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)



October 22 – Asteroid 209 Dido

Asteroid 209 Dido, discovered by C H F Peters on October 22nd 1879, is a large, C-type main belt asteroid with a very low albedo.  It is about 140 km (87 miles) in diameter, and completes one rotation every eight hours of its 2039 day journey around the Sun.

Dido was the mythological queen and founder of Carthage, and sister of Pygmalion (the guy who fell in love with a statue he had carved).  She is best known for (i) her affair with Aeneas, the Trojan hero, and (ii) being the subject of an opera by Henry Purcell.

Guercino's "Death of Dido" (1631)

Guercino’s “Death of Dido” (1631)

Today’s artistic offering is by Giovanni Francesco Barbieri (1591 – 1666), the self-taught, cross-eyed, fast painting Italian genius, more commonly known as Guercino (meaning “squinter”), responsible for more than 100 altarpieces and nearly 150 paintings.

1969  ⇒ Splashdown of Apollo VII, the first manned Apollo mission.

1905  ⇒ Birth of Karl Jansky, one of the founding fathers of radio astronomy.

October 04 – Sputnik 1

Sputnik 1, the world’s first artificial satellite, was launched by the USSR on October 4th 1957, straight into the history books. It was launched from what is now the Baikonur Cosmodrome into a low orbit, and transmitted simple radio signals (basically just beeps) back down to anyone who cared to listen (plenty did, including Jodrell Bank, just up the road) as it orbited the Earth every 96 minutes. This continued for 26 days, after which the batteries were flat. About eight weeks later Sputnik re-entered Earth’s atmosphere and was burned to a crisp.

Sputnik 1 (replica)

Sputnik 1 (replica)

The original Soviet plan had been for a much larger satellite, known by the working name Object D. Unfortunately though, the number one priority of the Soviet space agency at that time was not to draw gasps of astonishment from the world’s scientists with a complex marvel, bristling with useful experiments, but to fling any old thing up there as long as it was before the Americans. So they went for the simplest shape (a 2-foot wide sphere with 4 antennae sticking out the back) and downsized to an easily launchable 83kg weight.  Object D wasn’t forgotten though, and eventually became Sputnik 3.

Sputnik 1, being quite diminutive, would have been hard to spot from down here, but fortunately it was part of a convoy of three objects. The actual satellite itself was sandwiched between the nose cone that had protected it before separation, and the much larger (and therefore much brighter) second stage rocket booster.

Also today, asteroid 50 Virginia was discovered by James Ferguson in 1857 from Washington DC. It may have been named after the Roman noblewoman Verginia, but then again it may not. The jury is still out.

1885  –  Discovery of asteroid 251 Sophia by Johann Palisa, and named after the wife of Hugo von Seeliger, Professor of Astronomy at the University of Munich.

1959  –  Launch of Luna 3, the first mission to photograph the far side of the Moon.

Other asteroid discoveries today include 650 Amalasuntha (queen of the Ostragoths) and 651 Antikleia (mother of Odysseus), both spotted on October 4th 1907 by prolific asteroid hunter August Kopff of Heidelberg.

September 29 – OSO-7

The Orbiting Solar Observatory 7 (OSO-7 ) was the seventh of eight similar satellites, and was launched on September 29th 1971, straight into a drama, when a problem with the second-stage guidance system left it in an unplanned orbit, and pointing in unexpected directions. Fortunately, John Thole at NASA (who we might well come across again in connection with Echo 2) managed to get the mission back on course with a mix of skill and luck, saving the day. I can’t imagine how he must have felt, slewing this huge craft around from so far away he couldn’t even see it. It’s bad enough when your spaceship is made by Nintendo and you get to start again if you crash.

OSO-& (image credit: NASA)

OSO-& (image credit: NASA)

OSO-7, like its brethren, came in two main parts, known as the “sail” and the “wheel”. The sail faced the Sun (during its day) and measured solar x-rays and coronal activity. The wheel, as the name suggests, rotated continuously, measuring solar x-rays and cosmic x- and gamma-rays. The spinning of the wheel, combined with the axial movements that kept the sail pointing at the Sun, allowed two of the wheel-based experiments to cover the whole sky every six months.

OSO-7 re-entered the Earth’s atmosphere on July 9th 1974.

