Cassini’s lessons | Sunday Observer

Cassini’s lessons

24 September, 2017

When Giovanni Domenico Cassini gazed at the magnificent ringed planet Saturn and its moons around 1675 from his earthbound observatory, he would never have thought that just 340 years later, a namesake robotic probe would be exploring that very planet at close range.

Cassini the scientist added volumes of knowledge on Saturn, but even his effort pales in comparison to the treasure trove of images and knowledge sent to the Earth by Cassini the robotic probe during the past 13 years.

The multi-country, US$ 3 billion probe that lasted 20 years in space, 13 of them around Saturn, vaporized in Saturn’s atmosphere on September 15 after NASA decided to destroy the probe.

This was to prevent any hitchhiking terrestrial microbes from contaminating the primordial surfaces of Titan and Enceladus, two of Saturn’s moons which have some probability of harbouring microscopic alien life due to the presence of liquid water and certain other chemicals needed for life to begin.

Cassini was truly a one of a kind endeavour that shows the power of international cooperation. Headlined by the National Aeronautics and Space Administration (NASA) of USA and the European Space Agency (which designed the Huygens mini probe that landed on Titan, making it the first object to land in a moon on the Solar System other than our Moon), 27 countries participated in the effort either through funding or scientific input, expertise or manpower.

Cooperation

Indeed, the best takeaway from Cassini is that future space exploration – be it a manned mission to Mars or a long-term unmanned voyage to Alpha Centauri – must necessarily involve international cooperation.

A manned mission even to Mars will be outrageously costly and every country will have to pitch in, with some scientists already saying that Mankind only has a 100-year window to get out of the Earth for good.

But, long before that happens, we have the Plutonium-powered Cassini to thank for literally showing us what lies ahead in the Solar System for any spaceship carrying us to Earth 2.0. Designed to last just four years around Saturn, Cassini performed flawlessly for an astonishing 13 years, taking more than 400,000 digital images (635 GB, so you can have them all in external hard disk) that have fundamentally changed the way we think about the huge ringed planet and its moons. Most, if not all, of these images are now in the public domain on NASA and other websites and smartphone apps for us to wonder and appreciate.

The dozen scientific instruments Cassini carried on board took a range of measurements from every angle of Saturn and some of its 60-plus moons. Needless to say, scientists will study the images and scientific data for at least two more decades, adding to the 4,000 papers already published off Cassini’s data stream, given that there are no immediate plans to send another probe to Saturn and no other existing craft is scheduled to go near Saturn.

While landing a mini probe on Titan was exciting enough, the most exciting discovery made by Cassini was that Enceladus has liquid water. The moon actually has geysers which shoot water up into the air, much like the geysers in Yellowstone or Iceland.

Cassini in fact travelled through the water jets, getting a “taste” of what lies beneath this moon, which may harbour some primitive form of life. Unsurprisingly, scientists are itching for a probe that can actually collect some samples from the moon’s surface and return to Earth. Short of a manned probe (unlikely at this stage), this will be the best way to learn more about this enigmatic world and answer that ultimate question – is there life out there?.

Any confirmation of life elsewhere in our own Solar System will put to rest the debate on life in other star systems and galaxies.

In fact, two NASA probes are speeding to outer space as we write – the two Voyager spacecraft heading out to the distant stars, carry a Golden LP Record about life on Earth and a star chart to identify the Earth’s location in space should any alien civilization come across oneof the probes.

(As an aside, this Golden LP is finally available to buy in a public version after four decades). But, Cassini may have laid the foundation and spurred a yearning to get an answer to this question sooner than we think.

Probes

Later this year, NASA is expected to pick one or more candidates for the next New Frontiers mission. Current probes OSIRIS-REX (an asteroid-exploring mission that launched last year, heading towards Bennu, a distant asteroid), Juno (Jupiter Orbiter), and New Horizons (Pluto flyby, asteroid study) were all funded through the New Frontiers program.

NASA is currently reviewing 12 proposals and in November, will select candidates for a preliminary study, which could demonstrate the feasibility of the project and help further narrow the field.

Possible candidates include Titan, Enceladus, Venus and Saturn again. In October 2018, the European Space Agency (ESA) and Japanese Space Agency JAXA will launch BepiColumbo, a set of two orbiters on a one-year mission to Mercury.

Lucy is a probe set for a 2021 launch that would see it zipping past the main asteroid belt in 2025 before it gets to the Trojan asteroids from 2027 to 2033.

The Europa Clipper, which will use ice-penetrating radar and other instruments to study the outer planets has been in development since 2012 and is projected to launch in the early 2020s.

There is some talk of a possible manned mission to Mars by the 2030s – several scientists who simulated Martian conditions in a capsule on Earth for several months emerged to the outside world, almost coinciding with the self-destruction of Cassini.

This brings us to the question of funding for space missions. Elon Musk of Tesla fame has made no secret of his ambitions for a manned Martian mission, which indicates the strong desire of the private sector to undertake space exploration.

Along with eminent scientist, Stephen Hawking, he is also one of the most passionate advocated for finding Earth 2.0.

In the future, Government funding alone may not be enough to initiate ultra-expensive space missions. This is where the likes of Musk’s SpaceX and Jeff Bezos’ (of Amazon fame) Blue Origin can come in. It will necessarily be a joint public-private effort.

In just two years, we will have completed 50 years since the first manned mission to the Moon. It is perhaps incomprehensible that we have not been to another plant in the flesh since then.

But, our robotic probes have made amends, boldly going where no man has gone before and likely will not for the next century or so. This is why we have to celebrate the “life” and times of Cassini, for it has shown us the way forward to a celestial future. 

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