(CNN) Vera Rubin, a pioneering astrophysicist who proved the existence of dark matter, had a gift for overcoming daunting challenges. While there were indications going back to the 1930s that dark matter existed, her work confirmed it. If dark matter doesn`t fit that description, I don`t know what does. Her colleagues and those who admired her spirit remember her as someone who revolutionized our understanding of the cosmos by confirming the existence of dark matter, invisible material that comprises more than 90% of the universe. Others worked on the subject of dark matter, and it`s important to remember that in science, each person`s achievements are built on the backs of those who came before.

The hotel is located around 40 miles from the helicopter crash site, on the other side of the Gran Sasso mountain. Story highlights Rescue helicopter was transporting an injured skier in the central Italian mountainsTwo police officers, three medics and the skier were all killed(CNN) An emergency helicopter crashed in the mountains of central Italy Tuesday, killing at least six people. Two members of the Guardia di Finanzia police, three medical personnel and the injured skier were killed. The crash near the ski resort of Campo Felice in the province of L`Aquila happened during an operation to rescue an injured skier, according to the Prefecture of L`Aquila. The crash took place around 12:15pm at an altitude of 600 meters and was caused by bad weather, according to the Prefecture.