JOTH 80: Space \M\a\d\n\e\s\s Radiation

[stickmaker]

The Joy of High Tech

by

Rodford Edmiston

Being the occasionally interesting ramblings of a major-league technophile.

Please note that while I am an engineer (BSCE) and do my research, I am not a professional in this field. Do not take anything here as gospel; check the facts I give. If you find a mistake, please let me know about it.

Radiation in Space

Enter your cut contents here.

Connected with the previous JOHT (the one about relative motions of our solar system) in their study, recently published in the journal Space Weather, researchers found that large fluxes in Galactic Cosmic Rays (GCR) are rising fast and are on path to exceed any other level recorded at any time in the space age. They also point out that one of the most significant Solar Energetic Particle (SEP) events happened in September 2017, releasing large doses of radiation that could pose significant risk to both humans and satellites. Unshielded astronauts could experience acute effects like radiation sickness or more serious long-term health issues like increased cancer risk and direct organ damage, including to the heart, brain, and central nervous system.

In 2014, Schwadron and his team predicted around a 20 percent increase in radiation dose rates from one solar minimum to the next. Four years later, their newest research shows current conditions exceed their predictions by about 10 percent, revealing that the radiation environment is worsening even more than expected.

"We now know that the radiation environment of deep space that we could send human crews into at this point is quite different compared to that of previous crewed missions to the moon," says Schwadron.

The authors used data from CRaTER on NASA's Lunar Reconnaissance Orbiter (LRO). Lunar (and other space-based) observations show that GCR radiation doses are rising faster than previously thought. Researchers point to the abnormally long period of the recent reduction of solar activity as one reason. In contrast, an active sun has frequent sunspots, which can intensify the sun's magnetic field. That magnetic field is then dragged out through the solar system by the solar wind and deflects galactic cosmic rays away from the solar system – and from any astronauts in transit between worlds with their own magnetic fields.

For most of the space age, the sun's activity ebbed and flowed like clockwork in 11-year cycles, with six- to eight-year lulls in activity, called solar minima, followed by two- to three-year periods when the sun is more active. However, starting around 2006, scientists observed the longest solar minimum and weakest solar activity measured during the space age.

Despite this overall reduction, the September 2017 solar eruptions produced episodes of significant Solar Particle Events and associated radiation caused by particle acceleration through successive, magnetically well-connected coronal mass ejections. The researchers concluded that the space radiation environment continues to pose significant hazards associated both with historically large galactic cosmic ray fluxes and large but isolated SEP events, which still challenge space weather prediction capabilities.

Read more at: https://phys.org/news/2018-03-space-increasingly-hazardous.html