5 Lessons From NASA's Lunar Reconnaissance Orbiter

Although NASA ’s ongoing Lunar Reconnaissance Orbiter (LRO) mission continues to hone global maps that will be used by lunar explorers for decades to come, the science generated by the mission’s more than four billion measurements continues to beguile lunar scientists in ways not seen since the Apollo era.

At least that’s the unofficial take-away from six and a half years of detailed LRO mapping of more than three-quarters of the lunar surface. To date, LRO’s Camera (LROC) and the orbiter’s six other instruments have successfully sent back NASA’s largest planetary science dataset.

Now in an extended mission phase, the hope is that LRO will continue to function and be operational in its lunar-synchronous orbit for years to come.

Here are a few of LRO’s lessons:

--- The Moon was very recently volcanically active.

“An overall surprise is just how [geologically] dynamic the Moon has been during its youngest epoch, the Copernican Age (about 1.1 billion years); [roughly] defined by the presence of brightly-rayed craters like Tycho,” Benjamin Greenhagen, an LRO team-member and planetary scientist at Johns Hopkins University’s Applied Physics Lab, told me. “We’ve also identified areas of [estimated] 100 million year-old volcanism.”

Young cliff-like scarp faults, of a few miles long and only tens of yards high, confirm that the Moon’s current interior is hotter than previously thought and that it’s still cooling and contracting some 4.5 billion years after it was formed in the aftermath of the collision between our young Earth and a Mars -sized impactor.

Thousands of these young fault scarps --- indicating that the Moon is likely still tectonically active; have surface orientations that appear to be shaped by gravitational forces exerted on the lunar surface as the Moon orbits the Earth.

What a surprise to find the Earth is still helping to shape the Moon, Tom Watters, a senior scientist at the Smithsonian’s National Air and Space Museum, told me.

--- The Moon’s environmental extremes also continue to surprise.

“Permanently Shadowed Regions (PSRs) at the poles are colder than expected , with some lower than -415 F,” said Greenhagen. “They could preserve volatile [compounds] beyond water-ice.”

LRO also mapped areas that received nearly continuous 24-hour sunlight for as long as 243 days at a stretch. Such areas may enable future colonists to generate much of their energy from large solar arrays, while these permanently shaded regions offer the potential for access to water and other volatiles.

--- The Moon has more resources for water and life-support than ever imagined.

While water had been previously detected in permanently shadowed regions, LRO also found hydrogen gas to be prevalent at both poles and along the sides of craters primarily in the Moon’s southern hemisphere. The LRO team reports that it remains uncertain if the hydrogen is abundant enough to economically mine.

But the hope is that these PSRs will contain enough water, hydrogen, ammonia and methane to produce fuel and sustain some level of life support.

--- The Moon still holds much promise for future researcher-astronauts.

The South Pole-Aitken Basin remains a very strong candidate to sample rock that may actually originate from the lunar mantle itself. But LRO has helped characterize other potential landing sites as well.

Greenhagen notes the farside Moscoviense Basin may contain surface samples of nearly every known type of lunar rock.

John Keller, LRO’s project scientist at NASA Goddard Spaceflight Center, told me he hopes future researchers will actually take core samples from permanently shadowed craters, which would help constrain the Moon’s earliest chemical history.

--- The Moon can teach us a lot about the hazards of sending astronauts to Mars.

LRO’s radiation measurements have already provided excellent data on what future human explorers will be exposed to while en route to Mars or on the lunar surface.

To avoid incoming galactic cosmic rays, which are more prevalent in the inner solar system during phases when the Sun is quieter, Noah Petro, LRO’s deputy project scientist at NASA Goddard Space Flight Center, told me that sending future human explorers to deep space may actually be safer when the Sun is more active.

Even so, it’s been four decades since the last Apollo astronauts blasted off from the Taurus-Littrow Valley. But LRO’s work may also keep future lunar researcher-astronauts safe.

“The Apollo seismic network recorded thousands of moonquakes,” said Watters. “These shallow quakes could be due to slip events on the young faults. When considering locations for a lunar base, it will be important to know if there are any young faults in the area.”

Beyond that, when lunar mining and commercialization become routine, Greenhagen fears for the Moon’s pristine environment.

“The scientist in me desperately hopes that we honor the Moon as a global scientific legacy,” said Greenhagen. “We should not treat it like a giant open strip mine.”

Follow me on Facebook, Twitter and Google +.