January 19 – Launch of New Horizons (2006)

We have two quick asteroids to start us off today.  Asteroid 502 Sigune was discovered on January 19th 1903 by old hand Max Wolf at Königstuhl Observatory near Heidelberg.  On the same day, young whippersnapper Raymond Smith Dugan, also working at Heidelberg, discovered the second asteroid of his career, 503 Evelyn (named after his mother).


On January 19th 2006, NASA launched the New Horizons probe to Pluto, so long ago it was still a planet at the time (and always will be for some of us).  I clearly remember thinking back then that it was going to take such a long time to arrive that I’d probably have forgotten all about it, but here we are more than a decade later and the visit is now on the cusp of becoming a fond and fading memory.

New Horizons (image credit: NASA)
New Horizons (image credit: NASA)

New Horizons was a fairly large program by today’s standards, costing about $650m, which sounds expensive, but it’s actually only about $5 per US taxpayer, and spread over the 15 years of the project it’s a mere 33 cents a year: a bargain!  The mission has also visited Jupiter, and once Pluto had been passed there was a rendezvous with a Kuiper Belt Object in 2019.  The object chosen didn’t have a particularly catchy name at the time (2014 MU69), and was apparently also known in New Horizons circles as PT1 (and yes, it did stand for “Potential Target”).  PT1 later got the nickname Ultima Thule (it’s two planetesimals stuck together with one name each) but is now officially named 486958 Arrokoth.  From a typing point of view I think I prefer PT1.

The Jupiter flyby, as well as being a scientific mission in its own right, and a useful testing-ground for the instrumentation before an extended period of hibernation for the long journey to Pluto, was used to increase the speed of New Horizons by “gravity assist” to 9,000 miles per hour.  I think I’ll have to get myself one.  At that speed I could travel across the Atlantic to visit my friend Joanne in Arizona in about 20 minutes.

During the visit to Jupiter, New Horizons imaged the moon Callisto, and studied Jupiter’s ring system, magnetosphere, and the atmospheric conditions on the planet.

Calisto from New Horizons (image credit: NASA)
Calisto from New Horizons (image credit: NASA)

Scientific instruments on New Horizons are under the command of the Clyde Tombaugh Science Operations Centre in Colorado, and a small quantity of the ashes of the centre’s namesake, the man who discovered Pluto in February 1930, have been sent along for the ride.  Tombaugh died on January 17th 1997.

Imaging of Pluto using New Horizons LORRI imager began in January 2015. Hundreds of photographs were taken of the Pluto system, enabling navigators to fine tune Pluto’s exact position, and calculate the precise distance between New Horizons and its target.

And at the time we thought these images were pretty impressive; but they were nothing compared to what we got when the Pluto system was finally reached.

 

Pluto from the New Horizons probe (image credit: NASA/APL/SwRI)
Pluto from the New Horizons probe (image credit: NASA/APL/SwRI)
Surface detail of Pluto from New Horizons (image credit: NASA)
Surface detail of Pluto from New Horizons (image credit: NASA)
Pluto (image: NASA)
Pluto (image: NASA)
Charon (image: NASA)
Charon (image: NASA)
Nix (image: NASA)
Nix (image: NASA)

See what I mean?


1747Birth of Johann Elert Bode in Hamburg. The “law” named after Bode uses a formula to predict the distances of the planets from the Sun. It’s great for the first six, and was hailed a success when Uranus (a name suggested by Bode) was found in the right place. Unfortunately, the existence of the asteroid belt and Neptune were not part of the plan. Bode has a comet, an asteroid (998 Bodea) and a galaxy (M81, Bode’s Galaxy) named after him (though I suspect any inhabitants of M81 might disagree).


1965Launch of Gemini 2 from Cape Canaveral. This was an unmanned flight, but it did include a practice ingress (clambering in) and egress (being pulled out) by crewmembers of Gemini 3. Following two occasions on which the launch assembly had to be dismantled (for hurricanes Cleo and Dora) and an aborted launch on December 9th, 1964, the eighteen minute flight took place on the morning of January 19th, 1965, and was only slightly inconvenienced by a power outage at Mission Control caused by the electricity demands of the television coverage.


