Why Solar Flares are good for youJuly 6, 2010
Well Our Sun has been usually quiet but that’s the Solar Cycle for you. There are no sunspots for months on end… and then three come along at once. We shall see if the predictions of a Dalton Minimum or even a Maunder Minimum play out to be a load of cold air. And, as the cycle ramps up, put paid to the Skeptics who believe that the solar output has a greater climate forcing function than we do!
(Personally I think it’s all bad!)
Even in scientific circles it is tempting to use sensationalism about the Sun shutting down or alternatively frying our power grids. This sensible article restores some balance to the subject.
This sensationalist (see title above!) believes that it is, in part, due to the large number of Solar Eyes we now have in place:
- SOHO still giving us some great data and lovely images (Ro.)
- STEREO providing the now obligatory third dimension
and the new kid on orbit:
- SDO The latter links to an awesome home page that provides live pictures of the surface of Sol! With a zoom feature and multispectral filter.
- As well as PICARD; HINODE; RHESSI et al
With such an abundance of data, it is easy to get carried away. Like IKAROS. Yo Ho Ho!
So why all the hardware? Well apart from the dangers of an over- or under-heated primary and the fact that an erupting sun makes for some awesome public outreach. With a bit of luck sometime during the next solar maximum we will be venturing out beyond the cosy blanket of our Earth’s magnetosphere. The magnetic screen that protects Gaia and her extensions such as the humans aboard the ISS from the worst excesses of an angry sun…
But I hear you say “Hang on a minute you said Solar Maximum! Surely we should travel during a Solar MINIMUM.”
Well you would be right. In a perfect Universe. But there are a lot of other Suns out there: some of them very nasty indeed. Also colliding supermassive black holes, magnetars and other such exotica that throw out what are called Galactic Cosmic Rays. [GCRs] Now whilst a solar flare or coronal mass ejection [CME] are pretty bad, these two types of Solar Particle /Proton Event [SPE] do not have the penetrating power of a GCR. Which, according to Wikipedia, have energies (measured in Electron Volts) …so high that no known natural process could have created them!
If a SPE produces proton bullets, these GCRs are heavy metal cannonballs: stripped nuclei of elements ranging from hydrogen up to iron; with some exotics from even higher up the atomic mass scale!
To take the analogy further: a machine gun bullet is easier to stop than a cannon ball. As the SPE energies are, on average, lower than those of an individual GCR. Also in the Cosmic Battlefield Beyond Earth Orbit [CBBEO] a spray of bullets from a SMG (Solar Machine Gun) will kill you but… here the analogy breaks down. Whilst on the terrestrial battlefield the effects of human vs cannonball are …messy; the chances of being hit by a cannonball are markedly less than that of being hit by a machine gun bullet. More significantly whilst a GCR will cause significant cellular damage, the body can repair itself. At a biochemical level: the damage to DNA could trigger cancer or inherited genetic defects. However both these effects can be mitigated. Either with post mission scanning and prompt oncological techniques. Or techniques commonly used by in-vitro fertilisation labs all over the world. Should a mission require astronauts still wanting children even at the end destination(?) It would be a simple task to produce some viable embryos, freeze them down and store in a radiation hardened medical space located in the ‘storm cellar’ within the space craft. On arrival at the colony: implant and gestate to taste!
As to the long term effects of GCRs the jury is still out. Only 27 humans: the Apollo Astronauts have ventured beyond our magnetosphere through the Van Allen Radiation Belts and out into the CBBEO. Whilst dodging the SPE bullet, the solar storm of August 1972 during the gap between Apollo 16 and 17; all the astronauts encountered GCRs. Causing scintillations as they zipped through their eyeballs! Fortunately none of them seem to have experienced any lasting damage except a almost imperceptible increase in contracting cataracts and mild forms of cancer. However as a statistical sample, the population is too small and the exposure largely unmeasured.
A heavy and prolonged SPE is, however, lethal. Even a lesser event will cause the gamut of symptoms of radiation poisoning. Ranging from slight nausea at around 50 milli Sieverts (Sv) to radiation burns, bleeding from all orifices and death due to metabolic breakdown. (LD 50 is around 4 to 5 Sieverts.)
Now the above Solar Eyes and their successors will allow us to predict ‘inclement’ solar weather. But as for the GCRs that sleet across our solar system in all directions: there is no warning. And to protect a crew from all their effects would require positively herculean amounts of shielding. So much so, that vast amounts of fuel and massive engines would be required. Further complicating an already complex mission.
But to quote Wiki:
“The Mars Radiation Environment Experiment (MARIE) was launched in 2001 in order to collect more data. Estimates are that humans unshielded in interplanetary space would receive annually roughly 400 to 900 milli-Sieverts (mSv) (compared to 2.4 mSv on Earth) and that a Mars mission (12 months in flight and 18 months on Mars) might expose shielded astronauts to ~500 to 1000 mSv. These doses approach the 1 to 4 Sv career limits advised by the National Council on Radiation Protection and Measurements for Low Earth orbit activities.”
But any radiation is to be avoided. Like compound interest, it is a killer!
So here we are in the middle of the CBBEO, SMG’s to the centre and GCRC’s in all directions. What is the poor spacegrunt to do. Well curiously nature has provided an answer. At the height of the Solar Maximum: the magnetic field strength of the solar system or “Heliosphere” is vastly increased and, just like our Magnetosphere, prevents many but not all of these GCR Cannonballs from entering the inner solar system. Perversely the safest time to travel to Mars or anywhere else is at the peak of the solar storm season! Hoping that the sun only flares and any CME is heading directly away from your path. My best guess: a set of sequential hydrocarbon rich walls filled with water surrounded by more hydrocarbon composite fuel tanks filled with methane or hydrogen reaction mass. A bit of advanced British Boffinry, light ship, a big engine and a short journey!
Nautical parallels abound and spacefarers will add to the legacy of their seafaring ancestors. We even have icebergs!
Of course we now know that the whole solar system is sailing; bobbing up and down as it circum-navigates our Home Galaxy. Some time ago we left the sunny doldrums of of the Local Bubble. Currently our Solar System is cruising the choppy waters of the Local Interstellar Cloud but what’s that ahead the G-Cloud?
We may be entering some rough waters. We have 1,000 – 100,000 years to get ready. (Don’t say I didn’t warn you!)
Some advanced reading: Galactic cosmic ray response to heliospheric environment changes and implications for cosmogenic isotope records.
V. Florinski and G.P. Zank
Brilliant! One cup of really hot tea and this appears on the Interwebs:”
Thus proving once again that all we really need to know is where our towel is!