Wenceslaus Pantaleon Kirwitzer (ca. 1589–1626), a Jesuit priest from Kadan and member of the Collegium Romanum, passed through Goa during his journey to China. In 1618, he was among the 22 missionaries who set sail from Lisbon under the leadership of Nicolas Trigault (1577–1628). This group included renowned priest-astronomers such as Giacomo Rho (1592–1638), Johannes Schreck-Terrentius (1576–1630), and Adam Schall von Bell (1592–1666). They traveled equipped with telescopes, measuring instruments, and an impressive collection of books.
Arriving in Goa on October 4, 1618, they witnessed a rare celestial spectacle: two comets gracing the November skies, appearing one after the other. Recognizing the importance of these events, Kirwitzer sought assistance from fellow Jesuits; Fr. Jacobus Rho in Goa and Fr. Antonius Rubinus in Cochin. Together, they conducted observations at Collegio de Rachol, the island of Divar, and São Paulo’s College in Velha Goa. Though Kirwitzer used a telescope to study the comets, the precise type, whether a Galilean telescope with a mount or a hand-held version with draw tubes, remains uncertain. Other instruments, including the astrolabe and cross-staff, were also employed.
The first comet was tracked between November 10 and 30. Kirwitzer made his observations from Divar and Old Goa, while Fr. Rho contributed from Rachol and Old Goa. The second comet appeared on November 24, observed that very night by Fr. Terrentius in the fields of Rachol College, and continued to be visible until January 12, 1619. These Jesuit scholars carefully recorded data such as altitudes, azimuths, angular distances from bright stars like Spica, as well as their impressions of the comets’ appearance. They noted the challenges posed by moonlight and sunlight, which often hindered visibility. Their collected work was later published in 1620 under the title Observationes Cometarum Anni 1618, In India Orientali Factae a Societatis Iesu Mathematicis in Sinas Regnum Navigantibus by Schönwetter in Ursellis.
Interestingly, these same comets were also charted independently by Emperor Jahangir (1569–1627), the fourth Mughal ruler of India, using instruments such as astrolabes, sundials, clepsydras (water clocks), and sandglasses.
This moment holds profound significance: it not only marked the first documented telescopic observation in India but also established Goa on November 10, 1618, as the true birthplace of telescopic astronomy in the country, correcting the earlier misbelief that Surat held this honor. Consequently, Goa, with Rachol Seminary at its center, secured an enduring place in global scientific history.
The legacy continues today where modern Goan Jesuit scientist Fr. Richard D’Souza now advances global knowledge as a researcher at the Vatican Observatory. In fact, he gained international acclaim by discovering a long-lost sibling galaxy of the Milky Way. Fr D’Souza, 47, holds a doctorate in astronomy and has been part of the Vatican Observatory’s staff since 2016. His recent appointment as the new Director of the Vatican Observatory marks a proud moment for Goa and the global Jesuit scientific community, reflecting the Church's ongoing commitment to bridging faith and science.