• Photo by Nicolas J Leclercq on Unsplash
  • Photo by Nicolas Tissot on Unsplash
  • Photo by NASA on Unsplash
  • Photo by USGS on Unsplash

IAGA-IAPS Memorandum


 

IAGA and the International Association of Physics Students (IAPS) are taking joint efforts for academic growth by signing a Memorandum of Understanding. This has been done with the aim to establish future collaborations and to expand both the communities.


IAPS is an international, student-run educational association, which aims to encourage physics students in their academic and professional growth by developing an ever-growing worldwide community within which peaceful relations are established in a collaborative, diverse and friendly social environment.

The Naming Game : Moon Edition

What are moons? Moons are satellites that orbit around a planet. So, technically they'd be 'natural satellites of the planets' because "Moon" is just one, but, practically, don't we all just call them "moons"?! Currently, there are over 200 moons in our Solar System, and that's excluding the ones orbiting the dwarf or minor planets. 

Some moons have atmospheres, some have volcanic activities going on them and some even have oceans. Some moons orbit in direction of the rotation of planet and some orbit in opposite direction. But do you know how or what they are named?


The official names of celestial bodies are taken care of by the International Astronomical Union. Most of them are named after Greek and Roman mythology characters, but some are also named after literary characters.

While Mercury and Venus don't have any moons, our moon has many different names in different languages. The word "Moon" was named after two Latin words meaning 'to measure' and 'month'.

Mars, named after the Greek mythological God of war, Ares, has two moons -  Phobos and Deimos - named after the sons of Ares meaning 'fear' and 'dread'.

Jupiter has a plethora - 53 named moons and 26 unnamed ones. The planet is named after the Greek God, Zeus, and its moons are named after his lovers or descendants. Galileo first discovered the moons of Jupiter and hence the four biggest moons - Ganymede, Callisto, Io and Europa - are called the Galilean moons.

Saturn has such a large family of moons - around 82 which we know of - that there was a shortage for names. They were named after the Titans (children of Greek Gods Uranus and Gaia) and their descendants, but are now named also after the giants of the Norse, Gallic and Inuit mythology.


Uranus has 27 moons and they are named after Shakespeare's characters. A few are named after Alexander Pope's characters. Look them up to know if your favorite character made the cut; the maximum number coming from 'The Tempest'.

And finally, Neptune has 14 moons. Neptune, named after the Roman God of sea has its moons named after other Roman and Greek sea gods and nymphs.

Moons that are yet to be confirmed are named with a letter and year. 

Images : (1) Kevin Gill on Flickr. (2) Hubble. (3) Adobe Stock.



Shivangi Sharan is a second year PhD student at the Laboratory of Planetology and Geodynamics in France. Her research focusses on the study of the magnetic field of Mars and to infer its internal structure from it. She is an active member of the IAGA Blog Team and can be contacted via e-mail here.



  

IGY by ICH

A thorough insight into the International Geophysical Year (IGY) project from a 60‐year later perspective has been depicted by Y. Lyubovtseva, A. Gvishiani, A. Soloviev et al. in “Sixtieth anniversary of the International Geophysical Year (1957–2017) – contribution of the Soviet Union” published in the History of Geo‐ and Space Sciences journal (https://doi.org/10.5194/hgss‐11‐ 157‐2020). 

The IGY was the most significant international scientific event in geophysical sciences in the history of mankind. This was the largest international experiment that brought together about 300 000 scientists from 67 countries. Well‐planned activity of national and international committees was organized for the first time.


Read also about the "The IGY and Me" blogs published in our last blog here.



Contributed by the Chair of the Interdivisional Commission on History, Dr. Anatoly Soloviev, from the Geophysical Center, Russian Academy of Sciences, Moscow. The Commission encourages historical geophysical research and preservation of IAGA's history.


"The IGY and Me" Blogs

Rob Sternberg has started a blog entitled “The IGY and Me: Science, History, Culture, Philately and Memorabilia of the International Geophysical Year (1957-58).” It can be found at https://internationalgeophysicalyear.blogspot.com/



Posts are approximately weekly. You can subscribe and receive emails of the entries when they are posted. The themes are indicated in the blog’s subtitle, along with occasional thoughts about how they have intersected with Sternberg’s life and career over the years. 

IAGA was one of many scientific communities that provided official (via resolutions) and organizational support to the IGY in 1957-1958. 

 




Sternberg was born in1950, just a couple of months and a few miles from a historic soiree hosted by James and Abigail Van Allen in the Washington, D.C. area; with guests including Sydney Chapman and Lloyd Berkner, the idea for the IGY was conceived that evening. 

Rob’s childhood education was shaped by the fervor for science following the launch of Sputnik in 1957 as part of the IGY. He obtained his Ph.D. in geophysics at the University of Arizona. Sternberg was a geophysics professor at Franklin & Marshall College (Lancaster, Pennsylvania, USA) for over 30 years. 


For the last two decades he has been collecting books, philatelic items, and other items related to the IGY. He presented “The IGY and American Popular Culture” at the XXIV General Assembly of the IUGG, Perugia, Italy, July 2007, in a session on “The International Geophysical Year: A 50-yr Retrospective" (conveners Gregory A. Good and Ed Cliver). Sternberg can be contacted at rssternberg@gmail.com

Photos show Rob in second grade during the IGY and today.

