COSPAR 2021 Week at a Glance

New High Energy Astrophysics Involving Gravitational Waves and Satellite Observations

A new exploration of the Universe has recently started through gravitational-wave observations. On September 14, 2015, the first detection of gravitational waves from the coalescence of a binary system of black holes by the Advanced LIGO detectors marked the dawn of gravitational-wave astronomy. On August 17, 2017, the first observation of gravitational waves from the inspiral and merger of a binary neutron-star system by the Advanced LIGO and Virgo network, followed 1.7 s later by a weak short gamma-ray burst detected by the Fermi and INTEGRAL satellites initiated the most extensive world-wide observing campaign which led to the detection of multi-wavelength electromagnetic counterparts. Multi-messenger discoveries are revealing the enigmas of the most energetic transients in the sky, probing relativistic astrophysics, nuclear physics, nucleosynthesis and cosmology. The talk will give an overview of the astrophysical implications of the gravitational-wave and multi-messenger observations, focusing on the key role of multi-wavelength satellites operating together with the current and future gravitational-wave detectors.

Marica is president of the commission of Gravitational Wave Astrophysics of the International Astronomical Union and member of the Gravitational Wave International Committee. She is member of the Virgo Collaboration, where she coordinated the LIGO and Virgo collaboration electromagnetic follow-up program from 2014 to 2018. She was in the panel that announced the first gravitational-wave signal from the coalescence of two neutron stars at the NSF international press-release. She was listed in “Nature’s 10” as one of the most impactful scientists of the year 2017. Her scientific interest lies in the (astro)physics governing emission, formation and evolution of black holes and neutron stars. Her research activity is aimed at developing the multi-messenger astronomy, which uses electromagnetic and gravitational-wave observations to probe the physics of the most energetic transient phenomena in the Universe.

John Church

University of New South Wales, Sydney, Australia

John Church is a Professor in the Climate Change Research Centre, University of New South Wales. He has published across a broad range of topics in oceanography. His area of expertise is the role of the ocean in climate, particularly anthropogenic climate change and in understanding global and regional sea-level rise. He is the author of over 160 refereed publications, over 100 other reports and co-edited three books. He was co-convening lead author for the Chapter on Sea Level in the IPCC Third and Fifth Assessment Reports. He was awarded the 2006 Roger Revelle Medal by the Intergovernmental Oceanographic Commission, a CSIRO Medal for Research Achievement in 2006, the 2007 Eureka Prize for Scientific Research, the 2008 AMOS R.H. Clarke Lecture, the AMOS Morton Medal in 2017 and was a joint winner of the BBVA Frontiers of Knowledge Climate Change Category Prize in 2019. He is a Fellow of the Australian Academy of Science, the Australian Academy of Technology and Engineering, the American Meteorological Society and the Australian Meteorological and Oceanographic Society.

Climate Change, the Ocean, the Cryosphere and Regional Sea-level Change

Climate change has become one of the most important economic, environmental and social challenges of the 21st century, with sea-level rise a key aspect. Today, the order of 100 million of people live within a metre of high tide level and more people are moving towards the coast in both the developed and developing world. Historical and paleo observations, the advent of modern satellite and in situ ocean, cyosphere and climate observing systems and the development of improved ocean, ice sheet and climate models has greatly improved our understanding of contemporary sea-level change. There is now a reasonable understanding of the reasons for sea-level change over recent decades and since 1900, including the attribution of the observed change to the climatic drivers. There are important implication for the 21st century and beyond. Critically important for regional sea level around the globe is the changing structure of the oceans and glaciers, the role of the oceans and atmosphere in the future of the ice sheets of Antarctica and Greenland and the vertical movement of coastal regions. Projections for the 21st century indicate sea levels could rise by a metre or more for unmitigated emissions. Sea levels will not stop rising in 2100, even for the strongest mitigation scenario. Indeed, failure to mitigate our greenhouse gas emissions will lead to a world of catastrophic changes. Avoiding these changes will require significant, urgent and sustained mitigation of greenhouse gas emissions. But even with successful mitigation, society will have to adapt to that component of climate change we cannot avoid. As a result, sea-level rise will have major impacts around the world.

Michele Dougherty

Head of the Physics Department at Imperial College London and a Fellow of the Royal Society

Michele Dougherty is Head of the Physics Department at Imperial College London and a Fellow of the Royal Society. She was the Cassini magnetometer Principal Investigator and with her team discovered outgassing of water vapour from Saturn’s moon Enceladus. She is Principal Investigator for the magnetometer on the ESA JUICE spacecraft, due for launch to Jupiter and its moons in 2022.

