NASA’s recent discovery of a seven-planet solar system didn’t just give the possibility of alien life – it helped contribute to a theory that far-away planet systems are shaped like our Solar System – multiple planets aligning with the host star on a flat plain.
Today NASA announced that a team of scientists has confirmed seven Earth-sized exoplanets orbiting TRAPPIST-1, a star located just 39 light-years away from our Sun. The six inner planets are very likely to be rocky, are roughly the same mass as Earth, and are thought to have comparable surface temperatures to our own planet. Three of the planets may even be able to support liquid water and perhaps, life.Read more
Associate Professor Charley Lineweaver from the ANU Research School of Astronomy and Astrophysics (RSAA) said NASA’s discovery supported the research, which challenges the usual assumption that planet systems are flared like bellbottoms.
“Other planet systems in the Universe seem to be much like our Solar System,” said Dr Lineweaver, “The more we find out about these planet systems the more it seems the Solar System is unexceptional.”
The Kepler space telescope has detected more than 4,000 planets orbiting 3,200 stars. The majority of these host stars have only one detected planet, while 656 have multiple planets.
Lead researcher and RSAA PhD student Tim Bovaird says the wealth of the Kepler planet data allows – for the first time – detailed studies of planet systems outside the Solar System.
“We are now able to ask and answer questions like, how common are planet systems like our own?” Mr Bovaird said.
Simulations of these planet systems had previously only matched the observed data by assuming a Kepler Dichotomy, an assumption that there are two types of star: one type with only one planet, and another type with multiple planets.
“Simulations with flared planet systems were slightly easier to perform and that is what researchers had assumed,” Mr Bovaird said. “But this is an odd assumption because the inner part of our Solar System is flat, not flared. When we dropped the assumption that planet systems are flared, simulations naturally matched the observed data without using the Kepler Dichotomy.”
Dr Lineweaver said the team’s result should demote the Kepler Dichotomy and allow more realistic interpretations of new planet systems.