Could Cosmic Radiation Fry Astronaut’s Brains During Space Travel? A Galaxy Insight
“The
exceptional sensitivity of these neural stem cells suggests that we are
going to have to rethink our understanding of stem cell susceptibility
to radiation, including cosmic radiation encountered during space
travel, as well as radiation doses that accompany different medical
procedures.”
~ Dennis A. Steindler, Ph.D., executive director of UF’s McKnight Brain Institute
Imagine being stuck in a tin can for 3 years while all crew members increasingly lose their ability to adapt and control mood…not a pleasant picture. A new study has found that space radiation is something that will definitely have to be addressed before man can take long space flights. The researchers discovered that space radiation selectively kills stems cells within the brain.
If a rare GRB (gamma ray burst) from a hypernova should be directed towards our erstwhile astronuats they may be in serious trouble. Given the rarity of highest mass stars, we might expect on in a galaxy as large as ours to occus every 100,000 to one million years. But the radiation killing zone for a hyperstar, which is concentrated into a narrow cone,is around six thousand light years! An ordinary supernova explode in its small 30-light year danger zone at best once every 250 million years.
Closer to home, astronomers have uncovered evidence that a powerful gamma-ray burst, occurred in our own Milky Way galaxy just a few thousand years ago. Only 35,000 light years away lies W49B, the supernova remnant left over from the cataclysmic burst. New evidence pointing to a gamma ray burst origin for this remnant was discovered by X-ray data from the Chandra X-ray Observatory, combined with infrared observations from the Palomar 200-inch telescope in southern California.
The research indicates the need to find a way to protect astronauts from this health risk before anyone heads out to Mars, or camps out on the moon at the proposed lunar base.
Using a mouse model designed to reveal even slight changes in brain cell populations, scientists found radiation appeared to target a particular type of stem cell in an area of the brain believed to be important for learning and mood control.
These findings from a team of researchers from the Cold Spring Harbor Laboratory, Brookhaven National
Laboratory, NASA’s Kennedy Space Center and the McKnight Brain Institute of the University of Florida,
suggest that identifying medications or physical shielding to protect
astronauts from cosmic and solar radiation is necessary for the success
of all human space missions beyond low Earth orbit.
Stem cells are especially important cells because they alone have the remarkable ability to renew themselves, and produce a vast variety of different cell types.
For the study, Cold Spring Harbor Laboratory scientists developed mice that were genetically engineered with easily identifiable, fluorescent stem cells. The stem cells lose their fluorescence when they transform into neurons, which makes it easier to account for them.
Next, scientists at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory in Upton,
N.Y., administered a single dose of radiation to the mice about equal
to the amount astronauts would receive after a three-year space voyage
to Mars.
Unexpectedly, researchers found that a special type of stem cell is selectively killed in the hippocampus,
according to Grigori Enikolopov, Ph.D., a neurobiologist at Cold Spring Harbor Laboratory. The cell is
described as quiescent — or quiet — because even though it is the
wellspring that repopulates the brain with new cells, it exists in
relative repose while its daughter cells divide and reproduce in great
numbers.
“Our findings are surprising because it is assumed that dividing cells are the most vulnerable to radiation — that is why radiation is used in cancer therapy,” Enikolopov said. “These stem cells divide quite rarely and it was unexpected that they would be the most vulnerable to this type of radiation. But at least two thirds of these quiescent cells died. The challenge now is to find something to protect those cells.”
What specific types of cells are at risk is vital information for scientists planning long lunar expeditions or deep space missions. The President’s Commission on Implementation of United States Space Exploration Policy outlined plans to send a human expedition to the moon by 2020. For this to become a reality, NASA must find a way to ensure the safety and health of the crew.
“Space radiation has not been a serious problem for NASA human missions because they have been short in duration or have occurred in low Earth orbit, within the protective magnetic field of the Earth,” said Philip Scarpa, M.D., a NASA flight surgeon at NASA’s Kennedy Space Center in Florida. “However, if we plan to leave low Earth orbit to go back to the moon for long durations or on to Mars, we need to better investigate this issue and assess the risk to the astronauts in order to know whether we need to develop countermeasures such as medications or improved shielding.”
The finding raises concerns about the cognitive and emotional risks associated with radiation exposure during human space exploration missions.
Philip Scarpa, M.D., a NASA flight surgeon at NASA’s Kennedy Space Center acknowledged, “We
currently know very little about the effects of space radiation,
especially heavy element cosmic radiation, which is expected on future
space missions and was the type of radiation used in this study. In
addition, we should expect that within each critical organ system,
there may be different cell sensitivities that need to be considered
when defining space radiation dose limits.”
Posted by Rebecca Sato with Casey Kazan
Source: http://images.google.com/imgres?imgurl=http://www.nasa.gov/images/content/60098main_w49b.jpg&imgrefurl=http://www.nasa.g
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What they need is a force field!
Posted by: Jojo | October 22, 2009 at 02:13 AM
Strange physic’s contradiction
1
On the one hand :
The particles in the Universe are more than antiparticles
/ Baryon asymmetry /
2.
On the other hand:
Dark matter in the Universe is more than visual matter
Question :
Does one physic’s hand know that the other hand do ?
Israel Sadovnik Socratus
=== .
Comment:
It does seem like a paradox, doesn't it?
Actually, these are two unrelated concepts.
Baryons represent detectable matter.
Dark matter represents undetectable matter.
Different stuff.
That still leaves the question about physic's hands, though....
/ NoPlate /
=== .
I think that actually, the ‘Baryon asymmetry ‘and ‘Dark matter ‘
both belong to one conception.
Why?
Because antiparticles exist in ‘ Dirac sea ‘, in Vacuum and
‘ dark matter ‘, by idea, must exist there too.
They both belong to one and the same reference frame.
Now the questions are:
‘ does dark matter consist of antiparticles or of
some kind of different particles ? ’ or
‘ do antiparticles make dark matter ?’
To answer to this question we must know that Vacuum is.
But it is a pity, we still don’t have answer to this question.
And Dirac said:
‘ The problem of the exact description of vacuum, in my opinion,
is the basic problem now before physics. Really, if you can’t correctly
describe the vacuum, how it is possible to expect a correct description
of something more complex? ‘
==== .
So ,
all discussions are tautology without understanding what Vacuum is.
Israel Sadovnik Socratus
http://www.worldnpa.org/php2/index.php?tab0=Scientists&tab1=Display&id=1372
www.socratus.com
========== .
Posted by: socratus | October 22, 2009 at 05:51 AM
Very interesting article to read, didn't know that was possible at all. We'll see if in a future they fix the problem (if any) and how they come up with new missions. Lately this is all stopped... I think they should invest more money in spatial research for our own good in a near future.
Posted by: microgaming | October 22, 2009 at 01:19 PM
In my simplistic view It will be not only a GRB that can fry out the brain of astronauts but also the more modest but continuous Solar radiations and galaxy radiations.
More : why the brain of astronauts are exposed only during their trip to moon and NOT on the Moon itself ???
I do not think the moon has an ATM and therefore cannot absorb radiations of the sun and galaxy .
Metallic Screens and similar stuff cannot shelter the humans from all the wavelenghts of the radiations..therefore there is a Main survival problem in both space travels and planets exploration and colony.
I am sure tha NASA and ESA are thinking about these issues.
Regards
Posted by: claudio | October 25, 2009 at 01:07 AM