Astronomers unravel mysteries of Pluto using India's largest optical telescope
A team of Indian and international scientists has made several key revelations about Pluto—the dwarf planet which was demoted from the status of a full-fledged planet over 16 years ago. The researchers, hailing from India, Brazil, and France, claim to have derived an accurate value of Pluto's atmospheric pressure, besides making other discoveries. Here are some key takeaways from the study.
The atmospheric pressure on Pluto was found to be 12.23 µbar, which is over 80,000 times less than the value on Earth. The scientists observed a stellar occlusion, an event where a planet coming in the way of a bright star is viewed from Earth. This was done on June 6, 2020, through the Devasthal optical telescope—India's largest telescope, and Devasthal Fast Optical Telescope.
"An international team of scientists...used signal-to-noise ratio light curves obtained from the sophisticated instruments used in the observations to derive an accurate value of Pluto's atmospheric pressure at its surface," read a statement from the Ministry of Science & Technology. "It was found to be 12.23 µbar (unit of pressure), 80,000 times less than the atmospheric pressure at mean sea level on Earth."
The study, published in the Astrophysical Journal Letters, said there had been a three-fold increase in the atmospheric pressure on Pluto between 1988 and 2016. "This increase can be explained consistently by a Pluto volatile transport model, which predicts that the pressure should peak around 2020. A gradual decline should then last for two centuries," according to the paper.
The study also confirmed earlier findings that Pluto suffers intense seasonal episodes due to a large depression known as Sputnik Planitia. "Pluto's poles remain, for decades, in permanent sunlight or darkness over its 248-year long orbital period leading to strong effects on its Nitrogen atmosphere that is mainly controlled by vapour pressure equilibrium with the surface Nitrogen ice (sic)," researchers said.
"As Pluto is now moving away from the Galactic plane as seen from Earth, stellar occultations by the dwarf planet are becoming increasingly rare, making this event a decisive one," the statement added. Reportedly, the Indian set of researchers included experts from the Aryabhatta Research Institute of Observational Sciences-Uttarakhand, Physical Research Laboratory-Ahmedabad, and the Indian Institute of Space Science and Technology-Thiruvananthapuram.