April 22, 2015
NASA decided to form a group of experts from various fields, pool their knowledge and expertise and turn a new page in search for planets outside of our solar system that could harbor life. They call it the Nexus for Exoplanet System Science - “NExSS”.
Ever since the genre of science fiction was created, we assumed there were planets around other stars and that they were inhabited by extraterrestrials. When the first extrasolar planet, or exoplanet, was discovered in 1995, it was an amazing discovery, but it hardly surprised anyone who was even an occasional fan of science fiction. Since Kepler space telescope was launched in 2009, the number of known exoplanets passed the 1900 mark and is still rising. Nevertheless, our knowledge is still limited by our technology and our inability to observe exoplanets more closely.
In our Solar System we have eight planets and over 170 moons, but they were all formed at the same time in similar conditions around a single star. By studying planets and moons in the Solar System, we have a limited variety of cases on which to base our theories that should explain which planets can harbour life and which can’t.
By looking outside, we have potentially billions of planets at various distances from their stars, with various sizes, atmospheric and geological compositions, orbiting one, two or three stars, planets of different ages and so on. So far, our search for other civilisations or even simple life on other planets has been fruitless, but with time, as we gather more information, we will hopefully be able to figure out from far away which planets could be suitable for us or for meeting other intelligent species.
NExSS initiative will help astrophysicists, geologists, heliophysicists, exobiologists, planetary and climate scientists to exchange their knowledge by sharing research results and to come up with new ideas by sharing their perspectives on various topics and issues. All this has one goal - to answer one of the most interesting questions we have ever asked ourselves: Are we alone?
"This interdisciplinary endeavor connects top research teams and provides a synthesized approach in the search for planets with the greatest potential for signs of life," says Jim Green, NASA’s Director of Planetary Science. "The hunt for exoplanets is not only a priority for astronomers, it’s of keen interest to planetary and climate scientists as well."
Tasks standing in front of NExSS are wide in range. The group will classify the diversity of discovered worlds, past and future, gain deeper understanding of potential habitability of these worlds and help develop new tools and technologies that will improve the search for exoplanets and life on them.
NExSS will have an approach dubbed system science, where Earth scientists come up with the system by studying our planet. Then, planetary scientists apply this system to planets in our Solar System and heliophysicists add their touch by taking into the account the Sun’s influence on our neighbouring planets. Finally, astrophysicists add data gathered on exoplanets and stars that they orbit, thus completing the system which will be applied on exoplanets already found, but should be also future-proof, since there are many more worlds to be discovered.
"NExSS scientists will not only apply a systems science approach to existing exoplanet data, their work will provide a foundation for interpreting observations of exoplanets from future exoplanet missions such as TESS, JWST, and WFIRST," says Dr. Paul Hertz, Director of NASA’s Astrophysics Division. TESS is Transiting Exoplanet Survey Satellite set for 2017 launch, JWST is James Webb Space Telescope, launch in 2018, and WFIRST stands for Wide-field Infrared Survey Telescope, being developed for launch sometime in 2020s.
The extensive list of teams included in NExSS and their area of expertise can be found on NASA website, but as expected, it includes experts from 10 universities and two research institutes, leaders in all imaginable fields like evolution of planet formation, planetary habitability from chemical perspective, history of Solar System’s rocky planets, research of atmospheres of gas giants, computer simulations and so on.