Scientists obtain an accurate value of the atmospheric pressure of Pluto on the surface
A team of scientists, including Indian and international collaborators, have derived the precise value of Pluto’s atmospheric pressure on its surface. It is more than 80,000 times lower than atmospheric pressure at mean sea level on Earth.
The pressure was calculated from data obtained by observing the stellar occultation of Pluto on June 6, 2020 using the 3.6m Devasthal Optical Telescope (DOT) (the largest optical telescope in the world). India) and 1.3m Devasthal Fast Optical Telescope (DFOT) telescopes located in Devasthal, Nainital.
In astronomy, an occultation occurs when a celestial object is hidden from view by the observer due to another celestial object passing between them. A compilation of twelve stellar occultations by Pluto observed between 1988 and 2016 showed a monotonous triple increase in atmospheric pressure during this period.
An international team of scientists, including members of the Aryabhatta Research Institute of Observational Sciences (ARIES), used bright signal-to-noise ratio curves obtained from the sophisticated instruments used in the observations to derive an accurate pressure value. atmosphere of Pluto on its surface. It turned out to be 12.23 μbar, which is 80,000 times less than atmospheric pressure at mean sea level on Earth. They also found that the surface pressure is near Pluto’s seasonal peak.
Research published in ‘Astrophysical Journal Letters (ApJL)’ has shown that since mid-2015, Pluto’s atmosphere has been in a near-peak plateau phase and is in excellent agreement with model values calculated earlier by the volatile transport model of Pluto in 2019. The team further explained that this occultation was particularly timely because it can test the validity of current models of the evolution of Pluto’s atmosphere.
The study also confirms previous findings that Pluto suffers from intense seasonal episodes due to a Great Low on Pluto, known as Sputnik Planitia. Pluto’s poles remain, for decades, in permanent sunlight or darkness during its long orbital period of 248 years, resulting in strong effects on its nitrogen (N2) atmosphere which is mostly controlled by vapor pressure equilibrium with surface N2 ice. Moreover, as Pluto now moves away from the galactic plane as seen from Earth, stellar occultations by the dwarf planet are becoming increasingly rare, making this event a watershed event.
(With GDP entries)