SPACE
Long missions, frequent travel take a toll on astronauts’ brains, study shows
As we enter a new era in space travel, a study looking at how the human brain reacts to traveling outside Earth’s gravity suggests frequent flyers should wait three years after longer missions to allow the physiological changes in their brains to reset.
Researchers studied brain scans of 30 astronauts from before and after space travel. Their findings, reported today in Scientific Reports, reveal that the brain’s ventricles expand significantly in those who completed longer missions of at least six months, and that less than three years may not provide enough time for the ventricles to fully recover.
Ventricles are cavities in the brain filled with cerebrospinal fluid, which provides protection, nourishment and waste removal to the brain. Mechanisms in the human body effectively distribute fluids throughout the body, but in the absence of gravity, the fluid shifts upward, pushing the brain higher within the skull and causing the ventricles to expand.
“We found that the more time people spent in space, the larger their ventricles became,” said Rachael Seidler, a professor of applied physiology and kinesiology at the University of Florida and an author of the study. “Many astronauts travel to space more than one time, and our study shows it takes about three years between flights for the ventricles to fully recover.”
Seidler, a member of the Norman Fixel Institute for Neurological Diseases at UF Health, said based on studies so far, ventricular expansion is the most enduring change seen in the brain resulting from spaceflight.
“We don’t yet know for sure what the long-term consequences of this is on the health and behavioral health of space travelers,” she said, “so allowing the brain time to recover seems like a good idea.”
Of the 30 astronauts studied, eight traveled on two-week missions, 18 were on six-month missions, and four were in space for approximately one year. The ventricular enlargement tapered off after six months, the study’s authors reported.
“The biggest jump comes when you go from two weeks to six months in space,” Seidler said. “There is no measurable change in the ventricles’ volume after only two weeks.”
With increased interest in space tourism in recent years, this is good news, as shorter space junkets appear to cause little physiological changes to the brain, she said.
While researchers cannot yet study astronauts who have been in space much longer than a year, Seidler said it’s also good news that the expansion of the brain’s ventricles levels off after about six months.
“We were happy to see that the changes don’t increase exponentially, considering we will eventually have people in space for longer periods,” she said.
The results of the study, which was funded by NASA, could impact future decision-making regarding crew travel and mission planning, Seidler said.
JOURNAL
Scientific Reports
ARTICLE TITLE
Impacts of Spaceflight Experience on Human Brain Structure
ARTICLE PUBLICATION DATE
8-Jun-2023
Space health: The dark side of multiple spaceflights on human brain structure
Spaceflight experience, in particular longer missions and shorter inter-mission recovery time, induce fluid changes in the brain that may not return to normal before subsequent flights, reports a study published in Scientific Reports. Ventricles — cavities in the brain filled with cerebrospinal fluid — expand increasingly with longer spaceflight missions up to six months, and inter-mission intervals of less than three years may not allow sufficient time for the ventricles to fully recover.
Spaceflight induces widespread changes in the human brain including ventricle volume expansion, but it is unclear if these changes differ with varying mission duration or number of previous spaceflight missions. Rachael Seidler and colleagues scanned the brains of 30 astronauts using MRI, pre- and post-spaceflight, including those on two-week missions (eight astronauts), six-month missions (18 astronauts) and longer (four astronauts). They found that longer spaceflight missions resulted in greater ventricular enlargement, which tapered off after six months in space.
The authors found that for 11 astronauts who had more than three years to recover in between missions, there was an associated increase in ventricle volume after their most recent mission. However, the authors found that in seven astronauts who had a shorter recovery time in between missions there was little to no enlargement of the ventricles post-flight compared to pre-flight. They propose that less than three years between spaceflights may not be enough time to allow ventricles to recover their compensatory capacity to accommodate the increase in intracranial fluid and they remain enlarged when the astronauts return to space within this time frame.
As spaceflight becomes more frequent and of longer duration, the findings provide insight into how spaceflight experience, both previous and current, may influence brain changes. The authors conclude that their findings can help to improve guidance for future mission planning.