IAGA Summer School 2021

The pandemic's plan to keep students and scientists from interacting and working together was a fail, because the first virtual IAGA Summer School 2021 was a success! 7 lecturers and 34 students were well managed and coordinated by the organisers. The interactions took place using various online platforms.



The first interaction started much before the summer school using Slack. Everybody was informed about the activities and lectures here. The platform was active till after two weeks of the end of the school, in case people wanted to interact or ask any questions regarding the topics discussed. 

A few days before the school, social interactions took place through Gather. All networking events as well as practical lessons during the school happened here. People could roam around in the different classrooms to work and discuss. The space was open 24/7 for whoever wanted to stay and chat.



All participants and lecturers came together from different time zones for the classes on Zoom. The lectures were on topics discussing the magnetism and modelling of the geomagnetic field and related phenomena. The organisers were always present in case of any technical or communication difficulties.

Finally, here are some testimonies from the participants themselves -

Shivangi Sharan, a PhD student working on the magnetic field of planets, says: The screens were our contact links as well as our barriers. The school was *almost* like a physical meet where everybody would come for the classes and eat together later. Just that some were eating their breakfast, some lunch and the rest dinner!

Sarasija Sanaka, another PhD student studying magnetotellurics, says : I felt very blessed to attend such an event. Lectures were organised very well and Gather is a very interactive platform. I didn't expect we all could interact so lively. It was my pleasure to take part in such an event. I heartfully thank the organisers for providing such an opportunity.

Hannah Rogers, a final year PhD student in geomagnetism, says : The summer school was an amazing way to meet other early career researchers from around the globe. Despite the challenges faced due to the global pandemic, it was an educational experience with many benefits from the excellent lecturers. I particularly enjoyed the chance to use jupyter notebooks to cement my understanding. Thanks so much to the organisers for all their hard work and to IAGA for facilitating this wonderful opportunity. I hope to take the knowledge gained with me into my future work in my PhD and beyond.  

All in all, the school went very smoothly, with its goal for imparting knowledge and interaction achieved.



K index digitization

K index is one of the oldest universal indices of geomagnetic activity that is still being widely used. The multidecadal practice of its application makes it an indispensable source of information for retrospective and historical analysis of solar‐terrestrial interaction for nearly eight Solar cycles. 

Example of range limits of K-index at different observatories. Credit : http://isgi.unistra.fr/what_are_kindices.php 

Most significantly, while studying the historical geomagnetic data, K index datasheets are in most cases more convenient for automated analysis than the analogue magnetograms. World Data Center for Solar‐Terrestrial Physics (Moscow, Russia) collected and digitized the results of the K index determination at 41 geomagnetic observatories of the former USSR for the period from July 1957 to early 1990s. 


This unique historical data collection is valuable for retrospective analysis and studying geomagnetic events in the past as well as for data validation or forecasting. This data collection is now available from the PANGEA data archive (https://doi.org/10.1594/PANGAEA.922233), and the relevant data paper has been published in the ESSD journal: N.Sergeyeva, A.Gvishiani, A.Soloviev, L.Zabarinskaya, T.Krylova, M.Nisilevich, and R.Krasnoperov (2021), Historical K index data collection of Soviet magnetic observatories, 1957–1992, ESSD, https://doi.org/10.5194/essd‐2020‐270.




Contributed by the Chair of the Interdivisional Commission on History, Dr. Anatoly Soloviev, from the Geophysical Center, Russian Academy of Sciences, Moscow. The Commission encourages historical geophysical research and preservation of IAGA's history.

Planetary Magnetic Fields : Gas Giants

Ever wondered how the beautiful auroras we see are formed? You are right, it’s due to the energetic particles carried along with the solar wind from the sun, that enter the magnetic field shield, called the magnetosphere of the planet, interacts there and collects at the poles. Why at the poles? Because that’s how the field lines travel. But it doesn’t just happen on Earth. And it doesn’t just emit visible light spectrum, at least on the outer planets.

Interior models of the giant planets. Image : NASA/Lunar and Planetary Institute

The gas and ice giants of our Solar system - Jupiter, Saturn, Uranus and Neptune - have extremely large magnetic fields and magnetospheres. Their interiors are unlike the interior of the terrestrial planets. They are mostly composed of gases and have a small solid core. Their magnetic fields are similar to that of Earth, i.e, dominantly dipolar, but the magnitudes are much larger than the terrestrial value. 

The interiors of Jupiter and Saturn consist of hydrogen and helium in different forms. Jupiter has the largest magnetic field in the Solar system that is assumed to be generated from the metallic hydrogen in its interior. The magnetosphere is so large that its tail almost reaches Saturn. The metallic hydrogen of Saturn is considered smaller in size comparatively and thus produces a lower magnetic field, but still much larger than Earth’s. The dipole magnetic field axis and the rotation axis almost align.

Magnetic field of the outer planets. Image : Stevenson 2018

The ice giants, Uranus and Neptune, have no metallic hydrogen but have molecular hydrogen and compounds like methane and ammonia in their interior. Uranus has an off-centered field. It rotates on its side due to its large tilt and its magnetic and rotation axes make a 59 degrees angle between them. The magnetic field and magnetosphere of Neptune is similar except that the planet is not as tilted.

Read about the magnetic fields of terrestrial planets here.



Shivangi Sharan is a second year PhD student at the Laboratory of Planetology and Geodynamics in France. Her research focusses on the study of the magnetic field of Mars and to infer its internal structure from it. She is an active member of the IAGA Blog Team and can be contacted via e-mail here.