Yeah, that was my first thought too. Sample bias all the way.
1) Things which orbit rapidly are easy to spot as we get lots of observations from occlusion and wobble. You can identify a planet over the course of a few weeks if it has a period measured in days.
2) Things which are massive are easy to detect using wobble methods. The closer in they are, the more wobble there is. GMm/r^2 and all that.
3) Massive close-in things with short periods are the easiest planets to detect by a country mile, as you get a nice big occlusion along with a nice big wobble, all happening on nice short timescales.
This entire article is oriented around sample bias due to current instrumentation and techniques. We have little hope of spotting the equivalent of, say, Uranus, with the same orbital period and distance, as we'd need, um, a good few centuries of observations using wobble and occlusion to be certain - and the net effects measured would be tiny, so you'd need a huge pile of data to get a statistically significant measure.
Finally, earth-mass planets at an earth-like distance - again, tricky. Less tricky than the above, arguably, particularly if they have atmospheres (spectral changes are a dead giveaway), but still tricky.
I think sampling bias is definitely the most likely reason we haven't seen any solar systems like ours, but...
Even with sampling bias, we could still be seeing something legitimately weird. We expect to detect some certain number of exo-planets with a certain range of characteristics with our current technology. We don't think this set of exo-planets is necessarily representative of the average exo-planet in the galaxy, because of the limits of our technology, but we expect to look at X stars, and see Y planets, which look about like Z (where Z is probably Jupiter-sized planets orbiting at Jupiter-like distances). We might also expect to see a few weird planets, where the solar systems are aberrations or we just got lucky and detected something better than we'd expect with our technology.
But what this article seems to be saying (maybe a little poorly) is that the set of planets observed is not the subset of planets we expected to observe. We expected (say) to look at 100,000 stars, see 100 normal Jupiters, fail to see 9,900 other normal Jupiters that were there but we didn't detect, and see 1 aberration, like an Earth-like planet we accidentally detected or a hot Jupiter representing a weirdly captured wandering planet. Instead, we saw 1000 aberrations, hot Jupiters. More than we expected to see based on how we thought solar systems formed.
Just because the unexpected thing is actually extremely easy to detect once you're looking at the universe in the right way doesn't make it any less unexpected. Even if we eventually find millions more solar systems that look like ours than ones with hot Jupiters, we might still have to figure out why there are so many more hot Jupiters than we expected.
I think there's a meta argument encoded in the sampling bias discussion. That being: some people want to expose NPR as just another media center that produces watered down content labeled as science with a complete lack of journalistic integrity. Other people want to believe NPR and perhaps a few other select content producers are publishing articles such as this with the utmost respect to the material. I.e. Things like page views are not considered when it comes to telling a somewhat complete version of the story.
I think this case falls under the lack of journalistic integrity, regardless of whether the overall claim is right or wrong. My view is that when a science article wants introduce the idea that reality may be different than conventionally believed, the goal should be to write an (at least mildly) well rounded, informative piece, not a strictly persuasive piece. When the first response in hundreds of armchair physicists' minds around the world is surprise that selection bias wasn't even mentioned (mine included), I think it's fair to say the article falls more into the persuasive category.
Yeah, but the other possibility is that our tech hasn't lived up to our expectations, and therefore we haven't made the observations and measurements we might have hoped for, which I'd wager is far more likely.
"Hot Jupiter" type planets aren't as much of a revelation as one might expect, however, given the prevalence of binary systems, many of which have very, very short periods (J0106-1000 has one of 39 minutes) - and there's still nothing to say that those same systems don't have rocky worlds tucked away that we can't see due to the overwhelming noise from the massive inliers.
1) Things which orbit rapidly are easy to spot as we get lots of observations from occlusion and wobble. You can identify a planet over the course of a few weeks if it has a period measured in days.
2) Things which are massive are easy to detect using wobble methods. The closer in they are, the more wobble there is. GMm/r^2 and all that.
3) Massive close-in things with short periods are the easiest planets to detect by a country mile, as you get a nice big occlusion along with a nice big wobble, all happening on nice short timescales.
This entire article is oriented around sample bias due to current instrumentation and techniques. We have little hope of spotting the equivalent of, say, Uranus, with the same orbital period and distance, as we'd need, um, a good few centuries of observations using wobble and occlusion to be certain - and the net effects measured would be tiny, so you'd need a huge pile of data to get a statistically significant measure.
Finally, earth-mass planets at an earth-like distance - again, tricky. Less tricky than the above, arguably, particularly if they have atmospheres (spectral changes are a dead giveaway), but still tricky.
JWST could serve up the goods.