The Priorities in Solar System Exploration


It has long been held that a manned mission to Mars is and should be Humanity’s next big step in space exploration. The red planet has captivated our imagination for a long time, especially since Italian astronomer Giovanni Schiaparelli mistakenly called a network of dark areas he observed on Mars, ‘canals.’ The intrigue and beckoning only seemed to increase as our knowledge of our solar system and the inner rocky planets improved. Venus, long considered to be Earth’s twin, turned out to be a hellish and completely inhospitable world with it’s rampant runaway greenhouse effect. Mercury is a world of extremes that despite having reservoirs of water ice at its poles, is way to close to the sun for comfort and a voyage to the iron rich and atmosphere absent world would prove difficult to return from (not to mention the question of what rewards going to such a barren, scorched world would reap). Mars, it seems with its moderate temperatures (considering the other planets) canyons, gorges and mountains waiting to be trekked and the presence of organic molecules and compounds is the next destination of choice for humanity in our quest to explore space and discover extraterrestrial life. But there’s a problem, getting Humans to the fourth planet from the sun is not an easy business and as Nasa has rightly pointed out, if we are going to embark on the expedition we have to be confident that it will be successful; meaning all crew members return to earth safely. While no doubt, there are many prestigious scientists who see the obstacles of going there as relatively ‘easy’ to surmount if we put the focus to solving them, NASA and the government as a whole, does not seem to be willing to commit fully to going to Mars at the moment. Clearly as a society, we lack that same drive that drove us to go the moon in the 60s. If this truly is the case and a reality that we must accept at the moment, then where should we focus our exploration in the solar system that will accelerate scientific progress and reinvigorate space exploration? Just as our breadth of knowledge of Mars has grown and our probes and robots touched down on it’s surface, human made space craft have ventured to the outer planets as well and have discovered the potential for life in the unlikeliest places; the icy moons of Jupiter and Saturn.


My interest in Europa was perked early on in my research career, when reading that thanks to the Galileo spacecraft, it was discovered that the huge cracks of ice on Europa’s surface could be hiding a subsurface ocean. Based on data from Galileo, it appears that tidal forces from a large body of water beneath the surface, cause the extreme lines and cracks that characterize the surface when Europa’s orbit gets closest to Jupiter. The enormous crank of Jupiter’s gravity seems to cause a heating affect in the interior of the moon allowing for water to remain in liquid form. Thus, the constant raising and lowering of a Europa sea, would be a perfect explanation for the shifting and wide cracks that adorn the surface (1). Further observation of the moon revealed that it may be host to plate tectonics which has long been thought to be unique to Earth. It is believed that Plate tectonics allow for the recycling and replenishing of nutrients and organic compounds which helped give rise to life on Earth (2). Some of the latest installments of intriguing discoveries of the Jovian moon show that plumes of water may be shooting up from its surface, further exciting the notion of the subsurface ocean.

Obviously what makes Europa so appealing to many, is just what exactly may be lurking in the mysterious subsurface ocean that no one expected to find among the outer gas planets. And as readers probably know, it is not just Europa that may be host to some form of oceanic life but it is Saturn’s moon Enceladus as well. Enceladus has confirmed jet streams of water sprouting up from its surface. The Cassini spacecraft has detected organic molecules in these plumes which goes without saying, has awe stricken and excited astrobiologists’.

But despite the promise of Enceladus, it is even further out in the solar system, making a manned mission there at this current time, pretty much impossible. Many convincingly argue that Europa is in the same boat for that matter and I would agree. Sending advanced probes there is another story and focusing our attention on unraveling the mysteries of these icy and oceanic worlds could reveal secrets that rival science fiction. We know that where there is water, there is a huge potential for life and Europa has even more water than Earth does (3). In order to make huge discoveries in space science, the focus has to be narrowed and if Nasa truly isn’t serious about sending Humans to Mars yet, then getting our probes and landers out to the gas giants could reap monumental benefits.

The reality is, Mars, while more accessible than Europa, may not be the best place to focus our attention and money, unless we finally hit the ground running and decide we are going to send humans there and not just merely flirt and dabble with the idea which is what NASA seems to be doing right now. Mars has huge potential for life, dont get me wrong but in order to find it, it appears we’re going to have to send humans there and not rely solely on robots. Just sending flybys with more sensitive instruments than the spacecraft Cassini, to probe the plumes of Enceladus or Europa could make revolutionary discoveries. NASA’s Europa Clipper mission that is slated to launch in the early 2020’s, is huge progress and exciting for those who are literate in Europa’s lure. But with a landing mission being postponed until the 2030’s, it may be awhile before we really discover what, if anything, is lurking beneath the surface. Interestingly, a recent study revealed that robot landers might not have to dig far to find evidence for life thanks to Europa’s constantly shuffling surface (4). There just seems to be to much promise in the icy worlds of the outer solar system to not be fervently focused on unraveling their mysteries. I fear we may be multi tasking to much in the realm of space exploration and missing out on the benefits of what one focused mission could bring. The discovery of life in our solar system, even at a uni-celled level would absolutely transform and accelerate space science. Not to mention the philisophical implications that would affect the whole of human civilization. Just as we set our minds to going to the Moon in the 60’s, if we set our best and brightest minds to the expeditions of probing Europa’s or Enceladus’ oceans, huge breakthroughs could be made.

What do you think? Where should our focus be in exploring the solar system? I would love to hear your thoughts











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