###
Article details
Impacts of spaceflight experience on human brain structure
DOI: 10.1038/s41598-023-33331-8
Corresponding Author:
Rachael Seidler
University of Florida, Florida, USA
Email: rachaelseidler@ufl.edu
Please link to the article in online versions of your report (the URL will go live after the embargo ends): https://www.nature.com/articles/s41598-023-33331-8
JOURNAL
Scientific Reports
Elusive planets play “hide and seek” with CHEOPS
Peer-Reviewed PublicationIMAGE: CHEOPS CONFIRMED THE EXISTENCE OF FOUR WARM EXOPLANETS WITH SIZES BETWEEN EARTH AND NEPTUNE, ORBITING THEIR STARS CLOSER THAN MERCURY OUR SUN. THESE SO-CALLED MINI- NEPTUNES ARE UNLIKE ANY PLANET IN OUR SOLAR SYSTEM AND PROVIDE A 'MISSING LINK' THAT IS NOT YET UNDERSTOOD. MINI-NEPTUNES ARE AMONG THE MOST COMMON TYPES OF PLANETS KNOWN, AND ASTRONOMERS ARE STARTING TO FIND MORE AND MORE ORBITING BRIGHT STARS. view more
CREDIT: ©ESA
CHEOPS is a joint mission by the European Space Agency (ESA) and Switzerland, under the leadership of the University of Bern in collaboration with the University of Geneva. Since its launch in December 2019, the extremely precise measurements of CHEOPS have contributed to several key discoveries in the field of exoplanets.
NCCR PlanetS members Dr. Solène Ulmer-Moll of the Universities of Bern and Geneva, and Dr. Hugh Osborn of the University of Bern, exploited the unique synergy of CHEOPS and the NASA satellite TESS, in order to detect a series of elusive exoplanets. The planets, called TOI 5678 b and HIP 9618 c respectively, are the size of Neptune or slightly smaller with 4.9 and 3.4 Earth radii. The respective papers have just been published in the journals Astronomy & Astrophysics and Monthly Notices of the Royal Astronomical Society. Publishing in the same journals, two other members of the international team, Amy Tuson from the University of Cambridge (UK) and Dr. Zoltán Garai from the ELTE Gothard Astrophysical Observatory (Hungary), used the same technique to identify two similar planets in other systems.
The synergy of two satellites
The CHEOPS satellite observes the luminosity of stars in order to capture the slight dimming that occurs when, and if, an orbiting planet happens to pass in front of its star from our point of view. By searching for these dimming events, called “transits”, scientists have been able to discover the majority of the thousands of exoplanets known to orbit stars other than our Sun.
“NASA’s TESS satellite excels at detecting the transits of exoplanets, even for the most challenging small planets. However, it changes its field of view every 27 days in order to scan rapidly most of the sky, which prevents it from finding planets on longer orbital periods,” explains Hugh Osborn. Still, the TESS satellite was able to observe single transits around the stars TOI 5678 and HIP 9618. When returning to the same field of view after two years, it could again observe similar transits around the same stars. Despite these observations, it was still not possible to conclude unequivocally to the presence of planets around those stars as information was incomplete.
“This is where CHEOPS comes into play: Focusing on a single-star at a time, CHEOPS is a follow-up mission which is perfect to continue observing these stars to find the missing bits of information,” complements Solène Ulmer-Moll.
A lengthy game of “hide and seek”
Suspecting the presence of exoplanets, the CHEOPS team designed a method to avoid spending blindly precious observing time in the hope to detect additional transits. They adopted a targeted approach based on the very few clues the transits observed by TESS provided. Based on this, Osborn developed a software which proposes and prioritizes candidate periods for each planet. “We then play a sort of ‘hide and seek’ game with the planets, using the CHEOPS satellite,” as Osborn says.
