The Lunar Reconnaissance Orbiter, or LRO, is a multipurpose NASA spacecraft launched in 2009 to make a comprehensive atlas of the Moon’s features and resources. Since launch, LRO has measured the coldest temperatures in the solar system inside the Moon’s permanently shadowed craters, detected evidence of water ice at the Moon’s south pole, seen hints of recent geologic activity on the Moon, found newly-formed craters from present-day meteorite impacts, tested spaceborne laser communication technology, and much more.
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Moon Phase and Libration Gallery
More in this series:
Moon Phase and Libration Gallery
More in this series:
Moon Phase and Libration Gallery
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Moon Phase and Libration Gallery
Well, at least something worked on this flight.One day earlier, a catastrophic failure of an oxygen tank in the Service Module left the crew without power, air, and water in their Command Module, forcing them to use their Lunar Module as a lifeboat. The Moon landing, and all of the science they would do on the lunar surface, was lost. The only major science objective that yielded results was the intentional impact of their booster. After sending the astronauts out of Earth orbit on a path to the Moon, the detached upper stage of the Saturn V rocket, called the S-IVB (“ess four bee”), was aimed squarely at the Moon. Its impact at 77:56:39.7 mission elapsed time was detected by several scientific instruments left on the surface by Apollo 12. A seismometer (a moonquake detector) recorded the tremor, and particle detectors sensed molecules from both the impact itself and the resulting deflection of the solar wind. More than four decades later, the Lunar Reconnaissance Orbiter (LRO) mission located and photographed the Apollo 13 S-IVB impact site about 135 kilometers west of the Apollo 12 landing. In this visualization, we first see the location of the impact on the night side of the waxing gibbous Moon. (It isn’t certain whether the impact could have been seen from Earth in this way, but the energy of the impact was roughly twice that of the bright flash recorded on March 17, 2013.) The view then zooms rapidly to the LRO image of the impact crater before pulling back to show its location relative to the Apollo 12 landing site. The close-up NAC (Narrow Angle Camera) view is a detail from image M140087684L and has a resolution of 50 centimeters per pixel. The wider view, at 100 meters per pixel, is a detail from the LROC WAC global morphological map.
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Moon Phase and Libration Gallery
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Moon Phase and Libration Gallery
For more information on the Lunar Reconnaissance Orbiter, visit: LRO Website All of LRO’s data is archived and can be viewed at: LRO Planetary Data System To see images from the Lunar Reconnaissance Orbiter Camera, visit: LROC Website
moonlightin French). The piece was published in 1905 as the third of four movements in the composer's Suite Bergamasque, and unlike the other parts of this work, Clair is quiet, contemplative, and slightly melancholy, evoking the feeling of a solitary walk through a moonlit garden. The visuals were composed like a nature documentary, with clean cuts and a mostly stationary virtual camera. The viewer follows the Sun throughout a lunar day, seeing sunrises and then sunsets over prominent features on the Moon. The sprawling ray system surrounding Copernicus crater, for example, is revealed beneath receding shadows at sunrise and later slips back into darkness as night encroaches. The visualization was created to accompany a performance of Clair de Lune by the National Symphony Orchestra Pops, led by conductor Emil de Cou, at the Kennedy Center for the Performing Arts in Washington, DC, on June 1 and 2, 2018, as part of a celebration of NASA's 60th anniversary. The visualization uses a digital 3D model of the Moon built from Lunar Reconnaissance Orbiter global elevation maps and image mosaics. The lighting is derived from actual Sun angles during lunar days in 2018.
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Moon Phase and Libration Gallery
More in this series:
Moon Phase and Libration Gallery
Click on the image to download a high-resolution version with labels for craters near the terminator.
The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2018, at hourly intervals. Until the end of 2018, the initial Dial-A-Moon image will be the frame from this animation for the current hour.
More in this series:
Moon Phase and Libration Gallery
Lunar Reconnaissance Orbiter (LRO) has been in orbit around the Moon since the summer of 2009. Its laser altimeter (LOLA) and camera (LROC) are recording the rugged, airless lunar terrain in exceptional detail, making it possible to visualize the Moon with unprecedented fidelity. This is especially evident in the long shadows cast near the terminator, or day-night line. The pummeled, craggy landscape thrown into high relief at the terminator would be impossible to recreate in the computer without global terrain maps like those from LRO.
