Lunar eclipse will give NASA moon orbiters the shivers

Artist’s view of Earth eclipsing the sun next Tuesday morning April 15 as seen from the Lunar Reconnaissance’s Orbiter’s perspective. For several hours, it and NASA’s LADEE dust explorer will be cut off from sunlight. Back on Earth, we see the moon slide into our planet’s shadow. Credit: NASA

While we’re all bundled up for next Monday’s late night total eclipse of the moon, NASA will be taking special precautions to ensure its two moon probes survive the deep chill they’ll experience when the moon dives into Earth’s shadow.

NASA’s LRO has been orbiting, mapping and studying the moon since 2009. Credit: NASA

The Lunar Reconnaissance Orbiter (LRO), launched in 2009, has spent the past four-plus years photographing and mapping the moon in great detail from an orbit dipping as low as 31 miles (50 km). One of its goals is to determine future lunar landing sites. The craft also examines the moon’s radiation environment and maps the concentration of hydrogen – the main ingredient of water – across the globe. Hydrogen “hot spots” imply potential locations of water ice beneath the surfade or bound to moon rocks.

LRO will orbit the moon twice in Earth’s shadow. All instruments will be shut down since they would otherwise drain the batteries which can’t recharge without sunlight. Credit: NASA

LRO depends on sunlight to keep its batteries charged and instruments running. During the upcoming lunar eclipse, the moon will be either partially or fully within Earth’s shadow for several hours. With no sunlight reaching the probe’s solar panels, recharging the batteries isn’t possible.

To prevent damage to the either instruments or batteries, NASA plans to shut down all of LRO’s science instruments next Monday night for the duration of the eclipse. As soon as the event is over, the sun will slowly recharge the batteries and mission control will bring everything back online.

While LRO’s no stranger to eclipses,this time the spacecraft will have to pass through the complete shadow twice before the eclipse ends – longer than in any previous event.

“We’re taking precautions to make sure everything is fine,” said Noah Petro, Lunar Reconnaissance Orbiter deputy project scientist. “We’re turning off the instruments and will monitor the spacecraft every few hours when it’s visible from Earth.”


Understanding lunar eclipses

During other briefer eclipses, scientists have used the opportunity to study how the moon’s surface cools during these events, shedding light on the composition of the lunar crust. During the June 15, 2011 eclipse, temperatures on some areas of the moon dropped 180 degrees F compared to sunny, pre-eclipse conditions.

While LRO is expected to emerge from the shadow with flying colors, the forecast for NASA’s Lunar Atmosphere and Dust Explorer (LADEE) spacecraft is sketchy. The probe was never designed to withstand hours in the deep freeze of a shadowed moon.

“The eclipse will really put the spacecraft design through an extreme test, especially the propulsion system,” said Butler Hine, LADEE project manager.

Prior to impact on or before April 21, ground controllers at NASA’s Ames Research Center in Moffett Field, Calif., are maneuvering the spacecraft to fly approximately 1 to 2 miles (2-3 km) above the lunar surface to gather science measurements at the lowest altitude possible. Credit: NASA

LADEE (pronounced ‘laddie’) has been circling the moon studying dust in its extremely rarefied atmosphere since last fall. Much of the dust sputters off the surface during small meteorite impacts. If it survives the eclipse, LADEE will perform additional week of science before the mission is terminated. Rather than just shutting the probe off, mission control will direct it to crash into the moon near on or around April 21. LRO will locate study the impact site when it makes its next flyover a few months later.

Meanwhile, NASA invites you to  “Take the Plunge Challenge” and guess  what date LADEE will slam into the surface. Winners will be announced after impact and e-mailed a commemorative, personalized certificate from the LADEE program. The submissions deadline is 5 p.m. CDT tomorrow April 11.

For more information on the April 14-15 total eclipse of the moon including viewing times for your time zone, please see my earlier blog.

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About astrobob

My name is Bob King and I work at the Duluth News Tribune in Duluth, Minn. as a photographer and photo editor. I'm also an amateur astronomer and have been keen on the sky since age 11. My modest credentials include membership in the American Association of Variable Star Observers (AAVSO) where I'm a regular contributor, International Meteorite Collectors Assn. and Arrowhead Astronomical Society. I also teach community education astronomy classes at our local planetarium.

2 thoughts on “Lunar eclipse will give NASA moon orbiters the shivers

  1. 10:15 Pacific Time. Kp index went from “0″ to “5″ in past 24 hours. Ovation showing promising glows but Luna present.
    Although a visible aurora during upcoming totality would be great :)

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