ALSO TODAY . . . .

1884  —  Discovery of asteroid 243 Ida by Johann Palisa.  Ida has been visited by the Galileo spacecraft.  Thanks to Galileo, we have pretty good photographs of Ida, and we now know it has a small companion, Dactyl.

Ida and Dactyl, courtesy of Galileo (image: NASA/JPL)

Ida and Dactyl, courtesy of Galileo (image: NASA/JPL)

Dactyl is pretty teeny, measuring just over a kilometre across in most directions. The name comes from a race of mythical beings who inhabited Mount Ida in Crete.  They are credited with discovering how to use fire to work metal.

1962  —  Launch of satellite Alouette 1.

1988  —  Launch of shuttle mission STS-26 (“Discovery“).

July 26 – Apollo 15

Today in 1971David ScottJames Irwin and Alfred Worden became the first philatelists in space.  Their attempt to smuggle unauthorised postage stamps to the Moon and back to be sold later did rather put a bit of a downer on the reputation of the fourth Moon landing, which was a shame, because the mission (including the first use of the lunar rover), was otherwise a great success.

Apollo 15 crew (image credit: NASA)

Apollo 15 crew (image credit: NASA)

Apollo 15 was the first to land somewhere other than a lunar mare, and was longer than previous visits, with over 18 hours spent outside the lunar module.  The landing site chosen for Apollo 15 was Hadley Rille, a valley to the southwest of Mons Hadley, a ‘massif’ in the Moon’s northern hemisphere.

1958 – launch of Explorer 4. Launched this day in a blaze of secrecy, Explorer 4 spent the summer of 1958 collecting data on the Van Allen radiation belts. The Explorer family is the longest running series of spacecraft ever, from Explorer 1 in 1958 to Explorer 78 in 2000.

July 21 – Small Step; Big day

July 21st 1969 is going to take some beating as far as big days go.  I’ve been thinking about it, and it’s just really obvious that nobody has ever done anything even remotely as impressive as walking on the Moon.  The more one thinks about it, the less likely it seems that it was even possible with 1960′s technology (don’t forget that the processors used in the guidance system were smaller than the ones available in home computers just a decade later, and my android phone is obviously from a different planet).

Pretty big shoes to fill (image credit: NASA)

Pretty big shoes to fill (image credit: NASA)

Maybe something to top it will come along eventually (the first gay pope to visit  Mars, maybe?) but in the meantime, here are a couple of other events being commemorated in the enormous shadow thrown by Neil Armstrong’s boots.

1914  –  Discovery of Jupiter’s moon Sinope by S B Nicholsonwhile he was working as a summer assistant at Lick Observatory.  The ninth satellite of Jupiter to be spotted, Sinope was, as I say, discovered in 1914, but didn’t receive a proper name until 1975; until then it was simply “Jupiter IX”.  It was named, along with eight other moons, “on the recommendation of the Working Group for Planetary System Nomenclature” of the IAC.  Nicholson’s discovery was slightly serendipitous, as he was actually photographing “Jupiter VIII” at the time with the 36-inch British-built Crossley Reflector, a device the observatory had bought from it’s previous owner when it became obvious that the skies above Halifax, England, were a waste of a large telescope.

1998  –  RIP Alan Shepard.  Shepard (another of the Mercury Seven) was, as commander of Apollo 14, the fifth man on the Moon, and the first to play golf there.  It’s perhaps just as well that the Americans conquered the Moon.  I doubt the effect would have been quite the same when the first Briton on the surface got his dartboard out.

1961  – Launch of MR-1, the first unmanned spacecraft of the Mercury project.  A spectacular failure, it managed to attain an altitude of four inches in a flight lasting 2 seconds.

2006  –  Discovery of Actaea, the satellite of trans-Neptunian object  120347 Salacia.

July 20 – Sea of Activity

Today was a very big day in 1969, as it was the day on which, at 17 minutes past 8 in the evening, Neil Armstrong and Buzz Aldrin (but not Michael Collins) landed their lunar module in the Sea of Tranquility, becoming the first humans to land on the surface of the Moon.

Apollo 11 Crew (image credit: NASA)

Apollo 11 Crew (image credit: NASA)

There has been a great deal written and said about this event, with which I won’t attempt to compete. I will just say that although the intrepid moon men brought back 21.5 kg of lunar material, the main impact of their visit from the Moon’s perspective was to leave behind several tonnes of extremely expensive scrap metal.

