Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 


Hydrogen offers a new way to study the Moon

The Moon is a surprisingly strong source of hydrogen atoms. That is the surprise discovery from the Swedish Institute of Space Physic's instrument SARA on board the Indian Chandrayaan-1 lunar orbiter. It gives scientists an interesting new way to study both the Moon and any other airless bodies in the solar system.

According to conventional wisdom, the lunar surface is a loose collection of irregular dust grains. Any particle that hits it should bounce between the grains and be absorbed. But the new results clearly show that one out of every five protons incoming from the solar wind rebounds from the Moon's surface. In the process, the proton joins with an electron to become an atom of hydrogen.

"We didn't expect to see this at all," says Stas Barabash, Swedish Institute of Space Physics (IRF), who is the European Principal Investigator for the SARA (Sub-keV Atom Reflecting Analyzer) instrument, which made the discovery.

"It's an amazing discovery for the planetary scientific community in general and for lunar science in particular," says Anil Bhardwaj, who is the Indian Principal Investigator from the Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum. SARA was one of three instruments that the European Space Agency (ESA) contributed to Chandrayaan-1, the lunar orbiter that completed its mission in August 2009, and was built jointly by scientific groups from Sweden, India, Japan and Switzerland.

Although Barabash and his colleagues do not know what is causing the Moon to act as a hydrogen mirror, the discovery paves the way for a new type of picture to be made of the lunar surface. This is because the hydrogen atoms shoot off with speeds of around 200 km/s and so escape without being deflected by the Moon's weak gravity. Also, because hydrogen is electrically neutral, it is not diverted by the magnetic fields in space. So the atoms fly in straight lines from the surface of the Moon, just like photons of light. In principle, each detection can be traced back to its origin and an image of the surface can be made. The areas that emit most hydrogen will show up the brightest.

Barabash and his team are currently analysing the data to see if they can make such pictures, in order to look for so-called lunar magnetic anomalies. Whilst the Moon does not generate a global magnetic field, some lunar rocks are magnetised. These generate magnetic bubbles that deflect incoming protons away into surrounding regions. In a hydrogen image, the magnetic rocks will therefore appear dark.

The incoming protons are part of the solar wind, a constant stream of particles given off by the Sun. They collide with every celestial object in the Solar System but are usually stopped by the object's atmosphere. On objects without such a natural shield, for example asteroids or the planet Mercury, the solar wind reaches the ground. The SARA team expects that these objects too will reflect many of the incoming protons back into space as hydrogen atoms.

This knowledge provides timely information for the scientists and engineers who are readying ESA's BepiColombo mission to Mercury. The spacecraft will be carrying two similar instruments to SARA and may find that the inner-most planet is reflecting more hydrogen than the Moon because the solar wind is more concentrated closer to the Sun. In the meantime, the SARA team is combing the lunar data for insight, and puzzling over just why the Moon is so good at reflecting hydrogen.

The SARA instrument was built jointly by the Swedish Institute of Space Physics, Kiruna, Sweden; the Vikram Sarabhai Space Centre, Trivandrum, India; University of Bern, Switzerland; and the Institute of Space and Astronautical Science, Sagamihara, Japan.

Notes to Editors:

"Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space" by Martin Wieser, Stas Barabash, Yoshifumi Futaana, Mats Holmström, Anil Bhardwaj, R. Sridharan, M.B. Dhanya, Peter Wurz, Audrey Schaufelberger, Kazushi Asamura will be published in a forthcoming issue of Planetary and Space Science and is now available online: Planetary and Space Science (2009), doi: 10.1016/j.pss.2009.09.1210

More information:
* Dr Martin Wieser, Swedish Institute of Space Physics, tel. +46-980-79198,

* Prof. Stas Barabash, Swedish Institute of Space Physics, tel. +46-980-79122,

* Rick McGregor, Information Officer, Swedish Institute of Space Physics, tel. +46-980-79178,

Rick McGregor | idw
Weitere Informationen:

Weitere Nachrichten aus der Kategorie Physik Astronomie:

nachricht Das VLT entdeckt unerwarteterweise riesige leuchtende Halos um ferne Quasare
26.10.2016 | ESO Science Outreach Network - Haus der Astronomie

nachricht Quantencomputer – Rechner der Zukunft?
24.10.2016 | Deutsche Physikalische Gesellschaft (DPG)

Alle Nachrichten aus der Kategorie: Physik Astronomie >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Mikrostrukturen mit dem Laser ätzen

Mit dem Ultrakurzpulslaser lassen sich nicht nur feine Strukturen schneiden, in einem Verbundprojekt haben Wissenschaftler untersucht, wie man damit auch Mikrostrukturen in Dünnglas erzeugen kann. Anwendungen gibt es im Analytikbereich (lab-on-a-chip), aber auch in der Elektronikbranche und im Consumer-Bereich gibt es großes Interesse.

Am Anfang dieser neuen Methode stand ein überraschender Effekt: Wenn Glas mit dem Ultrakurzpulslaser in der richtigen Weise bestrahlt wird, wird es so...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Tarnkappe aus Nanostrukturen

Linsen, Objektive, Brillengläser oder auch Laser sind in der Regel mit einer Antireflexschicht versehen. Solche Schichten haben oft den Nachteil, dass sie nur innerhalb enger Wellenlängenbereiche optimal wirksam sind. Forscher des Max-Planck-Instituts für Intelligente Systeme in Stuttgart stellen nun eine alternative Technologie vor. Anstatt eine Beschichtung aufzubringen, bearbeiten sie die Oberfläche selbst. Im Vergleich zu herkömmlichen Verfahren können sie so den gewünschten Effekt über einen größeren Wellenlängenbereich erzielen, und das bei besonders großer Lichtdurchlässigkeit.

Der Nachtfalter macht es vor. Seine Augenoberflächen sind so beschaffen, dass sie einfallendes Licht praktisch nicht reflektieren. Keine Lichtreflexe – das...

Im Focus: Lichtinduzierte Rotationen von Atomen rufen Magnetwellen hervor

Terahertz-Anregung ausgewählter Kristallschwingungen führt zu einem effektiven Magnetfeld, das kohärente Spindynamik antreibt

Die Kontrolle funktionaler Eigenschaften durch Licht ist eines der großen Ziele moderner Festkörperphysik und der Materialwissenschaften. Eine neue Studie...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Alle Focus-News des Innovations-reports >>>



im innovations-report
in Kooperation mit academics

Wissen.schafft.Vernetzung - Vernetzte Forschungsergebnisse sichtbar machen

26.10.2016 | Veranstaltungen

Science or Fiction? MHH-Forscher beleuchten Stammzellforschung

25.10.2016 | Veranstaltungen

BAM und Bildungswerk VDV laden zur Fachtagung „Messen im Bauwesen“ am 08.11.2016

25.10.2016 | Veranstaltungen

Weitere VideoLinks >>>
Aktuelle Beiträge

VDI verleiht International Bionic Award 2016 der Schauenburg-Stiftung

26.10.2016 | Förderungen Preise

Baufritz erhält Anton-Jaumann-Innovationspreis 2016

26.10.2016 | Unternehmensmeldung

Gute Sänger tragen grosse Krawatten

26.10.2016 | Biowissenschaften Chemie