Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate model for Earth also describes changes on Mars

26.09.2002


Orbit affects climate on Mars similar to the way it affects climate on Earth, say three scientists, who used a model of climate change on Earth to explain the layers of deposits in the polar regions of the Red Planet.


An image from the Hubble Space Telescope shows the full disk of Mars. Clouds and weather can be seen at the poles. [Image: NASA, Hubble Heritage Team (STScl/AURA) Hubble Space Telescope WFPC2 STScl-PRC01-24].


This image, from an exposure of layers in the North Pole of Mars, is the actual image used in the analysis. Mustard and his colleagues say the alternating bright and dark bands are due to changes in climate recorded in these layers. The image is of an area about a mile across. [Image: NASA/JPL/Malin Space Science Systems].



Their study appears in the Sept. 26 issue of Nature, and suggests that a climate change theory for Earth can also be applied to Mars and possibly to other Earth-like planets.

“The orbital theory of climate change has been successful in explaining changes in the Earth’s climate, and we have used cores of the Greenland and Antarctic ice caps to reconstruct past climates and atmospheres on Earth,” said author Jack Mustard, associate professor of geological sciences at Brown University. “This means that we can now use the Mars caps in a similar way.”


The study also produced “a much better constraint on the time required to form the layers on the polar cap of Mars,” he said. “This has importance in understanding the Martian climate, and also the water cycles and history. We have so little information on the rates of change on Mars, but this gives us a solid marker.”

Besides Mustard, the other two authors of the study are Jacques Laskar and Benjamin Levrard of the Astronomie et Systèmes Dynamiques in Paris.

The trio used orbital calculations and rotational parameters of Mars, new high-resolution images of its north pole terrain, and high-resolution topography data to correlate exposed layers of ice and dust with changes in climate, particularly the sum of solar radiation reaching the terrain. Their techniques mirrored those used for orbital-based climate studies on Earth.

Changes in the ratio of dust and ice over time are visible in the variations of brightness seen in the layers of polar deposits on Mars. First noticed in the earliest Mars missions, the layers were thought to be related to changes in climate possibly linked with the evolution of Mars’ orbit such as the tilt of the axis and deviations in circularity. But the image resolution of past data was insufficient to resolve such key details.

High-resolution images from the Mars Global Surveyor allowed Mustard to resolve the fine detail and analyze the patterns. “After correcting the observations for topography, we produced a measure of the brightness of the layers as a function of depth,” he said. “We assume that depth equals time and thus can peer into the past. We then compared this record with the predicted amount of sunlight received at the pole over the last 10 million years, which varies with orbital evolution involving tilt and circularity.”

The researchers’ goal was to determine whether the sunlight record at the north polar cap of Mars correlated with the brightness-depth profile, and over what time frame. If the record correlated, that would solidify their hypothesis that the layers are due to climate changes related to orbit and allow the researchers to determine the formation rate of the layers.

“Indeed we find an excellent correlation and show that the 350-meter thick package of layers formed within the last 1 million years or so,” Mustard said. For the most recent 250-meter thick deposit of the north ice polar cap, the researchers found an average deposition rate of 0.05 cm/yr. “For the first time, we showed that the orbital theory of climate change has a record in the polar deposits on Mars.”

In orbit, Earth tilts about 23-25 degrees. In contrast, Mars tilts as little as 15 degrees and as much as 40 degrees, which is enough to redistribute moisture from polar caps to equatorial regions, Mustard said. In the 1970s, research by geologists at Brown first showed an orbital effect on climate change for Earth.

“This study further ties Mars and Earth as similar planets and strengthens the foundations to compare their climates and orbital evolutions,” Mustard said. “Showing that a planet with as strange an orbit as Mars has climate changes recorded in its surface means we have a tool in this orbital driver to explore what happens on the surface of planets with differences and similarities to Earth. And as we learn more about deposits on Mars we can compare what we find with what we know about Earth.”

The Centre Nationale de la Recherche Scientifique Programme Nationale de Planétologie and NASA’s Solar System Exploration programs supported the research.

Scott Turner | EurekAlert!
Further information:
http://www.brown.edu/Administration/News_Bureau

More articles from Earth Sciences:

nachricht Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University

nachricht Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>