The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration.
The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead.
The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by about 14%.
The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.
Celestial north is up in these images, corresponding to the view from the northern hemisphere. The descriptions of the print resolution stills also assume a northern hemisphere orientation. (There is also a south-up version of this page.)
From this birdseye view, it's somewhat easier to see that the phases of the Moon are an effect of the changing angles of the sun, Moon and Earth. The Moon is full when its orbit places it in the middle of the night side of the Earth. First and Third Quarter Moon occur when the Moon is along the day-night line on the Earth.
The First Point of Aries is at the 3 o'clock position in the image. The sun is in this direction at the March equinox. You can check this by freezing the animation at the 1:03 mark, or by freezing the full animation with the time stamp near March 20 at 10:00 UTC. This direction serves as the zero point for both ecliptic longitude and right ascension.
The north pole of the Earth is tilted 23.5 degrees toward the 12 o'clock position at the top of the image. The tilt of the Earth is important for understanding why the north pole of the Moon seems to swing back and forth. In the full animation, watch both the orbit and the "gyroscope" Moon in the lower left. The widest swings happen when the Moon is at the 3 o'clock and 9 o'clock positions. When the Moon is at the 3 o'clock position, the ground we're standing on is tilted to the left when we look at the Moon. At the 9 o'clock position, it's tilted to the right. The tilt itself doesn't change. We're just turned around, looking in the opposite direction.
The subsolar and sub-Earth points are the locations on the Moon's surface where the sun or the Earth are directly overhead, at the zenith. A line pointing straight up at one of these points will be pointing toward the sun or the Earth. The sub-Earth point is also the apparent center of the Moon's disk as observed from the Earth.
In the animation, the blue dot is the sub-Earth point, and the yellow dot is the subsolar point. The lunar latitude and longitude of the sub-Earth point is a measure of the Moon's libration. For example, when the blue dot moves to the left of the meridian (the line at 0 degrees longitude), an extra bit of the Moon's western limb is rotating into view, and when it moves above the equator, a bit of the far side beyond the north pole becomes visible.
At any given time, half of the Moon is in sunlight, and the subsolar point is in the center of the lit half. Full Moon occurs when the subsolar point is near the center of the Moon's disk. When the subsolar point is somewhere on the far side of the Moon, observers on Earth see a crescent phase.
The Moon's orbit around the Earth isn't a perfect circle. The orbit is slightly elliptical, and because of that, the Moon's distance from the Earth varies between 28 and 32 Earth diameters, or about 356,400 and 406,700 kilometers. In each orbit, the smallest distance is called perigee, from Greek words meaning "near earth," while the greatest distance is called apogee. The Moon looks largest at perigee because that's when it's closest to us.
The animation follows the imaginary line connecting the Earth and the Moon as it sweeps around the Moon's orbit. From this vantage point, it's easy to see the variation in the Moon's distance. Both the distance and the sizes of the Earth and Moon are to scale in this view. In the HD-resolution frames, the Earth is 50 pixels wide, the Moon is 14 pixels wide, and the distance between them is about 1500 pixels, on average.
Note too that the Earth appears to go through phases just like the Moon does. For someone standing on the surface of the Moon, the sun and the stars rise and set, but the Earth doesn't move in the sky. It goes through a monthly sequence of phases as the sun angle changes. The phases are the opposite of the Moon's. During New Moon here, the Earth is full as viewed from the Moon.
Click on the image to download a high-resolution version with labels for craters near the terminator.
The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2018, at hourly intervals. Until the end of 2018, the initial Dial-A-Moon image will be the frame from this animation for the current hour.
More in this series:
Moon Phase and Libration Gallery
Lunar Reconnaissance Orbiter (LRO) has been in orbit around the Moon since the summer of 2009. Its laser altimeter (LOLA) and camera (LROC) are recording the rugged, airless lunar terrain in exceptional detail, making it possible to visualize the Moon with unprecedented fidelity. This is especially evident in the long shadows cast near the terminator, or day-night line. The pummeled, craggy landscape thrown into high relief at the terminator would be impossible to recreate in the computer without global terrain maps like those from LRO.
