Thammasat University students may have noticed international media reports that on Monday, December 21, the planets Jupiter and Saturn will line up to as double planet for the first time since Middle Ages, according to astronomers.
When the sun sets on 21 December – the winter solstice – people looking into the sky will see Jupiter and Saturn closer than they have been for some 800 years.
The Thammasat University Library owns several books about astronomy and the planets.
In addition, students in the humanities who are not specialists in science may wish to visit the Rewat Buddhinan Audiovisual Center on the Underground 2 level of the Pridi Banomyong Library, Tha Prachan campus. There they may listen to an orchestral work, The Planets, written by the English composer Gustav Holst.
The Planets is a seven-movement orchestral suite written between 1914 and 1916. Each movement of the suite is named after a planet of the solar system and its corresponding astrological character as defined by Holst.
From its premiere to the present day, the suite has been popular, influential, widely performed and frequently recorded.
As one online description of Holst’s music about Jupiter describes it,
Jupiter, the Bringer of Jollity
As the round-faced cheery uncle of all the planets, and king of the gods, Jupiter is impressive and majestic. The swelling brass and slow waltzing strings are met with moments of poignant beauty in the glorious tune now known as ‘I Vow to Thee My Country’.
This is followed in the suite by Saturn, the Bringer of Old Age:
A favourite movement of Holst’s, Saturn is quite a shift from the positive music heard in Jupiter. The opening is slow and almost unsettling, until the music expands into a heavy march.
As scientists have explained, the opportunity on December 21 to see the two planets so close together is unusual, although they do approach one another every 20 years or so.
They will be separated by less than the width of a full Moon and will look like a double planet.
The best time to look for this phenomenon will be about one hour after sunset – when the planets will appear low in the western sky.
For any students who are too busy to see the planets on December 21, there will be another opportunity in the year 2080, when today’s students will be quite old. But after that, it will not happen again until after the year 2400.
Some observers are referring to this lining up as a Christmas Star. Since the planets will seem to almost collide, becoming one bright point of light, they will look like a double planet.
Another term for this phenomenon is a conjunction, or alignment, of the planets. Since Jupiter and Saturn are the largest gaseous bodies in the solar system, experts call it a Great Conjunction.
The noun conjunction means a joining or meeting of individuals or distinct things. The term was originally developed to describe how planets or stars appear to meet in the same part of the sky. The term conjunction derives from a Latin word meaning to join together.
Thailand and the Great Conjunction
TU students are familiar with the National Astronomical Research Institute of Thailand (NARIT) a research institute under the Ministry of Higher Education, Science, Research and Innovation. Its main missions are to carry out, support, and promote the development of astronomy and astrophysics in Thailand through research, public outreach, and educational activities.
NARIT was first established in 2004 as NARI (National Astronomical Research Institute), a statutory government institute under the Ministry of Science and Technology, to commemorate His Majesty the King Bhumibol Adulyadej’s 80th birthday. On 27 December 2008, the status of NARIT was changed to a non-profit governmental public organization.
The Thai National Observatory (TNO) is NARIT’s main facility, atop Thailand’s highest mountain, Doi Inthanon in Doi Inthanon National Park, Chom Thong District, Chiang Mai Province.
In 2020, NARIT completed the construction of the Thai National Radio Telescope (TNRT), a 40m single-dish short-millimetre telescope in Huai Hong Khrai Royal Development Study Centre at Doi Saket District in Chiang Mai Province.
Astronomy in the Kingdom
As a Siam Rat webpage explains, there is a long history of astronomy in Thailand, dating back to the 1600s, when Siamese ambassadors to Holland learned about the new invention of the telescope:
These Siamese ambassadors were still at the Dutch court two weeks later when Lipperhey arrived with his telescope. The Siamese would undoubtedly have heard about and very possibly seen first hand the world’s first telescope.
Dutch Surveying in Siam
The Siamese ambassadors returned to Siam after 17 months in Europe but surviving records do not tell us what they reported upon concerning their journey. But we do know that within a few years telescopes had arrived in Siam itself. The Ayutthaya Chronicles record that during the reign of King Songtham (r.1611 – 1628), a footprint of the Buddha was discovered in rocks near Saraburi. The king ordered a temple to be built at the site, called naturally Wat Phra Phuttabat (Temple of the Buddha’s Footprint).
King Songtham ordered two brigades of farangs “to survey and cut a wide passage for a land route all the way straight to the boat landing, to cut down the jungle with knives and to pound the surface level so it was pleasingly smooth to form a finished imperial highway.” In order to make the road as straight as possible a Dutch engineer with a telescope was employed to survey the construction route by climbing tall trees to take sightings of the mount where the footprint was located.
This 20km stretch of straight road between Tha Rua on the Pasak River and Wat Phra Phuttabat still exists, officially called King Songtham Road. The locals however, still know it as “Thanon farang song klong” or “Foreigner looking through a telescope road”.
Diplomatic Astronomy
Eight decades after those first ambassadors had traveled from Ayutthaya to Europe, diplomatic relations were reaching a splendid peak as the court of King Narai exchanged numerous embassies with the courts of Europe, especially that of King Louis XIV of France. In September 1685 the first of Louis XIV “great embassies” arrived in Siam…
The French ambassadors and the Jesuit astronomers followed the king to Lop Buri where the Jesuits prepared to observe a lunar eclipse predicted for the 11th December. Initially they were lodged in a bamboo house where they quickly found that constant vibrations caused havoc with their pendulum clocks and carefully positioned telescopes. But on 10th December the king invited the Jesuits to join him at his “country retreat”, a palace now known as Kraison Siharat Palace, then located on a peninsula within a large reservoir outside of Lop Buri city.
The Jesuits set up their equipment on “the water terrace” beside the reservoir. A 1.5 metre telescope was set up for the king’s use whilst the Jesuits set up other telescopes for their scientific observations. The lunar eclipse commenced about 3am at which time the king was called to join the observations. The king soon requested to look through a longer 3.5 metre telescope being used by one of the priests. In order to move and adjust this telescope for the king it was necessary for the priests to stand in the royal presence, an exceptional honour which all those present noted.
King Narai had long been interested in scientific and technical knowledge and he clearly enjoyed his observations of the lunar eclipse, commenting on the spots (i.e. craters) seen on the moon and engaging the Jesuits with many questions about the observations and what could be learnt from them.
The 1688 Solar Eclipse
Following the great success of the 1685 observations, King Narai was readily persuaded to erect an observatory building similar to that in Paris. Furthermore, when just a few days later the French ambassadors embarked for the return journey to France he wrote a letter to King Louis XIV inviting him to send more Jesuit missionary-astronomers. King Louis XIV obliged by sending sixteen new Jesuits to Siam, these arriving in late September 1687. On their arrival they were greeted by the original Jesuit contingent and at Lop Buri they admired the newly constructed Wat San Paulo observatory…
(All images courtesy of Wikimedia Commons)