View allAll Photos Tagged LowellObservatory
Early Mars observers had a hard time. Photography was useless. Surface details had to be glimpsed by eye and sketched with a pencil in near darkness. These vintage globes - reading from left to right - show their progress (if that’s the word) in divining Mars’ features.
2nd from left is an 1884 globe based on drawings of the famous observers Schiaparelli and Flammarion. They got the pattern of dark and light areas more or less right. They thought that the dark areas were seas. Unfortunately they joined up the dark patches - our eyes tend to do that. More unfortunately, they named their broad links ‘canali’ – Italian for channels which soon got misinterpreted as ‘canals’.
Canals stuck! The centre globe of 1898 from observations of Eugene Antoniadi has far more ‘canals’ and they are narrower.
Then along came Percival Lowell. Rich Bostonian - he built an observatory at Flagstaff, Arizona specially for Mars observing. At right is a 1913 globe showing his observations. He webbed Mars everywhere with fine lines with oases where they crossed! He published widely and the Mars Myth was firmly established. Intelligent beings lived there. Mars was dying. Martians built planet wide canals to carry scarce water from the polar ice caps. H.G. Wells wrote 'War of the Worlds'. It became the 1938 CBS radio broadcast that panicked a slice of the US.
There are no canals, no linear features.
It’s easy to laugh. One clear evening (several decades ago) I drove up the hill to Lowell’s observatory just to see the outside. By pure chance I met a very kind and helpful postdoc who let me observe through Lowell’s massive 24-inch Clark telescope – cutting edge tech when built. Mars was a fuzzy expanding and contracting orange ball. Every so often for just a split second the atmosphere steadied and beautiful detail shone out on the Martian disk but it was gone too fast to study let alone remember.
That’s how it was – early visual observers had everything against them. Admire them for their perseverance. Remember - us really smart people (some like to think) of the 21st Century do not even know what 95% of the Universe is made of!
The globes are in the Whipple Museum of the History of Science, Cambridge.
I lie to collect rocks wherever we travel. Keep on my desk at work. Notice the Lowell Observatory marble. This is the observatory that discovered Pluto - the demoted planet.
There were two versions of this photo taken. One you've already seen. This one was with a lower white balance. We'll see what you think.
This intricate wooden dome at Lowell Observatory outside Flagstaff, Arizona is home to the Clarke 24" Refractor telescope used by Percival Lowell in his studies of Mars between 1893 and 1908. It was here that he made his controversial drawings of "canals" on the red planet.
The telescope at Lowell Observatory in Flagstaff, Arizona that was used to discover Pluto, currently classified as dwarf planet in the Solar System. Formally known as the Lawrence Lowell Telescope, it is a 13-inch aperture refracting telescope. lowell.edu/discover/telescopes-exhibits/pluto-discovery-t...
This is the telescope that was used in a sky survey, resulting in the discovery of Pluto. The black box in the center, bottom, held large sheets of film.
Photographed at Lowell Observatory, Flagstaff, AZ using a Nikon 1 V2, 10mm f/2.8 lens at 1/25 second. This room was very dimly lit.
The Z-WINPHX slices through downtown Flagstaff and is climbing the last few miles to the top of the AZ Divide. With the leaves gone for the winter, shooting from the Lowell Observatory area is again possible if the weather and trains cooperate.
Thank you everyone for visiting, commenting and fav'ing - very much appreciated!
"One small step for man, one giant leap for mankind." Neil Armstrong became the first man to step onto the lunar surface 44 years ago on 1969-07-21. Wikipedia article on Apollo 11: bit.ly/13RkUQ5.
I took this self portrait using the helmet of an Apollo 11 space suit as a mirror at the Lowell Observatory museum in Flagstaff, Arizona.
HDR, 1 exposure, NEX-6. DSC05401_2_3_hdr3pai1b
Computer! This device is called The Millionaire, and was used to help make the calculations that led to the discovery of Pluto. See previous picture in my photostream for the placard describing the device.
***Click the photo to view large!!!***
I took this image of Saturn with my D7000 a couple nights ago in average to slightly below average seeing conditions, using the 24" Alvan Clark refractor at Lowell Observatory in Flagstaff, Arizona. Perks of the job!
On the night the image was captured, Saturn was about 9.02 AU from the Earth--roughly 839,000,000 miles!
To capture this image, I had to do a lot of work and post-processing. Saturn is shining at an apparent magnitude of 1.06 right now, making it impossible to capture the dimmer moons in one exposure.
I took 1500 frames of video, which I then aligned and stacked in Registax 6 to produce the image of Saturn. To capture the moons, which range in magnitude from 8 to almost 14, I took a ten second exposure.
I then blended the two together to create this composite. To see which moons are which, mouse over the photo.
4K video @ vimeo.com/228554021
During our trip to Sedona and the Grand Canyon in July / August 2017 we toured the Lowell Observatory (elev. 7250 ft.) and the historic 24 - inch Clark refractor (used by Percival Lowell to document the "canals" on Mars). Unfortunately the "Pluto" telescope was not available for viewing as it was undergoing extensive restoration offsite.
