About Joel Parker


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Joel Parker has written 67 articles so far, you can find them below.


Nuclear Tests and the Van Allen Belts

explosion-beltsIn 1963, the United States, the Soviet Union, and Great Britain signed the Limited Test Ban Treaty, agreeing to not test nuclear weapons in the atmosphere, underwater, or in outer space.  France continued atmospheric testing until 1974, and the last atmospheric test was done by China on October 16, 1980. Over 500 atmospheric nuclear tests have been performed before then, but none since.

That could soon change.  North Korea has threatened to do an atmospheric nuclear test.  Even if that test doesn’t lead to a chain of more dangerous events, and considering the potential health impacts of the dispersed radiation, it turns out that simply testing a missile in the atmosphere could lead to highly charged electrons that would tend to fry the electronics of Earth-orbiting satellites.

It’s a complex issue, and one that ties in with the huge magnetic fields that protect the Earth and the satellites orbiting around it.  Those magnetic fields include some areas that attract highly charged particles, called the Van Allen belts.  Earlier this year, we reported on a discovery from the Laboratory of Atmospheric Space Physics in Boulder, about how very low frequency radio transmissions sent to military submarines deep under that water, accidentally help satellites high above the Earth by reducing the impact of the Van Allen belts’ highly charged particles.  So, could those very low frequency waves also protect us from the satellite-frying effects of an atmospheric nuclear weapons test?  If things get too crazy here on Earth, could a spacecraft with a well-designed magnetic field help people escape?  Those are questions that come to mind for How on Earth’s Shelley Schlender.  Now here’s Shelley’s investigation about the Van Allen belts, whether cell phones would work after a nuclear explosion, and escaping to outer space.

Hosts: Joel Parker, Chip Grandits
Producer, Engineer: Joel Parker
Additional Contributions: Beth Bennett, Alejandro Soto
Executive Producer: Beth Bennett

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The Cassini Mission to Saturn

pia03883-nohuygensThe Cassini mission to Saturn launched 20 years ago, on October 15, 1997.  It took seven years to reach Saturn, and has been orbiting and intensely studying Saturn ever since…until last week when the mission ended in a final dive into Saturn’s atmosphere.  The mission studied Saturn, its famous rings, and its many moons using a suite of instruments that observed a broad range of wavelengths from ultraviolet, to visible, infrared, and radio as well as examining dust, charged particles, and magnetic fields.  It also delivered the Huygens probe that descended through the atmosphere of Saturn’s giant moon, Titan.

In this edition of How on earth, we have two scientists from the Cassini mission team.  Dr. Larry Esposito is a Professor at the Astrophysical and Planetary Sciences department at the University of Colorado at Boulder and member of the Laboratory for Atmospheric and Space Physics at CU.  Dr. Carly Howett is a planetary scientist and manager at the Southwest Research Institute in Boulder.  They share with us some of the science from Cassini-Huygens and experiences working on such a long-term and successful space mission.

Host / Producer / Engineer: Joel Parker
Additional Contributions: Beth Bennett, Shelley Schlender
Executive Producer: Alejandro Soto

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Climate Change and Extinctions Following an Asteroid Impact

asteroid_impactClimate Change and Extinctions Following an Asteroid Impact (starts at 8:45) It has been hypothesized that the dinosaurs were killed off by a large asteroid that struck the Earth. The details of how the impact of a 10 kilometer diameter asteroid led to global scale extinction have remained elusive. Recently, climate researchers from the Boulder area published new climate model results that show how the asteroid impact ultimately leads to widespread cooling in the atmosphere and increased exposure to ultraviolet radiation. These drastic and rapid changes to the climate due to the asteroid impact may explain the global scale extinction.

Two of the authors join us today to talk about this new research. Dr. Charles Bardeen works as a scientist at the National Center for Atmospheric Research, and is the lead author of the new paper. Joining Dr. Bardeen is Professor Brian Toon, a co-author of the new research and a professor at the University of Colorado, Boulder.

