Landau، Elizabeth R.؛ Medina، Enrique؛ Angrum، Andrea. "Frequently Asked Questions". برنامج فوياجر. مختبر الدفع النفاث / ناسا. مؤرشف من الأصل في 21 يوليو 2011. اطلع عليه بتاريخ 8 يوليو 2015. "Voyager 1 could have been aimed on to Pluto, but exploration of Titan, because of it being the only known moon to have a significant atmosphere (determined by جيرارد كايبر in 1944 to be methane), and the rings of Saturn was a primary scientific objective. This caused the trajectory to be diverted upward out of the ecliptic plane such that no further planetary encounters were possible for Voyager 1."
Landau، Elizabeth R.؛ Medina، Enrique؛ Angrum، Andrea. "Frequently Asked Questions". برنامج فوياجر. مختبر الدفع النفاث / ناسا. مؤرشف من الأصل في 21 يوليو 2011. اطلع عليه بتاريخ 8 يوليو 2015. "Voyager 1 could have been aimed on to Pluto, but exploration of Titan, because of it being the only known moon to have a significant atmosphere (determined by جيرارد كايبر in 1944 to be methane), and the rings of Saturn was a primary scientific objective. This caused the trajectory to be diverted upward out of the ecliptic plane such that no further planetary encounters were possible for Voyager 1."