Thursday, June 08, 2023

SPACE

Long missions, frequent travel take a toll on astronauts’ brains, study shows

Peer-Reviewed Publication

UNIVERSITY OF FLORIDA



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.

Space health: The dark side of multiple spaceflights on human brain structure


Peer-Reviewed Publication

SCIENTIFIC REPORTS





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.

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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


Elusive planets play “hide and seek” with CHEOPS

Peer-Reviewed Publication

UNIVERSITY OF BERN

Cheops confirmed the existence of four warm exoplanets with sizes between Earth and Neptune 

IMAGE: 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 journalstwo 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

 

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