New aspects of the magnetospheres of Jupiter and Saturn

The focus for the search for liquid water within our solar system has expanded in the last 20 years to include the moons of Jupiter and Saturn. Our understanding of the magnetospheres of these two planets and their moons has greatly increased following the orbital spacecraft missions at these two giant planets. This orbital exploration began with the Galileo spacecraft at Jupiter from 1995-2003, the Cassini-Huygens spacecraft at Saturn from 2004-2017 and the Juno spacecraft which began its orbital tour at Jupiter in 2016. Discoveries from all of these orbital planetary missions will be described as well as comparisons made between the two giant systems.

Hitoshi Kuninaka

Director General, Institute of Space and Astronautical Science, Vice President, Japan Aerospace Exploration Agency

Dr Hitoshi Kuninaka researches the plasma interaction of satellites and develops electric propulsions. He participated in the satellite project, Space Flyer Unit, from 1988 to 1996 and successfully brought it back to Earth via Space Shuttle STS-72. Microwave discharge ion engines, which were invented and developed by Dr Kuninaka, took Hayabusa explorer on a round-trip journey between Earth and an asteroid from 2003 to 2010. The engines also have been propelling Hayabusa2 explorer toward another asteroid since 2014.

The Status of Hayabusa 2 Asteroid Explorer and Its Results

JAXA has completed the space mission of Hayabusa asteroid sample return from 2003 to 2010. The retrieved capsule contained a lot of particles originating from the S-type asteroid Itokawa. Hayabusa 2 project was initiated in 2011 for the sample return from a C-type asteroid Ryugu. The bus system is designed more robustly than the original. The spacecraft was launched by H2A rocket December 2014 and then achieved rendezvous with the asteroid in June 2018 after the orbital maneuver by ion engines in 3.5 years. Three robots of MINERVAs and MSCOT successfully landed on and sent back pictures of the asteroid surface in close-up.

The detail localization and mapping of the surface identified several points for the touch-down and the sample collection. On February 2019 Hayabusa 2 bravely tried the first touch-down and scattered a lot of fragments, some of which might be collected by Hayabusa 2, from the surface. The spacecraft fired the impactor and made an artificial crater with 10m diameter in April 2019. The second touch-down was executed beside the new crater in July. Hayabusa 2 will come back Earth at Woomera Australia on December 2020.

Carlé McGetchin Pieters

Brown University, USA

Dr Pieters received her PhD from MIT in 1977 and is currently a Professor (Research) at Brown University. Her research focuses on remote compositional analyses and planetary regolith processes. She has extensive laboratory experience with lunar samples and meteorites and managed the multi-user Reflectance Experiment Laboratory (RELAB) for the community [1980-2014]. She has been a productive planetary astronomer as well as science team member on exploration missions to the Moon and asteroids. Dr. Pieters was PI of the Moon Mineralogy Mapper (M3) on the Indian Chandrayaan-1 mission and was an affiliate member of the JAXA Kaguya Science Team. She then co-led international cross-calibration investigations comparing optical results from several lunar missions. She was an active CoI on NASA’s Dawn Mission to the large asteroids Vesta and Ceres (2007-2018).

The Earth-Moon System: Our Past, Present and Future

It has been 50 years now since a human first stepped on another planetary body and began exploration of a totally new environment. Some remember that initial step as a once-in-a lifetime event that brought a dramatic change of perspective and understanding. To others it represents just a waypoint in history that occurred two generations in the past. Regardless of how that first venture from the Earth to the Moon is viewed, the space science world of today is quite different from that of 50 years ago. The number of space faring nations participating in exploration has greatly expanded and the community is irreversibly international in nature, talents and objectives. Technical capabilities of instruments and sensors have improved exponentially and will continue to push new boundaries, pose new questions and stumble upon profound surprises. What have we learned about our home through exploration of the Moon? Are we prepared for the next 50 years?

The Past. We now know that the Earth and Moon have been intimately linked since our violent origin billions of years ago. The Moon’s surface documents the subsequent formative period of the Earth-Moon system and provides a lasting record of that early era, one that has long since been transformed and lost on Earth.

The Present. Similarly, we recognize that the Earth and the Moon will continue to uniquely share the same environment at 1 AU. This includes the same ongoing interaction with the residual flux of large and small pieces of solar system debris. The Earth and Moon are also both simultaneously awash in the Sun’s variable magnetic environment and each faces the same amount of energetic solar and galactic plasma and neutral particles.

The Future. Humanity inhabits all continents of Earth, albeit with different degrees of comfort and prosperity. To meet more of humanity’s vital needs and demands (which will only grow) in the next century, the Moon presents a newly accessible “8th continent” for future exploration as well as potential resources. We must plan carefully and proceed wisely.