Recently in the Radiation Category

The onset and nature of the earliest geomagnetic field is important for understanding the evolution of the core, atmosphere and
life on Earth.

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation.

As a copious source of gamma-rays, a nearby Galactic Gamma-Ray Burst (GRB) can be a threat to life.

In this work, we studied the stability of the glycine molecule in the crystalline zwitterion form, known as {alpha}-glycine (+ NH3 CH2 COO− ) under action of heavy cosmic ray analogs.

Weakly Interacting Massive Particles (WIMPs) may constitute a large fraction of the matter in the Universe.

If you have been watching the new series "Cosmos" recently then you have see Tardigrades or "water bears" featured. These creatures are remarkably resistant to a wide range of conditions that humans would consider extreme - if not deadly.

Capitalizing on the ability of an organism to evolve in response to punishment from a hostile environment, scientists have coaxed the model bacterium Escherichia coli to dramatically resist ionizing radiation and, in the process, reveal the genetic mechanisms that make the feat possible.

The problem of the contribution of cosmic rays to climate change is a continuing one and one of importance. In principle, at least, the recent results from the CLOUD project at CERN provide information about the role of ionizing particles in 'sensitizing' atmospheric aerosols which might, later, give rise to cloud droplets.

Comparative Survival Analysis of Deinococcus Radiodurans and the Haloarchaea Natrialba Magadii and Haloferax Volcanii, Exposed to Vacuum Ultraviolet Irradiation

Ximena C. Abrevaya, Ivan G. Paulino-Lima, Douglas Galante, Fabio Rodrigues, Pablo J.D. Mauas, Eduardo Corton, Claudia de Alencar Santos Lage
(Submitted on 29 Sep 2011)

The haloarchaea Natrialba magadii and Haloferax volcanii, as well as the radiation-resistant bacterium Deinococcus radiodurans, were exposed to vacuum-UV (V-UV) radiation at the Brazilian Synchrotron Light Laboratory (LNLS). Cell monolayers (containing 105 - 106 cells per sample) were prepared over polycarbonate filters and irradiated under high vacuum (10-5 Pa) with polychromatic synchrotron radiation. N. magadii was remarkably resistant to high vacuum with a survival fraction of ((3.77 ± 0.76) x 10-2), larger than the one of D. radiodurans ((1.13 ± 0.23) x 10-2). The survival fraction of the haloarchaea H. volcanii, of ((3.60 ± 1.80) x 10-4), was much smaller. Radiation resistance profiles were similar between the haloarchaea and D. radiodurans for fluencies up to 150 J m-2. For fluencies larger than 150 J -2 there was a significant decrease in the survival of haloarchaea, and in particular H. volcanii did not survive. Survival for D. radiodurans was 1% after exposure to the higher V-UV fluency (1350 J m-2) while N. magadii had a survival lower than 0.1%. Such survival fractions are discussed regarding the possibility of interplanetary transfer of viable micro-organisms and the possible existence of microbial life in extraterrestrial salty environments such as the planet Mars and the Jupiter's moon Europa. This is the first work reporting survival of haloarchaea under simulated interplanetary conditions.

Full paper

Comments: Draft version (without figures), Accepted for publication in Astrobiology
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Citeas: arXiv:1109.6590v1 [astro-ph.EP]
Submission history
From: Ximena Celeste Abrevaya [view email]
[v1] Thu, 29 Sep 2011 17:02:52 GMT (131kb)

The National Aeronautics and Space Administration (NASA) Lyndon B. Johnson Space Center (JSC) has released NASA Research Announcement (NRA) NNJ11ZSA001N, entitled "Ground-Based Studies in Space Radiobiology." This NRA solicits ground-based proposals for the Space Radiation Program Element (SRPE) component of the Human Research Program (HRP). Proposals are solicited by the SRPE in the area of Space Radiation Biology utilizing beams of high energy heavy ions simulating space radiation at the NASA Space Radiation Laboratory (NSRL), at Brookhaven National Laboratory (BNL) in Upton, New York.

The full text of the solicitation is available on the NASA Research Opportunities homepage at under menu listing "Open Solicitations." Potential applicants are urged to access this site well in advance of the proposal due date to familiarize themselves with its structure and to register in the system. Proposals solicited through this NRA will use a two-step proposal process. Only Step-1 proposers determined to be relevant with respect to the Research Emphases outlined in Section (I)(F) of this NRA will be invited to submit full Step-2 proposals. Step-2 proposals must be compliant with respect to all sections of this NRA or they will be declined without review. Proposals must be submitted electronically.

Step-1 proposals are due March 2, 2011. Step-2 proposals are due May 11, 2011.

This email is being sent on behalf of and is intended as an information announcement to researchers associated with the NASA Exploration Systems Mission Directorate (ESMD) Human Research Program (HRP).

Thank you for your continued interest in NASA. Please reference the above solicitation for contact information.