Hi! We work on NASA’s Lunar Reconnaissance Orbiter mission – the only spacecraft orbiting the Moon right now. We’re here to answer your questions on anything Moon-related – from the super lunar eclipse on Wednesday to Apollo to the latest science! Ask us anything!

Abstract

*The ARTEMIS mission has two spacecraft in orbit around the Moon, collecting data on how the Moon and the Sun interact.

Yes, the Moon landings were real. Now that that is out of the way, we are a group of scientists who work on the Lunar Reconnaissance Orbiter (LRO) mission. LRO has been in orbit around the Moon since 2009, gathering data on the Moon’s resources, temperature, radiation, geologic history, and potential landing sites. The long duration of our mission has enabled us to map the Moon as it changes over time. We’ve seen new craters form, calculated global temperature changes, and measured the topography in such detail that we now know the shape of the Moon better than any other celestial body in the universe! Plus, all of our instruments on the spacecraft are refining how they collect data – so we’re using our tools more efficiently.

In addition to talking about LRO, we can answer your questions about Earth’s Moon and lunar exploration, past, present and future. We’re especially excited to talk to you about the lunar eclipse coming up on Wednesday and give you the inside scoop on why people are calling it a Super Blue Blood Moon.

Dr. Catherine Elder: I’m a planetary geologist at the Jet Propulsion Laboratory, California Institute of Technology. I study the surfaces and interiors of planets and moons and work on the Diviner instrument on the LRO spacecraft, that measures lunar temperatures.

Andrea Jones: I’m a planetary geologist and the Public Engagement Lead for LRO at NASA Goddard Space Flight Center.

Dr. Erwan Mazarico: I am a geophysicist at NASA Goddard Space Flight Center and have worked on the LRO and GRAIL missions that mapped the lunar shape (via laser altimetry) and its gravity field.

Dr. Noah Petro: I am a planetary geologist at NASA Goddard Space Flight Center and the Deputy Project Scientist for LRO at NASA Goddard Space Flight Center. My research includes the use of lunar data from Apollo as well as from LRO, in an effort to understand how the surface of the Moon has changed over billions of years.

Ernie Wright: I am a science visualizer at NASA Goddard Space Flight Center. I’m a computer scientist by training, and use programming and data to create lunar visualizations, like this one: https://svs.gsfc.nasa.gov/4604

Steve Odendahl: I’m the Mission Operations Director for LRO. I manage our engineering team to make sure that our spacecraft runs smoothly.

Learn more about LRO: lunar.gsfc.nasa.gov

The Moon: moon.nasa.gov

Follow us @NASAMoon and @LRO_NASA to stay updated.

**We are signing off now. Thank you for all of your excellent questions. We had a lot of fun. Stay in touch with us with @NASAMoon, @LRO_NASA, and LRO's Facebook page! And learn the latest on nasa.gov/moon.

How realistic is the discussion about creating a moon base in one of the large caverns there? If it is possible, what timeline would we be looking at for something like this?

Reddit_Account_2

There was a workshop very recently to discuss possible landing sites for future missions. https://lunar-landing.arc.nasa.gov/program (a lot of presentations are posted on youtube btw) Several presentations were focused on lunar pits and lava tubes, a kind of cavern left behind after a volcanic event (1, 2, 3 ).

The first missions to start exploring this, and confirm there are big enough, safe enough for future bases, could come online relatively soon. To establish a full-scale Moon base is a different question. -- Erwan.


Can you speak a bit to the calculations necessary to keep the LRO in a stable orbit?

Is it in a truly stable orbit, or does it need to be adjusted? If so, how often?

What other factors influence the satellite’s path? I’m sure the Earth’s gravity is a factor, but is it influenced by other bodies in the solar system?

true_spokes

The satellite orbit is primarily affect by the Moon gravity (including the mascons mentioned). The Earth and Sun gravity are significant as well. When computing the spacecraft orbits, we also account for the gravity of other planets, and the solar radiation pressure that acts onto the solar panel. EM


Can you speak a bit to the calculations necessary to keep the LRO in a stable orbit?

Is it in a truly stable orbit, or does it need to be adjusted? If so, how often?

