In this week’s international journal Ambio, two sustainability scholars at Michigan State University (MSU) outline how today’s catastrophes — pandemics, wars, natural disasters — play out differently in the modern world, with effects often reverberating farther and faster than their historic counterparts. Understanding the true impacts both near the source and across the world — and often months or years later, will be crucial.

“Given the current globalized world, our challenges have also become global,” said Andrés Viña, of MSU’s Center for Systems Integration and Sustainability (CSIS). “The solutions to these challenges then need to also be global. Even though our individual actions operate at the local level, collectively they have worldwide repercussions. Therefore, we need to find ways of working together for the common good, irrespective of political boundaries.”

Technology — particularly telecommunications and transportation — has made the world smaller and more connected as people, goods and information move fast. While history can be a good teacher, examining new disasters in an updated way shows today’s problems — like the COVID-19 pandemic — are having a broader, faster impact than earlier global shocks.

Public transportation innovations allowed The Spanish Flu pandemic of 1918 to spread fast and furious, and quick action by governments to mandate lock downs and travel bans helped. But today’s COVID outbreaks and impacts were much faster and farther. Obvious disruptions such as shortages, changes in the costs of goods, restrictions and disruptions in travel are giving way to more subtle but significant changes.

The paper’s authors note how coping strategies on one part of the world, such as a country shifting from local food to imported, can cause a country far away to turn more forests into farmland to meet a new need, creating environmental stresses to fragile wildlife. And then transporting the goods can create other impacts, like pollution, but also jobs, at many places between those farms and their new customers.

The point, the authors note, is that if the global community doesn’t learn to spot and address the short- and long-term changes, both harm and opportunity can be unchecked. Viña and co-author Jianguo “Jack” Liu, Rachel Carson Chair in Sustainability and CSIS director, use a new method to uncover the complexities of the real world.

The metacoupling framework creates an integrated way to look at how people and nature interact across the world and provides a new language to look at the big picture and at details simultaneously.

“Events such as war, drought and disease that start in one place set off chain reactions worldwide that are often hard to observe if we look at the world through traditional lenses,” Liu said. “And that also means solutions will require a new way of both thinking and reacting to take advantage of them.”

“Effects of global shocks on the evolution of an interconnected world” notes that COVID has shifted much of modern life — where people get their food and goods, how we travel for work and pleasure, how health care is distributed, and how natural resources are used and abused. The pandemic is one of many examples that show building resiliency is a global project.

The work was supported by the National Science Foundation and Michigan AgBioResearch.

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Materials provided by Michigan State University. Original written by Sue Nichols. Note: Content may be edited for style and length.

As galaxies move through the Universe, they sometimes encounter other galaxies. As they interact, each galaxy’s gravity pulls on the other. The ensuing tug-of-war flings gas and stars away from the galaxies, leaving behind streams of material known as tidal tails.

And that’s just what scientists believe happened to SDSS J1448+1010, but with a plot twist. The massive galaxy, which was born when the Universe was about half its current age, has nearly completed merging with another galaxy. During observations with the HST and ALMA — an international collaboration in which the U.S. National Science Foundation’s National Radio Astronomy Observatory (NRAO) is a partner — scientists discovered tidal tails containing roughly half of the entire system’s cold, star-forming gas. The discovery of the forcefully discarded material — equal to 10 billion times the mass of Earth’s Sun — was an indication that the merger may be responsible for snuffing out star formation, and that’s something scientists didn’t expect.

“What initially made this massive galaxy interesting was that, for some reason, it suddenly stopped forming stars about 70 million years ago immediately following a burst of star-forming activity. Most galaxies are happy to just keep forming stars,” said Justin Spilker, an astronomer at Texas A&M University and the lead author of the paper. “Our observations with ALMA and Hubble proved that the real reason the galaxy stopped forming stars is that the merger process ejected about half the gas fuel for star formation into intergalactic space. With no fuel, the galaxy couldn’t keep forming stars.”

The discovery is shedding light on the processes by which galaxies live or die, and helping scientists to better understand their evolution.

“When we look out at the Universe, we see some galaxies that are actively forming new stars, like our own Milky Way, and some that aren’t. But those ‘dead’ galaxies have many old stars in them, so they must have formed all of those stars at some point and then stopped making new ones,” said Wren Suess, a cosmology fellow at the University of California Santa Cruz and a co-author of the paper. “We still don’t yet understand all of the processes that make galaxies stop forming stars, but this discovery shows just how powerful these major galaxy mergers are, and how much they can affect how a galaxy grows and changes over time.”

Because the new result is from a single observation, it is currently unclear just how common this tug-of-war and its resultant quiescence may be. However, the discovery challenges long-held theories about exactly how star formation stops and galaxies die and has provided scientists with an exciting new challenge: to find more examples.

“While it’s pretty clear from this system that cold gas really can end up way outside of a merger system that shuts off a galaxy, the sample size of one galaxy tells us very little about how common this process is,” said David Setton, a graduate student in the department of physics and astronomy at the University of Pittsburgh and a co-author of the paper. “But, there are many galaxies out there like J1448+1010 that we’re able to catch right in the middle of those crashes and study exactly what happens to them when they go through that stage. The ejection of cold gas is an exciting new piece of the quiescence puzzle, and we’re excited to try to find more examples of this.”

