News

12.10.13

Juno Gives Starship-Like View of Earth Flyby 

This montage of images shows Juno's view of Earth and the moon as the spacecraft approached our planet in advance of its close flyby. Image credit: NASA/JPL-Caltech/DTU Full caption >

When NASA’s Juno spacecraft flew past Earth on Oct. 9, 2013, it received a boost in speed of more than 8,800 mph (about 7.3 kilometer per second), which set it on course for a July 4, 2016, rendezvous with Jupiter, the largest planet in our solar system. One of Juno's sensors, a special kind of camera optimized to track faint stars, also had a unique view of the Earth-moon system. The result was an intriguing, low-resolution glimpse of what our world would look like to a visitor from afar.

"If Captain Kirk of the USS Enterprise said, ‘Take us home, Scotty,’ this is what the crew would see," said Scott Bolton, Juno principal investigator at the Southwest Research Institute, San Antonio. “In the movie, you ride aboard Juno as it approaches Earth and then soars off into the blackness of space. No previous view of our world has ever captured the heavenly waltz of Earth and moon."
This movie sequence of images was obtained by Juno's Advanced Stellar Compass, or ASC. The musical accompaniment is an original score by Vangelis.  Full movie caption >

The cameras that took the images for the movie are located near the pointed tip of one of the spacecraft's three solar-array arms. They are part of Juno's Magnetic Field Investigation (MAG) and are normally used to determine the orientation of the magnetic sensors. These cameras look away from the sunlit side of the solar array, so as the spacecraft approached, the system's four cameras pointed toward Earth. Earth and the moon came into view when Juno was about 600,000 miles (966,000 kilometers) away -- about three times the Earth-moon separation.

During the flyby, timing was everything. Juno was traveling about twice as fast as a typical satellite, and the spacecraft itself was spinning at 2 rpm. To assemble a movie that wouldn't make viewers dizzy, the star tracker had to capture a frame each time the camera was facing Earth at exactly the right instant. The frames were sent to Earth, where they were processed into video format.

"Everything we humans are and everything we do is represented in that view," said the star tracker's designer, John Jørgensen of the Danish Technical University, near Copenhagen.

Also during the flyby, Juno's Waves instrument, which is tasked with measuring radio and plasma waves in Jupiter's magnetosphere, recorded amateur radio signals. This was part of a public outreach effort involving ham radio operators from around the world. They were invited to say "HI" to Juno by coordinating radio transmissions that carried the same Morse-coded message. Operators from every continent, including Antarctica, participated. 
The video presents natural radio signals from Earth’s magnetosphere along with pieces of the repeated Morse code message sent by amateur radio operators, recorded by Juno, and turned into sound. Full movie caption >

This image presents data from Juno's Waves instrument and includes natural radio signals from Earth’s magnetosphere along with pieces of the repeated Morse code message sent by amateur radio operators, received by Juno. Full caption >

A four-minute mini-documentary depicts the efforts of a few of the amateur radio operators who participated in the "HI Juno" event.
This mini-documentary tells the story of how amateur radio operators sent a Morse Code “HI” to NASA’s Jupiter-bound Juno spacecraft. Would Juno hear their call? Credit: NASA/JPL-Caltech/University of Iowa  View on YouTube >

The Juno Morse code HI signal as a ringtone: 

"With the Earth flyby completed, Juno is now on course for arrival at Jupiter on July 4, 2016," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The Juno spacecraft was launched from Kennedy Space Center in Florida on August 5, 2011. Juno’s launch vehicle was capable of giving the spacecraft only enough energy to reach the asteroid belt, at which point the sun’s gravity pulled it back toward the inner solar system. Mission planners designed the swing by Earth as a gravity assist to increase the spacecraft’s speed relative to the sun, so that it could reach Jupiter. (The spacecraft’s speed relative to Earth before and after the flyby is unchanged.)

After Juno arrives and enters into orbit around Jupiter in 2016, the spacecraft will circle the planet 33 times, from pole to pole, and use its collection of science instruments to probe beneath the gas giant's obscuring cloud cover. Scientists will learn about Jupiter's origins, internal structure, atmosphere and magnetosphere. Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief from his wife, but the goddess Juno used her special powers to peer through the clouds and reveal Jupiter's true nature. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology in Pasadena.

More information about Juno is online at the NASA website
News media inquiries:
DC Agle
Jet Propulsion Laboratory
818-393-9011 
agle@jpl.nasa.gov

Members of the media, please contact:

D.C. Agle
Juno Media Relations Representative
NASA's Jet Propulsion Laboratory

(818) 393-9011
Dwayne Brown
NASA Public Affairs Officer
NASA Headquarters

(202) 358-1726

Where is Juno now?

Visualize Juno’s journey through space and get up-to-date data sets using NASA's Eyes on the Solar System 3D interactive.