Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, is interviewed prior to serving on a panel at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Gary Knell, President and CEO of National Geographic Society, gives opening remarks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ann Druyan, writer/producer and golden record visionary, speaks on a panel at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, speaks on a panel at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ed Stone, Voyager project scientist, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Suzy Dodd, Voyager project manager, NASA's Jet Propulsion Laboratory, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Gary Flandro, Voyager mission grand tour creator, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Ann Druyan, writer/producer and golden record visionary, speaks about the last image of Earth from the Voyager spacecraft, at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Alan Cummings, Voyager researcher, Caltech, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ann Druyan, writer/producer and golden record visionary, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Ann Druyan, writer/producer and golden record visionary, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, gives opening remarks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

An audience member asks a question at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, gives opening remarks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ann Druyan, writer/producer and golden record visionary, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, gives opening remarks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Morgan Cable, researcher, NASA's Jet Propulsion Laboratory, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, gives opening remarks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Eric Zirnstein, researcher, Princeton University, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Ann Druyan, writer/producer and golden record visionary, speaks on a panel with moderator Victoria Jaggard, National Geographic Magazine science editor, left, Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, right; and Ed Stone, Voyager project scientist, not pictured, at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ed Stone, Voyager project scientist, right, speaks on a panel with Thomas Zurbuchen, NASA associate administrator, Science Mission Directorate, left, at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Ed Stone, Voyager project scientist, speaks at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

William Shatner of Star Trek, is seen on a live feed from NASA's Jet Propulsion Laboratory, giving the order to send a message into deep space, during an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey

Gary Flandro, Voyager mission grand tour creator, speaks on a panel at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at Smithsonian's National Air and Space Museum in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Panelists, from left to right, Ed Stone, Voyager project scientist; Victoria Jaggard, National Geographic Magazine science editor and moderator for the panel; Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate; and Ann Druyan, writer/producer and golden record visionary, visit in the green room before speaking at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Victoria Jaggard, National Geographic Magazine science editor, left, moderates a panel discussion with, Ann Druyan, writer/producer and golden record visionary, second from left; Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, second from right; and Ed Stone, Voyager project scientist, right, at an event to celebrate the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at National Geographic Society Headquarters in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Matthew Shindell, curator, Smithsonian National Air and Space Museum (NASM), far left, moderates a panel including, from left to right, Ed Stone, Voyager project scientist; Gary Flandro, Voyager mission grand tour creator; Alan Cummings, Voyager researcher; Suzy Dodd, Voyager project manager, NASA's Jet Propulsion Laboratory; and Ann Druyan, writer/producer, Golden Record Visionary during a celebration of the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at NASM in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)

Matthew Shindell, curator, Smithsonian National Air and Space Museum (NASM), far left, moderates a panel including, from left to right, Ed Stone, Voyager project scientist; Gary Flandro, Voyager mission grand tour creator; Alan Cummings, Voyager researcher; Suzy Dodd, Voyager project manager, NASA's Jet Propulsion Laboratory; and Ann Druyan, writer/producer, Golden Record Visionary during a celebration of the 40th Anniversary of the launch of the Voyager 1 and 2 missions, Tuesday, September 5, 2017 at NASM in Washington. Voyager 1 was launched September 5, 1977, with a mission to study Jupiter and Saturn, but now the twin Voyager spacecrafts are on a journey into interstellar space to search for the heliopause, a region never reached by any other spacecraft. Photo Credit: (NASA/Aubrey Gemignani)