Spilker added, “Astronomers used to think that the only way to make galaxies stop forming stars was through really violent, fast processes, like a bunch of supernovae exploding in the galaxy to blow most of the gas out of the galaxy and heat up the rest. Our new observations show that it doesn’t take a ‘flashy’ process to cut off star formation. The much slower merging process can also put an end to star formation and galaxies.”

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The heavy elements in interstellar matter significantly impact the mechanism of star formation. In the early universe, the abundance of heavy elements was lower than in the present universe because there was not enough time for nucleosynthesis to produce heavy elements in stars. It has not been well understood how star formation in such an environment differs from present-day star formation.

An international team led by Professor Toshikazu Onishi, Osaka Metropolitan University, and Project Assistant Professor Kazuki Tokuda, Kyushu University/NAOJ, used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe high-mass young stellar objects in the Small Magellanic Cloud.

The Small Magellanic Cloud is characterized by a low abundance of elements heavier than helium, similar to the galaxies 10 billion years ago. The target provides a detailed observational view thanks to the relatively close distance from Earth. In this study, researchers detected a bipolar gas stream flowing out of the “baby star” Y246 and determined that the molecular flow has a velocity of more than 54,000 km/h in both directions.

In the present universe, growing “baby stars” are thought to have their rotational motion suppressed by this molecular outflow during gravitational contraction, accelerating the star growth. The discovery of the same phenomenon in the Small Magellanic Cloud suggests that this process of star formation has been common throughout the past 10 billion years. The team also expects this discovery to bring new perspectives to studying stars and planet formation.

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PNe are the ejected, glowing shrouds of dying stars that shine with a rich emission line spectrum and display, as a result, their distinct colours and shapes that make them photogenic magnets for public interest. It was no coincidence that one of the first James Webb Space Telescope (the largest optical telescope in space) images released to the public was a PN.

The PN, with the rather ungainly name of “IPHASX J055226.2+323724,” is only the third example of an association between a PN and an OC out of the ~4,000 PNe known in our Galaxy. It also appears to be the oldest PN ever found. The small team led by Professor Quentin PARKER, Director of the HKU LSR, have determined some interesting properties for their discovery: the authors found the PN has a “kinematic age” of 70,000 years. This estimate is based on how fast the nebula is expanding, as determined from the PN emission lines, and assuming this speed has remained effectively the same since the beginning, and is the time elapsed since the nebular shell was first ejected by the host, a dying star. This compares to typical PN ages of 5,000-25,000 years. It is truly a grand old dame in PN terms but of course a mere “blink of the eye” in terms of the life of the original star itself that runs to hundreds of millions of years.

Because this “grand old dame” lives in a stellar cluster, this environment enables the team to determine powerful additional parameters not possible for the general Galactic PN population. These include estimating the mass of the PN’s progenitor star when it turned off the stellar main sequence, as derived from the observed properties of the thousands of stars in the cluster when plotted in a so-called colour-magnitude diagram. The team can also estimate the residual mass of the central star that ejected the PNe via theoretical isochrones and observed properties of the hot, blue central star. As a result, they figured how massive the star was that ejected the PN gaseous shell when it was born and how much mass is now left in its residual, contracting hot core (which is already a so-called ‘White Dwarf’ star). Fresh “Gaia” data for the hot blue, PN central star also provide a good distance estimate allowing the PN’s actual size at this extreme age to be determined as 3.2pc (parsec, an astronomical unit of measure for interstellar space with 1pc equals to 3.26 light-years) in diameter — unsurprisingly perhaps also at the extreme end of known PN physical sizes.

Former HKU PhD student Dr Vasiliki FRAGKOU, the first author of the study stated, “I am so excited to be able to work on these fascinating rare cases of OC-PN associations because they keep turning up important science results, like all three cases we have found are butterfly (bi-polar) PN in terms of shape, all are very faint and highly evolved, and all have Type-I chemistry according to their emission lines, and of course all have intermediate to high progenitor masses.”

Corresponding author Professor Quentin Parker said, “This is only the third example of a PN found in a Galactic open star cluster, and my group has found all three confirmed examples. They are incredibly rare but also very important as these beautiful objects allow us to independently determine points on the so called initial to final mass relation (IFMR) for stars — an important astrophysical relation — independent of the traditional method of using white dwarfs in clusters. Intriguingly, all our points lie just below the empirical IFMR trend currently established but add to the “kink” in this relation found recently in the 2-3 Solar mass range for the original progenitor mass by Marigo et al in the Nature Astronomy journal. Our OC-PN points fortuitously are found in currently sparsely populated regions of the IFMR, making them even more valuable.”

Co-author Professor Albert ZILJSTRA, Hung Hing Ying Distinguished Visiting Professor in Science and Technology at HKU LSR from the University of Manchester commented on the PN visibility lifetimes which have previously been much shorter in the general Galaxy. “This new result implies that the location of a PN in an OC provides an environment suitable for allowing the PNe to expand and fade without disruption by the ambient ISM (which is typically much weaker in an OC) and not as would be the case in the Galaxy.”

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