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Thursday, October 10, 2013

Juno Spacecraft Flyby

Juno is a NASA New Frontiers mission to the planet Jupiter. Juno was launched from Cape Canaveral Air Force Station on August 5, 2011. The spacecraft is to be placed on July 2016 in a polar orbit to study the Jupiter's composition, gravity field, magnetic field, and polar magnetosphere.

On October 9 2013, the interplanetary probe Juno flew past the Earth on its way to Jupiter to receive a "gravity assist" and be put on a trajectory to reach Jupiter in 2016. Time of closest approach with Earth (in shadow) was 19:21UT of October 09, at an altitude of only 559 km over the southern tip of Africa. Then it left the eclipse at 19:39 UT and was visible from Europe and Asia (see graphs below).

Credit: Heavens-Above
Credit: Heavens-Above

We performed follow-up measurements of Juno on October 09.9, 2013. The spacecraft was then of at ~125,000 km from our planet, magnitude ~14 and moving at ~80"/min.

Below you can see our image of Juno, single 120-sec unfiltered exposure, obtained remotely from MPC code I89 (iTelescope Observatory, Nerpio, Spain) through a 0.43-m f/6.8 reflector + CCD. The spacecraft is trailed in the image due to its fast speed. Click on it for a bigger version.


A Pseudo-Mpec, using our follow-up observations and that of other observers, has been made by Bill Gray using his software Findorb. (the nominal orbit now impacts Jupiter... but with a large enough sigma that this seems rather unlikely. Especially assuming there will be a terminal correction maneuver or two, giving it an orbit that just barely skims over the north or south pole).


UPDATE - October 11, 2013

NASA’s Juno Spacecraft returns 1st Flyby images of Earth, taken at 19:06UT of October 09, 2013 while it was flying over South America and the southern Atlantic Ocean. Click on the image for a bigger version.


by Ernesto Guido, Nick Howes and Martino Nicolini

2 comments:

  1. 1 arc second at 125,000 km is 0.6 km; observations of this accuracy could be important for resolving the so-called "flyby anomaly"

    Will the Minor Planet Center (or someone else) archive these observations?

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  2. Yes, they have a special archive for artificial satellites obs. Also they issue special circulars (DASO) to disseminate the observations:

    http://www.minorplanetcenter.net/iau/DASO/DASO.html

    Ciao,
    Ernesto

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