Sick in Space: Stress Compromises Astronauts’ Immune Systems

Two days before the launch of a routine space shuttle mission, a 47-year-old healthy astronaut submitted a saliva sample and ended up testing positive for the varicella zoster virus — the virus responsible for chickenpox and shingles. This was, to say the least, unexpected. Following chickenpox infection, the varicella zoster virus remains dormant in our nervous system and often doesn’t reactivate in healthy people under 60. So why would it reappear in a 47-year-old who is among the healthiest, most physically fit individuals of our workforce? Furthermore, why would it emerge before launch, before any potential dangers of space even presented themselves?

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World of Concrete

World of Concrete

Like modern technology, concrete has become so ubiquitous, so important, that it perversely disappears altogether. The second most consumed substance on our planet after water, concrete defines our industrialized world. As with most every other aspect of industrialization, the rapid expansion of cement usage over the last century has come at a cost. Cement production accounts for 5% of the world’s total carbon dioxide (CO2) emissions. Gabe Falzone is a graduate student at UCLA working in the Laboratory for the Chemistry of Construction Materials run by Dr. Gaurav Sant. They’re working on ways to improve cement production, testing new techniques and chemical mixtures to make more durable, more sustainable concrete. 

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Predicting Heat Waves Using the Ocean

Heat wave illustration (Source: U.S. National Weather Service, http://www.srh.noaa.gov/jetstream/global/hi.htm)

Heat waves in the United States have become a problem over the past decade. According to the Center for Disease Control and Prevention, from 1999 to 2010, more than 600 people on average died annually in the US from heat-related causes. Relief, though, seems to be emerging. New research published this past week suggests that major heat waves in the US may be predictable two months before they hit. Climatologists from the National Center for Atmospheric Research combed through decades of data and connected sea surface temperature patterns in the North Pacific Ocean to subsequent extremely hot days occurring around 50 days later. The physical connection between sea surface temperature and hot days, though, remains unknown. Scientists think one possibility is that the sea temperatures may be affecting the movement of the jet stream, a fast and narrow air flow in the upper atmosphere that planes often hitch a ride on. The jet stream also helps organize the high-pressure air masses that typically cause extreme heating, so it's a likely suspect for connecting sea surface temperatures to future heat. The connection, though, as the researchers stress, is not a guarantee; the sea surface temperature pattern indicates that a heat wave is likely to occur, not that it definitely will. Still, the correlation is strong enough to make this research invaluable for forecasting and protecting those who may be exposed to extreme heat. 
 

Sean Faulk
Staff Writer, Signal to Noise Magazine
Graduate Student, Earth, Planetary, and Space Sciences

References:

McKinnon, K.A., et al. (2016). Long-lead predictions of eastern United States hot days from Pacific sea surface temperatures. Nature. DOI: 10.1038/ngeo2687

A Planet of Two Surfaces

Artist depiction of 55 Cancri e orbiting its star. (Source: University of Texas, NSF, NASA, http://antwrp.gsfc.nasa.gov/apod/ap040901.html)

Searching for exoplanets, or planets around other stars, can be agonizing. The small, rocky ones, which are tantalizing as they most closely resemble Earth, are the hardest exoplanets to find because they are so small compared to their host stars. But astronomers are discovering more about these worlds, and recently, a team from the University of Cambridge completed the most detailed heat map of a small planet yet: a rocky exoplanet about twice the size of Earth and forty light years away known as 55 Cancri e. Orbiting very close to its star, 55 Cancri e is inhospitable to life but its close orbit has another effect: the planet’s rotation is locked such that the same hemisphere always faces the star, just as the same hemisphere of the Moon always faces the Earth. This splits the planet’s surface into two sides, one of permanent ‘day’ and the other permanent ‘night.’ According to a new study using infrared data from NASA’s Spitzer telescope, the temperature difference between these two sides on 55 Cancri e is as extreme as it gets, with the day side reaching 2500 degrees Celsius under the endless scorch, while the night side chills at a relatively frigid 1100 degrees. The day side is so hot that the surface pulses with riverlike flows and pools of molten lava, while the night side’s surface remains solid rock. The astronomers believe that with such a small distance between planet and star, the extreme stellar heat may have blasted off the planet’s atmosphere, cutting off any atmospheric circulation and thereby preventing heat from traveling from the hot side to the cool. Technology hasn’t caught up with the theory yet - researchers will have to wait for the next generation of space telescopes to get a look at the atmospheres of small worlds such as this one as they continue to hunt for more planets like Earth.