Tranquility from the window of the Lunar Module (image credit: NASA)

Tranquility from the window of the Lunar Module (image credit: NASA)

The Sea of  Tranquility (Mare Tranquillitatis), once thought to be an ocean on the Moon, is a large basalt basin, probably produced by a lava flow following the impact of something quite large, at the time of the Pre-Nectarian epoch, meaning it was formed before the Mare Nectaris.  The Pre-Nectarian doesn’t really have an equivalent epoch on Earth, because any rocks of a similar age down here would long ago have been sucked back below the surface to be recycled.

Looking towards home from Apollo 11 landing site (image credit: NASA)

Looking towards home from Apollo 11 landing site (image credit: NASA)



July 09 – Voyager 2 Reaches Jupiter

July 9th 1979 was, I remember, an exciting day, and one I’d been looking forward to for years.  It was the day on which Voyager 2 got to within a cosmic whisker (350,000 miles) of Jupiter.

Jupiter from Voyager 2 (image credit: NASA)

Jupiter from Voyager 2 (image credit: NASA)

Several important discoveries were made during and after the approach, including three new moons (AdrasteaMetis and Thebe), the unexpectedly prolific volcanicity of Io, and several new rings to add to the Jovian collection. Jupiter’s rings are hard to spot at the best of times, as they are composed mostly of dust from the small moons Amalthea, Thebe, Metis and Adrastea.

Jupiter's Great Red Spot (and the less great White Oval) from V2 (image credit: NASA)

Jupiter’s Great Red Spot (and the less great White Oval) from V2 (image credit: NASA)

Asteroid 199 Byblis was discovered by C H F Peters, named after a daughter of Miletus, who, according to Ovid, fell in love with her twin brother and chased him all over Greece.  A little bit unusual, even by the standards of Greek gods.

"Biblis" (William-Adolphe Bouguereau, 1825-1905)

“Biblis” (William-Adolphe Bouguereau, 1825-1905)

July 08 – Adrastea

Adrastea, the second moon out from the “surface” of Jupiter, was discovered by analysis of Voyager 2 images in 1979 by David C Jewitt and G Edward Danielson.  A subsequent photograph is available (the Voyager one was of a tiny speck) taken by the Galileo spacecraft, and here it is, looking more like an out-of-focus lemon than a moon . . . .

Adrastea (image credit: NASA)

Adrastea (image credit: NASA)

Adrastea is like the Earth’s Moon, in that it always keeps one face pointing towards the parent planet, but it has an unusual orbital period of 7 hours 9 minutes, which is about two hours less than one Jovian day, even though Jupiter has the fastest rotation of all the planets (which accounts for its easily visible bulge).  Only a very few moons do this (three are known, the others being Metis and Mars’ moon Phobos).  As I mentioned two days ago, we can tell without looking it up that Adrastea will have a prograde orbit, because it ends with an “a”.

Metis and Adrastea share another unusual fact in common.  They orbit too close for comfort to their parent, meaning that at some point in the future they will impact the planet.

In Greek mythology, Adrasteia was the nymph who had to nurse Zeus and hide him from his father, Kronos.  Her name means “inescapable”.

1695   –   Death of Christian Huygens.

1959   –   Launch of Explorer 6.

2011   –   Final launch of shuttle Atlantis (flight number STS-135).

July 03 – SAMPEX

SAMPEX was the Solar Anomalous and Magnetospheric Particle Explorer. It was launched on July 3rd 1992 from Vandenberg Air Force Base in California on a Scout Rocket (and was RIP Nov 13, 2012).

SAMPEX (image: NASA)

SAMPEX (image: NASA)

SAMPEX’s instruments were far more sensitive than those of previous similar missions, which allowed a great deal of new information to be gathered on the composition of interstellar gas, the mechanism of solar atmospheric heating and the relative abundance of various isotopes.

As you can see from the photograph, SAMPEX was quite dinky.  This is because it was an early success of NASA’s Small Explorer Program, or SMEX. (Why not SEX? They could have improved their hit rate on Google by loads.)

SMEX funds projects costing no more than $120m.