Besides his Calabash pipe, Sherlock Holmes is always caricatured as having a huge magnifying glass to hunt for clues.
Astronomers attending the American Astronomical Society Meeting in Washington D.C. say that they have used nature's magnifying glass to hunt for solar systems like ours.
Scott Gaudi of Ohio State University reported that, in a preliminary survey, he concludes that at least 15 percent of the stars in our Milky Way galaxy have a planetary architecture like that of our solar system. That is, a family of gas giant planets located as far from the star as Jupiter and Saturn are from the sun. This leaves plenty of elbowroom for undetected terrestrial planets to huddle close their star, just as Mercury, Venus, Earth and Mars do.What's more, the gas giants could irrigate parched inner terrestrial planets with ices from comets and asteroids they perturb.
This may not seem like a big number, but if the statistics hold up with further observations, it works out to several hundred million solar system analogs in the Milky Way.
A phenomenon called gravitational microlensing, where the gravity from a foreground star momentarily bends and amplifies light from a background star, was used to do a statistical search for solar systems like ours. Massive planets accompanying a star, at a wide separation from the star of a billion miles or so, will also leave a detectable lensing signature during the brief celestial alignment.