Humanity has visited Uranus only once, and now it is 37 years. NASA’s Voyager 2 spacecraft made its closest pass of the mysterious distant gas planet on January 24, 1986.
Voyager 2 returned stunning images of the planet and its moons during the flyby, which allowed for about five hours of detailed study, only 81,500 kilometers away.
“We knew Uranus would be different because it’s tilted to one side.“, said Ed Stone, Voyager mission scientist, based at the California Institute of Technology in Pasadena, since 1972, reports NASA.
Uranus revealed to be the coldest known planet in our solar systemeven though it is not the farthest from the Sun. This is because it does not have any internal heat sources.
Scientists determined that Uranus’ atmosphere is 85 percent hydrogen and 15 percent helium. There was also evidence of a boiling ocean 800 kilometers below the clouds.
The scientists found that Uranus has a magnetic field unlike any that had ever been found previously. On Mercury, Earth, Jupiter, and Saturn, the magnetic field is roughly aligned with the axis of rotation.
“Then we got to Uranus and saw that the poles were closer to the equator.Stone said. “Neptune turned out to be similar. The magnetic field was not quite centered with the center of the planet.”
This Uranus magnetic field was also stronger than Saturn’s. Data from Voyager 2 helped scientists determine that Uranus’s magnetic tail spins in a helix that extends 10 million kilometers in the direction pointing away from the sun. Understanding how planetary magnetic fields interact with the sun is a key part of NASA’s goal to understand the nature of space. Not only does studying the sun-planet relationship provide useful information for space travel, but it helps shed light on the origins of the planets and their potential to support life.
Voyager 2 also discovered 10 new moons (there are 27 in all) and two new rings on the planet, which was also fascinating. An icy moon named Miranda revealed a peculiarly varied landscape and evidence of active geological activity in the past. Only about 500 kilometers in diameter, this small object has gigantic canyons that could be up to 12 times deeper than the Grand Canyon of Colorado. Miranda also has three unique features called “coronae,” which are groups of crater ridges and valleys. Scientists believe that this moon may have been torn apart and then reshaped.
Mission planners designed Voyager 2’s encounter with Uranus so that the spacecraft would receive a gravity assist to help it reach Neptune. In 1989 Voyager 2 added Neptune to its roadmap.
Voyager 2 was launched on August 20, 1977, 16 days before its twin, Voyager 1. In August 2012, Voyager 1 made history as the first spacecraft to enter interstellar space. Voyager 2 also accomplished this feat in November 2018.