Hosts: Alejandro Soto & Joel Parker
Producer and Engineer: Joel Parker
Additional Contributions: Susan Moran, Beth Bennett, Chip Grandits
Executive Producer: Alejandro Soto

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Chasing Shadows – Stellar Occultations and the Outer Solar System

Shadow Chasers (Photo: Jack Jewell)

Shadow Chasers
(Photo: Jack Jewell)

Chasing Shadows [starts at 9:40]  Astronomy is a science that depends on watching things happen in the universe that we don’t have control over: supernovae, formation of stars, orbits of planets, and the spectacle of solar eclipses.  You can’t grab a distant galaxy and bring it into the lab for experiments, so astronomers have to depend on studying the light that fortuitously comes to them from distant objects.  However, by studying just that light, we can learn much about the objects in the universe and how they formed and evolved.  For example, studying solar eclipses have taught us about the corona of the sun and about general relativity.   To make those observations and measurements, scientists have to chase the shadow and set up their laboratory in remote places to catch it.  In this edition of How on Earth we talk with one such shadow-chaser: astronomer Dr. Marc Buie from the Boulder office of the Southwest Research Institute.  Marc organized a set of expeditions around the Earth to observe occultations of the Kuiper belt object 2014 MU69, which is is the next flyby target of the New Horizons space mission that flew past Pluto in July 2015.  He explains the science of occultations, what can be gleaned from these shadowy observations of 2014 MU69, and talks about planning for observation expeditions to remote places around the world.

Hosts: Joel Parker, Chip Grandits
Producer / Engineer: Joel Parker
Executive Producer: Alejandro Soto

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The American Eclipse of 1878

Cover-300-wideThis August 21st, some parts of the Earth will be plunged into darkness in the middle of the day.  It will be a solar eclipse; the moon’s shadow will cross the United States from Oregon to South Carolina, with the path closest to Colorado passing through Wyoming and Nebraska.

There have been many eclipses across the US, but there was a particularly special one nearly 140 years ago on July 29th, 1878.  That eclipse came at a time in American history of western expansion, industrial growth, new inventions and World’s Fairs, and a young country wanting to establish itself on the international stage of science and technology.

Our guest today is David Baron, author of a book about that eclipse.  The book is “American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World”.  David joins us to talk about that eclipse, the people involved in observing it, and its part in Colorado history.

Hosts: Joel Parker, Susan Moran
Producer / Engineer : Joel Parker
Executive Producer: Susan Moran

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2017 Graduation Special (part 2)

diploma-and-graduation-hatWith graduation season is upon us, or in many cases in the rearview mirror, today’s edition of How on Earth is the second of a two-part “Graduation Special”. Our guests in the studio today are scientists who recently graduated with – or soon will receive – their Ph.D.  They talk about their thesis research, their grad school experiences, and what they have planned next.

abbyAbby Koss – CU Boulder, Chemistry and Biochemistry
Topic: New Insights into Fossil Fuel Volatile Organic Compound Emissions and Chemistry using H3O+ and NO+ Chemical Ionization Mass Spectrometry

 
matteoMatteo Crismani – CU Boulder, Department of Astrophysical and Planetary Sciences
Topic: Cometary Gas and Dust Delivered to Mars

 

Version 2Callie Fiedler – CU Boulder, Electrical Engineering
Topic: Characterizing the Properties of 3D Printed Hydrogels for Regenerative Medicine

 

 

Host / Producer / Engineer : Joel Parker
Executive Producer: Susan Moran

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2017 Graduation Special (part 1)

diploma-and-graduation-hatWith graduation season is upon us, or in many cases in the rearview mirror, today’s edition of How on Earth is the first of a two-part “Graduation Special”. Our guests in the studio today are scientists who recently graduated with – or soon will receive – their Ph.D.  They talk about their thesis research, their grad school experiences, and what they have planned next.

