As more research points toward the possibility of water on early Mars, scientists have increased their studies on the density of its atmosphere billions of years ago. It’s not an easy task. In fact, it’s very difficult to even determine Earth’s atmospheric pressure from the same time frame.
Georgia Tech Assistant Professor Josef Dufek is attempting to learn more about the past atmospheric conditions by analyzing two unlikely sources: ancient volcanic eruptions and surface observations by the Mars rover Spirit. His new findings, published by the journal Geophysical Research Letters, provide more evidence that early Mars was saturated with water and that its atmosphere was considerably thicker, at least 20 times more dense, than it is today.
“Atmospheric pressure has likely played a role in developing almost all Mars’ surface features,” said Dufek, an instructor in the School Earth and Atmospheric Sciences. “The planet’s climate, the physical state of water on its surface and the potential for life are all influenced by atmospheric conditions.”
Dufek’s first research tool was a rock fragment propelled into the Martian atmosphere during a volcanic eruption roughly 3.5 billion years ago. The deposit landed in the volcanic sediment, created a divot (or bomb sag), eventually solidified and remains in the same location today. Dufek’s next tool was the Mars rover. In 2007, Spirit landed at that site, known as Home Plate, and took a closer look at the imbedded fragment. Dufek and his collaborators at the University of California-Berkeley received enough data to determine the size, depth and shape of the bomb sag.
Dufek and his team then went to the lab to create bomb sags of their own. They created beds of sand using grains the same size as those observed by Spirit. The team propelled particles of varying materials (glass, rock and steel) at different speeds into dry, damp and saturated sand beds before comparing the divots with the bomb sag on Mars. No matter the type of particle, the saturated beds consistently produced impact craters similar in shape to the Martian bomb sag.
By varying the propulsion speeds, Dufek’s team also determined that the lab particles must hit the sand at a speed of less than 40 meters per second to create similar penetration depths. In order for something to move through Mars’ atmosphere at that peak velocity, the pressure would have to be a minimum of 20 times more dense than current conditions, which suggests that early Mars must have had a thicker atmosphere. Click here for a video demonstration.
“Our study is consistent with growing research that early Mars was at least a transiently watery world with a much denser atmosphere than we see today,” said Dufek. “We were only able to study one bomb sag at one location on the Red Planet. We hope to do future tests on other samples based on observations by the next rover, Curiosity.”
Curiosity is scheduled to land on Mars on August 5.
The material is based upon work supported by NASA under award No NNX09AL20G. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.
Jason Maderer | EurekAlert!
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy