Nose - The Tip of the Smelling Story

Researchers at Cold Spring Harbor Laboratory (CSHL) and Harvard have found that smell is based on more than the neuronal networks that receive various stimuli. Different from vision (that pays attention to edges, shading, brightness, and color), smell is affected by odor molecules and a lot of other intriguing unknowns. 

Odors, good or bad, enter the nose as the front door of the smelling (olfactory) mechanism. Some smells like your breath and sweat are identified as "self" and mostly ignored. (Unless you have been on the tennis court or football field for a heavy workout. Then the usual monitoring gets kicked up a notch and even YOU notice you stink.) 

Other smells set off different neural activity patterns across the brain. 

In mammals, the olfactory bulb has neuronal circuits that process information via receptors. It sends information to higher processing brain areas, including the cerebral cortex. There, smell messages are analyzed thoroughly and sent across the brain (i.e. chocolate=yum or skunk spray=yuck) before they return to the bulb in a feedback loop.

The latest research shows that signaling is linear and is further analyzed in the brain with respect to intensity, known characteristics, and past experience (i.e., banana or mountain lion). Go Science!

Auroras on Mars

As many of you know, I am super interested (some might say obsessed) in space exploration. So I'm excited to relate the latest Mars Atmosphere and Volatile Evolution (MAVEN) findings about auroras on Mars. 

Auroras happen on Earth when energy particles from space rain down on the upper atmosphere and are pulled to the Arctic and Antarctic poles by the planet's global magnetic field. On Mars, no organized planetary magnetic field exists so solar winds can blow them anywhere. Only pockets of magnetic fields draw them.

Since scientists know that Mars had a thick atmosphere billions of years ago, they are studying localized auroras to see if solar winds are still eroding the carbon dioxide and oxygen molecules present in the red planet's very thin atmosphere.

What does an aurora on Mars look like? 

"A diffuse green glow seems quite possible in the Mars sky, at least when the Sun is throwing off energetic particles," notes Nick Schneider who leads MAVEN's Imaging Ultraviolet Spectrograph (IUVS) instrument team at the University of Colorado.

MAVEN's mission is to explore the planet’s upper atmosphere, ionosphere, and interactions with the Sun and solar wind. Scientists will be watching for loss of volatile compounds—such as CO2, N2, and H2O—from the Martian atmosphere into space. Understanding this loss will offen insight into Mars' atmosphere and climate, liquid water and potential for habitability.

To see the aurora borealis or aurora australis on Earth is definitely a bucket list item for me, but perhaps auroras on Mars will be a common site for our children's children. I can only hope! Go science!

Interstellar Stardust and Its Absence

An international team of 23 scientists, has created maps (using data from 500,000 stars over a ten year period) of space materials located between the stars of the Milky Way. This material includes atoms and molecules left behind when a star dies, as well as building blocks for new stars and planets. The results published in the Aug. 15, 2014 issue of the journal Science may help astronomers solve a stardust puzzle that was first seen in 1922 in a graduate student's photographs of distant stars.

The research team focused on a strange feature in the light from stars; diffuse interstellar bands or "DIBs" (i.e., dark lines in the grad student's photographs). These visual and near-infrared spectra absorption lines seemed to show missing starlight as if something in the interstellar medium between Earth and the star was sucking up (not a technical term) the light. In fact, scientists have spotted more than 400 interstellar bands, but why the bands appear and their exact location are a mystery. 

Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a major role in the research reports, "But we still don't know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form."

Finding the cause will allow researchers to better understand the physical conditions and chemistry of the space between stars and more on how stars and galaxies form. Go science!