One of the unspoken caveats of most exoplanet discovery missions is that they only operate for a few years. Such a short observing window means there are planets with longer orbital periods, usually further out from the star, that those surveys would completely miss. Knowing this would be a problem, a team of astronomers arranged the California Legacy Survey three decades ago in order to monitor as many stars as possible for as long a time as possible. Recently, they released their first results, which show solar systems that are surprisingly like our own.
Click here for original story, Exoplanet surveys are leaning toward the possibility that our solar system is normal
Source: Phys.org