PRL CONFERENCE ON PLANETARY ATMOSPHERES DURING JULY 12,13th 2010

“The diversity of the phenomena of nature is so great, and the treasures hidden in the heavens so rich, precisely in order that the human mind shall never be lacking in fresh nourishment."
(Johannes Kepler)

One of the most wondrous and noble questions in this world is whether we are alone in this Universe or we are just one example of a much vaster and more varied tapestry. It seems desirable for us to inquire about exoplanets and civilisations outside our solar system. The thirst for planetary Observation and astronomy started with refracting telescopes when scientists pointed their telescopes to the sky and said “O telescope! Instrument of knowledge, more precious than any sceptre!”. Such dearest illusions took a dynamic form when men first set foot on Moon and enjoyed the Magnificent Desolation. From the days of Apollo to the current Mars science Laboratory and Kepler mission, we have studied and identified planets of many masses, varied atmospheres and extremely different Climatic conditions. Though we couldn’t conclude on life outside our Planet Earth or anywhere in our solar system, the data from these missions have made a big difference in how we look for evidence to answer the question of life. Thanks to Kepler team which has archived its data for the researchers around the world.

I had been enduring to write about a conference which I attended on ‘Planetary Atmospheres’ in Physical Research Laboratory, India during July 2010. It’s been very long, still, worth preserving the ideas. It was a wonderful and constructive meet which triggered the dream charge of many young researches to work in ‘Planetary science’. I have discussed here the crux of some striking lectures which engaged my interests during this conference.

First day of the conference was focussed on Terrestrial Planets, their evolution, present state of Knowledge, Atmospheric Escape and Magnetic field in those planets. The discussion on Colonization of Mars by Prof.U.R.Rao by melting the Polar Ice was my favourite lecture during this session. Martian Ionosphere was the most spoken topic. MARSIS sounding techniques revealed the peak electron density variations in Martian Upper Atmosphere due to dust storms in the neutral Atmosphere. The radio occultation experiments have derived a direct proportionality between peak electron density and solar zenith angle.

Comparative studies fostered both exploration and synthesis within diverse settings of Mars, Venus and Earth. Some fascinating similarities amongst these terrestrial planets include O+ ion flow, hot oxygen Corona and common dominant photo electron peak in Mars and Venus. The Photo e- peaks in Mars and Venus occur near tail unlike Earth where it occurs in Magnetosphere. The dominant composition of Martian Atmosphere and Venusian Atmosphere is Carbon-di-oxide. Yet, the current extreme and contradicting temperature in these planets digs questions about their Evolution and Primary Atmospheres which they inherited from Solar Nebula.

The last session on the first day was the most fascinating part as it spoke in volumes about India’s future Mars missions and Life on Mars. It was a lucid lecture by Prof.Murthy from PRL on Accretion, evolution, geochemistry and surface processes on Mars. Till now, we have had 4 orbiters, 3 rovers and 1 lander in Mars. Future Indian missions will carry Gamma Ray Spectrometers for studying the volatile chemistry, LASER sensors for terrain mapping, ultrasensitive magnetometers, and Hyperspectral imager for mineral analyses and Geological mapping camera. Another invigorating lecture was from Prof.B.C.Bhatt from Indian Institute of Astrophysics illustrated the telescopic observations which are being performed in India for analysing the Venusian cloud movement. He concentrated on the 2.3 window for cloud emissions and cloud opacity.

Day 2 was replete with lectures on diversified topics like Interplanetary Magnetic field, Heliospheric Physics, Outer planets, Aeronomy of Earth’s Atmosphere and Geomagnetic storms. Production of Sodium and water in Mercury is substantiated by proton sputtering of sodium bearing silicates by chemical spattering mechanisms (Ion spattering: Ion gives energy to target and releases neutrons). Craters can sustain magnetic field. When objects greater than Curie temperature when affected by impacts after cooling, can sustain permanent magnetic field.

Another mind blowing lecture series were about Saturn’s moon Titan. Titan , the only natural satellite ever found to possess dense Atmosphere with 1.5 bars of pressure dominated by Nitrogen and Methane. The nitrogen found in Titan is found to be of secondary origin. Ideal range of temperature in Titan is 150-250K. Methane has been evident in Titan through the process of Serpentinisation. RADAR data have revealed vast expanse of Methane lakes in northern Hemisphere and also specular reflection from these liquid bodies. Titan’s Atmosphere also contains Ethane clouds, Acetylene and uniform mixing ratio of Hydrogen. Titan’s methane cycle is similar to Hydrological cycle on Earth. In short, surface is the key to Titan’s mysteries.
The concluding lecture was about ‘Lightening in Planetary Atmosphere’. Dust storms in Venus stimulate turbo electric processes which cause lightening due to frictional charges. This electric field is similar to Earth’s electric field’. Though lightening in venus has been a matter of question, Lightening processes in Saturn and Jupiter has been confirmed.

I have only mentioned a few lectures which were fascinating me. Still, there were many on Jupiter’s moon, Mercury’s Magnetic field and Exoplanets. I would like to express my sincere thanks to Prof. Haider who gave us an opportunity to attend this conference.

When I started walking out of PRL after the conference, words of Dr. Lasio (Radio Astronomer, NASA, JPL) silently echoed in my ears, “Because nature is more clever than we are, it's quite possible that we will discover something we haven't thought of!” I continued walking saying to myself, ‘Yes, someday, the incredible will be known and we would be in other planets looking for some signals from living beings on Earth’.