EGU2020-17846, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-17846
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Re-analysis of limb anomaly detections in three HST/STIS transit images of Europa: No evidence for plumes

Lorenz Roth1, Gabriel Giono1, Nickolay Ivchenko1, Joachim Saur2, Kurt Retherford3, Darrell Strobel4, Stephan Schlegel2, and Marcus Ackland1
Lorenz Roth et al.
  • 1KTH Royal Institute of Technology, School of Electrical Engineering and Computer Science, Space and Plasma Physics, Stockholm, Sweden (lorenzr@kth.se)
  • 2University of Cologne, Cologne, Germany
  • 3Southwest Research Institute, San Antonio, USA
  • 4Johns Hopkins University, Baltimore, USA

After evidence for present-day geological activity on Jupiter’s moon Europa remained elusive for decades, several recent studies derived the existence of plumes on various locations. We have re-analyzed the three HST/STIS transit images in which Sparks et al. (2016) identified limb anomalies as evidence for Europa’s plume activity. After reproducing the results of Sparks et al. (2016), we find that positive outliers are similarly present in the images as the negative outliers that were attributed to plume absorption. A physical explanation for the positive outliers is missing. We identify two factors that affect the significance of the measured outliers in the region above Europa’s limb: The exact location of Europa on the detector and the description of the statistical fluctuations in the images. When accounting for these factors, the statistical significance of the plume candidate features is about 3 sigma or lower in the three images. The resulting positive and negative outliers are consistent with random statistical occurrence in a sample size given by the number of pixels in Europa's limb region.

How to cite: Roth, L., Giono, G., Ivchenko, N., Saur, J., Retherford, K., Strobel, D., Schlegel, S., and Ackland, M.: Re-analysis of limb anomaly detections in three HST/STIS transit images of Europa: No evidence for plumes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17846, https://doi.org/10.5194/egusphere-egu2020-17846, 2020

Displays

Display file