“We point CHEOPS towards a target at a given time, and depending if we observe a transit or not, we can eliminate some of the possibilities and try again at another time until there is a unique solution for the orbital period.” It took five and four attempts respectively for the scientists to clearly confirm the existence of the two exoplanets and determine that TOI 5678 b has a period of 48 days, while HIP 9618 c has a period of 52.5 days.
Ideal targets for the JWST
The story does not end there for the scientists. With the newly found constrained periods, they could turn to ground-based observations using another technique called radial velocity, which enabled the team to determine masses of respectively 20 and 7.5 Earth masses for TOI 5678 b and HIP 9618 c. With both the size and mass of a planet, its density is known, and scientists can get an idea of what it is made off. “For mini-Neptunes however, density is not enough, and there are still a few hypotheses as for the composition of the planets: they could either be rocky planets with a lot of gas, or planets rich in water and with a very steamy atmosphere,” explains Ulmer-Moll. “Since the four newly discovered exoplanets are orbiting bright stars, it also makes them targets of prime interest for the mission of the James Webb Space Telescope JWST which might help to solve the riddle of their composition,” Ulmer-Moll continues.
Most exoplanets atmospheres observed so far have been from Hot Jupiters, which are very big and hot exoplanets orbiting close to their parent star. “The four new planets which we detected have much more moderate temperatures of ‘only’ 217 to 277ºC. These temperatures enable clouds and molecules to survive, which would otherwise be destroyed by the intense heat of Hot Jupiters. And they may potentially be detected by the JWST,” as Osborn explains. Smaller in size and with a longer orbital period than Hot Jupiters, the four newly detected planets are a first step towards the observation of transiting Earth-like planets.
Publication details:
Two Warm Neptunes transiting HIP 9618 revealed by TESS & Cheops by H. P. Osborn et al. is published in the Monthly Notices of the Royal Astronomical Society.
https://doi.org/10.1093/mnras/stad1319
TOI-5678 b: a 48-day transiting Neptune-mass planet characterized with CHEOPS and HARPS by S. Ulmer-Moll et al. is published in Astronomy & Astrophysics.
https://www.aanda.org/10.1051/0004-6361/202245478
Refined parameters of the HD 22946 planetary system and the true orbital period of the planet d by Z. Garai et al. is published in Astronomy & Astrophysics.
https://www.aanda.org/10.1051/0004-6361/202345943
TESS and CHEOPS Discover Two Warm Mini-Neptunes Transiting the Bright K-dwarf HD15906 by A. Tuson et al. is published in the Monthly Notices of the Royal Astronomical Society.
https://doi.org/10.1093/mnras/stad1369
Contacts:
Dr. Hugh Osborn (French/English)
Physics Institute, Space Research & Planetary Sciences (WP), University of Bern and NCCR PlanetS
E-Mail: hugh.osborn@unibe.ch
Tel: +41 31 684 36 08
Dr. Solène Ulmer-Moll (French/English)
Département d’Astronomie, University of Geneva and Physics Institute, Space Research & Planetary Sciences (WP), University of Bern and NCCR PlanetS
E-Mail: solene.ulmer-moll@unige.ch
Tel: +41 22 379 22 82
CHEOPS – in search of potential habitable planets The CHEOPS mission (CHaracterising ExOPlanets Satellite) is the first of ESA’s “S-class missions” – small-class missions with an ESA budget much smaller than that of large- and medium-size missions, and a shorter timespan from project inception to launch. CHEOPS is dedicated to characterizing the transits of exoplanets. It measures the changes in the brightness of a star when a planet passes in front of that star. This measured value allows the size of the planet to be derived, and for its density to be determined on the basis of existing data. This provides important information on these planets – for example, whether they are predominantly rocky, are composed of gases, or if they have deep oceans. This, in turn, is an important step in determining whether a planet has conditions that are hospitable to life. CHEOPS was developed as part of a partnership between the European Space Agency (ESA) and Switzerland. Under the leadership of the University of Bern and ESA, a consortium of more than a hundred scientists and engineers from eleven European states was involved in constructing the satellite over five years. CHEOPS began its journey into space on Wednesday, December 18, 2019 on board a Soyuz Fregat rocket from the European spaceport in Kourou, French Guiana. Since then, it has been orbiting the Earth on a polar orbit in roughly an hour and a half at an altitude of 700 kilometers following the terminator. The Swiss Confederation participates in the CHEOPS telescope within the PRODEX program (PROgramme de Développement d'EXpériences scientifiques) of the European Space Agency ESA. Through this program, national contributions for science missions can be developed and built by project teams from research and industry. This transfer of knowledge and technology between science and industry ultimately also gives Switzerland a structural competitive advantage as a business location – and enables technologies, processes and products to flow into other markets and thus generate added value for our economy. More information: https://cheops.unibe.ch/ |
