Scientists thrilled at landing on Saturn’s Earth-like satellite

The remote and mysterious heavens have always beckoned to human beings: From the mythical Icarus who fell to Earth, to the first airplanes, the conquest of the moon – first in Jules Verne’s teeming imagination, then in reality – and then to the furthest reaches of our solar system (at present only with unmanned spacecraft), human beings have always striven for the heights. The universe can give us the answers to age-old questions: Who are we? Where did we come from? And are we all alone? Spurred on by these questions, Dr Athina Kousteni was one who tried and found the answers – as part of the successful Cassini-Huygens space mission to the ringed planet Saturn and its Earth-like satellite Titan, whose first results were beamed round the world last week. The 43-year-old astrophysicist, a highly placed member of the team working on the joint European Space Agency/NASA mission, spoke to Kathimerini about the project. «Since 1988-1990, Titan and I have become one,» declared Kousteni, whose doctorate had been on Saturn’s satellite. Talks on the mooted mission began in 1987, she said. In 1990, proposals were submitted on the instruments that it would use. «Since then, they’ve regarded me as an expert on Titan.» The Cassini orbiter and the Huygens probe, she explained, had a total of 18 instruments. «Of those, 12 are on Cassini. Three proposals made by my team were accepted. I now have the right to consider any data from them as mine.» Three instruments The three instruments in which she was involved include the Composite Infrared Spectrometer (CIRS), which is located on the Cassini orbiter. A remote sensor, it measures infrared light coming from an object to learn more about its temperature and composition. «It tells us about the atmosphere, what it’s made of, the temperature and climatic data. It’s with this that we’ll collect any data on the atmosphere,» said Kousteni. She also worked on the Huygens Atmospheric Structure Instrument (HASI). Equipped with a battery of sensors, HASI «measures atmospheric pressure, density and temperature in relation to altitude.» (Generally, it measures the physical and electric properties of Titan’s atmosphere.) «We need it, because in every analysis, we require temperature and atmospheric pressure readings,» Kousteni explained. The third instrument she worked on, the Descent Imager/Spectral Radiometer (DISR) – a spectrometer and camera – is also to be found on the Huygens probe. «It’s the camera that took the pictures that were made public. The data I will receive from those instruments will be enough for me to do a lot.» And she explained: «I can gather a lot of information that will enrich my knowledge of Titan. We now have pictures, spectrum measurements, temperature readings – all the data on the moon’s atmosphere and surface. In order to understand what’s going on in such a complex heavenly body, we need the data from all the instruments.» Primeval Earth? What does the mission mean for science and humankind, especially when the money spent on space missions could perhaps be put to better use, to alleviate world hunger or combat disease? The mission is of major importance to science. When we carry out such a mission, into which years and years of work have gone, it had better succeed. We learn things about a moon where conditions are the closest we can find to those on Earth before life began. Certain theories posit an atmosphere composed of nitrogen and methane, without oxygen. If that’s true, then Titan is like a primeval Earth, though it lies 10 times further away from the sun, has a temperature of -180 Celsius and absorbs one-hundredth of the light that the Earth gets. That’s the most significant difference. It’s important for us to understand how two bodies that are so alike came into existence in two places so far apart from each other. That’s why the Titan survey will help us better understand our own planet, and, at the same time, the creation and evolution of our solar system. As for the second part of your question, naturally, I’m aware of these views. But think: The total cost of the mission is $3.5 billion. That might seem like a large sum but it’s minuscule compared to the money spent every year by the USA and Europe on armaments. Moreover, this money has, all these years, provided work and a living to over 20,000 people, who spent a great part of their lives on the mission. We shouldn’t forget that in all these programs, there are medical and industrial spin-offs (e.g. anything to do with optics). Don’t these missions also serve military purposes? From the moment the research is published, you can’t forbid anyone from using the information. In any case, we don’t give such information to the military; on the contrary, we often receive it. But how do space missions apply to daily life? Since ancient times, human beings have wanted to know whether there is life elsewhere. I think this is a fundamental question. When they first raised their eyes to the skies, human beings became aware of the presence of a million bright lights that revolved around the Earth, which they considered the center of the universe. The nature of these points of light was unknown. Were they divine signs or simply shining stones? Were they suns like ours? And if so, could there be planets like ours around some of them? And did they then have alien beings who also explored their own heavens? Little by little, people discovered that the sun and the Earth were not the center of the universe. They came to understand that those points of light were bright, faraway suns, a good deal further away than our ancestors could have imagined. And they began to realize their dream, to go into space. Today, we are studying how to continue this cosmic adventure. Man differs from animals – he has dreams, ideas and imagination, he is not interested only in sleeping and eating. Space programs will help us find answers to these questions. That’s why I believe they will interest people. They feed imagination. What was it that first drew you to Titan? The results of the Voyager mission in 1980 led me to two conclusions. First: Titan is the heavenly body that most resembles Earth. Second: It was mysterious because it was covered in cloud and we didn’t know anything about its surface. I like mysteries, so I decided to take a closer look. I’ve spent many years of my life on research out of love, not money. If I’d wanted to make money, I’d have gone into the private sector.k