I had leave on account of Mahashivratri today and also heard of a public lecture on “Solar System Studies and Planetary Exploration“. Being a holiday, I decided to go down all the way to Colaba for the evening. A hop on the local and a lovely bumpy ride on a rickety seat along the dockyard and through the military establishments of south Mumbai brought me to TIFR.
The public lecture was organised by the TIFR Alumni Association (TAA). If you were an ex-student of TIFR and are interested in joining the TAA, do contact them since they are a new body and are still trying to track down alumni. The talk was organised on the occasion of National Science Day celebrated in India on February 28.
Image: Presentation. Image Credit: Pradeep Mohandas
Prof. J N Goswami is an alumni of TIFR and currently the Director of the Physical Research Lab , known as the cradle of space sciences in India. He was part of the Chandrayaan-I programme and is an advisor to the Mars Orbiter Mission and Chandrayaan-II.
Prof. Goswami’s primary interest is in the area of solar system studies. His talk was mostly based on this topic. He just dwelled for a little bit on the Planetary Exploration aspects. I would have, personally, have been more interested in the reverse. His talk wasn’t all dry though and it did expose me to an aspect of space exploration that I have not been following attentively.
Prof. Goswami began with a standard model of solar system formation. Referencing yesterday’s Kepler announcement he said that there was a need to have a standard model as against one just for our solar system. The model progresses from protostellar cloud to a fully formed solar system in about a few billion years. He said there were three forms of solar system studies – analytical, lab work and remote sensing. His talk considered lab work on meteorites. After explaining the geologies of the “pristine” and the “processed” meteorites he spoke of how studying the radioisotopic decomposition was used to determine a round figure for the time when the solar system was formed. He cited various studies and these seem to be continuing to the present date with increasing precision. A notable Indian contribution was a publication by Wadhwa M in Nature in 2010 that puts the age of the solar system at 4568.2 Ma. Prof. Goswami then went through various studies done at PRL and in labs in America and Europe to improve on this date by considering various radioisotopes.
He said that PRL also was building nascent capability in looking for exosolar planets. He said that we needed crazy people to take risks for such projects. He said that PRL backed one such guy and they now have an exosolar planet search facility at Mt. Abu Observatory.
Prof. Goswami is one of the few persons who worked with some of the Apollo moon samples which were sent to India. He says that a very influential person spoke to him for about 3 hours to get him to work on the Chandrayaan project. The person, whom Prof. Goswami admired and respected led him to abandon work on the solar system studies which he has now returned to at PRL to work on the Chandrayaan project.
Prof. Goswami said Indian Planetary Exploration programme is limited by its launch vehicle capability. Currently, with the GSLV still proving itself, ISRO can only claim reach upto Mars and the Moon and passing asteroids.
Prof. Goswami says that involving foreign partners in Chandrayaan was driven by the fact that India then faced economic sanctions that prevented the transfer of technology. ISRO hence invited foreign payloads on-board the project. On the discovery of water on the Moon, he says that it was always there and that we did not bother looking. Hence, when Moon Mineralogy Mapper found water in the 2.8 spectrum range, they asked for references from the Deep Impact and Cassini probes. These probes used the Moon as a way to calibrate their mass spectrometers. He said that they just did not look beyond the 2.6 spectrum range else these probes could have discovered the water as well. He stressed that the data had been in public domain for years but still no one looked! Having a re-look confirmed data from these probes as well as in the Apollo samples even ones which were in the possession of PRL. In the QnA a member of the audience asked about the Moon Impact Probe water discovery. Prof. Goswami said that the decision to not allow sufficient time for de-gassing the probe before it was sent in to impact the lunar surface would have raised doubts on the claim if they were made. He says the same instrument will be carried on the Chandrayaan-II for more studies.
Image: Chandrayaan’s achievements. Image Credit: Pradeep Mohandas
He says Chandrayaan achieved a lot. The major discovery was the water and hydroxyl molecules attached to lunar surface material. Besides this the probe also studied and obtained new results related to reflected solar wind components, mini-magnetospheres, sub-surface ice layers below permanently shadowed craters, water molecule in the lunar atmosphere, new rock types, composition of lunar surface and confirmed the basic concept (global magma ocean) of lunar evolution. The probe also provided a 3D map of the lunar surface and radiation environment of lunar space.
He said that the Mars Orbiter Mission was so well on course to Mars that it might not need a planned course correction. I couldn’t clarify if he was talking of the one in April or an interim course correction.
Image: Prof. Goswami during the QnA session. Image Credit: Pradeep Mohandas
The crowd there seemed to stick mainly to his studies of solar system formation, which was expected. He did not speak much about the planetary exploration project. He was much more fun in the QnA and was very good at analogies and I have to wonder why he spoke differently during his presentation and during his QnA.