Mars Express discovers aurorae on Mars

Jun 09, 2005
Mars Express discovers aurorae on Mars

ESA’s Mars Express spacecraft has for the first time ever detected an aurora on Mars. This aurora is of a type never previously observed in the Solar System.

Image: Terra Cimmeria is the area in the southern hemisphere of Mars where Mars Express has detected for the first time ever an aurora in the Red Planet. The aurora was detected at 177 degrees east and 52 degrees south. It is linked to anomalies in the crustal magnetic field, and it has a highly concentrated shape, making it unique in the solar system. Credits: NASA/ESA

Observations by the SPICAM instrument (SPectroscopy for the Investigations and the Characteristics of the Atmosphere on Mars) taken on 11 August 2004, revealed light emissions now interpreted as an aurora.
Aurorae are spectacular displays often seen at the highest latitudes on Earth. On our planet, as well as on the giant planets Jupiter, Saturn, Uranus and Neptune, they lie at the foot of the planetary magnetic field lines near the Poles, and are produced by charged particles – electrons, protons or ions – precipitating along these lines.

Aurorae have also been observed on the night side of Venus, a planet with no intrinsic (planetary) magnetic field. Unlike Earth and the giant planets, venusian aurorae appear as bright and diffuse patches of varying shape and intensity, sometimes distributed across the full planetary disc. Venusian aurorae are produced by the impact of electrons originating from the solar wind and precipitating in the night-side atmosphere.

Like Venus, Mars is a planet with no intrinsic magnetic field. A few years ago it was suggested that auroral phenomena could exist on Mars too. This hypothesis was reinforced by the recent Mars Global Surveyor discovery of crustal magnetic anomalies, most likely the remnants of an old planetary magnetic field.

SPICAM detected light emissions in the Southern hemisphere on Mars, during night time observations. The total size of the emission region is about 30 kilometres across, possibly about 8 kilometres high. Whilst the detected emission is typical for day-time, it must indicate the excitation of the upper atmosphere by fluxes of charged particles – probably electrons – if observed during night-time.

By analysing the map of crustal magnetic anomalies compiled with Mars Global Surveyor’s data, scientists observed that the region of the emissions corresponds to the area where the strongest magnetic field is localised. This correlation indicates that the origin of the light emission actually is a flux of electrons moving along the crust magnetic lines and exciting the upper atmosphere of Mars.

SPICAM observations provide for the first time a key insight into the role of the martian crustal magnetic field in producing original cusp-like magnetic structures. Such structures concentrate fluxes of electrons into small regions of the martian atmosphere. Eventually, they induce the formation of highly concentrated aurorae whose formation mechanism – a localised emission controlled by anomalies in the crust’s magnetic field – is unique in the Solar System.

The martian aurora was observed in the Mars region corresponding to 177 degrees east and 52 degrees south.

These results appear in the 9 June issue of the scientific journal Nature.

The authors of the findings are: J-L. Bertaux, SPICAM Principal Investigator, F. Leblanc, E. Quemerais (Service d’Aeronomie du CNRS/IPL, France), O. Witasse (European Space Agency – Noordwijk, The Netherlands), J. Lilensten (Laboratoire de Planetologie de Grenoble, France), S.A. Stern (Southwest Research Institute, Colorado, USA), B. Sandel (Lunar and Planetary Laboratory, University of Arizona, USA), O. Korablev (Space Research Institute-IKI, Moscow, Russia).

Source: ESA

Explore further: How ancient impacts made mining practical

add to favorites email to friend print save as pdf

Related Stories

Light of life

Aug 27, 2014

A fluorescent microscopic view of cells from a type of bone cancer, being studied for a future trip to deep space – aiming to sharpen our understanding of the hazardous radiation prevailing out there.

How do we terraform Venus?

Jul 25, 2014

It might be possible to terraform Venus some day, when our technology gets good enough. The challenges for Venus are totally different than for Mars. How will we need to fix Venus?

The science that stumped Einstein

Jul 01, 2014

In 1908, the physics world woke up to a puzzle whose layers have continued to stump the greatest scientists of the century ever since. That year, Dutch physicist Kamerlingh Onnes cooled mercury down to -450° ...

Recommended for you

Getting to the root of the problem in space

6 minutes ago

When we go to Mars, will astronauts be able to grow enough food there to maintain a healthy diet? Will they be able to produce food in NASA's Orion spacecraft on the year-long trip to Mars? How about growing ...

The difference between CMEs and solar flares

2 hours ago

This is a question we are often asked: what is the difference between a coronal mass ejection (CME) and a solar flare? We discussed it in a recent astrophoto post, but today NASA put out a video with amazing graphics that explain ...

Scientific instruments of Rosetta's Philae lander

2 hours ago

When traveling to far off lands, one packs carefully. What you carry must be comprehensive but not so much that it is a burden. And once you arrive, you must be prepared to do something extraordinary to make ...

Image: NGC 6872 in the constellation of Pavo

3 hours ago

This picture, taken by the NASA/ESA Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), shows a galaxy known as NGC 6872 in the constellation of Pavo (The Peacock). Its unusual shape is caused ...

Measuring the proper motion of a galaxy

4 hours ago

The motion of a star relative to us can be determined by measuring two quantities, radial motion and proper motion. Radial motion is the motion of a star along our line of sight. That is, motion directly ...

User comments : 0