Feeds

Cosmic rays hit Space Age high

Deflector shields activated, Mr Sulu?

Secure remote control for conventional and virtual desktops

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.

Boost IT visibility and business value

More from The Register

next story
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
Cutting cancer rates: Data, models and a happy ending?
How surgery might be making cancer prognoses worse
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Brit balloon bod Bodnar overflies North Pole
B-64 amateur ultralight payload approaching second circumnavigation
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?