Prediction of The Lifetime of Neptune's NDS-2018 (Northern Dark Spot of 2018)
Abstract
We discovered a new dark vortex on Neptune in the 2018 OPAL dataset (NDS-2018: Simon et al. 2019). The feature had a size of about 11,000 x 5,000 km, and was located at 23 deg. N planetographic latitude. We predict that NDS-2018 will still be visible in the 2019 OPAL Neptune dataset (currently scheduled for October), to be presented at the meeting, but that the feature will be gone by 2020 or 2021.
We derived our prediction by going through all the blue wavelength Hubble telescope Neptune imaging data, which detected 4 dark vortices and did not detect the two dark vortices seen by Voyager. We used a Monte-Carlo technique to simulate random dark spots uniformly distributed in time and compared those to actual time interval of Hubble telescope Neptune imaging data (Hsu et al. 2019). We found that the most likely lifetime of dark spots is one to two years, but no more than 6 years. We also concluded that dark spots have average occurrence rates of one dark spot every four to six years. Simon A.A., M.H. Wong, A.I. Hsu (2019), Formation of a new Great Dark Spot on Neptune in 2018. GRL 46, 3108-3113. Hsu, A.I., M.H. Wong, A.A. Simon (2019), Lifetimes and occurrence rates of dark vortices on Neptune from 23 years of Hubble Space Telescope images, Astronomical Journal 157, 152 (9 pp. ). Acknowledgement: This work is based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute. These observations are associated with 25 programs listed in Hsu et al. (2019). Support for programs 13937 and 14492 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.P13B3507H
- Keywords:
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- 5704 Atmospheres;
- PLANETARY SCIENCES: FLUID PLANETS;
- 5729 Ionospheres;
- PLANETARY SCIENCES: FLUID PLANETS;
- 6255 Neptune;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 6293 Uranus;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS