Hi, Barrett:

I understand your skepticism about NASA releases these days. Uncharacteristically, I'm not at the AAS meeting this winter, so I'm reading about this second-hand.

The release looks good to me, although I'd like to see the submitted paper to be sure (there's allusions to an accepted ApJ paper but I don't see it anywhere yet.)   They've gotten roughly 8 months of data on a planet that is so close to its star that a "year" is only about a day, so there should have been lots of orbits to confirm the results. Certainly the lightcurve on their webpage (http://kepler.nasa.gov/Mission/discoveries/kepler10b/) is pretty convincing.

I won't try to double check the calculations until I see the paper (trying to read these things off of a web plot is madness), but their numbers make sense - a planet of the size and mass they're claiming, and both seem reasonable, would be much more like Mercury then it would be like the usual "Hot Jupiters" that are usually seen.   The main questions would be about the error bars on their numbers.

While the AAS is a friendly crowd, all in all, for NASA, there are planet-finding competitors in attendance, so it would be very easy for journalists to find some "but some scientists expressed skepticism"-type quotes if the data wasn't up to the claims being made.  For instance, when discovery of the "Goldilocks Planet', Gliese 581g, was announced late last September by another group, the October IAU meeting already had people loudly doubting the firmness of the detection.  There are real advantages to working in fields where lots of people are doing similar things - one of the issues with the arsenic thing was that only one group was really looking at the critters in question.

NASA, notably, did do a press release about Gliese 581g:
http://www.nasa.gov/topics/universe/features/gliese_581_feature.html

as did NSF (even a news video)
http://www.nsf.gov/news/news_videos.jsp?cntn_id=117765&media_id=68454&org=NSF

but I think it was handled much more responsibly than the arsenic stuff - which is interesting, given the nature of the potential discovery.  It was a fantastically interesting result if true, and there was seemingly lots of data to back it up, but other groups with different data sets just didn't see the planet there, and that's where things stand pending a few more years worth of data.

Picking signal out of noise in these cases is just hard.  For exoplanets, the ones where detection is most obvious (and firmest, fastest) will always be about the ones that are in some sense least interesting -- super close to their sun, and/or extremely large.   The first real Earth-like planet in the sense of being nearly habitable will be an enormous discovery, and will likely (like Gliese 581g) be very controversial until many years (eg, many "sightings") have passed.

    - Jonathan