Telecon Notes
Green: 4.5 GYA something hit the Earth. As it cooled Earth lost most of its volatiles. Moon rocks 50 ppm water on Apollo returned moon rocks. If we extracted all the water form Apollo rocks it would fill a table soon. Based on our observations is that Moon is very dry. Lunar Prospector found Neutrons emitted by the moon due to cosmic rays hitting Moon surface and generating Neutrons. Over poles this flux dropped. Water is a known inhibitor of this. General thinking was that Moon is bone dry except for polar, shadowed regions. Today’s announcement is a major advancement of our knowledge of water on surface of the Moon. Measurements from three spacecraft were critical to confirm the findings that we will discuss today.
More below
Carle Pieters: The Moon continues to surprise us. Widespread water has been deteced on the surface of the Moon. You have to think outside the box – this is not what any of us extected a decade ago. We are looking at water and hydroxyl on the Moon. We are looking at radiation that is reflected from the Moon. We will be coming back to this fingerprint – this highly diagnostic figure of water on the surface of the Moon. There is spatial variability – some areas have a stronger signal than others. Detected at high latittudes as well also in craters.Even in small craters you get detection of a strong signal. We do not know what physical form water taks on the surface. What we are seeing in the uppermost 2mm surface of the lunar surface. It might be a layer on top of the soil, or altered rocks.
Green: Images that come on 19 Nov 2008 – measuring spectral response of the Moon. Very excited to see this. We have 1000 GB of data returned from M3 over 10 months. Mineral results: Iron bearing minerals similar to basalt lavas in Hawaiian volcanoes. I invite you to look at the Moon and understand that the Moon is much more than just a gray body orbiting the Earth – it is full of spectral content.
Clark: Cassini flew by Earth and Moon on a gravity assist in August 1999. What is astounding is that water and hydroxyl exist at all latitudes. The amount of water is small – a liter of water per ton of lunar material in the near surface area. There are some indications that young craters have excavated water and hydroxyl rich material from below the surface.
Sunshine: Deep Impact has been on an extended mission since 2005 for another comet encounter. Spacecraft made several observations of the Moon for calibration purposes. While our instrument was designed for comets is ideally suited to measure OH and H20 features on the Moon. We acquired lunar data in 2007 and June 2009. Process may be at work on other solar system bodies as well.
Jim Green: Even the driest desert on Earth has more water than the poles of the Moon.
Michael Wargo, ESMD: We are really excited about the results. We have an experiment on 9 Oct (LCROSS) that will look for potential of water in a shadowed crater near the lunar south pole. We will conduct that experiment by excavating the lunar surface – down a meter or so and look at potential distribution of water ice and other volatiles in the lunar surface.
NASA Watch: I asked why, if this data was collected in 2007, 2008, and 1999, that it was not published prior to this. {audio problems during question asking and response} Deep Impact collected data in the equator and we were not really looking at it – we did not know it until recently. As for Cassini all spacecraft have water in them and this needs to be calibrate dover time. It took 2004 to 2008 to do the calibration.
Editor’s note: OK, so if the Cassini calibration was done in 2008, then why wasn’t this calibrated 1999 lunar data released in 2008 or 2009 – and news of OH and H20 already common knowledge when Deep Impact and Chandrayaan-1 arrived and began to take their own measurements?