The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration.
The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead.
The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%.
The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.
Celestial south is up in these images, corresponding to the view from the southern hemisphere. The descriptions of the print resolution stills also assume a southern hemisphere orientation. (There is also a north-up version of this page.)
From this birdseye view, it's somewhat easier to see that the phases of the Moon are an effect of the changing angles of the sun, Moon and Earth. The Moon is full when its orbit places it in the middle of the night side of the Earth. First and Third Quarter Moon occur when the Moon is along the day-night line on the Earth.
The First Point of Aries is at the 3 o'clock position in the image. The sun is in this direction at the March equinox. You can check this by freezing the animation at the 1:03 mark, or by freezing the full animation with the time stamp near March 20 at 10:00 UTC. This direction serves as the zero point for both ecliptic longitude and right ascension.
The south pole of the Earth is tilted 23.5 degrees toward the 12 o'clock position at the top of the image. The tilt of the Earth is important for understanding why the north pole of the Moon seems to swing back and forth. In the full animation, watch both the orbit and the "gyroscope" Moon in the lower left. The widest swings happen when the Moon is at the 3 o'clock and 9 o'clock positions. When the Moon is at the 3 o'clock position, the ground we're standing on is tilted to the left when we look at the Moon. At the 9 o'clock position, it's tilted to the right. The tilt itself doesn't change. We're just turned around, looking in the opposite direction.
The subsolar and sub-Earth points are the locations on the Moon's surface where the sun or the Earth are directly overhead, at the zenith. A line pointing straight up at one of these points will be pointing toward the sun or the Earth. The sub-Earth point is also the apparent center of the Moon's disk as observed from the Earth.
In the animation, the blue dot is the sub-Earth point, and the yellow dot is the subsolar point. The lunar latitude and longitude of the sub-Earth point is a measure of the Moon's libration. For example, when the blue dot moves to the left of the meridian (the line at 0 degrees longitude), an extra bit of the Moon's eastern limb is rotating into view, and when it moves above the equator, a bit of the far side beyond the south pole becomes visible.
At any given time, half of the Moon is in sunlight, and the subsolar point is in the center of the lit half. Full Moon occurs when the subsolar point is near the center of the Moon's disk. When the subsolar point is somewhere on the far side of the Moon, observers on Earth see a crescent phase.
The Moon's orbit around the Earth isn't a perfect circle. The orbit is slightly elliptical, and because of that, the Moon's distance from the Earth varies between 28 and 32 Earth diameters, or about 356,400 and 406,700 kilometers. In each orbit, the smallest distance is called perigee, from Greek words meaning "near earth," while the greatest distance is called apogee. The Moon looks largest at perigee because that's when it's closest to us.
The animation follows the imaginary line connecting the Earth and the Moon as it sweeps around the Moon's orbit. From this vantage point, it's easy to see the variation in the Moon's distance. Both the distance and the sizes of the Earth and Moon are to scale in this view. In the HD-resolution frames, the Earth is 50 pixels wide, the Moon is 14 pixels wide, and the distance between them is about 1500 pixels, on average.
Note too that the Earth appears to go through phases just like the Moon does. For someone standing on the surface of the Moon, the sun and the stars rise and set, but the Earth doesn't move in the sky. It goes through a monthly sequence of phases as the sun angle changes. The phases are the opposite of the Moon's. During New Moon here, the Earth is full as viewed from the Moon.
Over 4000 students and teachers from across New England made the trip to see exhibits from the 7 different NASA missions and projects, demonstrations of space science concepts, and presentations from NASA scientists. Noah Petro, the Project Scientist from the Lunar Reconnaissance Orbiter Mission, led this endeavor, and astronaut Sunita Williams was the featured guest speaker. The list of speakers also included Elizabeth Rampe (JSC), Daniel Castro (Chandra X-ray Observatory), Kelly Korreck (SAO), David Draper (JSC), and Kimberly Kowal Arcand (Chandra X-ray Observatory). Molly Wasser (ADNET/GSFC) served as the Event Lead.
