Ice At the Moon - How the Moon Mineralogy Mapper on Chandrayaan-1 Will Help Noah E. Petro NASA Goddard Space Flight Center March 4 th, 2009

A Bit About Me Grew up in southern New York state Became interested in Geology as a student at the Fox Lane High School Earned a degree in geology and education from Bates College (2001) PhD from Brown University in 2006 Post Doctoral researcher at NASA Goddard

Clementine Albedo Topography Color Lunar Prospector FeO Th Polar H

The Moon’s Orientation 1.54º tilt to the ecliptic

Kaguya View of Shackleton/South Pole

Earth Based Radar View of the South Pole

Lunar South Pole The search for water …

Ice on the Moon Lunar Prospector Neutron Spectrometer looks for "slow" (or thermal) and "intermediate" (or epithermal) neutrons which result from collisions of normal "fast" neutrons with hydrogen atoms. The ice was thought to be spread over 10,000 to 50,000 square km and amount to 6 billion metric tons. A significant amount of hydrogen would indicate the existence of water - 4.6% over the north polar region and 3% over the south, at a depth of about 40 centimeters beneath dry regolith. 1) Fluxes of fast and epithermal neutrons from Lunar Prospector: Evidence for water ice at the lunar poles, Feldman et al., Science, v. 281, p. 1496, 1998 Moon’s inclination to the Sun is only 1.5°, allowing permanently shadowed regions inside craters No water (as OH-) was detected from the July 31, 1999 crash of Lunar Prospector into the Moon.Possible reasons: might have missed the target area; might have hit a rock; crash had too little energy to separate water from minerals; plume hidden from telescopes by crater walls; telescopes mispointed; or hydrogen simply may not be in the form of water ice.

Lunar South Pole The search for water … Lunar Prospector data Map of Hydrogen (red = greater abundance of H)

Lunar South Pole The search for water …

View into Shackleton Crater

Polar cold traps Scientists use the Kelvin absolute temperature scale, where ice melts at K. Dry ice forms at Mars atmospheric pressure at 145 K, water ice clouds form at ~ K. Liquid oxygen (1 bar): 90 K Liquid nitrogen (1 bar): 77 K Temperatures in Shackleton Crater: K No surface ices exposed?

Mission Overview: M3 on Chandrayaan-1

What We Know From Apollo

What We Learned Lunar samples are all very dry Limited compositional variability relative to the Earth Small amount of water in volcanic glasses

The Electromagnetic Spectrum &Lunar Mineral Signatures

Different wavelengths of light

M3 as a mapping spectrometer X

View into Shackleton Crater

Lunar Mineral Signatures

Lunar Reconnaissance Orbiter / Chandrayaan-1 Two most recent (late ) spacecraft orbiting Moon Powerful, modern radar experiments will image PSR’s in detail Lyman-Alpha Mapping Project (LAMP) will see interiors of PSRs by galactic far-ultraviolet light (hydrogen emissions) Lunar Orbiter Laser Altimeter will measure albedo on 5-m footprint scales, detecting 4% ice Neutron spectrometer (LEND) will resolve hydrogen atoms DIVINER will measure surface temperatures and rock environments

Lunar CRater Observation and Sensing Satellite [LCROSS]

For more information… Lunar Photo of the Day – Lunar and Planetary Institute - Lunar Resources – Apollo Surface Journal –