morganMorgan Rehnberg – CU Boulder, Department of Astrophysical and Planetary Sciences
Topic: Small-Scade Structure in Saturn’s Rings

 

davidDavid Horvath – Colorado School of Mines, Department of Geophysics
Topic: Planetary Hydrology: Implications for the Past Martian Climate and Present Titan Lake Hydrology Using Numerical Models of the Hydrologic Cycles on Titan and Mars

 
josephJoseph Lee – CU Boulder, Department of Atmospheric and Oceanic Sciences
Topic: Wind Energy and Interactions between Wind Turbines and the Atmosphere

 
Host / Producer / Engineer : Joel Parker
Executive Producer: Susan Moran

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New Adventures in Astronomy with Gerrit Verschuur

Gerrit-VerschuurToday’s How on Earth show is a special edition in conjunction with the Conference on World Affairs panel entitled: “New Adventures in Astronomy”. Our guest is Gerrit Verschuur, a radio astronomer who has worked at Jodrell Bank radio observatory in the United Kingdom, National Radio Astronomy Observatory in West Virginia, and Arecibo Observatory in Puerto Rico.  Dr. Verschuur also was a faculty member at the University of Colorado, Boulder and was the first director of the Fiske Planetarium.  His work has ranged from measuring the interstellar magnetic field, to the search for Extraterrestrial Intelligence, to measuring the small-scale structure in the cosmic microwave background.  He has published numerous books including “The Invisible Universe: The Story of Radio Astronomy” and “Impact! The Threat of Comets and Asteroids.”

Host / Producer / Engineer: Joel Parker
Executive Producer:Susan Moran

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Of Wasps and Figs

511tQZJac7L._SX322_BO1,204,203,200_Today’s feature has How on Earth’s Beth Bennett talking with Dr. Mike Shanahan, a biologist who has a degree in rainforest ecology.  He has lived in a national park in Borneo, bred endangered penguins, and investigated illegal bear farms.  His writing has appeared in The Economist, Nature, and The Ecologist, and he also was the illustrator for the book: Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals.  His interests delve into what people think about nature and our place in it.  Beth had a chance to talk with Dr. Shanahan about his new book: Gods, Wasps and Stranglers: The Secret History and Redemptive Future of Fig Trees.

Host: Joel Parker
Producer, Engineer, Executive Producer: Joel Parker
Additional contributions: Beth Bennett, Shelley Schlender

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Earth in Human Hands – Shaping our Planet’s Future

Dr. David Grinspoon (photo by Lawrence Cheng)

Dr. David Grinspoon
(photo by Lawrence Cheng)

Sometimes when we are having personal or health problems, it helps to get an outside perspective: talk to other friends who have experienced similar problems and how they dealt with them, and other friends about how they avoided those problems.  Talk to experts.  Then using all that input, we try to make the best choice to solve the problems and to live a long and happy life.  This is perhaps the situation we find ourselves in now with the health of our environment and the long-term viability of the human race.  So where to we look for that “outside perspective” and expert help?  The answer may be: look to other planets and talk to those who study them.  This is the approach astrobiologist Dr. David Grinspoon takes in his new book: “Earth in Human Hands: Shaping Our Planet’s Future”. Dr. Grinspoon is a senior scientist at the Planetary Science Institute, an adjunct professor at the University of Colorado, and in 2013 he was appointed the inaugural Chair of Astrobiology at the Library of Congress.  We had a chance to talk with Dr. Grinspoon about how he compares Earth’s story to those of other planets, and how our present moment is not only one of peril, but also great potential, especially when viewed from a 10,000-year perspective.

The podcast of the show is below, and you also can hear the extended interview here.

Hosts: Joel Parker, Susan Moran
Producer and Engineer: Joel Parker
Additional contributions: Beth Bennett
Executive Producer: Joel Parker

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