Graham writes …
This post is the first in a series looking at the implications of life elsewhere in the Universe. We start by considering our neighbouring planet Mars.
Way back in September 2019, a couple of good friends Pat and Sharon surprised me with a ‘Boarding Pass’ for Mars 2020. At first, I had no idea what it was about but they explained that there was to be a NASA launch of a mission to Mars in July 2020. They had registered my name on a data base, and this would be transported to the surface of Mars. As you can imagine, I was quite excited and inspired by the prospect that my name (in whatever form) would forever reside on the Martian surface. I printed out my ‘pass’ (see picture) and pinned it on my office notice board, where it remained unnoticed until this week.
Indeed, this week saw the arrival of the Mars 2020 mission. On the evening of 18 February 2021, I tuned into a live broadcast on NASA TV from the JPL Perseverance Rover Mission Control room to watch the events of the rover landing strategy unfold. After its 203 day, 472 million kilometer journey, the conical capsule carrying the rover hit the upper atmosphere of Mars at 20.48 GMT travelling at about 20,000 km per hour (5.6 km per second). Seven minutes later at 20.55 GMT the rover arrived successfully on the surface. Watching the broadcast, the descent time seemed to flash by. To reduce the speed of the rover to effectively zero in such a short amount of time required a pretty brutal and complex sequence of events (see NASA descent videos – animation and actual video coverage). Just 80 seconds after atmospheric entry, peak heating occurred, with the heat shield reaching temperatures of about 1,300 degrees Celsius. Ten seconds after this, the peak deceleration of 10 g occurred. At this rate of deceleration, the capsule speed is sapped at rate of about 1 km per second for each ten seconds of flight. Finally, a combination of parachute and retro thrusters brought the rover to rest on the surface in a 1200 km diameter crater called Jezero.
This particular landing site for Perseverance, was strongly prescribed by the principal mission objective – that is, to investigate the prospect that microbial life still inhabits the surface (or more likely the subsurface) of the Red Planet. So why Jezero Crater? Over decades, an armada of Mars orbiting spacecraft have looked down on the surface and imaged the spectacular landscape. Mars has the distinction of having the largest volcano (Olympus Mons) and canyon (Valles Marineris) in the Solar System.
However, perhaps the most surprising feature of the topography is the unmistakable evidence that water once flowed freely upon the surface. Scientist have estimated that around 3.8 to 3.5 billion years ago, the climate of Mars was warm and wet – effectively, the planet was a water world not unlike Earth today. Evidence of water features – tributaries, river deltas, flood plains – are abundant. So where has all the water gone? As Mars is only about half the size of Earth, with a surface gravity of 38% of ours, the atmosphere of Mars has slowly leaked away into space over the last 3.5 billion years. Current atmospheric pressure is only 0.7% of Earth’s, and any water on the surface would quickly evaporate. So now Mars is dry and arid.
So, all those years ago it is believed that Jezero was lake, with a river inlet and outlet, and Perseverance rover’s landing site is located near the inlet. The rover has the ability therefore to look for likely sites in the lake bed and river delta where Martian microbial life might still reside. This is likely to be found in the subsurface rocks, so the rover has the capability to drill into the surface to produce core samples. These precious samples will subsequently be left on the surface to collected, and returned to Earth for detailed analysis. The methodology of this retrieval process is quite torturous, and is perhaps the subject of another blog.
What then is to be learned from all this? It would be truly remarkable if life was discovered, and it was unambiguously based upon biology unlike that found on planet Earth. This would certainly be a paradigm-changing discovery, having great significance for our understanding of life elsewhere. However, another outcome could be that Martian life is found to be based on the same DNA code that is universal on Earth. This is entirely possible due to the fact that Earth and Mars are not biologically quarantined from each other. It has been known for many decades that chunks of rock from Mars can be found on Earth, and no doubt similarly bits of Earth reside on the Martian surface. The main mechanism accounting for this surprising situation is that highly energetic comet or asteroid impacts on Mars can blast rocks into orbit around the Sun, which can subsequently encounter the Earth. Presumably the reverse route is also viable. Of course, another overall mission outcome could be that no convincing evidence of microbial life is found. Only time will tell. For more information about the prospect of life on Mars, I can recommend Paul Davies’s book The 5th Miracle*.
Finally, it is worth pointing out that there are other places in the solar system where life may reside and where biological quarantine conditions are more stringent. Orbiting spacecraft missions to Jupiter (Galileo) and Saturn (Cassini) have shown that Jupiter’s moon Europa and Saturn’s moon Enceladus have significant water oceans beneath a thick surface crust of ice. The heat required to maintain this liquid state in both moons is generated by tidal heating. The source of this heating is likely to be active thermal vents on the ocean bed, around which conditions for the nuturing of life may exist. Although this is an exciting prospect, the opportunity to investigate this hypothesis is likely to be some significant time in the future. The task of delivering a submarine, robotic probe to these distant worlds is an extremely challenging one from the perspective of rocket science and spacecraft engineering.
* Paul Davies, The 5th Miracle: the Search for the Origin and Meaning of Life, Chapters 8 & 10, Simon & Schuster, 2000.
John writes …
I am composing this in January 2021, a month in which the UK has entered another phase of ‘lockdown’ in order to control the spread of the coronavirus SARS-CoV-2, which causes the disease Covid-19*. Our lives are very restricted but thankfully we are encouraged to go out in ones or twos or small household groups for exercise. I have had much more time to observe and consider the natural world in a different way from research work in the lab. Going out regularly in the same locations, whether on foot or by bike makes me very aware of the cycle of nature. Days are already 30 minutes longer than at the winter solstice. The buds of deciduous trees are beginning to exit from dormancy and some cold-tolerant plants and trees have started to flower.
