OK, and there was another announcement along with the recalculated orbit of Gliese 581 D.
That was the discovery of another planet in the system, Gliese 581 E.
Compared with other exoplanets, its mass is quite small, only about twice that of Earth.
Student: So, it Gliese 581 E a more earth-like planet?
Professor: Well, we have to consider its orbit.
Gliese 581 E orbits its host star in a much shorter period of time than the other planet in the system, meaning its very close to the star, and therefore too hot for water, for an ocean.
However, the fact that its relatively close to the size of Earth, small, in astronomical terms, that was pretty exciting.
Its impressive that we have the technology to detect it and it bodes well for future research.
Who knows what well find the more we search.