Astronomy and Planetary Science

The black holes found at the centres of most large galaxies are now found to be fundamental to galactic formation and evolution. Until recently, however, little was understood about how these massive bodies affect the behaviours of their host galaxies and beyond. Through their research, Dr Stefi Baum and Dr Christopher O’Dea at the University of Manitoba have made important strides towards untangling the many mysteries involved in this intriguing astronomical problem.

When Earth’s magnetic field is struck by violent geomagnetic storms, narrow streams of fast-moving ions can form, which pose serious threats to vital satellite systems. Through her research, Dr Amy Keesee at the University of New Hampshire is shedding new light on how these streams originate, by picking up the energetic neutral atoms they occasionally generate. Her team’s work has proved that these atoms can be used to build reliable temperature maps of the magnetosphere – the region around Earth dominated by the planet’s magnetic field. Such temperature maps can help us to better predict when satellite systems may be under threat.

Interactions between positive and negative ions are important processes in nature. However, there is a lack of experimental facilities designed to study them in detail. This picture could now be changing thanks to DESIREE: a facility where different ion beams can be stored and cooled for extensive periods within separate rings, before colliding with each other. Run by an extensive team of physicists at Stockholm University, the instrument is shedding new light on how ions interact in a wide range of environments – from dynamic stellar atmospheres, to interstellar space.

Earth’s upper atmosphere is home to a growing number of satellites. To prevent these valuable instruments from colliding with one another, operators often require accurate information about how the orbits of these satellites are affected by drag. However, due to the Sun’s continually changing activity, the density of air found in this region can vary drastically, making it difficult for operators to calculate how adjustments should be made. Using a combination of modelling approaches, a team led by Dr Daniel Weimer at Virginia Tech shows how air density throughout the upper atmosphere can be precisely calculated, over a wide range of timescales.

Launched in 2019, the African Astronomical Society (AfAS) is a diverse and inclusive Pan-African society of professional and amateur astronomers, which aims to create a globally competitive astronomy community in Africa. The mission of AfAS is to be the voice of astronomy on the continent and to address the challenges faced by Africa through the promotion and advancement of astronomy. In this exclusive interview, we speak with the Society’s president, Dr Jamal Mimouni, who discusses astronomical achievements in Africa and how AfAS supports and advances astronomy research and education across the entire continent.

Earth’s crust plays host to many different fluids, which are often pressurised and heated to extreme degrees by the geological processes taking place around them. Harnessing his previous experience at the US Geological Survey, Dr I-Ming Chou at the Chinese Academy of Sciences designs vessels suitable for containing these fluids, while also enabling researchers to easily measure them in the lab using advanced optical techniques. Through their work, Dr Chou’s team has presented cutting-edge designs based on fused silica capillary tubes. Their designs could soon transform geologists’ understanding of the chemical processes taking place far below us.

For years, scientists have been puzzled by the appearance of dark streaks appearing on Martian hillsides. The linear features look like water flows – and if water is present, they could be harbouring life on Mars. However, the freezing conditions on Mars mean that liquid water flows are unlikely. Previous theories suggest the flows could be dust avalanches, but this doesn’t explain why they only appear in the Martian summer. Dr Anthony Toigo and his colleagues at Johns Hopkins University Applied Physics Laboratory, NASA Goddard Space Flight Center, and the University of Colorado – Boulder, have modelled weather conditions near the Martian surface and recreated the Martian atmosphere in a laboratory. By doing so, they could examine how Martian dust and surface soils respond to the changing seasons on the red planet.

Hundreds of millions of years after the Big Bang, charged, ‘ionised’ particles not seen since the earliest ages of the universe began to re-emerge. Named ‘reionisation’, this event was crucially important in the history of our universe – but because it occurred so far back in the past, telescope observations can only offer astronomers limited clues about how it unfolded. In his research, Dr Nick Gnedin at the Fermi National Accelerator Laboratory uses advanced computer simulations to study reionisation. His team’s project, named ‘Cosmic Reionization On Computers’, or CROC, now offers a key resource to researchers studying this distant period.

The spaces in between galaxies may be unimaginably vast, but within galactic clusters, they are far from empty. Rather, these expanses are home to a wide range of interplaying, often violent plasma dynamics. In his research, Dr Tom Jones at the University of Minnesota plans to use cutting-edge computer techniques to simulate these processes – shedding new light on physical properties that have eluded astronomers so far. His team’s research will not only give crucial insights into some of the largest structures in the known universe, but will also capture the public imagination, and inspire a diverse new generation of astronomers.

Enshrouding the Martian surface with thick clouds of dust, the Red Planet’s unique global dust storms have long mystified astronomers and planetary scientists. James Shirley, at NASA’s Jet Propulsion Laboratory, has shown through his research that the occurrence of these global storms is strongly linked to the changes in Mars’ motion about the gravitational centre of the solar system. Already boasting strong observational evidence, his results could not only improve our understanding of the Mars atmosphere – they may also lead to a better understanding of turbulent weather patterns on Earth.

From brown dwarfs to supermassive black holes, many of the strangest objects known to astronomers are formed as material collapses in on itself under its own gravity. Through a combination of physical theories and the latest computer simulations, Dr Shantanu Basu at the University of Western Ontario in Canada is offering intriguing new insights into how these structures originate. His theories could help astronomers to understand the very earliest stages of bodies ranging from those too small to become stars, to the vast, all-devouring heavyweights that reside in the centres of galaxies.

We know much about fully-formed stars, such as our Sun, but the very earliest processes of star formation are still a mysterious area of astrophysical research. The original idea that a single new-born star (or ‘protostar’) forms within a single molecular cloud core has been dispelled by the discovery of new-born pairs, triplets, or even larger groups of protostars in cores. Dr Philip Myers of the Center for Astrophysics | Harvard and Smithsonian has been observing and interpreting protostar formation for many years using a range of sophisticated telescopes and theoretical models.

Despite many years of research aiming to unite quantum mechanics with cosmological theories, researchers in fields across physics and philosophy remain in disagreement about a solution. Now, Dr Peter Evans at the University of Queensland sheds new light on the debate. He argues that on quantum scales, the idea of cause and effect does not need to follow the one-way passage of time, as we understand it. If correct, his theories could dispel some of the most puzzling mysteries of quantum theory – a significant step forward in understanding the true nature of the universe.