What other factors influence the satellite’s path? I’m sure the Earth’s gravity is a factor, but is it influenced by other bodies in the solar system?

true_spokes

Lots of good information below already. LRO was selected to be a one-year mission (2009-2010), but has been extended several times since. It spent a couple of months in a 30x200 km orbit to test its instruments. In September 2009 it was placed in its nominal science orbit (~50 km average altitude), which did require monthly maneuvers for maintenance. LRO did have fuel reserves after the end of its original mission, and stayed in this same orbit for one more year. In December 2011, to allow the mission to continue, the spacecraft was transferred back to its original commissioning orbit, which is very stable. There has been no "station-keeping" maneuver since May 2015, and none is necessary to avoid impact until far into the future (at least 2025). This near-frozen orbit is not as optimal for several science instruments, because it's pretty high above the northern hemisphere, but of course the length of the LRO mission more than makes up for it. EM


Since Gene Cernan stepped off the Moon as the last human to visit, what are some of the most notable discoveries about the Moon that were not then known to Apollo Astronauts?

EatEmAndSmile73

What a great question, and what a difficult one to narrow down - we're continually learning so much about the Moon! Some of the discoveries that I think are most notable include our increasing awareness about water on the Moon - that it is there at all, where it is located, and how it migrates across the surface. A few places to find out more about this topic include https://www.nasa.gov/feature/goddard/2017/nasa-orbiter-finds-new-evidence-of-frost-on-moons-surface; http://lroc.sese.asu.edu/posts/989; https://www.sciencedirect.com/science/article/pii/S0019103515001335. We've also learned with LRO that the Moon is struck by a much larger number of small impactors than we previously thought, meaning, among other things, that the tracks left by Apollo astronauts will be erased within tens of thousands of years rather than in millions of years - and that lunar bases would have to be built anticipating that heavier rain of micrometeorites (e.g. https://www.nasa.gov/press-release/goddard/2016/lro-lunar-cratering). We also now know much more about the tides of the Moon, as well as the interior of the Moon (e.g. https://www.nasa.gov/press-release/goddard/shrinking-moon-tides). And, I think it's pretty neat that because of LRO we now know the shape of the Moon better than any other celestial object in the universe - including the Earth (if considering only the solid surface of the Earth - we know shape of the Moon better than the shape of the Earth's sea floors). Andrea


What is the strangest and/or least explainable thing your team has observed on the moon?

0xD153A53

There are a lot of possible answers to this. My favorite is irregular mare patches: http://lroc.sese.asu.edu/posts/818

Most people agree they're volcanic, but we don't know how they formed and we argue about how old they are too. They don't look like any volcanoes on Earth.

-CME


If you had to pick a spot for a future manned base on the moon, where would you put it?

jebkerbal

The rim of Shackleton crater is a site of utmost interest. The South Pole is an area with a lot of permanent shadow (lots of relief due to craters in particular, combined with the low obliquity of the Moon lead to a lot of crater floors never seeing the Sun), and has been linked to water deposits. The LCROSS impact provided definite evidence of water in the very-near subsurface, and many instruments on LRO and other recent missions have added information to this question. But the low obliquity also means that high terrain can see the Sun almost continuously, even at 'night' and during the winter. There are several places on or near the Shackleton rim that see more than 200 (Earth) days of sunlight every year. And of course such short nights and long days are very attractive for a lunar base. -- Erwan.


Is there any realistic way to make money by going back to the moon? Any way corporations might have an incentive to establish a base there?

tocksin

Several commercial space companies do think so. Even if the Moon itself cannot be used for resources just yet, a launch vehicle + landing system to carry spacecraft or instruments would open new possibilities for everyone. -- Erwan.


What is the most out of ordinary thing you have seen?

LuckyLatvia

There are a lot of possible answers to this. My favorite is irregular mare patches: http://lroc.sese.asu.edu/posts/818

Most people agree they're volcanic, but we don't know how they formed and we argue about how old they are too. They don't look like any volcanoes on Earth.

-CME


What are the benefits of having a LRO right now, what can we learn about the moon that we still dont' know? How long will the LRO last? Not being to be rude, just a honest question.

Crolys

One of the benefits of having LRO at the Moon, and over the past 8 years, is that we can not only map the Moon in exquisite detail, but also look for changes to the surface. For example we've identified new craters by LROC: http://lroc.sese.asu.edu/posts/943 This allows us to understand how the Moon is changing over human timescales.