Bernese space exploration: With the world’s elite since the first moon landing When the second man, "Buzz" Aldrin, stepped out of the lunar module on July 21, 1969, the first task he did was to set up the Bernese Solar Wind Composition experiment (SWC) also known as the “solar wind sail” by planting it in the ground of the moon, even before the American flag. This experiment, which was planned, built and the results analyzed by Prof. Dr. Johannes Geiss and his team from the Physics Institute of the University of Bern, was the first great highlight in the history of Bernese space exploration. Ever since Bernese space exploration has been among the world’s elite, and the University of Bern has been participating in space missions of the major space organizations, such as ESA, NASA, and JAXA. With CHEOPS the University of Bern shares responsibility with ESA for a whole mission. In addition, Bernese researchers are among the world leaders when it comes to models and simulations of the formation and development of planets. The successful work of the Department of Space Research and Planetary Sciences (WP) from the Physics Institute of the University of Bern was consolidated by the foundation of a university competence center, the Center for Space and Habitability (CSH). The Swiss National Fund also awarded the University of Bern the National Center of Competence in Research (NCCR) PlanetS, which it manages together with the University of Geneva. |
Exoplanet research in Geneva: 25 years of expertise awarded a Nobel Prize CHEOPS provides crucial information on the size, shape, formation and evolution of known exoplanets. The installation of the "Science Operation Center" of the CHEOPS mission in Geneva, under the supervision of two professors from the UNIGE Astronomy Department, is a logical continuation of the history of research in the field of exoplanets, since it is here that the first was discovered in 1995 by Michel Mayor and Didier Queloz, winners of the 2019 Nobel Prize in Physics. This discovery has enabled the Astronomy Department of the University of Geneva to be at the forefront of research in the field, with the construction and installation of HARPS on the ESO's 3.6m telescope at La Silla in 2003, a spectrograph that remained the most efficient in the world for two decades to determine the mass of exoplanets. ESPRESSO is the latest spectrograph built in Geneva and installed on the VLT in Paranal, and it is now reaching an even higher precision than HARPS. CHEOPS is therefore the result of two national expertise, on the one hand the space know-how of the University of Bern with the collaboration of its Geneva counterpart and on the other hand the ground experience of the University of Geneva supported by its colleague in the Swiss capital. Two scientific and technical competences that have also made it possible to create the National Center of Competence in Research (NCCR) PlanetS |
JOURNAL
Monthly Notices of the Royal Astronomical Society
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Two Warm Neptunes transiting HIP 9618 revealed by TESS & Cheops
ARTICLE PUBLICATION DATE
8-Jun-2023
CALorimetric Electron Telescope (CALET) captures charge-sign dependent cosmic ray modulation
The observations indicate that cosmic ray electron count rates are more strongly influenced by the solar modulation than that of protons
Peer-Reviewed PublicationIMAGE: IN A NEW STUDY BY THE CALET COLLABORATION, RESEARCHERS FROM JAPAN DEMONSTRATE THAT COSMIC RAY ELECTRON COUNT RATES ARE SIGNIFICANTLY MORE AFFECTED THAN THAT OF PROTONS DUE TO THE DRIFT EFFECT ON THE LONG-TERM SOLAR MODULATION. view more
CREDIT: YOSUI AKAIKE FROM WASEDA UNIVERSITY, JAPAN
The movement of cosmic ray particles across space, such as electrons and protons, is influenced by the Sun's magnetic field, causing fluctuations in the intensity of galactic cosmic rays (GCRs) reaching Earth in response to the solar cycle. During periods of low solar activity, such as the solar minimum, more GCRs have been observed to reach Earth compared to that for periods of high solar activity. This inverse correlation between the GCR-flux and solar activity is known as “solar modulation.”
