Hunting for high life: What lives in Earth's stratosphere?

Nov 16, 2012 by Jason Major, Universe Today
The Moon photographed through the layers of the atmosphere from the ISS in December 2003. Credit: NASA/JSC

What lives at the edge of space? Other than high-flying jet aircraft pilots (and the occasional daredevil skydiver) you wouldn't expect to find many living things over 10 kilometers up—yet this is exactly where one NASA researcher is hunting for evidence of life.

Earth's stratosphere is not a place you'd typically think of when considering hospitable environments. High, dry, and cold, the stratosphere is the layer just above where most weather occurs, extending from about 10 km to 50 km (6 to 31 miles) above Earth's surface. Temperatures in the lowest layers average -56 C (-68 F) with jet stream winds blowing at a steady 100 mph. is less than 10% that found at sea level and oxygen is found in the form of ozone, which shields life on the surface from harmful UV radiation but leaves anything above 32 km openly exposed.

Sounds like a great place to look for life, right? Biologist David Smith of the University of Washington thinks so… he and his team have found "microbes from every major domain" traveling within upper-atmospheric winds.

Smith, principal investigator with 's in the Stratosphere (MIST) project, is working to take a census of life tens of thousands of feet above the ground. Using high-altitude and samples gathered from Mt. Bachelor Observatory in central Oregon, Smith aims to find out what kinds of microbes are found high in the atmosphere, how many there are and where they may have come from.

Layers of the atmosphere. Credit: Smithsonian/NMNH

Although reports of microorganisms existing as high as 77 km have been around since the 1930s, Smith doubts the validity of some of the old data… the microbes could have been brought up by the research vehicles themselves.

"Almost no controls for are reported in the papers," he said.

But while some researchers have suggested that the microbes could have come from outer space, Smith thinks they are terrestrial in origin. Most of the microbes discovered so far are bacterial spores—extremely hardy organisms that can form a protective shell around themselves and thus survive the low temperatures, dry conditions and high levels of radiation found in the stratosphere. Dust storms or hurricanes could presumably deliver the bacteria into the atmosphere where they form spores and are transported across the globe.

If they land in a suitable environment they have the ability to reanimate themselves, continuing to survive and multiply.

Hunting for high life: What lives in Earth’s stratosphere?
Scanning electron microscope image of atmospheric bacterial spores collected from Mt. Bachelor Observatory. Credit: NASA/KSC

Although collecting these high-flying organisms is difficult, Smith is confident that this research will show how such basic life can travel long distances and survive even the harshest environments—not only on Earth but possibly on other worlds as well, such as the dessicated soil of  Mars.

"We still have no idea where to draw the altitude boundary of the biosphere," said Smith. This research will "address how long life can potentially remain in the and what sorts of mutations it may inherit while aloft."

Read more on Michael Schirber's article for Astrobiology Magazine here, and watch David Smith's seminar "The High Life: Airborne on the Edge of Space" held May 2012 at the University of Washington below:

This video is not supported by your browser at this time.


Explore further: SDO captures images of two mid-level flares

add to favorites email to friend print save as pdf

Related Stories

How did life on Earth originate?

Apr 03, 2007

Did life arrive from space? Rather than developing here, could the first life forms have been catapulted to Earth on a chunk of rock from outer space? Investigations show that microbes are capable of surviving ...

Mars Contamination Dust-Up

May 19, 2010

A new study finds that microbes on spacecraft might be able to survive on Mars longer than previously thought. The key to their survival? Dust.

Recommended for you

SDO captures images of two mid-level flares

6 hours ago

The sun emitted a mid-level flare on Dec. 18, 2014, at 4:58 p.m. EST. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts ...

Why is Venus so horrible?

12 hours ago

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

15 hours ago

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

15 hours ago

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

Spinning up a dust devil on Mars

16 hours ago

Spinning up a dust devil in the thin air of Mars requires a stronger updraft than is needed to create a similar vortex on Earth, according to research at The University of Alabama in Huntsville (UAH).

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.