The recent Siberian meteorite explosion has correctly alerted the world to the danger of big space rocks smashing into Earth with devastating effect. Indeed, new wheels have been set into motion to improve the science and technology available to detect these dangers and divert the orbits of near-Earth objects (NEOs) so they don’t wipe out human life on Earth. Yet if the truth is to be told, the cosmic hazard that is most likely to devastate Earth and wipe out our modern technological society first is not space rocks, but solar and cosmic radiation.
Oddly enough, when the solar weather is most extreme it helps to protect us from cosmic radiation from the rest of the universe, but when the sun is at solar max we have to worry about powerful solar flares and huge blasts called coronal mass ejections that spew billions of tons of ions from the sun’s surface. These solar events can do enormous damage to our global infrastructure such as the 1989 event that took out electrical transmissions systems from Chicago to Montreal. A powerful solar storm like the so-called Carrington Event of 1859 could potentially wipe out electrical grids, satellites, and even our computers and the Internet.
Why should we be concerned? Earth is protected by its atmosphere, the geomagnetosphere and the Van Allen Belts, which are shaped by Earth’s magnetic field. Satellite projects that are examining Earth’s magnetosphere such as Cluster, THEMIS (Time History of Events and Macroscale Interactions during Substorms) and the newly launched Van Allen Probes are showing us alarming data that there are “cracks” in the magnetosphere. Such gaps in the protective shield can allow poisonous gases and radiation to pour through, and such events are thought to have already killed millions of birds and fish. Earth’s protective atmosphere in recent decades has been weakened as demonstrated in the form of the so-called polar ozone holes. Meanwhile, solar radiation is gradually heating up Earth as we are witnessing in the form of climate change.
In short, we now need to worry not only about solar radiation heating that comes with greenhouse gas buildup but also about whether we will be adequately protected from solar and cosmic radiation and solar storms. Increasingly there seems to be legitimate concern that if we are not able to develop some form of “high-altitude blinds” against solar and cosmic radiation, we and lots of other species on Earth could be literally cooked to death. This does not mean we would be roasted medium well done like in an oven, but it could mean that genetic mutation could wipe out our natural reproductive powers, as has already been detected in frogs in locations under the ozone holes.
There is a lot to be done in terms of more research about solar storms, solar radiation and cosmic radiation to learn what is happening to our natural protective shields. This is where NASA, in partnership with other space agencies, needs to build better global space research programs — and quite a bit more.
This quite a bit more is the biggest challenge. It may turn out that humanity’s ultimate survival rests on our ability to develop effective shields against the most violent solar storms and solar and cosmic radiation. There are certainly innovative ideas out there. University of Chicago economist Steven Levitt and New York Times reporter Stephen Dubner, in their best-selling book “Super Freakonomics,” have supported the unorthodox concept of simulating massive volcanic eruptions by sending millions of tons of sulfur dioxide up into the clouds to turn them white and reflect much more of the sun’s radiation back into space. When Mount Pinatubo in the Philippines exploded in 1992, enough sulfur dioxide was spewed into the atmosphere to cool the Earth’s temperature about 1 degree Fahrenheit. Others have even suggested we could spray paint Earth’s clouds white. Such techniques would become a crutch that could eventually turn into a lethal long-term trap.
The point is that we simply do not know enough about solar and cosmic radiation and changing patterns within the sun’s radiation output, nor about changes to Earth’s stratosphere and magnetosphere. We do know that of the five mass extinction events that have occurred on Earth, four of these have involved overheating.
Much more needs to be known to assess just how dangerous new and emerging patterns of radiation can become — especially if linked to climate change. Even further to the point, we don’t know what technical strategies could be developed and implemented to create something like space-based venetian blinds to block out an overly bright sun or energetic cosmic radiation.
Some specific steps should be taken. The National Science Foundation should be assigned the task of assessing the extent of solar and cosmic radiation and its potential threat to the survival of the human race. These studies should take into account changes in the sun, changes to Earth’s atmosphere and ocean temperatures, and changes to the geomagnetosphere, calibrated against the historical record trapped in the frozen cores of the polar climes.
NASA should be specifically assigned the task of marshaling space research in this area and creating new forms of global space agency cooperation modeled after the Inter-Agency Space Debris Coordination Committee to address solar and cosmic radiation risks and to coordinate research on active radiation management strategies. This new interagency unit would coordinate with the U.N. Office of Outer Space Affairs to seek global input.
Finally, Congress and the president should require an annual report of progress against a five-year plan to address all of these issues and a comprehensive planetary defense plan that includes NEOs, space weather, and solar and cosmic radiation hazards.
Joseph N. Pelton is co-editor of the “Handbook of Cosmic Hazards and Planetary Defense” and former dean of the International Space University.