NASA JPL Perkolate Online

June 2017. Interview by Marelise Jacobs. Cover: Mars Exploration Rover - Opportunity. All images courtesy of NASA.

The biggest dream anyone with a love of looking up at the stars could have is to one day walk into the legendary, awe inspiring headquarters at NASA. Japie van Zyl did just that, and then some. Born and raised in Namibia, he later went on to study electrical engineering at the University of Stellenbosch before embarking on a journey that would eventually lead him to become the Director of Solar System Exploration at NASA's Jet Propulsion Laboratory. I had the incredible privilege of talking to Dr. Jakob van Zyl about our understanding of Mars, the future of human settlement in space and the mystery of Jupiter's core.

It has been five years since the Mars Curiosity landing, what has changed about your understanding about Mars?

Japie: The major discovery from the Curiosity Rover is in fact that Mars had water. At least in the place that we landed, in Gale Crater, there was water present for probably thousands of years and that the water was of such a quality that humans would have been able to drink it. In many other places we have discovered evidence of past water but they were usually very acidic so that probably life would not have been able to evolve there. In Gale Crater, the water was of such a quality that life would probably have been able to be sustained there. That was one of the major goals of the mission, to go to Mars and understand if the conditions were ever such that life could have existed and the answer is a resounding yes. So I think that probably is by far the biggest discovery and it changed our thinking of how Mars evolved over time. The big question that is still open, that we still don't know the answer to, is when did things change from that wet environment, where you clearly had water standing on the surface flowing episodically into lakes and things like that, to what we see today which is just a dry, desolate planet.

“...I think there is a good chance that in the next twenty years or so we will start the era where Mars would be very much like Antarctica is today, in that you would have research stations there...” - Dr. Japie van Zyl, Director of Solar System Exploration at NASA JPL.

In terms of the long-term plans for human settlement on Mars, do you think that is feasible?

Japie: It definitely is feasible and NASA is still working towards the goal of sending humans to Mars by the late 2030's. That is the timeline for NASA. Now, there are other people like Elon Musk and so on who claim that they can take people a lot faster and at some level, yes they can because they don't have all the restrictions that a government agency like NASA has. They can work much more aggressively towards the goal of going there and take more risks. I think there is a good chance that in the next twenty years or so we will start the era where Mars would be very much like Antarctica is today, in that you would have research stations there. There may not be a crew present all the time, but there would be certain periods of time where humans would actually occupy the research stations and people would live there. Then eventually of course, if you follow what people like Elon Musk want to do, there would be a colony on Mars.

What is Juno and what have you discovered about Jupiter because of this mission?

Japie: Juno is what we call a New Frontiers mission here at NASA. Roughly every five years or so NASA has these competitions for a mission that would go to some other place in the solar system and study it in great detail. Juno was selected to go study Jupiter because despite the fact that we have had a number of missions to Jupiter, we still don't fully understand when Jupiter was formed. It is believed to have been very early in the formation of our solar system, but we do not have the concrete evidence if that is the case. And so, basically Juno was chosen to go to Jupiter and study the interior of the planet. For example, we don't know yet whether Jupiter has a solid core or a liquid core or any core whatsoever. It is known as a gas giant but we have no evidence that there is in fact a solid core. The prevailing theory is that the gas is just getting denser and denser, to the point where you end up with a cloud of metallic hydrogen, but it is not a solid surface like we have on other planets. Juno is hoping to find out whether that is the case but we will need another twenty or thirty orbits and we have only done about six at the moment. So it will be a while before we know that answer.

I have heard about a planet's dynamo, can you explain that?

Japie: Yes, a dynamo is the engine that generates a magnetic field. So on earth, we have a dynamo that is inside the core of the earth which is a liquid core, and then there is a solid core inside of that. It is that spinning of that core inside the liquid that is causing the dynamo effect on the earth that generates our magnetic field. At least that is the theory. Now on Jupiter, if it doesn't have such a core, where does this magnetic field come from? We have always believed that we have to have some spinning, conducting medium that creates this electrical current which would then generate the magnetic field. So that is the fundamental question here, where is that dynamo and how does this dynamo work on Jupiter if it doesn't have a solid core?