Astronomy Now Home
Home Magazine Resources Store

On Sale Now!

The October 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). Astronomy Now is the only astronomy magazine specially designed to be read on tablets and phones. Download the app from Google Play Store or the Apple App Store.

Top Stories

Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...

Scientists announce evidence of water on Moon
Posted: September 24, 2009

Bookmark and Share

Data from the Indian Chandrayaan-1 Moon mission, supported with similar data collected during Deep Impact and Cassini flybys of the Moon, has provided unambiguous evidence of water locked up in the lunar soil, bringing dreams of a sustainable Moon base one step closer.

"The Moon continues to surprise us," says Carle Pieters of Brown University, lead author of one of three papers describing the new results and featuring in the journal Science this week. Pieters is the lead investigator of the M3 instrument. "Widespread water has been detected on the surface of the Moon. We need to think outside of the box, this is not what we expected a decade ago."

The new results follow in the wake of an announcement by the Lunar Reconnaissance Orbiter (LRO) team last week that detailed further evidence for water ice at the lunar poles (read our report here). This ahead of the planned impact of the Lunar Crater Observation Sensing Satellite (LCROSS) into a permanently shadowed crater on 9 October in a dramatic attempt to throw up icy debris for LRO and other ground- and space-based telescopes to analyse.

Water abundance is dependent on temperature in Deep Impact observations. Image: NASA/University of Maryland.

Now, new data from Chandrayaan-1's Moon Mineralogy Mapper, M3, suggest that water is still being formed on the Moon today, a finding that has exciting implications for the future of manned exploration of our nearest celestial neighbour, since astronauts could use water reserves to drink, extract oxygen to breathe and use hydrogen as fuel. Although the Moon is drier than any desert on Earth, the new results suggest that a cubic metre of soil could yield one litre of water.

Moreover, water molecules were found across the whole surface of the Moon, and not just at the frigid poles. “We’ve made a very important step with this discovery, and now there are some very important steps to follow up on,” says Pieters.

Scientists think that the stream of charged hydrogen ions carried from the Sun to the Moon by the solar wind might explain the possible presence of water on the Moon. Image: University of Maryland/F. Merlin/McREL.

An extremely sensitive imaging spectrometer, M3 detects the presence of water by soaking up the signature electromagnetic radiation emitted by minerals on or just below the surface. The M3 team found that the wavelengths of light detected by the instrument were consistent with the absorption patterns for water (H2O) and simple hydrogen-oxygen (OH) molecules. The data also suggests that water is created every day, cycling through a loss and gain process.

"At noon the absorption is weak but in the evening it is much stronger," says Jessica Sunshine, Deptuy Project Investigator for the Deep Impact mission which also observed signatures of water and hydroxyl on the Moon."We're seeing an entire cycle of loss and recovery of water features. In the daytime the solar wind, which includes hydrogen ions, interacts with oxygen in the lunar soil to form and accumulate hydroxyl and water molecules. Water is lost at noon when it is hotter, but when it cools down in the evening it can accumulate water again."

This proposed explanation has extremely important implications for the rest of the Solar System. "This cycle means that regardless of the location and terrain type, the entire surface of the Moon will be hydrated during at least part of the lunar day," says Sunshine. "If this is the explanation (which it may not be) the same process would cause similar hydrations effect on any oxygen rich environment that doesn't have an atmosphere, for example, Mercury."

The scientists also present hypotheses on the occurrence of the water bearing minerals. The data confirms that water exists in the top one or two millimetres of the lunar surface but that it could occur as single layer of molecules, it could be mixed in, or be in the form of altered minerals on the surface. Unravelling the nature and occurrence of the water will provide the focus for decades worth of research.

Altitude measurements from NASA's LRO mission show the location of Cabeus A, the target crater for the LCROSS impact scheduled for 9 October. Impact: NASA/GSFC.

Scientists have also speculated that water molecules migrate from high latitudes to the polar regions where it is colder, especially to the deep, dark traps of ancient craters where the water inventory there has likely been supplemented by deliveries from comet impacts that dominated the early years of the Moon's existence.

“If the water molecules are as mobile as we think they are — even a fraction of them — they provide a mechanism for getting water to those permanently shadowed craters,” says Pieters. “This opens a whole new avenue [of lunar research], but we have to understand the physics of it to ultilise it.”

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


© 2014 Pole Star Publications Ltd.