Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newfound Martian aurora actually the most common; sheds light on Mars' changing climate

13.12.2019

A type of Martian aurora first identified by NASA's MAVEN spacecraft in 2016 is actually the most common form of aurora occurring on the Red Planet, according to new results from the mission. The aurora is known as a proton aurora and can help scientists track water loss from Mars' atmosphere.

At Earth, aurora are commonly seen as colorful displays of light in the night sky near the polar regions, where they are also known as the northern and southern lights.


Conceptual image depicting the early Martian environment (right) -- believed to contain liquid water and a thicker atmosphere -- versus the cold, dry environment seen at Mars today (left).

Credit: NASA's Goddard Space Flight Center


This animation shows a proton aurora at Mars. First, a solar wind proton approaches Mars at high speed and encounters a cloud of hydrogen surrounding the planet. The proton steals an electron from a Martian hydrogen atom, thereby becoming a neutral atom. The atom passes through the bowshock, a magnetic obstacle surrounding Mars, because neutral particles are not affected by magnetic fields. Finally, the hydrogen atom enters Mars' atmosphere and collides with gas molecules, causing the atom to emit ultraviolet light. View animated GIF: https://cms.nasa.gov/sites/default/files/thumbnails/image/marsprotonauroramovie1080v4.gif

Credit: NASA/MAVEN/Goddard Space Flight Center/Dan Gallagher

However, the proton aurora on Mars happens during the day and gives off ultraviolet light, so it is invisible to the human eye but detectable to the Imaging UltraViolet Spectrograph (IUVS) instrument on the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft.

MAVEN's mission is to investigate how the Red Planet lost much of its atmosphere and water, transforming its climate from one that might have supported life to one that is cold, dry, and inhospitable.

Since the proton aurora is generated indirectly by hydrogen derived from Martian water that's in the process of being lost to space, this aurora could be used to help track ongoing Martian water loss.

"In this new study using MAVEN/IUVS data from multiple Mars years, the team has found that periods of increased atmospheric escape correspond with increases in proton aurora occurrence and intensity," said Andréa Hughes of Embry-Riddle Aeronautical University in Daytona Beach, Florida. Hughes is lead author of a paper on this research published December 12 in the Journal of Geophysical Research, Space Physics.

"Perhaps one day, when interplanetary travel becomes commonplace, travelers arriving at Mars during southern summer will have front-row seats to observe Martian proton aurora majestically dancing across the dayside of the planet (while wearing ultraviolet-sensitive goggles, of course).

These travelers will witness firsthand the final stages of Mars losing the remainder of its water to space." Hughes is presenting the research on December 12 at the American Geophysical Union meeting in San Francisco.

Different phenomena produce different kinds of aurora. However, all aurora at Earth and Mars are powered by solar activity, whether it be explosions of high-speed particles known as solar storms, eruptions of gas and magnetic fields known as coronal mass ejections, or gusts in the solar wind, a stream of electrically conducting gas that blows continuously into space at around a million miles per hour.

For example, the northern and southern lights at Earth happen when violent solar activity disturbs Earth's magnetosphere, causing high velocity electrons to slam into gas particles in Earth's nightside upper atmosphere and make them glow. Similar processes generate Mars' discrete and diffuse aurora - two types of aurora that were previously observed on the Martian nightside.

Proton aurora form when solar wind protons (which are hydrogen atoms stripped of their lone electrons by intense heat) interact with the upper atmosphere on the dayside of Mars. As they approach Mars, the protons coming in with the solar wind transform into neutral atoms by stealing electrons from hydrogen atoms in the outer edge of the Martian hydrogen corona, a huge cloud of hydrogen surrounding the planet. When those high-speed incoming atoms hit the atmosphere, some of their energy is emitted as ultraviolet light.

When the MAVEN team first observed the proton aurora, they thought it was a relatively unusual occurrence. "At first, we believed that these events were rather rare because we weren't looking at the right times and places," said Mike Chaffin, research scientist at the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics (LASP) and second author of the study.

"But after a closer look, we found that proton aurora are occurring far more often in dayside southern summer observations than we initially expected." The team has found proton aurora in about 14 percent of their dayside observations, which increases to more than 80 percent of the time when only dayside southern summer observations are considered.

"By comparison, IUVS has detected diffuse aurora on Mars in a few percent of orbits with favorable geometry, and discrete aurora detections are rarer still in the dataset," said Nick Schneider, coauthor and lead of the IUVS team at LASP.

The correlation with the southern summer gave a clue as to why proton aurora are so common and how they could be used to track water loss. During southern summer on Mars, the planet is also near its closest distance to the Sun in its orbit and huge dust storms can occur.

Summer warming and dust activity appear to cause proton auroras by forcing water vapor high in the atmosphere. Solar extreme ultraviolet light breaks the water into its components, hydrogen and oxygen. The light hydrogen is weakly bound by Mars' gravity and enhances the hydrogen corona surrounding Mars, increasing hydrogen loss to space. More hydrogen in the corona makes interactions with solar-wind protons more common, making proton aurora more frequent and brighter.

"All the conditions necessary to create Martian proton aurora (e.g., solar wind protons, an extended hydrogen atmosphere, and the absence of a global dipole magnetic field) are more commonly available at Mars than those needed to create other types of aurora," said Hughes.

"Also, the connection between MAVEN's observations of increased atmospheric escape and increases in proton aurora frequency and intensity means that proton aurora can actually be used as a proxy for what's happening in the hydrogen corona surrounding Mars, and therefore, a proxy for times of increased atmospheric escape and water loss."

This research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder, Colorado, and NASA Goddard manages the MAVEN project. NASA is exploring our Solar System and beyond, uncovering worlds, stars, and cosmic mysteries near and far with our powerful fleet of space and ground-based missions.

Bill Steigerwald | EurekAlert!
Further information:
https://www.nasa.gov/press-release/goddard/2019/mars-proton-aurora-common

More articles from Physics and Astronomy:

nachricht Astronomers discover class of strange objects near our galaxy's enormous black hole
16.01.2020 | University of California - Los Angeles

nachricht MOSHEMT—innovative transistor technology reaches record frequencies
16.01.2020 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

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: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

Im Focus: How Cells Assemble Their Skeleton

Researchers study the formation of microtubules

Microtubules, filamentous structures within the cell, are required for many important processes, including cell division and intracellular transport. A...

Im Focus: World Premiere in Zurich: Machine keeps human livers alive for one week outside of the body

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich have developed a machine that repairs injured human livers and keep them alive outside the body for one week. This breakthrough may increase the number of available organs for transplantation saving many lives of patients with severe liver diseases or cancer.

Until now, livers could be stored safely outside the body for only a few hours. With the novel perfusion technology, livers - and even injured livers - can now...

Im Focus: SuperTIGER on its second prowl -- 130,000 feet above Antarctica

A balloon-borne scientific instrument designed to study the origin of cosmic rays is taking its second turn high above the continent of Antarctica three and a half weeks after its launch.

SuperTIGER (Super Trans-Iron Galactic Element Recorder) is designed to measure the rare, heavy elements in cosmic rays that hold clues about their origins...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

A new 'cool' blue

17.01.2020 | Life Sciences

EU-project SONAR: Better batteries for electricity from renewable energy sources

17.01.2020 | Power and Electrical Engineering

Neuromuscular organoid: It’s contracting!

17.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>