Thanks to tracks created by outermost planet Neptune (if you accept that Pluto is no longer classed as a planet that is) in the dust of the Kuiper belt – a very large Asteroid belt like collection of frozen objects that reside on the edge of the solar system – astronomers on alien worlds should be able to detect the presence of the Sun’s planetary system:
“The planets may be too dim to detect directly, but aliens studying the solar system could easily determine the presence of Neptune – its gravity carves a little gap in the dust,” Goddard astrophysicist Marc Kuchner said in a press release yesterday. “We’re hoping our models will help us spot Neptune-sized worlds around other stars.”