Earth and Moon from Juno fly-by

"Earth and Moon as seen from passing spacecraft"

D C Agle
Jet Propulsion Laboratory

Steve Cole
NASA Headquarters 

When NASA’s Juno spacecraft flew past Earth on October 9, 2013, it received a boost in speed of more than 7.3 kilometers per second, which set it on course for a July 4, 2016 rendezvous with Jupiter. One of Juno's sensors, a faint star tracking camera, also had a unique view of the Earth-Moon system. The result was an intriguing, if low-resolution, glimpse of what it would be like to approach our worlds from a distance.

“In the movie, you ride aboard Juno as it approaches Earth and then soars off into the blackness of space," said Scott Bolton, Juno principal investigator at the Southwest Research Institute (SwRI) in San Antonio. "No previous view of our world has ever captured the heavenly waltz of Earth and Moon."

The Juno Earth flyby movie is available on YouTube HERE. The original score is by Vangelis.

Ancient cosmic pirouette of Earth and Moon from the Jovian-bound spacecraft Juno as it flew by Earth, October 9, 2013 [NASA/JPL-Caltech].

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 Moon came into view when Juno was about 966,000 kilometers away -- about thrice 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 precisely the right instant. The frames were then sent to Earth, where they were processed into video.

"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.

The Waves instrument aboard NASA's Juno spacecraft recorded amateur radio signals from ham radio operators from around the world [NASA/JPL-Caltech/University of Iowa].

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.

"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 California

Moon from Juno star-tracking camera, October 9, 2013 [NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo].

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 it could reach Jupiter. (The spacecraft’s speed relative to Earth before and after the flyby was unchanged.)

Earth - over the coast of Namibia, from mosaic of images captured from the Juno spacecraft's on-board Junocam, near the Jupiter-bound probe's close encounter with Earth and Moon, October 9, 2013 [NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo].

After Juno arrives and enters into orbit around Jupiter 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. At times personified in Earth's Moon, Juno was the goddess of the civil state.

More information about Juno is online, HERE

Mysterious Mars methane

Where does it come from.

(How does it last?)

Source: Space Pragmatism

Teachers and Franck Lefevre Francois Forget, University Pierret Marie Curie in Paris, used a computer model of the Martian atmosphere to apply the observations made previously by a team from the Goddard center of the NASA Astrobiology U.S.. Last January, U.S. scientists confirmed in the journal “Science” the existence of methane in the atmosphere of Mars, which, they said, is proof that this planet remains active, biologically or geologically.

Spectrometers for NASA telescopes in Hawaii detected in 2003 on the surface at least three stelae of this gas, which is a key to life as known on Earth. They noted that “the atmosphere of Mars quickly destroys methane in various ways,” which suggests that there must be a process issue, as explained by Michael Mumma, of the Space Flight Center of NASA in Maryland.

In the study published today, the French experts noted the difficulty of identifying patterns of behavior of gas in the red planet using the current atmospheric chemistry or physics that applies to terrestrial processes.

Methane has photochemical cycle of several centuries, it is expected to have a uniform distribution on the planet.

However, the observations on Mars indicate that the gas presents spatial and temporal variations (depending on the season). “It happens something else, something that lowers the life cycle of methane by a factor of 600. If the measurements are correct, we are missing something important,” Lefevre said in a statement by the British public channel BBC.

If these changes are confirmed, would imply that the gas is destroyed very quickly, which would suggest that the planet is in a very difficult environment for the survival of organic components.

Methane, whose molecule consists of one carbon atom attached to four hydrogen (CH4) is the main component of natural gas on Earth, and is also involved in other geological processes such as the oxidation of iron.

Moreover, many living organisms on Earth emit gas during the process of digestion of nutrients. Scientists currently unknown whether the methane on Mars is the product of biological or geological processes such as volcanic activity.