Rome, December 31 - Understanding what dark matter is made of may be one of the biggest scientific challenges ahead in the new year, Italian physicist Fabiola Gianotti told ANSA on Thursday. As of January 1, the 53-year-old Rome native who participated in the discovery of the Higgs boson will be the new director of the European Organization for Nuclear Research (CERN) - the first woman in the post since the particle physics lab was founded in 1954. The visible universe - the planets, stars, and galaxies - is made up of atoms or 'baryonic' matter, which makes up less than less than 5% of the total mass of the universe. The rest seems to be made of a mysterious, invisible substance called dark matter (25%), plus a force that repels gravity known as dark energy (70%). CERN scientists have been trying to prove the existence of the actual particles of dark matter by attempting to create them at the lab's Large Hadron Collider (LHC). The latest experiments, said Gianotti, may or may not have generated an actual dark matter particle. "Caution is of the essence," she said. "Our indications... could point to the first 'wail' of a newborn particle, or simply a statistical fluctuation. We'll know more in mid-2016". As far as her new leadership position at CERN, Gianotti says she will focus on developing innovative technologies, teaching, and peace. "(My goals are) training the younger generations and fostering the peaceful collaboration of thousands of scientists from around the world," she told ANSA.