125 years of Kodaikanal Solar Observatory: How the Great Drought of 1876 led to its establishment

125 years of Kodaikanal Solar Observatory: How the Great Drought of 1876 led to its establishment

Subject: Science and tech

Section: Space tech

History of Observatories  in India:

• In 1792, the British East India Company established the Madras Observatory, a first of its kind in this part of the world.
• Astronomical observations of the Sun, the Moon, bright stars and planets recorded during 1812-1825 were preserved in two large data volumes.
• The first dedicated solar observations were recorded later in 1878 from the Trigonometrical Survey Office in Dehradun.
• The spectroscopic observations taken during the August 18, 1868, total solar eclipse from Guntur in Andhra Pradesh led to the discovery of helium, the Universe’s second-most abundant element after hydrogen.
• For the first time, celestial and solar photography were attempted from the Madras Observatory during the total annual solar eclipse on December 12, 1871.

Links to the Great Drought:

• India, along with China, Egypt, Morocco, Ethiopia, southern Africa, Brazil, Columbia and Venezuela, suffered concurrent multi-year droughts during 1876-1878, later named the Great Drought, and an associated global famine that killed nearly 50 million.
• Based on the evidence that solar activity was linked to the seasonal rainfall distribution over India, the specially constituted Famine Commission of the British Raj recommended that the Government of India take regular solar observations.

Why study the Sun?

• Being the primary source of energy, life on Earth is supported by the Sun. 
• Any change on the solar surface or its periphery could significantly affect the Earth’s atmosphere. 
• Powerful solar storms and solar flares can be potentially harmful to Earth’s satellite-based operations, power grids and navigational networks.
• The KoSO (Kodaikanal Solar Observatory), which has been imaging the Sun for over a century now, has a rich repository of data.

Solar Physics Observatory in Palani Hills:

• The Indian solar observatory was established for carrying out systematic examinations and the study of changes in progress in the Sun and their co-relations with the larger features of Indian meteorology.
• The hills of Leh, Mussoorie and Shimla were rejected for being dusty and cloudy and the atmosphere around them being unstable.
• Hill stations located over 2,000 meters above the mean sea level in Tamil Nadu i.e. Kodaikanal in the Palani hills and Kotagiri in the Nilgiris were surveyed.
• The survey of rainfall, cloud cover and sky transparency, haze, atmospheric stability, humidity, fog and mist was completed and Kodaikanal was chosen as the ideal location for the observatory.
• In August 1893, the Government of India sanctioned a Solar Physics Observatory under the meteorological budget.
• In 1895, Lord Wenlock, the then Governor of Madras, laid its foundation stone.
• Supervised by Smith, who went on to become the first director of the renamed Kodaikanal Solar Observatory (KoSO), the ongoing civil construction picked pace.
• The Madras Observatory  was merged with the KoSO following the reorganization of all Indian observatories implemented by the Government of India on April 1, 1899. 
• The Bhavnagar Telescope, named after Maharaja of Bhavnagar, operated during KoSO’s nascent years. 
  • This 16-inch Newtonian (later Cassegrain) mobile telescope remained India’s largest from 1888-1968. It was imported from Dublin, Ireland, and was first established at the Maharaja Takhat Singh Ji Observatory in Poona (now Pune) around 1888.
• The radial motion of sunspots, better known as the Evershed Effect, was discovered from the sunspot observations made at KSO by John Evershed.
• The continuous recording of the solar radio noise flux commenced in 1952 is considered the earliest solar radio observations in the country.
• The contemporaries – Maharaja Takhat Singh Ji Observatory, Lucknow Observatory, and Calcutta Observatory – did not stand the test of time.

KoSO @125:

• The Government of India separated Astrophysics from the India Meteorological Department (IMD) in April 1971. 
• The KoSO was brought under the Indian Institute of Astrophysics (IIA), Bengaluru on April 1, 1971.
• KoSO is the only observatory offering high-resolution digitized images for such a long period (with coverage of more than 75 per cent).
• It houses a spectrum of advanced instruments like the H-alpha telescope to perform full disc imaging, a White light Active Region Monitor (WARM) with calcium and sodium filters to make full disc simultaneous observations of the photosphere and chromosphere layers of the Sun, a solar tunnel telescope and more.

What is Evershed Effect:

• The Evershed Effect is an observational effect in the penumbra of SUNSPOTS consisting in displacements of the spectral line profiles towards either shorter wavelengths (that is, blueshifts) in the zones closest to the Sun’s disk center or larger wavelengths (that is, redshifts) in those zones closest to the solar limb.
• The Evershed effect was first detected at Kodaikanal observatory in January 1909.

About Kodaikanal Hills:

• Kodaikanal is a town and hill station in Dindigul district in the state of Tamil Nadu, India. 
• It is situated at an altitude of 2,225 m (7,300 ft) in the Palani hills of the Western Ghats. 
• The earliest references to Kodaikanal and the Palani hills are found in Tamil Sangam literature.
• Kodaikanal Lake  also known as Kodai Lake, is a manmade lake located in the Kodaikanal city in Dindigul district in Tamil Nadu, India.