Slide 1 of 20
NASA's Juno Mission to JupiterNASA most advanced probe yet to study the planet Jupiter is on its way to the gas giant, but the new mission (called Juno) stands on the shoulders of giants, its managers said — specifically the eight robotic spacecraft that visited the gas giant planet previously.
"Each of the missions that we do are providing unique and very important information," said Juno's principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio, just before Juno's August 2011 launch. "Some of those earlier missions were reconnaissance, so we could figure out what are the right questions, and they essentially led us to ask the questions that we have with Juno." [Photos: NASA's Juno Mission to Jupiter]
Here's a rundown of all the manmade objects sent to visit Jupiter so far:
Pioneer 10Slide 2 of 20
Pioneer 10The first spacecraft ever to make it as far as Jupiter was NASA's Pioneer 10 probe, launched in March 1972 on a mission to study the asteroid belt, the atmosphere of Jupiter and the outer solar system. About a year-and-a-half later, in December 1973, Pioneer 10 encountered Jupiter.
The craft flew within 124,000 miles (200,000 kilometers) of the tops of the clouds covering the gas giant. It made a number of revelations about the gas giant, including measurements of the intense radiation in the environment of Jupiter.
Pioneer 10 is currently on a trajectory to leave the solar system, traveling toward the outskirts of the Milky Way in the direction of the star Aldebaran. Communication with the spacecraft was lost in 2003.Slide 3 of 20
Pioneer 11Slide 4 of 20
Pioneer 11A sister ship to its predecessor, Pioneer 11 was launched in April 1973. This craft became the second to fly through the asteroid belt and passed Jupiter in December 1974. Pioneer 11 went on to become the first spacecraft to encounter Saturn in July 1979.
This probe captured detailed images of the Jovian Great Red Spot, as well as the planet's poles, and measured the mass of Jupiter's moon Callisto.
Humans lost the ability to communicate with Pioneer 11 in 1995, but the probe is still traveling toward the center of the galaxy in the direction of the constellation Scutum.Slide 5 of 20
Voyager 1Slide 6 of 20
Voyager 1Launched in September 1977, Voyager 1 flew by Jupiter in March 1979, taking more than 18,000 images of the gas giant and its satellites. The vehicle made its closest approach at a distance of about 217,000 miles (349,000 kilometers) of the planet's center. Among Voyager's discoveries was the presence of volcanic activity on Jupiter's moon Io.
Voyager 1 is now on its way out of the solar system and is currently the most distant manmade object from Earth, at about 69 times the distance from the sun to our own planet.Slide 7 of 20
Voyager 2Slide 8 of 20