Featured Research

from universities, journals, and other organizations

How The Moon Produces Its Own Water

Date:
October 19, 2009
Source:
European Space Agency
Summary:
The Moon is a big sponge that absorbs electrically charged particles given out by the Sun. These particles interact with the oxygen present in some dust grains on the lunar surface, producing water. This discovery, made by the ESA-ISRO instrument SARA onboard the Indian Chandrayaan-1 lunar orbiter, confirms how water is likely being created on the lunar surface.

Chandrayaan-1 SARA measurements of hydrogen flux recorded on the Moon on 6 February 2009.
Credit: Elsevier 2009 (Wieser et al.), ESA-ISRO SARA data

The Moon is a big sponge that absorbs electrically charged particles given out by the Sun. These particles interact with the oxygen present in some dust grains on the lunar surface, producing water. This discovery, made by the ESA-ISRO instrument SARA onboard the Indian Chandrayaan-1 lunar orbiter, confirms how water is likely being created on the lunar surface.

It also gives scientists an ingenious new way to take images of the Moon and any other airless body in the Solar System.

The lunar surface is a loose collection of irregular dust grains, known as regolith. Incoming particles should be trapped in the spaces between the grains and absorbed. When this happens to protons they are expected to interact with the oxygen in the lunar regolith to produce hydroxyl and water. The signature for these molecules was recently found and reported by Chandrayaan-1’s Moon Mineralogy Mapper (M3) instrument team.

The SARA results confirm that solar hydrogen nuclei are indeed being absorbed by the lunar regolith but also highlight a mystery: not every proton is absorbed. One out of every five rebounds into space. 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, who is the European Principal Investigator for the Sub-keV Atom Reflecting Analyzer (SARA) instrument, which made the discovery.

Although Barabash and his colleagues do not know what is causing the reflections, the discovery paves the way for a new type of image to be made. The hydrogen shoots off with speeds of around 200 km/s and escapes without being deflected by the Moon’s weak gravity. Hydrogen is also electrically neutral, and is not diverted by the magnetic fields in space. So the atoms fly in straight lines, just like photons of light. In principle, each atom 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.

Whilst the Moon does not generate a global magnetic field, some lunar rocks are magnetised. Barabash and his team are currently making images, to look for such ‘magnetic anomalies’ in lunar rocks. These generate magnetic bubbles that deflect incoming protons away into surrounding regions making magnetic rocks appear dark in a hydrogen image.

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 body’s atmosphere. On bodies 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 advice 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.

SARA was one of three instruments that ESA contributed to Chandrayaan-1, the lunar orbiter that finished its mission in August 2009. The instrument was built jointly by scientific groups from Sweden, India, Japan, and Switzerland: Swedish Institute of Space Physics, Kiruna, Sweden; Vikram Sarabhai Space Centre, Trivandrum, India; University of Bern, Switzerland; and Institute of Space and Astronautical Science, Sagamihara, Japan. The instrument is led by Principal Investigators Stanislav Barabash, IRF, Sweden, and Anil Bhardwaj, VSSC, India.


Story Source:

The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Wieser, S. Barabash, Y. Futaana, M. Holmstrφm, A. Bhardwaj, R. Sridharan, M.B. Dhanya, P. Wurz, A. Schaufelberger and K. Asamura. Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space. Planetary and Space Science, 2009; DOI: 10.1016/j.pss.2009.09.012

Cite This Page:

European Space Agency. "How The Moon Produces Its Own Water." ScienceDaily. ScienceDaily, 19 October 2009. <www.sciencedaily.com/releases/2009/10/091015091605.htm>.
European Space Agency. (2009, October 19). How The Moon Produces Its Own Water. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2009/10/091015091605.htm
European Space Agency. "How The Moon Produces Its Own Water." ScienceDaily. www.sciencedaily.com/releases/2009/10/091015091605.htm (accessed October 22, 2014).

Share This



More Space & Time News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) — A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) — Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) — Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) — The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins