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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Space Dust

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Dr. Mihaly Horanyi and his colleagues at the University of Colorado are on the brink of watching an instrument they developed crash into the moon. It’s okay—it’s designed to. In the meantime, the instrument, LDEX, is measuring impacts from dust particles a fraction of the width of a human hair on NASA’s LADEE mission. It’s measured more than 11,000 of these tiny impacts since falling into orbit in October.

Dr. Mihaly Horanyi and an LDEX prototype. (Photo/Beth Bartel)

Dr. Mihaly Horanyi and an LDEX prototype. (Photo/Beth Bartel)

How On Earth’s Beth Bartel is on her own mission to figure out just what is so interesting about space dust. Think: space colonization, geologic mapping, and searching for signs of extraterrestrial life.

Hosts: Beth Bartel, Joel Parker
Producer: Beth Bartel
Engineer: Joel Parker
Additional Contributions: Jane Palmer
Executive Producer: Joel Parker

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How On Earth is produced by a small group of volunteers at the studios of KGNU, an independent community radio station in the Boulder-Denver metro area. KGNU is supported by the generosity and efforts of community members like you. Visit kgnu.org to learn more.

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