan was attempted on 14 April 1959, when a reentry vehicle was ejected, with the idea that it would come down somewhere conveniently near Hawaii for recovery.  Unfortunately, due to a malfunction, reentry was over the north polar region, and the capsule remains officially unrecovered, although there are those who say Soviet agents got to it first.  It has been suggested that this episode was partly the inspiration for Alistair MacLean’s novel, Ice Station Zebra.

Discoverer 2 Recovery vehicle being attached to the Thor-Agena launcher (image credit: USAF).
Discoverer 2 Recovery vehicle being attached to the Thor-Agena launcher (image credit: USAF).

Discoverer 2 successfully gathered a great deal of data on propulsion, communication, and stabilization. It was the first satellite to be stabilized in all three axes, and the first to be maneuvered by commands from Earth.

1906  –  Discovery of asteroid 598 Octavia by Max Wolf.  Octavia is a C-type asteroid of approximately 72 km diameter.  It was named for the prominent Roman noblewoman Octavia the Younger, sister of the emperor Augustus, fourth wife of Marc Antony, and great-grandmother of Caligula.  Octavia’s marriage to Marc Antony only lasted a few years before he abandoned her in favour of an old girlfriend, Cleopatra VII of Egypt.

Virgil reading the Aeneid to Augustus and Octavia, by Jean-Joseph Taillasson (National Gallery, London).
Virgil reading the Aeneid to Augustus and Octavia, by Jean-Joseph Taillasson (National Gallery, London).

In today’s picture, supposedly an actual historical event, Octavia is seen swooning on hearing Virgil reading a passage from Book VI of the Aeneid.  The book contains details of the famous people encountered by Aeneas in the underworld, one of whom is Octavia’s son Marcellus (by her first husband), who had died at the age of nineteen.  The shock of hearing it is supposed to have caused Octavia to have fainted with grief.

April 11 – Piers Sellers: British Astronaut

Piers John Sellers was born today in 1955.  Who?  Good question.  Sellers is a member of a group even smaller than the one comprising people who have been to the Moon: he’s a British astronaut.   I know of only seven potential members of this community, and nearly all of those have dual nationality.

Piers Sellers: British-born astronaut (image credit: NASA)
Piers Sellers: British-born astronaut (image credit: NASA)

Because NASA only wanted Americans to fly their shuttles at the time (quite understandable) Sellers had to become a naturalized US citizen in 1991 in order to have his job application considered.  But, even so, he was born in Sussex, went to school in Kent, flew for the RAF and studied in Edinburgh.  So he’s still British.

Sellers made three shuttle flights: STS-112 (Atlantis, October 2002), STS-121 (Discovery, July 2006), and STS-132 (Atlantis again, May 2010). He spent over 35 days in space, and performed 6 EVAs (spacewalks).

1878  –  Asteroid 187 Lamberta was discovered by the Corsican astronomer Jérôme Eugène Coggia.  It was named after Johann Heinrich Lambert, the mathematician who proved that pi is an irrational number.  Lamberta is a carbonaceous (C-type) main belt asteroid of approximately 131 km diameter.

Asteroid 530 Turandot was discovered by renowned astrophotographer Max Wolf from his observatory in Heidelberg on April 11, 1904. It is an “F-type”, a spectral class very similar to the carbonaceous B-types, and classified with them in the C-group. According to IRAS data in the JPL Small-Body Database Browser, Turandot is approximately 85 km in diameter.

1970  –   You’ve probably seen the film, and there’s loads been written about it, so I won’t dwell on this, but today was the launch day, in 1970, of the ill-fated Apollo 13.

Apollo 13 Crew
Apollo 13 Crew

The crew of Apollo 13 were Jim Lovell (in his fourth and final spaceflight), Jack Swigert and Fred Haise (pictured in that order from left to right in the photo).