Specifically, the intensity of GCRs on Earth is affected by the tilt angle of the heliospheric current sheet (HCS), a spiral surface separating the direction of oppositely directed magnetic field lines originating from the poles of the Sun. As the tilt angle of the HCS increases, the intensity of cosmic rays on Earth decreases. According to the drift model of GCR transport in the heliosphere, the negatively charged electrons in GCRs tend to travel along the HCS to reach Earth if the magnetic field is directed away from the Sun in the northern hemisphere, and towards the Sun in the southern hemisphere. In contrast, the positively charged protons reach Earth from the heliospheric polar region, suggesting that GCR electrons are more affected by solar modulation than the protons as they travel through the HCS to reach Earth.
While previous observations of cosmic ray particles made aboard space balloons and in space experiments show differences between the fluxes of positively and negatively charged GCR particles during the solar cycle, it is unclear whether the particle charge plays any role in the anticorrelation between GCR intensity and the tilt angle of the HCS. Now, in a recent observation of GCR charged particles made with the CALorimetric Electron Telescope (CALET) onboard the International Space Station’s “Kibo” Exposed Facility (EF) over a period of six years, researchers have revealed that this anticorrelation is, in fact, more prominent for electrons than for protons.
The study, published in Volume 130, Issue 21 of the Physical Review Letters journal on May 25, 2023, was co-led by three researchers from Japan, Associate Professor Yosui Akaike of the Waseda Research Institute for Science and Engineering (RISE) at Waseda University, Associate Professor Shoko Miyake of the National Institute of Technology (KOSEN) at Ibaraki College, and Professor Kazuoki Munakata of Shinshu University. It also included contributions from Professor Emeritus Shoji Torii from RISE. “Using CALET, we successfully observed a charge-sign dependent solar modulation of GCRs over six years,” says Akaike.
The researchers analyzed over 0.77 million electrons and 1.26 million protons collected in about 196 and 197 hours, respectively, over a six-year period from 2015 to 2021, which coincided with the end of solar cycle 24 and the beginning of solar cycle 25, the current solar cycle. The findings indicated that during the low activity state of the Sun towards the end of solar cycle 24, characterized by a reduction in the number of sunspots and HCS tilt angle, both electron and proton count rates were low but gradually increasing. This trend continued with the onset of solar cycle 25, reaching its peak in electron count rate six months after the beginning of the cycle in December 2019.
Thereafter, both electron and proton count rates gradually decreased as the Sun's activity and HCS tilt angle increased. Furthermore, the results showed that the variation in the count rates of electrons was significantly higher than that of protons during this period, suggesting that electrons are more susceptible to the effects of solar modulation, as predicted by the drift model.
“This is a clear signature of the drift effect dominating the long-term solar modulation of GCRs observed with a single detector,” highlights Akaike.
Overall, analyzing GCRs can shed important light on the composition of the universe and the acceleration mechanisms of high-energy particles observed in cosmic rays. Thus, the observations made by CALET could help better understand the space weather and its effects on the possibility of potential life on the Moon and other planets, like Mars.
Charge-sign dependent solar modulation of galactic cosmic rays.
The observations by CALorimetric Electron Telescope (CALET) reveal that the count rates of electrons (in blue) are more strongly influenced than that of protons (in red) with the changing tilt angle of the heliospheric current sheet.
