Our Goal:

The goal of the exoplanet project is to explore all the avenues to characterize exoplanets; to find out whether our Solar System is unique, or common; and to focus the search for extraterrestrial life at exoplanets with the best conditions for life.

 

Our Approach:

A revolution in astronomy occurred 28 years ago when astronomers discovered the first planet orbiting a Sun-like star outside of our Solar System. Today we know there are thousands of planets orbiting other stars and each of these planetary systems has its own architecture. Next, is to understand the general characteristics of those exoplanets.

Most exoplanets have been detected using the transit method where the light from a distant star dims as a planet passes in front. It’s best for detecting exoplanets with short orbital periods. Longer observations are needed to detect planets with multi-year orbits to find systems more like our own. Carnegie astronomers use radial-velocity and astrometry methods using ground-based telescopes to look for these. Planets distant from their star could also be directly imaged with the next generation of telescopes.

After the range of planetary architectures is defined, researchers can then determine exoplanet composition, with a combination of all three methods. They have started to address whether exoplanet composition is related to the composition of their stars.

They also want to measure the composition of exoplanet atmospheres to search for signatures of life. Time-varying atmospheric compositions, in carbon dioxide or sulfur dioxide, could also indicate volcanic activity.

A stable climate is also critical for life on Earth. Exoplanets within a “habitable zone,” the distance at which liquid water is stable has been a priority. However, some close to their stars are bombarded with energetic particles and X-rays that leads to sterility. So,  researchers will  search for exoplanet magnetic fields, like Earth’s magnetosphere, which protects our planet.

Image credit: This artist impression shows a gas-giant exoplanet transiting across the face of its star. Infrared analysis by NASA Spitzer Space Telescope of this type of system provided the breakthrough.

 NASA ExoplanetPIA10364