Recent science journal articles celebrate the achievements of the Voyager spacecraft. In 1977, NASA launched two Voyager spacecrafts, 1 and 2, each the size of a small car, to visit Jupiter, Saturn, Uranus, Neptune and their moons. Then the craft were programmed to head straight out beyond the reaches of the Sol star. Originally built for a five-year mission, the Voyager craft have been sending signals back to Earth for the past 36 years. Attached to the spacefarers are gold-plated copper phonograph records that contain pictures, languages and sounds about Earth and human culture.
Voyager fast facts
- The two Voyager craft are powered by radioisotope thermoelectric generators, which are miniature nuclear power plants fuelled by plutonium-238.
- Voyager 1 travels at 57,600 kph (35,790 mph), or 523.6 million kilometers per year.
- Voyager 1 has traveled 18 billion kilometers from Earth; it is the most distant human-made object.
- Communication between Voyager 1 and NASA’s Jet Propulsion Laboratory in Pasadena, California, takes 17 hours one way.
What have we learned from Voyager 1 and 2?
The Voyager craft are fitted with devices that measure low-energy charged particles and magnetic fields, and they have ultraviolet and infrared spectrometers for atmospheric analysis. In addition, the Imaging Science Subsystem camera on each has brought back some of the most awe-inspiring images from space. Among the Voyagers’ achievements are finding volcanic eruptions on Jupiter’s moon Io and discovering new moons and new rings around the outer gas planets.
Voyager also shot the famous 1990 “Pale Blue Dot” photo of a tiny Earth in the vastness of space, taken from 3.7 billion miles away. Astronomer Carl Sagan said, “That’s it. That’s home… a mote of dust, suspended in a sunbeam… There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish that pale blue dot, the only home we’ve ever known.” The quote was reprinted in “Into the void: After 35 years, Voyager 1 is finally leaving the solar system—the first man-made object ever to do so. What has its journey meant?” by Maggie Aderin-Pocock, in New Statesman, December 21, 2012.
Where is the official edge of the solar system?
The edge of the solar system is traditionally defined as the end of the influence of our star. This is the edge of the heliosphere, the reach of the sun’s solar wind and magnetic field, whereas interstellar space contains plasma, a kind of ionized gas ejected by giant stars millions of years ago. In March 2012, a coronal mass ejection burst from the sun and reached Voyager 1’s sensors in April 2013. The density of the oscillations in the spacecraft told scientists that the craft had officially reached interstellar space on August 25, 2012. Don Gurnett and his team at University of Iowa published the findings in the newest issue of the journal Science.
Voyager mission project scientist Ed Stone of Caltech remarked in the article “Leaving the solar system: Q&A with Voyager 1 chief scientist Ed Stone,” on Space.com, September 12, 2013: “it’s really a wonderful experience, because we’re now beginning the exploration of an entirely new region of space where nothing has ever been before… Voyager now has joined the other great expeditions of exploration.”
What is beyond the solar system?
What is in interstellar space? “Scientists were surprised by NASA’s finding that the galaxy’s magnetic field is apparently aligned in the same direction as the sun’s, forming a ‘magnetic highway.’ Space scientists had generally assumed that the galaxy’s magnetic field would have some other direction,” reported Dan Vergano in “Voyager 1 leaves solar system, NASA confirms,” in National Geographic, September 12, 2013.
The Voyager spacecraft are scheduled to be powered down in 2025 and will forever float among the stars. Sci-fi filmgoers pondered the fate of the craft in the 1979 movie Star Trek: The Motion Picture, in which Earth’s Voyager probe entered interstellar space and merged with a mechanized life form. Scientists calculate that in 40,000 years, Voyager 1 will pass within 1.7 light years of the red dwarf star AC+79 3888 in the Camelopardalis constellation. Is anyone out there? Will they find our little unmanned ship? Will they try to contact us? Will humanity still be around for them to speak with if they do?
What do you think Voyager will find out in space?