Feeds

Cosmic rays hit Space Age high

Deflector shields activated, Mr Sulu?

SANS - Survey on application security programs

The level of cosmic rays bombarding our solar system has hit a 50-year high - a "signficant" increase which could impact on future space missions.

The surge in cosmic rays - "subatomic particles, mainly protons but also some heavy nuclei", Space.com explains - was detected by NASA's Advanced Composition Explorer (ACE) spacecraft.

Richard Mewaldt of Caltech elaborated: "In 2009, cosmic ray intensities have increased 19 per cent beyond anything we've seen in the past 50 years. The increase is significant, and it could mean we need to rethink how much radiation shielding astronauts take with them on deep-space missions."*

The reason for the livelier cosmic ray levels is the current solar minimum. This lull in the Sun's activity means "flagging" solar winds and, as a result, a reduced heliosphere. Mewaldt explained: "Measurements by the Ulysses spacecraft show that solar wind pressure is at a 50-year low, so the magnetic bubble that protects the solar system is not being inflated as much as usual."

Accordingly, cosmic rays have a "shorter shot into the solar system", and once they enter the heliosphere, face weaker solar winds to impede their progress.

The rays are also less prone to interference from the "heliospheric current sheet" - a complex surface described as resembling a "ballerina's skirt", wrapped round the Sun and extending from its equatorial plane. The current sheet marks the boundary in the Sun's magnetic field where its polarity changes from north to south.

The current sheet's "folds" affect the progress of cosmic rays, but it's now "flattening itself out", allowing the charged particles "more direct access to the inner solar system".

Mewaldt noted: "If the flattening continues as it has in previous solar minima, we could see cosmic ray fluxes jump all the way to 30 percent above previous Space Age highs."

None of this, however, poses a serious threat to Earth. While a single cosmic ray could conceivably, if it hit the right spot, knock out a satellite's electronics, the present cosmic ray high is considerably lower than our planet has experienced in the past.

The proof comes in the form of an isotope of beryllium, 10Be, created by cosmic rays when they impact with Earth's atmosphere, and preserved in polar ice. Tests on ice cores have shown that "hundreds of years ago, cosmic ray fluxes were at least 200 per cent higher than they are now".

Mewaldt concluded: "The space era has so far experienced a time of relatively low cosmic ray activity. We may now be returning to levels typical of past centuries." ®

Bootnote

*Well, the way things are going at the moment, this won't be an issue, since the Sun will have reached solar maximum by the time we get our act together and head off to Mars.

Top three mobile application threats

More from The Register

next story
Red-faced LOHAN team 'fesses up in blown SPEARS fuse fiasco
Standing in the corner, big pointy 'D' hats
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
New FEMTO-MOON sighted BIRTHING from Saturn's RING
Icy 'Peggy' looks to be leaving the outer rings
Melting permafrost switches to nasty, high-gear methane release
Result? 'Way more carbon being released into the atmosphere as methane'
prev story

Whitepapers

Designing a defence for mobile apps
In this whitepaper learn the various considerations for defending mobile applications; from the mobile application architecture itself to the myriad testing technologies needed to properly assess mobile applications risk.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.