CREDIT
Yosui Akaike from Waseda University, Japan
***
Reference
DOI: https://doi.org/10.1103/PhysRevLett.130.211001
Authors: O. Adriani,1, 2 Y. Akaike,3, 4 K. Asano,5 Y. Asaoka,5 E. Berti,2, 6 G. Bigongiari,7, 8 W.R. Binns,9 M. Bongi,1, 2 P. Brogi,7, 8 A. Bruno,10 J.H. Buckley,9 N. Cannady,11, 12, 13 G. Castellini,6 C. Checchia,7, 8 M.L. Cherry,14 G. Collazuol,15, 16 G.A. de Nolfo,10 K. Ebisawa,17 A. W. Ficklin,14 H. Fuke,17 S. Gonzi,1, 2, 6 T.G. Guzik,14T. Hams,11 K. Hibino,18 M. Ichimura,19 K. Ioka,20 W. Ishizaki,5 M.H. Israel,9 K. Kasahara,21 J. Kataoka,22R. Kataoka,23 Y. Katayose,24 C. Kato,25 N. Kawanaka,20 Y. Kawakubo,14 K. Kobayashi,3, 4 K. Kohri,26 H.S. Krawczynski,9 J.F. Krizmanic,12 P. Maestro,7, 8 P.S. Marrocchesi,7, 8 A.M. Messineo,8, 27 J.W. Mitchell,12 S. Miyake,28 A.A. Moiseev,12, 13, 29 M. Mori,30 N. Mori,2 H.M. Motz,31 K. Munakata,25 S. Nakahira,17 J. Nishimura,17 S. Okuno,18 J.F. Ormes,32 S. Ozawa,33 L. Pacini,2, 6 P. Papini,2 B.F. Rauch,9 S.B. Ricciarini,2, 6 K. Sakai,11, 12, 13 T. Sakamoto,34 M. Sasaki,12, 13, 29 Y. Shimizu,18 A. Shiomi,35 P. Spillantini,1 F. Stolzi,7, 8 S. Sugita,34 A. Sulaj,7, 8 M. Takita,5 T. Tamura,18 T. Terasawa,5 S. Torii,3 Y. Tsunesada,36, 37 Y. Uchihori,38 E. Vannuccini,2 J.P. Wefel,14 K. Yamaoka,39 S. Yanagita,40 A. Yoshida,34 K. Yoshida,21 and W. V. Zober9
Affiliations:
1Department of Physics, University of Florence, Via Sansone, 1 - 50019, Sesto Fiorentino, Italy
2INFN Sezione di Firenze, Via Sansone, 1 - 50019, Sesto Fiorentino, Italy
3Waseda Research Institute for Science and Engineering, Waseda University, 17 Kikuicho, Shinjuku, Tokyo 162-0044, Japan
4JEM Utilization Center, Human Spaceflight Technology Directorate,
Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
5Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa, Chiba 277-8582, Japan
6Institute of Applied Physics (IFAC), National Research Council (CNR),
Via Madonna del Piano, 10, 50019, Sesto Fiorentino, Italy
7Department of Physical Sciences, Earth and Environment,
University of Siena, via Roma 56, 53100 Siena, Italy
8INFN Sezione di Pisa, Polo Fibonacci, Largo B. Pontecorvo, 3 - 56127 Pisa, Italy
9Department of Physics and McDonnell Center for the Space Sciences,
Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA
10Heliospheric Physics Laboratory, NASA/GSFC, Greenbelt, Maryland 20771, USA
11Center for Space Sciences and Technology, University of Maryland,
Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA
12Astroparticle Physics Laboratory, NASA/GSFC, Greenbelt, Maryland 20771, USA
13Center for Research and Exploration in Space Sciences and Technology, NASA/GSFC, Greenbelt, Maryland 20771, USA
14Department of Physics and Astronomy, Louisiana State University,
202 Nicholson Hall, Baton Rouge, Louisiana 70803, USA
15Department of Physics and Astronomy, University of Padova, Via Marzolo, 8, 35131 Padova, Italy
16INFN Sezione di Padova, Via Marzolo, 8, 35131 Padova, Italy
17Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210, Japan
18Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa, Yokohama, Kanagawa 221-8686, Japan
19Faculty of Science and Technology, Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo, Hirosaki, Aomori 036-8561, Japan
20Yukawa Institute for Theoretical Physics, Kyoto University,
Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
21Department of Electronic Information Systems, Shibaura Institute of Technology, 307 Fukasaku, Minuma, Saitama 337-8570, Japan
22School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
23National Institute of Polar Research, 10-3, Midori-cho, Tachikawa, Tokyo 190-8518, Japan
24Faculty of Engineering, Division of Intelligent Systems Engineering,
Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan
25Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
26Institute of Particle and Nuclear Studies, High Energy Accelerator
Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
27University of Pisa, Polo Fibonacci, Largo B. Pontecorvo, 3 - 56127 Pisa, Italy
28Department of Electrical and Electronic Systems Engineering,
National Institute of Technology (KOSEN), Ibaraki College,
866 Nakane, Hitachinaka, Ibaraki 312-8508, Japan
29Department of Astronomy, University of Maryland, College Park, Maryland 20742, USA
30Department of Physical Sciences, College of Science and Engineering, Ritsumeikan University, Shiga 525-8577, Japan
31Faculty of Science and Engineering, Global Center for Science and Engineering,
Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
32Department of Physics and Astronomy, University of Denver, Physics Building, Room 211, 2112 East Wesley Avenue, Denver, Colorado 80208-6900, USA
33Quantum ICT Advanced Development Center, National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795, Japan
34College of Science and Engineering, Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5258, Japan
35College of Industrial Technology, Nihon University, 1-2-1 Izumi, Narashino, Chiba 275-8575, Japan
36Graduate School of Science, Osaka Metropolitan University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
37Nambu Yoichiro Institute for Theoretical and Experimental Physics,
Osaka Metropolitan University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
38National Institutes for Quantum and Radiation Science and Technology, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
39Nagoya University, Furo, Chikusa, Nagoya 464-8601, Japan
40College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
About Waseda University
Located in the heart of Tokyo, Waseda University is a leading private research university that has long been dedicated to academic excellence, innovative research, and civic engagement at both the local and global levels since 1882. The University has produced many changemakers in its history, including nine prime ministers and many leaders in business, science and technology, literature, sports, and film. Waseda has strong collaborations with overseas research institutions and is committed to advancing cutting-edge research and developing leaders who can contribute to the resolution of complex, global social issues. The University has set a target of achieving a zero-carbon campus by 2032, in line with the Sustainable Development Goals (SDGs) adopted by the United Nations in 2015.
To learn more about Waseda University, visit https://www.waseda.jp/top/en
About Researcher (Associate Professor) Yosui Akaike from Waseda University
Yosui Akaike is a Researcher (Associate Professor) at the Faculty of Science and Engineering at the Waseda Research Institute for Science and Engineering (RISE) at Waseda University in Japan. His research interests include experimental studies related to particle physics, nuclear physics, cosmic rays, and astrophysics. He has published 85 research papers so far, which have been cited over 900 times.
About Associate Professor Shoko Miyake
Shoko Miyake is an Associate Professor at the National Institute of Technology (KOSEN) at Ibaraki College in Japan. She completed her Ph.D. from the Graduate School of Science and Engineering at Ibaraki College. Her research areas include theoretical studies related to particle physics, nuclear physics, cosmic rays, and astrophysics. She has authored 37 research papers and undertaken six research projects.
About Professor Kazuoki Munakata
Kazuoki Munakata is a Professor Emeritus and Professor at the Faculty of Science at Shinshu University in Japan. He has published over 380 research articles, which have been cited around 3,800 times. His current research work includes the study of heliospheric physics and space weather via observations of high-energy galactic cosmic rays with space probes.
JOURNAL
Physical Review Letters
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station
