Forum Network

Today, thousands of satellites orbit Earth. At the end of their missions they drop from space and burn up in Earth’s upper atmosphere.The resulting ash deposits thousands of tons of aerosols. Certain aerosols contain metal oxides and pollutants that can impact both the ozone layer and Earth’s thermal balance (heat and cooling factors).

Atmospheric scientist Dan Cziczo, an expert on aerosols and clouds, analyzes these particles that accumulate in Earth’s stratosphere, to determine their relationship to both ozone-depletion and climate change. He explains the concern about these unique space debris chemicals and their potential effect on the ozone layer and the cloud dynamics associated with climate. The studies on space debris represent a developing area of atmospheric science and is of great significance, given the continuing increase in the number of satellites.

Mario Livio, the distinguished former astrophysicist at Hubble Space Telescope (until 2015) and best-selling science author, discusses his latest book, co-authored with Nobel Laureate Jack Szostak, 'Is Earth Exceptional'? One of the most fascinating questions is whether there is life -and especially intelligent life- beyond our planet.

This book provides the best information about the requirements for life and how scientists search for life in the cosmos. Dr. Livio explains the challenge of identifying life elsewhere when we have only the example of life’s emergence on Earth. Importantly, the book combines the unique expertise of astrophysics (Mario Livio) and geochemistry (Jack Szostak) in a very timely consideration of the possibility of life elsewhere.

Dark matter accounts for some 27 percent of the universe but is invisible. One promising technique to reveal it is the analysis of gravitational lensing that very occasionally aligns galaxy clusters.

The much-noted “cosmic question mark” image for this event is the result of a rare alignment between two distant galaxies due to gravitational lensing. Professor Jacqueline McCleary explains how cosmologists use such examples of weak gravitational lensing between galaxy clusters to explore the nature of elusive dark matter and its interaction with galaxies. She discusses how cosmologists gather and analyze data from observatories on mountaintops, in the stratosphere, and in space.

Dr. McCleary is a collaborator in the Local Volume Complete Cluster Survey (LoVoCCS), the SuperpressureBalloon-borne Imaging Telescope (SuperBIT), and COSMOS-Web (a JWST collaboration).

Epidemiologist Joel Schwartz is noted for his work on the acute and chronic health effects of fossil fuel air pollution.  One of his recent collaborative studies revealed that exposure to fine combustion particles in the air at concentrations well below current standards are associated with a range of conditions, including dementia, asthma, heart attacks, and lung cancer.  The study indicated that the death rate from this pollution is almost 1 in 5 deaths worldwide, about twice the previous mortality estimate.  Not surprisingly, the pollution impact falls disproportionately on poorer communities.  This research is finally leading to tighter U.S. air quality standards. In this program, Dr. Schwartz discusses the wide health effects of fossil fuel pollution and why restrictions have been so lax.  

This is a most exciting period for cosmology, especially for scientists whose focus is the early universe. The James Webb Space Telescope and other advanced technologies are providing unprecedented new insights about the early universe, especially the emergence of the first stars and galaxies and the relationship between these formations and mysterious dark matter. Professor Julian Muñoz explains both the newest discoveries and the techiques he uses to investigate the very early universe.

Dr. John Ebel explains the geological forces that cause earthquakes and the areas on the planet most vulnerable to tsunamis. We learn how seismologists track earthquake-prone areas of the planet and how they predict the possibility of tsunamis. Dr. Ebel has conducted extensive research on methods for earthquake hazard computation and earthquake forecasting. He has been a consultant on seismic hazard and nuclear test ban treaty monitoring issues for government agencies, including Argonne National Laboratory, the U.S. Nuclear Regulatory Commission and Lawrence Livermore National Laboratory. And he has been a consultant on seismic hazard for over 20 major engineering projects in the US and other countries.