There is a greeting in Urdu that is floating in space more than 19 billion kilometers from Earth! How did get there? Is it at the edge of our solar system? For that matter, how do we even figure out the boundaries of our own solar system? To find out answers to these questions, please join us in this episode of Science ka Adda. For more videos in the series, please visit sciencekaadda.com or join us on Facebook at facebook.com/ScienceKaAdda.