After the STEM event, NASA Goddard scientist and professional harpist, Maria Banks, played the National Anthem before the Red Sox game. It was a fun day of science and sports.
day.At any given location on the Earth, a local solar day is the time it takes the Sun to return to the same point in the sky. To be more precise, we define a line in the sky, the meridian, which runs between due north and due south and passes through the zenith (the straight-up point). Local noon is the time when the Sun is centered on the meridian, and a local solar day is the time between two successive local noons. The length of this kind of day varies throughout the year. Currently, it can be as much as 21 seconds shorter or 29 seconds longer than 24 hours. This variation is due to the eccentricity of the Earth's orbit (the orbit is an ellipse, not a circle), and the obliquity of the ecliptic (the Earth's axis is tilted relative to its orbit). So that we don't have to reset our clocks all the time, it's convenient to define a mean solar day, the average of the local solar day over a full year. A mean solar day is exactly 24 hours long. In fact, we define an hour as 1/24 of a mean solar day. The mean solar day can't be the average over any arbitrary year. The eccentricity and obliquity vary over time, and because of precession of the equinoxes, the effect of obliquity slides through the calendar, alternately reinforcing and canceling the effect of eccentricity over tens of thousands of years. The Earth is also slowing down, primarily due to tidal interactions with the Moon. The mean solar day is the theoretical average local solar day, calculated by fixing the eccentricity, obliquity, precession, and rotation rate to the values at noon in Greenwich, England, on December 31, 1899, using the theory of the Sun's apparent motion developed by Simon Newcomb in the 1890's. We now have extremely accurate atomic clocks. We define the length of a second as a certain number of waves in the radiation from a cesium atom, and we say that a mean solar day is 86400 of these seconds. For historical continuity, the number of waves was chosen so that this second is 1/86400 of the mean solar day defined by Newcomb's theory. The concept of a solar day can be extended to other bodies in the solar system, including our Moon. A mean solar day on the Moon, a lunar day for short, is 29.5306 Earth days. Local lunar days can vary even more than solar days on Earth, over 6 hours shorter or 7 hours longer than the mean. The 100 lunar days celebrated by LRO in October of 2017 are mean lunar days. Because the Moon is tidally locked to the Earth, it always shows the Earth the same face. This also means that it rotates at the same rate that it orbits. A lunar day takes exactly as long as one complete orbit relative to the Sun. A lunar day also corresponds to one complete cycle of the phases visible from Earth, so a lunar day is the same as a synodic month. At this point, it shouldn't surprise you that there are other kinds of days (sidereal, for example) and months (anomalistic and draconic, to name two). But that's a story for another time.
JackSchmitt. As a geologist and Apollo 17 crewmember, Schmitt has a unique perspective about how data being collected by LRO enhances our current understanding of lunar science and lays the groundwork for future explorers.
On Aug. 21, 2017, a total solar eclipse caused the Salem-Keizer Volcanoes Minor League Baseball game to experience the first ever "Eclipse Delay" in professional baseball history. This wasn't a chance occurrence, however, but a planned event. With the Sun and the Moon set to provide the spectacle in the sky, representatives from the Lunar Reconnaissance Orbiter mission at NASA's Goddard Space Flight Center joined forces with the Volcanoes' management team to coordinate an "EclipseFest" on the grounds of the stadium. Over the course of a four-day home series, NASA showcased science experiments, presentations, and videos inside the ballpark for all to see and learn from. Noah Petro, the deputy project scientist for LRO, led the endeavor, bringing more eyes to the field of lunar science.
This video shows what took place at this "EclipseFest" in Keizer, Oregon, and how science and sports combined for one of the most unique viewing experiences in the country.
Scientists studying data from Lunar Reconnaissance Orbiter (LRO) have found evidence of surface frost near the poles on the Moon. Elizabeth Fisher, Paul Lucey, and their colleagues combined temperature data from LRO's Diviner instrument with reflectance from its laser altimeter (LOLA) to find places that are cold enough and shiny enough to indicate the possible presence of surface water ice. Their results appear in the August, 2017 issue of the journal Icarus.
For complete transcript, click here.
Watch this video on the NASAexplorer YouTube channel.
This entry contains the Evolution of the Moon video in mutliple formats, including stereoscopic 3D in both side-by-side and individual left/right channel versions. It also includes a narrated and non-narrated version. Each individual video is labeled to make it easier to find the version that works for you!