Europa, one of Jupiter's moons, has long been thought to harbor water underneath its icy crust. New research suggests that water gets close to Europa's surface sometimes, but doesn't stay there long.
Liquid water may be close to the moon's surface during some periods of time, but it migrates back downward after a few thousand years - the blink of an eye, in geological terms. Variations in gravitational pull from Jupiter produce the heat that temporarily melts the ice near the surface.
Klára Kalousová from the University of Nantes in France and Charles University in Prague, Czech Republic, presented the research at the European Planetary Science Congress in Madrid last week. She said that while her findings show water only a few kilometers below the surface is likely on Europa, it disappears quickly.
Editor's note: Meg Urry is the Israel Munson professor of physics and astronomy and chairwoman of the department of physics at Yale University, where she is the director of the Yale Center for Astronomy and Astrophysics.
(CNN) - In 2001, I became the first tenured female faculty member ever in Yale's physics department. Throughout my 30 years as a physicist, being the only woman in the room has been the norm. Women fill more than half of the jobs in the U.S. economy but constitute fewer than 12% of working physicists and engineers. For me and for others in STEM fields (science, technology, engineering and mathematics), the dearth of women is not news.
What was big news last week was a study, from colleagues in other departments at Yale, explaining why this deficiency of women persists.
Evidence shows that established scientists at top research universities - those choosing and training the next generation of STEM experts - unconsciously rate budding female scientists lower than men with identical credentials. They judge women less capable, less worthy of hiring and less deserving of mentoring. And they propose starting salaries that are on average 14% higher for men than for women.