“Understanding the causes of the differences between the Trojans will provide unique and critical knowledge of planetary origins, the source of volatiles and organics on the terrestrial planets, and the evolution of the planetary system as a whole,” said Dr. Catherine Olkin, Lucy mission’s deputy principal investigator.
“When I suggested this topic, I wondered whether two inhabited planets would exist (the Earth and Venus) if Mars and Venus formed in opposite locations,” said Chris Colose, a climate scientist based at the NASA Goddard Institute for Space Studies. “Being at Mars’s orbit would avoid the runaway greenhouse and a Venus-sized planet wouldn’t have its atmosphere stripped as easily as Mars.”
“The search for exoplanets using the Kepler data is still underway. Many are still hiding in the data, ready to be discovered,” said Susan Mullally, a scientist working on the Kepler mission at STScI.
Kepler has opened our eyes to the diversity of planets that exist in our galaxy. The most recent analysis of Kepler’s discoveries concludes that 20 to 50 percent of the stars visible in the night sky are likely to have small, possibly rocky, planets similar in size to Earth, and located within the habitable zone of their parent stars. That means they’re located at distances from their parent stars where liquid water – a vital ingredient to life as we know it – might pool on the planet surface.
“It has revolutionized our understanding of our place in the cosmos,” said NASA’s astrophysics director Paul Hertz. “Now we know because of the Kepler Space Telescope and its science mission that planets are more common than stars in our galaxy.”
Among its many findings, Dawn helped scientists discover organics on Ceres and evidence that dwarf planets could have hosted oceans over a significant part of their history—and possibly still do. The Kepler Mission, meanwhile, launched in 2009 and revealed that there is statistically at least one planet around every star in our galaxy.