- Sean Faulk
Staff Writer, Signal to Noise Magazine
Graduate Student, Earth, Planetary, and Space Sciences

References:

Demory, BO., et al. (2016). A map of the large day–night temperature gradient of a super-Earth exoplanet. Nature. DOI: 10.1038/nature17169

Channels Revealed Underneath Antarctic Ice Shelves

Ice shelves exist at the boundary between ocean and ice. They are the edges of ice sheets, massive sections of ice made of compacted snow and sitting atop continents. The ice shelf is where most of the action occurs: it’s where icebergs calve off, where friction with the underlying coastline affects ice flows, and where ocean water beneath the shelf causes melting. There are also basal channels of liquid water carved into the ice on the shelf’s underside. Hidden and inaccessible underneath giant blocks of ice, basal channels' distribution throughout the Antarctic ice shelves has remained largely unknown. But recently, researchers have used satellite imagery and correlations between ridges and depressions on the surface and the channels below to map out all of the larger basal channels of the Antarctic ice shelves. They’ve also found that these channels are conduits for warm water, and therefore critical in determining melting rates of collapsing ice shelves. Further study of these channels, their formation, and their dynamics will improve ice shelf models and help us understand the Antarctic ice sheet’s overall stability and health as the planet warms.

-Sean Faulk
Staff Writer, Signal to Noise Magazine

PhD Candidate, Earth, Planetary, and Space Sciences

References: 
Alley KE, Scambos TA, Sigrid MR, Fricker HA. Impacts of warm water on Antarctic ice shelf stability through basal channel formation. Nature Geoscience. (2016). DOI: 10.1038/ngeo2675

Satellite-based Aerosol Measurements Add to Climate Change Data

Measurements of greenhouse gas concentrations are fundamental towards understanding current climate trends, since higher amounts of greenhouse gases in the atmosphere are directly linked to global warming. Such measurements are easy to make using conventional air monitoring sites around the world. However, monitoring concentrations of other atmospheric substances is also needed for a complete picture, because the warming effect from greenhouse gases like carbon dioxide is opposed by the cooling effect of particles such as dust or smoke, also known as aerosols. These particles can make clouds brighter, which reflects sunlight and therefore heat back to space, but they’re devilishly difficult to measure with traditional aircraft and ground-based radar methods. Recently, researchers from the Hebrew University of Jerusalem have developed a satellite-based method of detecting aerosols in clouds and the speed of clouds as they rise and develop, which is important for determining particle concentration and cloud brightness. Combining these aerosol measurements with greenhouse gas measurements will greatly improve our understanding of the changing climate and will ultimately aid in future policy decisions.

- Sean Faulk
Staff Writer, Signal to Noise Magazine
PhD Candidate, Earth, Planetary, and Space Sciences

 

References:

Rosenfeld, D., Y. Zheng, E. Hashimshoni, M.L. Pöhlker, A. Jefferson, et al. Satellite retrieval of cloud condensation nuclei concentrations by using clouds as CCN chambers. Proceedings of the National Academy of Sciences, 2016. DOI: 10.1073/pnas.1514044113

A Facelift for Mars

The Tharsis region of Mars. (Source: NASA; https://commons.wikimedia.org/wiki/File:Tharsis.png)

More than three billion years ago, the surface of Mars underwent a drastic change. According to a recent model, built by the combined efforts of geophysicists and climatologists and described in Bouley et al., the change was triggered by the formation of the massive Tharsis volcanic plateau. A great elevated dome that accounts for nearly a quarter of the Martian surface and home to three of the largest volcanoes in the solar system, the Tharsis region is so massive that it initiated a complete shift in the outer skin of the planet upon its creation, with the crust and upper mantle swiveling about the core, like if the skin and underlying flesh of an avocado somehow rotated about the seed. The scientists came to this conclusion by modeling the Martian surface without the presence of Tharsis and found that the distribution of observed traces of ancient rivers and glaciers are much more consistent with a pre-Tharsis Mars, suggesting they formed during this pre-Tharsis time when the surface looked very different. Since Tharsis is such a major feature, likely impacting much of the climate through its volcanic activity and topography, this new development has major implications for our understanding of the evolution of Mars's climate - including, perhaps, implications for the possibility of life on its ancient surface.

- Sean Faulk
Staff Writer, Signal to Noise Magazine
PhD Candidate, Earth, Planetary, and Space Sciences

 

References:

Bouley S, Baratoux B, Matsuyama I, Forget F, Séjourné A, Turbet M, Costard F. Late Tharsis formation and implications for early Mars. Nature. (2016). DOI: 10.1038/nature17171

Two Degrees of Danger - Why Uncertainty is the Biggest Risk in Climate Change

Two Degrees of Danger - Why Uncertainty is the Biggest Risk in Climate Change

This past December, delegates from nearly two hundred countries met in Paris for the latest round of climate talks, the culmination of nearly a decade of meetings with the hope of finally landing on an agreement that would firmly unite the world — in a legally binding way — against worsening climate change. On December 12th, an agreement was reached and in the official document, the Paris Agreement, is the promise that member nations will hold the increase in global average temperature to well below 2°C above pre-industrial levels.

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