The annual cycle of seasons was of course also known in Biblical times although the specific reasons for the seasons (the passage of the Earth around the Sun, coupled with the tilt of the Earth’s axis) were not known. Indeed, from early in human history, any group of people who did not live close to the equator (where daylength is constant or nearly so) would have been aware of the annual changes in season and the resultant changes in the biological world, including new growth, flowering and fruiting, bird migration and so on. In the Bible we can also see a sense of wonder at the natural world. Psalmists were amazed and in awe of the starry heavens; Job wrote extensively and wonderingly about both physical and biological aspects of nature; Jesus himself talked about the beauty of wild flowers. And we, many centuries later, also react in awe and wonder as we know about and understand so much more about our planet and the ‘balance of nature’ thereon (see especially Chapters 5 and 8 of the book). Indeed, as I have described in the Preface and in another blog (Magic and Metamorphosis), my wonder in response to the natural world was one of the factors that led me into science.
All this brings me to the BBC, Britain’s national non-commercial broadcasting organisation. Currently, they are running a weekly series (five episodes in all) called A Perfect Planet, with commentary by ‘national treasure’ David Attenborough (see BBC One – Introducing A Perfect Planet and also BBC iPlayer). The filming is truly wonderful, bringing us everything from volcanic eruptions through ecosystem dynamics, predator-prey relationships to the minutiae of certain plant-animal interactions. In the latter category we learn about the role of the fig wasps in pollination of figs (Ficus species). It is a story as specific as, but even more bizarre than the pollination of Yucca that we describe in Chapter 8 (see Fig wasp | insect | Britannica).
In the TV programme, we learn about the essential role of tectonics and volcanoes, about being the right distance from the sun (the Goldilocks zone). We learn that ‘Our planet is one in a billion’ and that … ‘incredible, awe-inspiring life is driven by its natural forces’. And, in the final episode we will learn about what humans have done to the balance of nature, leading to the ecological crisis and the climate emergency.
Overall, it is as if someone at the BBC has read From the Big Bang to Biology … and has set out to make a wonderful film of the book. But there is of course one thing missing. One of the features that comes over strongly in the films is a sense of awe and wonder that is almost religious in tone but there is no mention of God. This is not a criticism of the programmes - they are not part of the BBC’s religious broadcasting – and yet we wonder whether the sense of awe and wonder that comes over so strongly will lead to any viewers, or indeed, any members of the production or presentation teams, to ask deeper questions, questions that require more than science and good filming to reach an answer.
* This raises the difficult topic of disease and suffering. I do not deal with it here but readers may be interested to look at Café Théologique an online interview: A God of Genes and Viruses - Prof John Bryant.
See also Perfect Planet: A Statement in Response - Ruth Valerio.
You may be surprised to learn that this brief contribution is about something that happened 19 years ago. So, you may also be asking why would this be of interest to anyone after all this time? For me, the events that occurred in November 2001 were the first tremors which heralded the personal revelation that there was more to the world than the bits described by the physicists. The shockwaves that subsequently radiated from those tremors were to profoundly change my life. It was then, at age 51, that God chose to reveal Himself to me, and I have no idea why He chose that time in my life, or why He decided to do it at all.
Perhaps a bit of back story would be helpful here. I was raised in a loving family that had no explicit faith in God, and consequently church attendance, or any other manifestation of religion, played no part in my up bringing. From a very early age I was captivated by science, which steered my education to culminate in a doctorate in mathematical physics in 1975. Subsequently, I spent a very fulfilling career in space science and engineering, both in industry and academia, before retirement in 2010. However, it was during busy years at Southampton University that I became a Christian. How this came to be was very much related to the issue of ‘science and faith’, and I wish to say something briefly about this transformation in this account. Prior to this extraordinary event, I would have described myself as a tolerant agnostic, firmly entrenched in the notion that science had explained everything to the extent that any form of god was entirely irrelevant.
My story starts in the unusual setting of a family holiday in Guernsey in the summer of 2001. Time by the pool gave me plenty of opportunity for reading and thinking, and I experienced a rare, startling insight about the nature of the Universe! This was along the lines of the universe is defined by our existence within it. This is something that these days we call cosmic fine-tuning. The argument goes that the fundamental constants of the laws of nature have to take very precise values in order that life of any form can exist in the Universe. This kind of notion has been with us for some time in the form of something called the anthropic principle, that can be expressed as – the laws of nature must be constrained to allow human existence. So why the big deal? The startling character of the insight arose because of the degree to which the fundamental constants have to be finely tuned. Most scientists are hard headed about this, and agree that if it wasn’t so we wouldn’t be here to think about it. And they are quite right. But for me, by the poolside, it was the precision of the fine-tuning that was startling. You could say that the Universe is an extremely unlikely place. Put another way, if you saw a well-shuffled pack of cards being dealt in perfect suit and numerical order, you might wonder how this could happen. Was it by chance (odds of 1 in 10^68) or was there more to it? Something behind it?
Cutting a long story short, I pondered the options, and after many weeks of reflection I had arrived at a place in which I was comfortable with the notion that there may be such a thing as a Creator God. Given my background, this was not an easy journey but it did put me in a position where I could consider attending an Alpha course at the local church in the Autumn of 2001, and the rest is history as they say. An encounter with the numinous occurred and finally convinced me that there was such a thing as the ‘spiritual realm’.
One thing I have learned from all this, and in particular in the context of courses such as Alpha, is that people are convinced not by endless academic discussion of the issues, but rather by the simple means of personal experience of God transforming power in their own lives, and in the lives of others.
Read my story in more detail in ‘From the Big Bang to Biology: Where is God?’ by Graham Swinerd and John Bryant (Nov 2020). This blog post is adapted from a contribution to the blog section of the Faraday Churches website. See the original here.