Juno Flyby Anomaly - Searching for Answers

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Discussion Overview

The discussion revolves around the Juno flyby anomaly, specifically the observations and data related to the anomaly during the Juno spacecraft's flyby of Earth. Participants are exploring the existence of any anomalies, the data collected, and the implications of previous studies on similar phenomena.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants inquire about the existence of data from the Juno flyby anomaly and whether the observed anomaly matched predictions.
  • Links to various papers are shared, including speculation on the anomaly and previous studies that reported unexplained energy changes during Earth flybys.
  • One participant notes that preliminary results were revealed but expresses difficulty in finding the actual documents.
  • Concerns are raised regarding the authors of the papers, particularly the fact that many are retirees, which some speculate may relate to budget cuts affecting the dissemination of results.
  • There are conflicting reports about the anomaly, with one participant claiming to have learned from a private source that no anomaly was observed, while another challenges the validity of private sources as references.
  • Some participants express frustration over the lack of published results from NASA/ESA regarding the Juno flyby anomaly.

Areas of Agreement / Disagreement

The discussion contains multiple competing views regarding the existence of the anomaly and the availability of data. There is no consensus on whether an anomaly was observed or what the implications of the findings might be.

Contextual Notes

Participants highlight limitations in accessing published results and the potential impact of authors' affiliations on the availability of information. There is also uncertainty regarding the status of the anomaly and the reliability of private sources.

nearc
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i did a search for juno flyby here and did not find anything, hence this post:

i've not been able to find any info on the juno flyby anomaly. i know there was a hiccup but did we get any data? was the observed anomaly match the predicted anomaly?
 
Astronomy news on Phys.org
You mean this anomaly?
http://arxiv.org/abs/1311.4218

Compare:
http://arxiv.org/abs/1311.4978

All kinds of speculation (in lit):
http://www.worldscientific.com/doi/abs/10.1142/S0217751X13500747

Certainly there should be data:
http://www.spaceflight101.com/juno-mission-updates-2013.html

I heard that preliminary results were revealed Dec 11 ... but cannot find documents.
CONTROL ID: 1799584
TITLE: Juno Earth Flyby as a Sensitive Detector of Anomalous Orbital-Energy Changes

AUTHORS (FIRST NAME, LAST NAME): John D Anderson1, James F Jordan1, James K Campbell1, John E Ekelund1, John J Bordi2, Mathew Abrahamson2, Shadan M Ardalan2, Paul F. Thompson2
INSTITUTIONS (ALL): 1. Retiree, Jet Propulsion Laboratory, Pasadena, CA, United States.
2. Mission Design & Navigation Section, Jet Propulsion Laboratory, Pasadena, CA, United States.
ABSTRACT BODY: The fact that unexplained energy changes occur in some Earth flybys, but not all, was reported in 2008 by Anderson et al., Phys. Rev. Lett. 100, 091102. The anomaly is detected by analyzing radio Doppler and ranging data used for space navigation. It is most significant for the closest flybys at altitudes of 539 km for the NEAR spacecraft , 960 km for the first Galileo flyby, and 1956 km for the first Rosetta flyby, with anomalous total changes in the hyperbolic excess velocity at infinity of 13.5 mm/s, 3.9 mm/s and 1.8 mm/s, respectively. There is also a correlation with the amount of asymmetry of the flyby trajectory with respect to the Earth’s equator. As it turns out, the Juno flyby is well suited for another detection of this anomaly, with an altitude of about 500 km, and a declination of the incoming hyperbolic asymptote of 14.6 deg and an outgoing asymptote of 40.4 deg. Further, the control sequence for the spacecraft introduces no significant translational forces for an interval of plus and minus four days of perigee. Based on eight flybys analyzed previously, and an empirical formula given in the 2008 paper, the expected size of the Juno anomaly is about 7 mm/s. The standard error of the measurement is about 0.01 mm/s. We report first results of the data analysis.​
... OK but where?!

The 2008 paper mentioned in the absract I found:
http://virgo.lal.in2p3.fr/NPAC/relativite_fichiers/anderson_2.pdf
 
Last edited by a moderator:
yep sounds like we still need to wait a bit but thanks
 
I cannot find the results of this flyby. The Wikipedia page has data for the previous spacecraft flyby, but still nothing for Juno. Does anyone know anything about this?
 
The fact that half the authors are listed as "retirees" might have something to do with it, in an age of budget cuts.
 
Oh, I thought you were talking about the Juno spacecraft when if flew by the Earth :p Anyway, those were interesting texts, Simon. I did learn something today.

cb
 
Cosmobrain said:
Oh, I thought you were talking about the Juno spacecraft when if flew by the Earth :p Anyway, those were interesting texts, Simon. I did learn something today.

cb
I learned from a private source recently that no anomaly was observed.
 
Earth'shrink said:
I learned from a private source recently that no anomaly was observed.

Private sources are not allowed as references at the PF. Can your private source give you a link to a published paper?

BTW, this thread is a bit old... :smile:
 
Yes, the thread is old, but there have been a couple of new papers this year. Don't believe NASA/ESA have published the zero results, though.
 

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