Chandrayaan-I finds water on the Moon

Scientists in NASA have discovered water molecules in the polar regions of the Moon. It has been said that more water has been found than was predicted by scientists. The analysis of the data by the Moon Mineralogy Mapper (M3) on board Chandrayaan-I has led to the find. The result was published in the journal, Science.

Here is the video of Press Meet compiled by the society exclusively in order to share the historic announcement of Water Ice on Moon . Other parts of the Video would be uploaded in a day.



What is the Moon Mineralogy Mapper?
The M3 scientific instrument is a high throughput pushbroom imaging spectrometer, operating in 0.7 to 3.0 µm range. It measures solar reflected energy, using a two-dimensional Hg-Cd-Te detector array. A spectrometer is a device which is used to measure properties of light which helps to identify materials. It is a payload on board Chandrayaan-I from Brown University and Jet Propulsion Laboratory through NASA, USA.


What is the role of Chandrayaan-I in this finding?
Chandrayaan-I is India's first mission to the Moon. Chandrayaan-I carried the Moon Mineralogy Mapper (M3) which is the instrument that found nearly 700 parts per million of water molecules on the Moon. M3 is an instrument provided by NASA. It was results from M3 which led scientists to re-check the information found by Cassini, Deep Impact and the samples from the Moon returned during the Apollo missions. The results were analysed jointly by Indian and American scientists jointly led by Dr. Carla Pieters of Brown University while the Indian team led by Prof. J. N. Goswami of Physical Research Laboratory, India.

When did Cassini and Deep Impact look at the Moon?
Deep Impact (now called Epoxi) had studied the Moon during June 2 and June 9 2009. Cassini is a spacecraft that is now studying Saturn and her Moons. Cassini studied the Moon on its way to Saturn in 2005. Both these data confirmed the finding that M3 had proposed.

Image Explanation: This graph compares detailed measurements of light from the moon, called spectra, taken by the Visual and Infrared Mapping Spectrometer (VIMS) on NASA' Cassini spacecraft and NASA's Moon Mineralogy Mapper instrument on the Indian Space Research Organization's Chandrayaan-1 spacecraft. The agreement between the two spacecraft is an excellent confirmation of the existence of water and hydroxyl (gray regions on the graph where wavelengths of infrared light range from 2.7 to 3.2 micrometers). The red dashed lines show the thermal emission, or heat, from the moon, which must be removed to better see the signature of water. The solid lines are the spectra after this thermal emission was removed. Image credit: NASA/ISRO/JPL-Caltech/USGS/Brown Univ.

Image Explanation: Since successfully carrying out its spectacular impact experiment at comet Tempel 1 on July 4, 2005, the Deep Impact spacecraft has been on an extended mission, called Epoxi, which culminates in a flyby of comet Hartley 2 on November 4, 2010. En route to the second comet, the spacecraft observed the moon for calibration purposes on several occasions. In June 2009, the northern polar regions were observed and detailed measurements of light from the regions, called spectra, were collected (blue and cyan). These data unambiguously show the signature of water and hydroxyl (hashed regions). The water signature varies in strength; in particular, data acquired over the warm equator in December 2007 have a distinct but weaker signature (purple). Credit: NASA/JPL-Caltech/University of Maryland

What did the Apollo Mission samples say?
Apollo mission returned a lot of samples of lunar soil (called regolith). Earlier traces of water were found in these samples. However, the scientists thought that this was contamination of the sample and not water on the Moon. They believed water may have leaked into the regolith.

Image Explanation: These graphs show detailed measurements of light as a function of color or wavelength. The data, called spectra, are used to identify minerals and molecules. On the left are spectra of lunar rocks, minerals and soil returned to Earth by NASA's Apollo missions, taken in the visible to shorter-wavelength infrared range. The blue bar shows where a dip in the light is expected due to the presence of water and hydroxyl molecules. To the right are model spectra for pure water (H2O) and hydroxyl (OH-). Image credit: ISRO/NASA/JPL-Caltech/Brown Univ.

How did the M3 find water on the Moon?
M3's spectrometer measured the light reflecting off the surface of the Moon in infrared wavelengths. It found that certain wavelengths of light were not being reflected and was absorbed on the lunar surface. These wavelengths are absorbed by water and hydroxyl molecules. Thus, the M3's scientists were able to say that they had found the presence of water on the Moon.

Image Explanation: The Moon Mineralogy Mapper is a state-of-the-art NASA imaging spectrometer. Sunlight reflected off the moon enters the telescope and then is passed by mirrors to the spectrometer. In the spectrometer, white light is dispersed into different wavelengths (from 0.43 to 3 micrometers) for every point in an image. Once in orbit around the moon, the instrument generates three-dimensional cubes of data that allow scientists to map the composition of the surface. Image Credit: NASA/JPL-Caltech

What does water on the Moon really mean?
On Earth, we see water in the forms of water vapour, steam, liquid water and ice. However water on the Moon does not look like this. It is present in the form of molecules and has been found interacting with regolith on the top layers of the lunar surface. Scientists claim it is anywhere between 700 to 1000 molecules of water in one million molecules. Another estimation says that if we could squeeze 1 ton of regolith, we could get between one-half to one litre of water.

Image Explanation: This image of the moon is from NASA's Moon Mineralogy Mapper on the Indian Space Research Organization's Chandrayaan-1 mission. It is a three-color composite of reflected near-infrared radiation from the sun, and illustrates the extent to which different materials are mapped across the side of the moon that faces Earth. Small amounts of water and hydroxyl (blue) were detected on the surface of the moon at various locations. This image illustrates their distribution at high latitudes toward the poles. Blue shows the signature of water and hydroxyl molecules as seen by a highly diagnostic absorption of infrared light with a wavelength of three micrometers. Green shows the brightness of the surface as measured by reflected infrared radiation from the sun with a wavelength of 2.4 micrometers, and red shows an iron-bearing mineral called pyroxene, detected by absorption of 2.0-micrometer infrared light. Image credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS

How was water formed on the Moon?
Scientists have not found a correct explanation for where the water came from. There are two theories - 1. Water formed by solar winds and 2. Water formed by impact with asteroids and comets.

How can water be formed by solar winds?
This is the more popular theory. It is believed that the solar winds carried hydrogen atoms. When these winds hit the surface of the Moon, they took the oxygen atom from the mettalic oxide present on the surface of the Moon. Together these formed one hydroxyl molecule consisting of one atom of hydrogen and another atom of oxygen.

How can water be formed by impact with asteroids and comets?
Asteroids and comets are believed to be rich in water ice and water molecules. It is possible that when these impact the surface of the Moon, the water molecules that they carried were scattered on the lunar surface.

What is the impact of this find?
The first impact of this find is that we have to change the way we understand how the Moon was formed and how it has become what it is today. It also holds the possibility of helping humankind when they build homes on the Moon by being a source of water.

We will post more information, images and results as they are shared with members of the public.