Extreme Space Weather Event #23072012

You may have seen some dramatic headlines in the news last week: “‘Extreme solar storm’ could have pulled the plug on Earth” (Guardian); “Solar ‘superstorm’ just missed Earth in 2012” (CBS); “How a solar storm two years ago nearly caused a catastrophe on Earth” (Washington Post blog). Also see this Physics Today article, which was published online today and reviewed the press attention to the event.

Though journalists and editors often write hyperbolic headlines, the danger from solar storms is very real, though extreme ones are as rare as massive earthquakes. When you think of solar flares and eruptions threatening humans, it may evoke Stanislaw Lem’s Solaris or the Doctor Who episode 42, but at least our sun isn’t sentient (as far as we know)!

A less threatening solar storm on the Sun

The solar storm in question occurred two years ago on 23 July 2012, and the media reported on it following a NASA public-information release and accompanying four-minute YouTube video (see below). It seems that those of us who live on Earth and use electronic technology were lucky that this was a near miss. The threat of solar storms is also relevant to “space security”, which I wrote about in a previous post.

The paper itself was published last fall in the Space Weather journal by Daniel Baker, of the Laboratory for Atmospheric and Space Physics at the University of Colorado, and six colleagues from NASA, Catholic University, and the University of New Hampshire. Its full title is “A major solar eruptive event in July 2012: Defining extreme space weather scenarios,” and here is their abstract (abridged):

A key goal for space weather studies is to define severe and extreme conditions that might plausibly afflict human technology. On 23 July 2012, solar active region 1520 (141°W heliographic longitude) gave rise to a powerful coronal mass ejection (CME) with an initial speed that was determined to be 2500 ± 500 km/s [5.6 million miles/hr!]… In this paper, we address the question of what would have happened if this powerful interplanetary event had been Earthward directed. Using a well-proven geomagnetic storm forecast model, we find that the 23–24 July event would certainly have produced a geomagnetic storm that was comparable to the largest events of the twentieth century…This finding has far reaching implications because it demonstrates that extreme space weather conditions such as those during March of 1989 or September of 1859 can happen even during a modest solar activity cycle such as the one presently underway. We argue that this extreme event should immediately be employed by the space weather community to model severe space weather effects on technological systems such as the electric power grid.

The solar storm missed the Earth but hit NASA’s STEREO-A spacecraft, which was safely outside the Earth’s magnetosphere and was able to measure and observe the approaching CME, a billion-ton cloud of magnetized plasma. “I have come away from our recent studies more convinced than ever that Earth and its inhabitants were incredibly fortunate that the 2012 eruption happened when it did,” says Baker. “If the eruption had occurred only one week earlier, Earth would have been in the line of fire.” According to the simulations in their follow-up paper by Chigomezyo Ngwira et al., had the 2012 CME hit the Earth, it could have produced comparable or larger geomagnetically induced electric fields to those produced by previously observed Earth-directed events and would have put electrical power grids, global navigation systems, orbiting satellites, etc. at risk.

Pete Riley, a physicist at Predictive Science Inc., published a paper in 2012 in the same journal entitled “On the probability of occurrence of extreme space weather events.” He analyzed historical records of solar storms, and by extrapolating the frequency of ordinary storms, he calculated the odds that a Carrington-class storm (which occurred in 1859) would hit Earth in the next ten years is between 8.5 and 12%!

NASA has calculated that the cost of the 2012 CME hitting the Earth would have been twenty times the devastation caused by hurricane Katrina—on the order of $2tn. The storm would have begun with a solar flare, which itself can cause radio blackouts and GPS navigation failures, and then it would have been followed by the CME a few minutes later, potentially causing widespread havoc with global technological infrastructure. Anything that uses electricity, including water supplies, hospital equipment, and radio and television broadcasts could be shut down. How do we prepare as a society for an event like that?

An introduction to “space security”

I’m curious about what people refer to as “space security”, as well as space policy and sustainability, and if you’re interested, you can learn with me. This post will just be an introduction to some of the issues involved. Note that I’m not an expert on many of these issues, so take my comments and thoughts with a grain of salt.

images

The idea of “space security” might conjure images of invading aliens, but as much fun as that is, that’s not what I’m talking about. I’m also not planning on talking about killer asteroids and dangerous radiation, though these are much less far-fetched. For example, the Pan-STARRS survey (of which I was briefly a member a few years ago) received funding from NASA to assess the threat to the planet from Near Earth Objects, some of which pass closer to us than the moon. (A limitation of Pan-STARRS, however, was that images that happened to contain passing satellites had software applied to black out or blur the pixels in the region.) On the other hand, solar flares can produce “coronal mass ejections” and intense cosmic rays that could be hazardous to spacecraft but on Earth we’re somewhat protected by our atmosphere and magnetosphere. This and other forms of “space weather” could be the subject of another post later.

I’d like to talk about the issue of satellites, as well as weapons and reactors, in space. More than 5,000 satellites have been launched into orbit and about 1,000 are in operation today. The act of destroying a satellite or of colliding satellites can damage the space environment by creating dangerous amounts of debris. (If you’ve seen the Oscar-winning Gravity, then you know that debris from satellites can be a serious problem.) For example, in a demonstration of an anti-satellite weapon in 2007, China destroyed one of its own satellites; the resulting “space junk” then struck and destroyed a small Russian satellite last year. The following computer-generated images of the growing number of objects in low-earth orbit (courtesy of the NASA Orbital Debris Office) illustrates the problem. Only 5% of the objects are satellites; the rest are debris. Currently more than 21,000 pieces of debris larger than 10cm are being tracked, and there are as many as 500,000 additional untracted pieces larger than 1cm.

Satellites and orbital debris_500x350

In addition, the loss of an important satellite could create or escalate a conflict, especially during a time of tension between states. The US and other countries possess “anti-satellite” weapons (ASATs) and have or are considering space-based missile defense systems. Attacks on satellites are a very real possibility, and it is important to beware of the destabilizing effects and potential for proliferation with such weapons. Moreover, since the Cold War, the US and other governments have considered deploying nuclear reactors on spacecraft, which have proven to be controversial (such as the dubiously named Project Prometheus, which was cancelled in 2006); an intentionally or unintentionally damaged nuclear reactor in space could have major consequences.

Considering that we are increasingly dependent on satellites and that there are military, commercial, and civil interests in space, how can we attempt to ensure space security and sustainability in the future? In the US, the Obama administration has a National Space Policy, which was released in June 2010. The policy mainly consists of: (1) limit further pollution of the space environment; (2) limit objects from colliding with each other and/or exploding; (3) actively removing high-risk space debris. The policy a good start, but much more could be done. An emphasis on international cooperation rather than unilateral action would help; space debris are clearly a global problem requiring global solutions. It is also important to negotiate on the control of space weapons. The US and other space powers should declare that they will not intentionally damage or disable satellites operating in accordance with the Outer Space Treaty and that they will not be the first to station weapons in space. Moreover, “space situational awareness” (SSA), which allows for the coordination of space traffic, can be improved in collaboration with other countries, and satellites can be made less vulnerable to collision or attack. Finally, the US should play an active role in negotiations with the international community on space security and sustainability. The United Nations has the Committee on the Peaceful Uses of Outer Space (COPUOS), with 76 member states, has been working on a variety of programs to improve the long-term sustainability of space activities, and in particular, to develop and adopt international standards to minimize space debris.