During its mission to investigate martian mysteries, the orbiter has revolutionised our knowledge of Mars, probing every facet of the Red Planet in unprecedented detail. Some of the most visually astonishing results have been returned by the High-Resolution Stereo Camera (HRSC), which has produced breathtaking, 3D colour images of the diverse martian surface – with giant volcanoes to sinuous valleys and ice-modified craters.
An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a 6-month journey, and has been thoroughly investigating the planet since early 2004. Credits: ESA - D. Ducros
One of the most surprising discoveries has been the youthful appearance of the country-sized volcanoes of the Tharsis ridge, suggesting they may have been active only a few million years ago. The images also show that glacial landforms are widespread over much of the planet, with glacial activity continuing in some areas until perhaps 20 000 – 30 000 years ago. Among the peculiar landforms imaged by HRSC is what appears to be a recently frozen body of water in Elysium, close to the equator.
While the camera has been imaging the surface in exquisite detail, other instruments have been examining different aspects of the planet’s environment. One of the most significant results from the Visible and Infrared Mineralogical Mapping Spectrometer OMEGA has been the discovery of clays, hydrated minerals that formed early in the planet’s history, when liquid water was fairly abundant. However, the presence of sulphates and iron oxides suggests that the planet subsequently became colder and drier, with only episodic eruptions of water onto the surface.
At the poles, OMEGA has measured the surface composition and produced unprecedented maps of water ice and carbon dioxide ice. Further insights into the martian poles have come from the Mars Advanced Radar for Subsurface and Ionospheric Sounding, MARSIS, which is revealing, for the first time, the secrets of the planet’s subsurface.
It has so far identified the presence of water ice deposits several kilometres underground and revealed fine, layered material near the poles. Similar soundings of the north polar cap have confirmed that it is dominated by water ice, with variable amounts of dust. The larger southern cap seems less dusty, but, with a maximum thickness of 3.7 km, it contains enough ice to produce a global ocean 11 m deep.
The multi-frequency radar has also been probing the upper atmospheric layer (the ionosphere) and found that the distribution of charged particles is linked with patchy magnetic fields in the martian crust.
Although Mars’ atmosphere is very thin, it plays an important role in the planet’s evolution, and new breakthroughs have been made possible by Mars Express. The Planetary Fourier Spectrometer (PFS) has made the most complete map to date of its chemical composition. Evidence for the presence of methane could indicate that volcanic activity, or even simple lifeforms may still be present today.
Meanwhile, the Ultraviolet and Infrared Atmospheric Spectrometer, SPICAM has provided the first complete vertical profile of the atmosphere’s carbon dioxide density and temperature. It has revealed a nightglow and aurorae at mid-latitudes, produced the first ozone map and discovered the highest clouds ever observed on Mars.
The Energetic Atoms Analyser (ASPERA) has confirmed that the solar wind is slowly stripping atoms from the atmosphere down to an altitude of 270 km, although the rate of loss is surprisingly slow.
The MaRS radio science experiment has studied surface roughness by pointing the craft’s high-gain antenna at the planet and recording the echoes. It has also been used to measure small changes in the spacecraft’s orbit caused by gravity anomalies. Some of the most marked increases in surface gravity have been found over the volcanic Tharsis ridge, indicating a higher-than-average crustal density. Another discovery has been the existence of an ionospheric layer created by meteors burning up in the atmosphere.
With the mission already extended until at least 2009 and the possibility of further extensions into the next decade, ESA is keen to ensure that Mars Express will continue to provide the best possible scientific return. In an effort to meet the needs of the various science teams with instruments on Mars Express, controllers at ESA’s Space Operations Centre in Darmstadt, Germany, are currently fine-tuning the spacecraft’s orbit.
“Between 18 November and 16 December, the thrusters will be fired five times to make minor alterations to the orbit,” said Tanja Zegers, Mars Express Science Operations Co-ordinator.
“This will ensure that HRSC and OMEGA will continue to have suitable lighting conditions for their observations in the future, while meeting the needs of the MARSIS scientists, who need observing time at night to look beneath the surface. It will also enable the imaging instruments to continue their programme of detailed observations, so that they can eventually complete the global mapping of the planet.”
Agustin Chicarro | alfa
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto
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