 

January 13 – Discovery of Asteroid 1999 AN10

Asteroid 137108, also known as 1999 AN10 was discovered on January 13th 1999 by the Lincoln Near-Earth Asteroid Research (LINEAR) project run by the USAF, NASA and MIT to discover and track near-Earth asteroids (NEAs).

On August 7th 2027, which is sooner than you think, it will zip past the earth at less than 250,ooo miles (that’s closer then the Moon) and should be visible in fairly modest binoculars.

1999 AN10 is part of the group known as the Apollo asteroids. These are a particularly interesting group for astronomers because they all have orbits which cross that of the Earth, making some of them potentially hazardous. The Apollos are named, as usual, after the first of their number to be discovered, 1862 Apollo, found in 1932 by Karl Reinmuth. The Chelyabinsk meteor that we all saw streaking across the Russian sky in February 2013 on dashcam footage is believed to have been an Apollo.


1901 – Discovery of asteroid 465 Alekto by Max Wolf. Alecto was one of the Furies of Greek mythology.


2003 – Launch of the Cosmic Hot Interstellar Spectrometer (CHIPS).


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 15 – Discovery of Saturn’s Moon, Janus (1966)

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, 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 – Birth of 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 12 – Launch of Uhuru (1970)

Uhuru, also known as the X-Ray Explorer Satellite or SAS-1 (for Small Astronomical Satellite) was an orbiting observatory, specifically for X-ray astronomy (the first of its kind). It was launched from the Italian San Marco offshore launch platform off the coast of Kenya on December 12th 1970, Kenyan independence day, hence the post-launch choice of a new name, which, as all good Star Trek fans know, is the Swahili for “freedom”. Its three year mission was to seek out new X-ray sources via a survey of the entire sky.

Uhuru (image credit: NASA)
Uhuru (image credit: NASA)

Uhuru was the first US satellite to be launched by another country.  Under the terms of a memorandum of understanding between NASA and the University of Rome, the Americans provided the rocket and satellite, while the Italians were responsible for the assembly and launch (following training with NASA in Virginia). The site was chosen principally to enable easier access to an equatorial orbit than would be possible from Cape Canaveral (which would have needed a much larger rocket).

The joint mission was very successful, with Uhuru producing a catalog of some 300 X-ray objects during its three years, mostly binary systems and supernova remnants.

 

December 04 – Launch of Gemini VII (1965)

We have slightly odd numbering here. Gemini 7 (VII) was launched on December 4th, 1965, after Gemini 5, but before Gemini 6A. Gemini 6 was obviously originally planned to go between 5 and 7, but had to be cancelled and rescheduled with an “A”.

The crew of gemini VII (Lovell, left, and Borman)
The crew of Gemini VII (Lovell, left, and Borman)

The plan for Gemini 7 was to observe the effects of prolonged spaceflight on astronauts. The two-man crew, Frank Borman and James Lovell, circled the globe 206 times during their two week confinement. After 11 days they were joined briefly by Walter Schirra aboard Gemini 6A, and practiced rendezvousing (at closest approach during their extra-atmospheric ballet they were just one foot apart).

Gemini, of course, is the constellation that lies between Cancer and Taurus in the sky (and therefore in the zodiac) and is historically associated with the twin brothers Castor and Polydeuces (or Pollux if you prefer the later Roman name). I prefer Polydeuces myself, because the translation is “much sweet wine”, which you just don’t get with “Pollux”. Castor, as any rodentologist will tell you, is Greek for “beaver”.

The Diskouri, in the Museum of Modern Art (image credit: Marie-Lan Nguyen)
The Diskouri, in the Museum of Modern Art (image credit: Marie-Lan Nguyen)

The twins now immortalized in the heavens were collectively known to the Greeks as the Diskouri, or “sons of Zeus” (the noun Gemini is from Roman mythology). They also had twin half-sisters, even more famous than themselves: Helen (of Troy) and Clytemnestra.

