Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars Express observes aurorae on the Red Planet

21.11.2008
Scientists using ESA’s Mars Express have produced the first crude map of aurorae on Mars. These displays of ultraviolet light appear to be located close to the residual magnetic fields generated by Mars’s crustal rocks. They highlight a number of mysteries about the way Mars interacts with electrically charged particles originating from the Sun.

The aurorae on Mars were discovered in 2004 using the SPICAM ultraviolet and infrared atmospheric spectrometer on board Mars Express. They are a powerful tool with which scientists can investigate the composition and structure of the Red Planet’s atmosphere.

Now Francois Leblanc, from the Service d’Aéronomie, IPSL/CNRS, France and colleagues have announced the results of coordinated observation campaigns using SPICAM, the MARSIS sub-surface sounding radar altimeter’s radar, and the energetic neutral atoms analyser, ASPERA’s electron spectrometer on Mars Express.

They have observed nine new auroral emission events, which have allowed them to make the first crude map of auroral activity on Mars. They see that the aurorae seem to be located near regions where the martian magnetic field is the strongest. MARSIS had previously observed higher-than-expected electrons in similar regions. This suggests, although it does not prove, that the magnetic fields help to create the aurorae.

On Earth, aurorae are more commonly known as the northern and southern lights. They are confined to the polar regions and shine brightly at visible as well as ultraviolet wavelengths. The existence of similar aurorae is well known on the giant planets of the Solar System. They occur wherever a planet’s magnetic field channels electrically charged particles into the atmosphere.

In all of these planets, the magnetic fields are large-scale structures generated deep in the interior of the planet. Mars lacks such a large-scale internal mechanism. Instead, it just generates small pockets of magnetism where areas of rocks in the crust of Mars are themselves magnetic. This results in many magnetic pole-type regions all over Mars.

The aurorae are caused by charged particles, in this case most probably electrons, colliding with molecules in the atmosphere. The electrons almost certainly come from the Sun, which constantly blows out electrically charged particles into space. Known as the solar wind, this constant stream of particles provides the source of electrons to generate the aurorae, as suggested by MARSIS and ASPERA.

But how the electrons are accelerated to sufficiently high energies to spark aurorae on Mars remains a mystery. “It may be that magnetic fields on Mars connect with the solar wind, providing a road for the electrons to travel along,” says Leblanc.

Any future astronauts expecting a spectacular light show, similar to aurorae on Earth, may be in for a disappointment. “We’re not sure whether the aurorae will be bright enough to be observed at visible wavelengths,” says Leblanc.

This is because the molecules responsible for the visible light show on Earth – molecular and atomic oxygen and molecular nitrogen – are not abundant enough in the martian atmosphere. SPICAM is designed to work at ultraviolet wavelengths and cannot see whether visible light is being emitted as well.

Nevertheless, there is plenty of work for the scientists to do. “There's now a large domain of physics that we have to explore in order to understand the aurorae on Mars. Thanks to Mars Express we have a lot of very good measurements to work with,” says Leblanc.

Agustin Chicarro | alfa
Further information:
http://www.esa.int/SPECIALS/Mars_Express/SEMY1B5DHNF_0.html

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>