Today's post – part of a series of reports marking the MEX 10th anniversary – was submitted by Marco Giuranna, the Principle Investigator for the PFS instrument. Marco works at the IAPS Istituto di Astrofisica e Planetologia Spaziali (INAF), Rome - Ed.
It’s been ten years since Mars Express was launched on 2 June 2003. Ten years full of exciting moments, challenges, and beautiful memories. I could never forget that moment.
It was 10 January 2004. We were all insidem a small room at the European Space Operations Centre (ESOC), Darmstadt, Germany, in the very early morning hours. It was very cold outside, something like -10°C, or even colder. All the PIs for the various instruments were in that room, together with a couple members of each science team. I was among them, as a member of the Planetary Fourier Spectrometer (PFS) team. We were all waiting for the very first observation of Mars!
At that time, Vittorio Formisano was the PI for PFS. I was only a young student. I was responsible for the calibration of PFS; in other words, I had to transform the raw data sent by the instrument into quantitative measurements of Mars.
The room was silent, with only some whispering here and there. “Will the instrument switch on? Will it work properly?” I bet everyone was wondering the same questions.
All of a sudden: sounds of keyboards everywhere, people running around talking loudly… It took me a few seconds to realize what was going on: the first data were arriving!
We checked our data… everything was OK and PFS was working well. Everyone was so happy!
Everyone, except me.
Well, it's not that I wasn't happy. Of course I was, but an additional challenge was awaiting me: calibration.
Will the algorithms developed in the laboratory work also for Mars? I couldn’t answer that question – I was so nervous. But the moment has come. I got the data and loaded them into the software. All I had to do was to press the 'run' button… and hope for the best. Click.
“Mars is warmer than the Earth!” I shouted.
Single PFS measurement of Mars acquired during the very first set of observations around the equator, January 2004. The signal around 1300 cm-1 gives a first estimation of the surface temperature: 285K.
Yes! The calibration was successful!
The first PFS observations of the Red Planet passed over the equator, and allowed a first estimation of the temperature of the surface there: around 285 K (~12 °C), much warmer than in Darmstadt!
I was so happy, I took a screenshot of the first calibrated measurements of PFS and sent it by email to all the Co-investigators around the world. I will never forget the expression of Vittorio. After all those years of hard work, his instrument was finally observing Mars!
Since then, PFS has collected almost two million measurements of Mars, allowing analyses of its atmospheric composition, circulation and climatology: ten years of top-quality science and exciting results. Who could imagine that a little feature observed in the PFS measurements would have led to one of the ten most important discoveries of the last years, and of Mars Express: methane on Mars!
First detection of methane (CH4) with PFS (adapted from Formisano et al., 2004. Science 306, p1758).
PFS is still operating and will continue to monitor the Martian atmosphere for new, exciting results.
Happy Birthday, Mars Express!