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Takahashi Y, Sato M, Imai M, Lorenz R, Yair Y, Aplin K, Fischer G, Nakamura M, Ishii N, Abe T, Satoh T, Imamura T, Hirose C, Suzuki M, Hashimoto GL, Hirata N, Yamazaki A, Sato TM, Yamada M, Murakami SY, Yamamoto Y, Fukuhara T, Ogohara K, Ando H, Sugiyama KI, Kashimura H, Ohtsuki S. Initiation of a lightning search using the lightning and airglow camera onboard the Venus orbiter Akatsuki. EARTH, PLANETS, AND SPACE : EPS 2018; 70:88. [PMID: 31007533 PMCID: PMC6448279 DOI: 10.1186/s40623-018-0836-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 04/14/2018] [Indexed: 06/09/2023]
Abstract
The existence of lightning discharges in the Venus atmosphere has been controversial for more than 30 years, with many positive and negative reports published. The lightning and airglow camera (LAC) onboard the Venus orbiter, Akatsuki, was designed to observe the light curve of possible flashes at a sufficiently high sampling rate to discriminate lightning from other sources and can thereby perform a more definitive search for optical emissions. Akatsuki arrived at Venus during December 2016, 5 years following its launch. The initial operations of LAC through November 2016 have included a progressive increase in the high voltage applied to the avalanche photodiode detector. LAC began lightning survey observations in December 2016. It was confirmed that the operational high voltage was achieved and that the triggering system functions correctly. LAC lightning search observations are planned to continue for several years.
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Affiliation(s)
- Yukihiro Takahashi
- Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 Japan
| | - Mitsuteru Sato
- Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 Japan
| | - Masataka Imai
- Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 Japan
| | - Ralph Lorenz
- Johns Hopkins University Applied Physics Lab, 11100 Johns Hopkins Road, Laurel, MD 20723 USA
| | - Yoav Yair
- School of Sustainability, Interdisciplinary Center Herzliya (IDC), P. O. Box 167, 46150 Herzliya, Israel
| | - Karen Aplin
- Physics Teaching Laboratories, Oxford University, Denys Wilkinson Building, Keble Rd, Oxford, OX1 3RH UK
| | - Georg Fischer
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, 8042 Graz, Austria
| | - Masato Nakamura
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Nobuaki Ishii
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Takumi Abe
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
- Department of Space and Astronautical Science, School of Physical Sciences, SOKENDAI, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Takehiko Satoh
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
- Department of Space and Astronautical Science, School of Physical Sciences, SOKENDAI, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Takeshi Imamura
- Graduate School of Frontier Sciences, The University of Tokyo, Kiban-tou 4H7, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 Japan
| | - Chikako Hirose
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Makoto Suzuki
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - George L. Hashimoto
- Department of Earth Science, Okayama University, 3-1-1 Tsushimanaka, Kita, Okayama, 700-8530 Japan
| | - Naru Hirata
- School of Computer Science and Engineering, The University of Aizu, 90 Kami-Iawase, Tsuruga, Ikki-machi, Aizu-Wakamatsu, Fukushima 965-8580 Japan
| | - Atsushi Yamazaki
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Takao M. Sato
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Manabu Yamada
- Planetary Exploration Research Center, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016 Japan
| | - Shin-ya Murakami
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Yukio Yamamoto
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 Japan
| | - Tetsuya Fukuhara
- Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501 Japan
| | - Kazunori Ogohara
- School of Engineering, University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533 Japan
| | - Hiroki Ando
- Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto, Kyoto 603-8555 Japan
| | - Ko-ichiro Sugiyama
- Department of Information Engineering, National Institute of Technology, Matsue College, 14-4 Nishi-Ikuma, Matsue, Shimane 690-8518 Japan
| | - Hiroki Kashimura
- Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 Japan
| | - Shoko Ohtsuki
- School of Commerce, Senshu University, 2-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8580 Japan
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Gurnett DA, Zarka P, Manning R, Kurth WS, Hospodarsky GB, Averkamp TF, Kaiser ML, Farrell WM. Non-detection at Venus of high-frequency radio signals characteristic of terrestrial lightning. Nature 2001; 409:313-5. [PMID: 11201733 DOI: 10.1038/35053009] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The detection of impulsive low-frequency (10 to 80 kHz) radio signals, and separate very-low-frequency (approximately 100 Hz) radio 'whistler' signals provided the first evidence for lightning in the atmosphere of Venus. Later, a small number of impulsive high-frequency (100 kHz to 5.6 MHz) radio signals, possibly due to lightning, were also detected. The existence of lightning at Venus has, however, remained controversial. Here we report the results of a search for high-frequency (0.125 to 16 MHz) radio signals during two close fly-bys of Venus by the Cassini spacecraft. Such signals are characteristic of terrestrial lightning, and are commonly heard on AM (amplitude-modulated) radios during thunderstorms. Although the instrument easily detected signals from terrestrial lightning during a later fly-by of Earth (at a global flash rate estimated to be 70 s(-1), which is consistent with the rate expected for terrestrial lightning), no similar signals were detected from Venus. If lightning exists in the venusian atmosphere, it is either extremely rare, or very different from terrestrial lightning.
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Affiliation(s)
- D A Gurnett
- Department of Physics and Astronomy, The University of Iowa, Iowa City 52242, USA.
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Kivelson MG, Kennel CF, McPherron RL, Russell CT, Southwood DJ, Walker RJ, Hammond CM, Khurana KK, Strangeway RJ, Coleman PJ. Magnetic Field Studies of the Solar Wind Interaction with Venus from the Galileo Flyby. Science 1991; 253:1518-22. [PMID: 17784092 DOI: 10.1126/science.253.5027.1518] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
During the 10 February 1990 flyby of Venus, the Galileo spacecraft skimmed the downstream flank of the planetary bow shock. This provided an opportunity to examine both the global and the local structure of the shock in an interval during which conditions in the solar wind plasma were quite steady. The data show that the cross section of the shock in planes transverse to the flow is smaller in directions aligned with the projection of the interplanetary magnetic field than in directions not so aligned. Ultralow-frequency waves were present in the unshocked solar wind, and their amplitude peaked when the spacecraft was downstream of the foreshock. At large distances down the tail, the Mach number of the flow normal to the shock is low, thus providing the opportunity to study repeated crossings of the collisionless shock in an interesting parameter regime. Some of the shock crossings reveal structure that comes close to the theoretically predicted form of intermediate shocks, whose existence in collisionless plasmas has not been confirmed.
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