Dr Catherine Cesarsky, has recently been elected as the first woman president of the International Astronomical Union. This is the body of almost 1000 distinguished professional astronomers who last month demoted Pluto from its planet status.
Dr Cesarsky is also Director General of the European Southern Observatory which operates the Very Large Telescope in Chile. This is helping astronomers to expand the boundaries of the known universe by examining other galaxies and finding planets outside our solar system.
So what first drew her to the stars? Jenni talks to Dr Cesarsky about her work and her plans to celebrate the 400th anniversary of Galileo's first recorded astronomical observations with an International Year of Astronomy in 2009.