LRO is funded to operate through September 2019, we will propose to NASA HQ for an additional three years of funding at that point. We have fuel onboard for roughly 10 more years of operations.

Noah


The LRO is a multi million dollar craft. How do you make sure that all your calculations are a 100% correct? How do you deal with the stress that if you make a mistake it's $600 million dollars down the drain?

Warlock31415

Great question! We have a lot of checks and balances built into the spacecraft, so that any commands that might do something we didn't anticipate would be stopped. We double and triple check all commands that are sent to the spacecraft. For example, we have "sun sensors" on the spacecraft that would prevent us from looking at the Sun. The operations team here at Goddard are extremely talented and take great care to avoid any mistakes! : )

Noah


Is there a GIS portal where I can play around with some data to figure out where the best moon base should be located? I would love to see LRO’s data in qgis.

If you could pick out the spot for the first moon colony, where would you want to go?

WalkingTurtleMan

NASA mission data is publicly available on the planetary data system: http://pds-geosciences.wustl.edu/missions/lro/default.htm

The LRO Camera team also maintains a site for easy viewing of the data: http://quickmap.lroc.asu.edu/

-CME


Is there a GIS portal where I can play around with some data to figure out where the best moon base should be located? I would love to see LRO’s data in qgis.

If you could pick out the spot for the first moon colony, where would you want to go?

WalkingTurtleMan

A few options for interacting with LRO data is available here: http://lroc.sese.asu.edu/archive

There are a lot of ways to answer where we should put a colony, areas that receive lots of sunlight, areas that have ample volatiles, inside a lunar pit... where do you think it should be?

Noah


I have a REALLY specific one... Im designing a CubeSat with a team for my school, and its meant to operate in extreme LEO (200km). We're trying to find the atmospheric heat flux that will be caused due to the gasses in the free molecular flow regime on the blunt end of our CubeSat, but we can't come up with a solid number!

And a more general question, do you think the relatively low cost of CubeSats and their potential to test new technologies would have some application to lunar science? Thanks! Hopefully I'll be working with you all some day soon!

pjk922

Interesting question! 200 km is very low, so it would not last too long. I'm not sure where you'd get that number, but it's below the ISS.

CubeSats will be important for very focused science questions, there are a number on their way to the Moon in the coming years (FlashLight, IceCube, etc.).

Noah


What's the biggest impact you've seen with the LRO

twitchmain76-

About 70 meters. The LROC instrument is actually carrying a systematic campaign to re-image parts of the Moon with the same illumination conditions but separated in time by several years to detect new impacts. They found a lot more churning of the top surface ('gardening') than anticipated. See for instance this entry. -- Erwan.


How much of an impact would mining the resources from the moon have on things like tidal forces on Earth, its rotational and orbital speed, etc.?

DasJuden63

Mining resources from the Moon would result in a relatively small change in mass, so it wouldn't have a noticeable effect on tidal forces on the Earth or the Moon's orbit.

-CME


If our moon was geostationary instead of synchronous (disregarding tidal effects) how would it look from Earth?

Would we have all moon cycles each day? Full solar eclipses at noon?

Adam_habibi

Some good answers already. In geostationary orbit, the Moon would be 10 times closer and therefore 10 times bigger. It'd literally be stationary over one point on the Earth's surface, so half the Earth would see it all the time, and the other half would never see it. The plane of its orbit would be the Earth's equator, rather than (pretty close to) the plane of Earth's orbit (the ecliptic).

On the half of the Earth that can see it, there would be both daily cycles of phases (New Moon at noon, Full Moon around midnight) and daily solar eclipses. The path of totality would be over 3000 km (1900 miles) wide, and the latitude would depend on the season, more north or south depending on which hemisphere is closer to summer.

  • Ernie

Have you seen any major variations in Moon's temperature over the years?

marcandrebill

The Moon's temperature varies a lot over a single lunar day. At the equator it reaches almost 400K (260.6 ºF) at noon and drops to below 100K (-279.4 ºF) during the night. We haven't seen any noticeable changes over the course of the LRO mission, except for the LCROSS impact which increased the temperature of the surface at the site of the impact: https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/diviner_lcross.html

-CME


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