b'The Presidents CommentaryHabitability:Conditions for Life on Earth and ExoplanetsLooking beyond our planet and our Solar System, Carnegies scientists are pursuing the question of habitabilityworking at the interdisciplinary boundaries of astronomy, geophysics, geochemistry, planetary science, and 10 astrobiology to understand the planetary conditions that are necessary for life to emerge and flourish. The search for planets outside our Solar System began in earnest only about 25 years ago. Since then, Carnegie researchers have been leaders in the hunt for evidence of exoplanets; our recent work using computer simulations suggests that there may be an estimated 700 million trillion terrestrial planets in the observable universe. With so many planets swirling through the cosmos, it seems almost implausible that Earth could be the only planet with the capability to sustain life. S4 HD 61005 (The Moth) HD 32297 Solar MantleSystem O2 size0 Si Core-2 72 AU 130 AU 100 AU C-4 No Gas (Asteroids) Gas (Comets) COMPOSITION Mg 5 mmMacGregor, Weinberger,et al. 2018Alycia Weinberger studies how planets form by observing youngAnat Shahar simulates conditions in the interior Earth and other stars and their disks, from which planets are born. The light fromplanetary bodies using high-pressure methods. Earths interior these systems yields information on the existence and abundances ofcontains sulfur, oxygen, silicon, carbon, and magnesium, among different molecules and conditions, such as temperature and pressure,other elementsimportant ingredients for the rise of life on Earth. that are important for understanding what makes a planet habitable. Top image courtesy Carnegie Institution for Science; bottom image courtesy Anat ShaharTop image courtesy Roberto Molar Candanosa; bottom image courtesy Alycia Weinberger and Meredith MacGregor,Carnegie Institution for Science'