This week during the 219th meeting of the American Astronomical Society a number of announcements were made about recent discoveries, today we will take a looks at some of these.
One of the most significant is the announcement that almost every star in the galaxy has at least one planet orbiting it. Recently we discussed the results of the Kepler data that had been released to date that estimated that there could be as many as 7 sextillion planets in the universe. However with this new announcement this would increase to 300 sextillion planets at least and we know for certain that there are multi-planetary systems out there, including the one we live in. One estimate suggested there are 1.6 planets for every star; therefore we are looking at potentially 480 sextillion planets in the universe.
Based on this information we can speculate that there are 1500 planets within a 50 light-year radius of earth. While we still don’t have the technology to get to these any time soon we do have instruments powerful enough to start investigate these in a lot more detail. The next few years in planetary hunting are going to be very exciting as more and more of the Kepler candidates are confirmed and as more and more powerful telescope come online.
The Kepler team recently announced that they are finding that smaller planets are actually more common than the larger gas giant planets. Combined with the above announcements the possibility of finding other habitable worlds has increased significantly.
In another announcement astronomers at the California Institute of Technology announced the discovery of the smallest Explanets so far. Measuring 0.57 to 0.78 times the size of earth the three planets orbit the star KOI-961, which is 130 light-years away in the Cygnus constellation. The team used the Kepler data combined with additional observations of the star, due to the star’s similarity to Barnard’s star they were also able to use information gathered from previous observations of this year which is much closer at only 6 light-years from Earth.
Following the previous announcement of a circumbinary planet, one that orbit’s two stars. The Kepler team announced two additional circumbinary systems. It would seem that these systems are not rare exceptions, and one day we could well see a double sun-set just like Luke did in Star Wars. Again we don’t have the technology to visit these systems today but I believe one day humans will.
The final announcement we will look at today is the discovery of a ring like system similar to Saturn’s transiting a distant star. Unlike a planetary transit these are harder to detect because the light dip will be different depending on the structure of the rings. The team studied light curve data from SuperWASP (Wide Angle Search for Planets) and All Sky Automated Survey (ASAS).
So why the reference to The Pale Blue Dot, I am reminded as we discover more and more planets in the Universe that we live on a tiny island in the vast sea of the Universe. As a christian I believe that we are the only intelligent species out there, however I also believe that there are many habitable worlds and one day we will go out from our tiny place and visit them. I don’t know what the future holds for the discovery of planets but I believe within the next 5 years we will directly image planets orbiting other stars and be able to read their chemical signatures.