Curiosity – Arm Camera on Sol 30

Arm
The Mars Hand Lens Imager (MAHLI) on Curiosity’s Tool Arm
Image Credit: NASA / JPL-Caltech / MSSS

This image of MAHLI was taken from the left eye of the Mast Camera (MastCam) during the 30th Sol on Mars. The pink circle in the center of the image is the dust cover on the MAHLI camera, which is about 10 cm in diameter. The triangular mechanism to the right of the camera is the wire brush dust removal tool.

Curiosity has now traveled more than the length of a football field (American Football). The tracks left on the surface have been imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (image below).

The next week will be filled with testing the robotic arm. Daniel Limondi said:

We will be putting the arm through a range of motions and placing it at important ‘teach points’ that were established during Earth testing, such as the positions for putting sample material into the inlet ports for analytical instruments. These activities are important to get a better understanding for how the arm functions after the long cruise to Mars and in the different temperature and gravity of Mars, compared to earlier testing on Earth.

Once these tests are completed and results analyzed, Curiosity will continue on toward Glenelg, where it is expected to scoop soil, drill into rocks, process collected samples and deliver a sample into the analytical instruments.

Tracks
Tracks from the first Drives by Curiosity seen from HiRISE
Image Credit: NASA / JPL-Caltech / University of Arizona

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Sloan Digital Sky Survey 3D Map And Dark Energy

Baryon Acoustic Vibrations
Baryon Acoustic Vibrations at 5.5 Billion Light Years From SDSS Data
Image Credit: E.M. Huff, the SDSS-III team, and the South Pole Telescope team.
Graphic by Zosia Rostomian.

Dark Energy drives the accelerating expansion of the Universe, and the imprint can be found in the distribution of galaxies.

Now, researchers, including several associated with the University of Arizona in Tucson, have published a series of six papers (see below) concerning the distribution of galaxies 5.5 billion light years from Earth, using data from the Sloan Digital Sky Survey.

The papers detail how mapping the position of galaxies can measure how fast the Universe was expanding six billion years ago. The expansion is the result of Dark Energy, which makes up 72% of the universe in which we live (the remainder is Dark Matter (23%) and atoms (5%), found in intergalactic gas and stars).

The image above illustrates how variations in the cosmic microwave background (due to baryon acoustic vibrations during inflation, which followed the Big Bang) are reflected by later distribution of galaxies, and measuring the distribution of galaxies at different times reflects the accelerating expansion of the universe. The original work on the accelerating expansion came from observations of type Ia supernovae in 1998 and and 1999, and led to the Nobel Prize in 2011.

The Baryon Oscillation Spectroscopic Survey (BOSS) is one of four SDSS surveys, and the team of scientists and engineers that make up the team are the authors of these six papers.

Will Percival, a professor at the University of Portsmouth in the United Kingdom, and one of the leaders of the analysis team noted that:

We have only one-third of the data that BOSS will deliver, and that has already allowed us to measure how fast the Universe was expanding six billion years ago — to an accuracy of two percent.

This coupled with the previously released data on the distribution of galaxies at 3.8 billion light years, shows the accelerating expansion: the rate at 3.8 billion light years is more than the earlier rate at 5.5 billion light years.

Due to the original oscillations in the universe, theory predicts that the average distance between galaxies would be 500 million light years. And this is what the BOSS results have shown. They are the best measurements to date.

From the SDSS article we have the references to the arxiv papers:

Bugs In Space

In contrast to the running gags on the “Pigs In Space” vignettes on The Muppet Show, problems associated with Bugs In Space are no laughing matter.

Immunobiologist Ty Lebsack et. al., from the University of Arizona‘s department of Immunobiology in the College of Medicine., have just published “Microarray Analysis of Spaceflown Murine Thymus Tissue Reveals Changes Gene Expression Regulating Stress and Glucocorticoid Receptors” in the 15 May 2010 edition of Journal of Cellular Biochemistry (110:372-381 2010). They flew four healthy mice aboard NASA’s STS-118 Endeavour mission to the International Space Station in September 2007. The mice spent 13 days aboard the Space Shuttle. The researchers compared the gene-expression patterns in thymuses of the four space mice to those from an equal number of control mice on the ground.

“The altered genes we observed were found to primarily affect signaling molecules that play roles in programmed cell death and regulate how the body responds to stress,” Lebsack said.

The down-regulation of proteins regulating cell death has implications for the body of astronauts to combat infections. The decrease in the body’s ability to push infected cells into apoptosis means that astronauts would be more susceptible to infections. Further, based on previously released studies, which indicate that bacteria in space become more virulent, space places a double whammy on astronauts: their immune system becomes less efficient and invading bacteria become more sinister.

In Part II of NASA – ISS Science Success, we noted the Microbe experiments conducted during the STS-115/12A mission to the ISS concerning differential gene expression leading to increased virulence, from NASA’s report on “International Space Station Science Research Accomplishments During the Assembly Years: An Analysis of Results from 2000-2008″ (p 97-98).

Two other reports in the NASA report on ISS science bear on these issues:

Commercial Biomedical Testing Module (CBTM): Effects of Osteoprotegerin (OPG) on Bone Maintenance in Microgravity (Principal Investigator(s): Ted Bateman, Clemson University, Clemson, S.C. on Expedition 4 – Research Area Physiological Studies: Bone and Muscle (p 120).

Data obtained from the mice following return to Earth also indicated some alternations in immune functions. Analysis of the spleenocytes (immune cells produced by the spleen) indicated an increase in B-cell (a white blood cell that matures in the bone marrow and, when stimulated by an antigen, differentiates into plasma cells) production compared to T-cells (white blood cells that complete maturation in the thymus and have various roles in the immune system). A slightly lower white blood-cell count in the flight animals compared to the controls was not statistically significant. The spleen mass was 18% to 28% lower in flight mice compared to controls. Results also indicate that flight mice weighed 10% to 12% less than ground controls (Pecaut et al. 2003).

and the second article, where the experiments were flown on the same STS-118 mission from which Lebsack et. al. obtained their results :

Commercial Biomedical Testing Module-2 (CBTM-2) (Principal Investigator(s): H.Q. Han, M.D., Ph.D., Amgen Research, Thousand Oaks, Calif.
David Lacey, M.D., Amgen Research, Thousand Oaks, Calif. on Expedition 15. (p122-123)

CBTM-2 examined the effectiveness of an experimental therapeutic in preventing muscle loss in mice that were exposed to microgravity.

Further:

Certain T- and B-cell counts from the spleens of the flight animals were also low, and the natural killer cells were increased. Analysis of cancer-related genes in the thymus from the flight animals showed that 30 out of 84 genes were expressed differently after flight.

These results were published here: Gridley DS, Slater JM, Luo-Owen X, Rizvi A, Chapes SK, Stodieck LS, Ferguson VL, Pecaut MJ. Spaceflight effects on T lymphocyte distribution, function and gene expression. J Appl Physiol. 2008 Nov 6.

Overall, the results indicate that long term space flight poses two serious problems for astronauts: their immune system becomes less capable under microgravity; and the bugs become more capable.

These problems will need to be resolved before humanity ventures very far into the Solar System.