December 02 – Launch of SOHO (1995)

Built in Europe, the Solar and Heliospheric Observatory (SOHO) was launched on December 2nd, 1995 and, despite being planned as a two year mission, it is still going, with the latest predicted end date being in 2020. It is a joint project between ESA and NASA, built by Matra Marco I Aerospace, and designed to provide data to help predict solar weather, and answer questions about the solar interior, solar wind, and why the corona is so hellishly hot. The mission has been a great success, providing significant insights into such areas as the structure of sunspots, the flow of gases inside the Sun, and the dynamics of the solar wind.

Prominence spotted by SOHO (image: ESA / NASA)
Prominence spotted by SOHO (image: ESA / NASA)

In addition to all this, SOHO has still found time to become history’s greatest ever discoverer of comets, with the total ticking over to an astonishing 3000 on September 13th 2015. Comet number 3000 was spotted by Thai astronomer Worachate Boonplod, part of an amateur army of spotters who betwen them have been responsible for the majority of SOHO discoveries.


The Broad Band X-ray Telescope (BBXRT) was launched today (1990) on board shuttle Columbia flight STS-35. It formed part of the partly-successful “ASTRO-1” payload of four instruments.

In-flight view of BBXRT (image: NASA)
In-flight view of BBXRT (image: NASA)

The mission was somewhat shorter than the previously-mentioned SOHO, as the telescope was attached to the shuttle, and had to go wherever it went (back to Earth).

November 29 – Launch of Mercury-Atlas 5 (1961)

Mercury-Atlas 5 is classed as an unmanned flight, launched from Cape Canaveral on November 29th, 1961. And yes, I suppose that it was technically unmanned, because there were no men on board. But there was an astronaut, and that astronaut was male.

ENOS in his launch position. (Image: NASA)
ENOS in his launch position. (Image: NASA)

Enos, pictured above, was the second chimpanzee to fly into space, and the first to orbit the Earth. The idea behind Enos’ trip was to stage a flight that would be as close as possible to the planned MA-6 launch, but without the less-expendable John Glenn.

Enos survived his odyssey, but it was touch and go. A problem with the environmental controls made it rather warmer than planned in the capsule, and fuel consumption concerns led to the intended three orbits being curtailed at two.

The World’s most traveled chimp lived for just under a year following his triumphant return to Earth, and died of dysentery on November 4th, 1962. It is not known what became of his remains. And if you still think I’m being silly, sentimental and anthropomorphic by suggesting that MA-5 should be called a manned trip, the name Enos (a biblical name, one of the grandchildren of Adam and Eve) means “man”.

November 20 – Launch of Swift (2004)

The Swift Gamma Ray Burst Explorer was launched on November 20th 2004 by NASA as part of their medium-sized “MIDEX” program.  Now the first thing you’re probably thinking is “why isn’t the name Swift in capital letters?”  The answer is that Swift is not an acronym.  It doesn’t mean anything (except that you’re supposed to think of a small, fast bird).

Swift (image: NASA)
Swift (image: NASA)

If you look at some of the early press releases about Swift, NASA were hopeful that it would last for the duration of its two year mission, and survey over 200 gamma ray bursts (GRBs).  Now, 11 years later, and with over 1000 GRBs under its belt, Swift has exceeded all expectations and is still going strong.

Gamma rays are extremely high frequency emissions formed by the decay of atomic nuclei, and a burst of gamma rays is exactly what it sounds like: in a Universe where most things happen over millions of years, GRBs are astoundingly quick.  Slow ones can take a couple of hours; but the quickest have been and gone in a few milliseconds.  Also, there are only a few every million years in an average galaxy, which you might think would make them hard to spot, but fortunately they are so unbelievably powerful that the energy has no problem travelling the millions or billions of light years between the source and the detectors on board Swift.

One of Swift's collection: GRB 090429B, 13 billion light years away (image: NASA)
One of Swift’s collection: GRB 090429B, 13 billion light years away (image: NASA)

Swift has observed some pretty unusual events over its lifetime, including the most distant GRB ever seen, an x-ray source right in the centre of the galaxy, and a two-week long blast of stellar flares from a red dwarf reckoned to be 12 times hotter than the centre of the Sun.