1) In the paper "The Lick-Carnegie Exoplanet Survey: A 3.1 M_Earth Planet in the Habitable Zone of the Nearby M3V Star Gliese 581" you and your team are evaluating the results of a survey. How long did you work on this survey and what were the results?
This was the result of 11 years of observing, part of a survey covering over 1500 stars that has been going on for the past 15 years now. Out of this survey, we have found hundreds of planets around other stars, from transiting planets, to multiple planets, etc. We have discovered the full range of planets, from large planets many times larger than Jupiter, to planets as small as only a few times the mass of the Earth, and orbits from less than 2 days to orbits as long as 12-15 years.
2) What are the main characteristics of Gliese 581g? How does it differ from the planets a-f?
GJ 581g has a mass of 3-4 Earth-masses, an orbital period of about 37 days, and an orbital radius of about 0.146 Astronomical Units. GK 581f has a mass of about 7-9 Earth-masses, an orbital period of about 433 days, and an orbital radius of about 0.76 AU. So GJ 581f is probably more like a Uranus and GJ 581g is more like an Earth.
3) How do you think these findings will change the way the universe is viewed?
I think that, knowing how common Earth-size planets are tells us a lot about the likelihood of finding life, intelligent or otherwise, out there. These findings suggest that potentially habitable planets, approximately Earth-sized, with surface temperatures capable of supporting liquid water, may be quite common out there, and thus that there are likely billions of such places in our own Galaxy alone, not to mention the many trillion of other galaxies we know are out there.
4) What is the next step for your research?
The next step is to continue this survey work, looking to confirm this detection as well as to find more of these potentially habitable planets, preferably around the very nearest stars. I am also interested in SETI follow-ups where we listen intently to each such system, hoping to detect evidence of advanced life forms there. Such work is indeed quite along shot, but eminently worth the effort in my opinion. I am also now completing a facility called the Automated Planet Finder at Lick Observatory 20 miles east of San Jose. This dedicated facility will robotically scan the skies every night of the year for the kind of signatures that led to the discovery of GJ 581g. With this facility, we hope to find many more such planets.
These are Dr. Steve Vogt's written remarks. Please refer to the video interview for exact quotes.