Latest Posts

Dunes in a row

A Piece of Mars: Look at the alignment of the ~100 m dunes in this 713×750 m (0.44×0.47 mi) scene. How do dunes form in such straight lines? And why don’t they always do that? It’s likely that these dunes were once long ridges stretching from the lower right to upper left. The shape of the slip faces suggests they’re formed from two winds that blow from similar directions, both of which push sand toward the upper left. To stay stable, this sort of dune needs a constant influx of sand from upwind (from the lower right), but if that flow of incoming sand lessened, then a long dune would be forced to break up into a series of smaller dunes. That may be what’s happened here. Check out the whole image, and you’ll see other long ridges that haven’t yet broke up into smaller dunes. (HiRISE ESP_052798_2565, NASA/JPL/Univ. of Arizona)

Ripples of rock

A Piece of Mars: To the upper right of this 0.85×0.6 km (0.53×0.37 mi) scene is a flat-lying plain strewn with large ripples. To the lower left is a rugged hill with gray rock laced with white veins (this might be part of an impact megabreccia identified nearby in Holden crater). Notice that some of the ripples on the rugged hill are also veined – this is evidence that they are actually eroded into the bedrock, rather than fine-grained deposits like their counterparts on the plain. It’s not yet clear how these “Periodic Bedrock Ridges” form, and they may be unique to Mars. (HiRISE ESP_052789_1520, NASA/JPL/Univ. of Arizona)

Marie Curie at 150

Marie Curie at 150 – Celebrating Women in STEM
The Struggle for Equality, Recognition and Reward
Written by: Athena Coustenis & Thérèse Encrenaz

Planetary Sciences 2014 Prize Winners

AAS Division For Planetary Sciences Announces 2014 Prize Winners
Athena Coustenis: recipient of the Harold Masursky Award for outstanding service to planetary science and exploration.
Link to DPS 2014 Prize Recipients

Women in Planetary Science

Link to Women in Planetary Science


Link to Matrix24 (in Greek language)

Full Curriculum Vitae

Dr Athena Coustenis

LESIA (Bat. 18)
Observatoire de Meudon
5, place Jules Janssen
92195 Meudon Cedex


Born in Athens, Greece. French and Greek citizenship.

Professional status: Athena Coustenis is Director of Research 1st class with the National Centre for Scientific Research (CNRS) of France, working at Paris Observatory in Meudon. Her specialty is Planetology (exploration and study of the Solar System from ground-based and space observations). She is currently the Chair of the European Science Foundation Space Science Committee (ESF-ESSC).

1986: Master in Astrophysics and Space techniques, Univ. Paris 7 (P. & M. Curie)
1987: Master in English Literature, Univ. Paris 3 (Nouvelle Sorbonne)
1989: PhD in Astrophysics and Space techniques, Univ. Paris 7 (P. & M. Curie)
1996: Habilitation to Direct Research (HDR), Univ. Paris 6 (P. & M. Curie). (more…)


What is an astrobiologist?
I came to Astrobiology quite early in my research. How could I miss the implications ‘Titan: the frozen Earth’, ‘organic chemistry closest to our planet’, the ‘methane cycle mimicking the water cycle on Earth’, etc. Of course, ancient Greek philosophers (them again !) had already thought of a universe consisting of “many worlds”. Thales, from Militos, and his students in the 7th century BCE argued for a Universe full of other planets, teaming with extraterrestrial life. They also proposed the idea with which we’re all familiar today (through Drake’s equation, among other and Carl Sagan’s musings, and the contributions of many other scientists’ arguments), i.e. that a Universe so full of stars must also have a large number of populated worlds. This proposal, was already defended by Epicurus and other Greek atomists who countered the geocentric models brought forward later on by Aristotle. The latter concept stuck, though, and hindered scientific progress in this domain for quite a long period of time. In 1862, the French scientist Camille Flammarion , published ‘La pluralité des mondes habités’ (‘on the plurality of inhabited worlds’), in which the conditions of habitability and the presence of life on such habitable planets of our Solar System is discussed. The public loved the book, but Urbain Le Verrier, then Director of the Paris Observatory , and many of his colleagues completely rejected Flammarion’s arguments, as did many of his colleagues. Flammarion was consequently fired from the Observatory… I have had better luck so far…

I’m allowed to be fascinated by the possibility that we could find information on how human beings arose and/or discover life forms elsewhere. Mars, Venus, Titan, Enceladus, Europa and other such places have been our favorite targets for exploring habitats in the Solar System and pushing current models of the origin and evolution of life to their limits, and beyond. Subsurface liquid water oceans, organic constituents swimming in exposed hydrocarbon lakes, water-laden geysers, the possibility of water hiding beneath the CO2 ice fields of Mars: All these new opportunities for exploration in the field of Astrobiology make my every day life and research work exciting and busy. Learning about and contributing to future missions to the Saturnian and Jovian systems are constant sources of joy and reward. And I love sharing these new findings in Astronomy with the public, always supportive and sometimes as passionate as we are… [an excerpt of this text was published in the “Pioneers in Astrobiology” section of the Astrobiology Magazine in February 2012]

future exploration

cassini-huygens era

The Cassini-Huygens era
how does an astronomer work?
In July 2004 the Cassini mission finally arrived at Saturn and entered into orbit around the planet, visiting the whole system. Even our wildest models and speculations hadn’t prepared us for what we’ve seen since then with instruments performing beyond our expectations. During one freezing cold night, on 15 January 2005, at Darmstadt, ESA’s Ccontrol Center in Germany, “we heard the baby cry” as Jean-Pierre Lebreton announced after the successful descent and landing of the Huygens probe. The images and all the data returned by that probe, the farthest landed man-made machine, are extraordinary and have taught us so much. Since then, many scientists and engineers around the world have participated in this extraordinary adventure by processing and analyzing the huge amount of data returned by the mission. The orbiter’s lifetime has been extended to 2017, so I’ll be busy for quite some time more. … When I think how the Voyager flyby of 1980 allowed me, a decade later, to do research not only during my Ph.D. but also for years afterwards, I have no doubt that the Cassini-Huygens data will keep several future generations of astronomers busy.
We mainly work in front of a computer if the data come from space missions. We wait for the data to be retrieved and processed at the different instruments centers. They are then sent to the team, where the people are called “co-investigators”. Each one of these has a specific expertise and a task and so they work on the data from a given point of view and produce results which are then published in a scientific journal.
If, on the other hand, we go observing at a big telescope somewhere, we then do the observations ourselves, bring back the data on a CDROM and then process them and analyze them ourselves at our institute.
It is extremely rewarding both ways, observing on a clear night from the top of a large telescope in Hawaii or Chile, or watching in awe as a space mission arrives and turns on the instruments that then send you back all the wonderful images, spectra and other data, are among the most wonderful experiences in my life…