A bird's eye view is had of a long snake from the roadside overlook on the way up to the Lowell Observatory. A quick 5 minute walk to a semi-open hillside yields this completely filled double stacker working its way uphill towards the AZ Divide. The sound of the GE's carried beautifully up here and I can only imagine how great it use to sound before downtown became a quiet zone.
With Saturn just a few days past opposition, it rises just after sunset and is up almost all night. The rings look stunning as they really start to dip toward us again. Saturn is currently almost 810 million miles from us, yet shines at magnitude 0.8--not bad! I wanted to try out my new D7000 in stable air, so I braved fatigue and stayed out late!
This was taken last night (4/20) through the 24" Clark Refractor at Lowell Observatory. The seeing was pretty good, so I only took 31 seconds of video data at 24 frames per second. The resulting image is the best 350 of 744 frames, aligned and stacked in Registax 6, and processed for contrast and brightness in Photoshop CS4.
The images below are (1) the uncropped version of this photo and (2) another image I took a few nights ago in poor seeing conditions. What a difference good seeing makes!
Stargazers gather at the Clark Refractor Telescope for an intimate look at the night sky. The room is lit in red to protect observers' night vision.
Lowell Observatory,
Flagstaff, Arizona.
Photography and editing by Geoffrey Liu
The weather yesterday was unsuitable for anything we do at work... No telescopes, no tours, no fun--but, we were treated to this awesome rainbow just about 15 minutes before sunset. And I actually had my camera with me at work this time!
At Lowell Observatory a couple nights ago scouting options for a night photography workshop in a few weeks. The Slipher Rotunda is a beautiful building. Porch lights were a touch brighter/whiter than I recall from past visits, but these are the things that add delightful spices to the processing workflow.
It was here that Clyde Tombaugh took the photos that led to the discovery of Pluto. You can call it a planet or a Kuiper Belt Object. It is an important discovery either way.
A beautiful view last night at Anderson Mesa, southeast of Flagstaff. Giselle and I headed up there about the time the crescent moon was setting. Tom Polakis was operating the Hall Dome for Lowell Observatory and gave us a rundown of what was on the target list. While the 42-inch scope collected photometry on selected asteroids, we had a chance to grab shots of both the Hall and Perkins domes as the Milky Way lofted over the trees.
One of my favorite views at Lowell Observatory. The Clark Telescope Dome broke ground in 1894 and still houses the 24” refractor Percival Lowell used to pursue a keen interest in Martian canals. It’s also known for the discovery of galactic redshift and creation of Lunar maps for the Apollo Moon missions.
Strangely the first time I’ve had a chance to photograph it on a clear, moonless night with the Milky Way. The site overlooks downtown Flagstaff just a mile away, so it’s awesome that the Milky Way is still visible from there.
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]
I took this about two weeks ago through the 24" Clark Telescope at Lowell Observatory, with a 2X Barlow and my D90 on a night with pretty decent seeing. I have been so busy I just forgot about these images. Better late than never, right? Even on nights where you get good astronomical seeing, using Photoshop is essential to coaxing out some of the finer detail. This image was adjusted for color correction, curves (each channel individually then mixed), and a couple scrubs with noise reduction.
I had been waiting for an opportune time when the Great Red Spot was facing Earth that also allowed me private time on the telescope during non public hours. It took six weeks! The day this photo was taken also happened to coincide with Jupiter being at opposition (on the same side of the sun as us and at its closest distance for the year).
Named for the gorgeous actress Lena Headey:
farm4.static.flickr.com/3276/2557361296_db8ee25797_z.jpg?...
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]
One of the many baretable trains now on the move to the west coast easily climbs the grade out of downtown. With the labor strike at the west coast ports over, lots of equipment is heading that way to unplug the docks. Most of the WB trains had empty well cars tacked onto the rear of them to expedite their placement.
In this activity, visitors explore the history of asteroid impacts on earth and chart their frequency and damage caused.
Ideum collaborated with Lowell Observatory on an exhibition all about asteroid science. The entire exhibition is a fictional school, Space Guard Academy, where cadets learn all about asteroids and "rank up" as they participate in different interactive learning modules.
Ideum developed 5 connected interactives, as well as a student registration station, a system to track student scores and ranks, and a "hall of fame" displaying the pictures of recent graduates. To learn more about Ideum's Creative Services, visit our website.
Percy has a bust along the Pluto Walk at Lowell Observatory. Red uplighting is kind of ominous though.
This is the chandelier in Percival Lowell's library at the Lowell Observatory in Flagstaff Arizona. It is designed to resemble the planet Saturn. Using the Clark refracting telescope, Pluto was discovered from this observatory.
Press L to view large and get a real sense of this amazing telescope dome!
This is the 24" Clark, the original telescope up here on Mars Hill, Flagstaff, Arizona. It was built in 1896, shipped across the country by rail, and placed here--where it has been ever since. This telescope is older than the State of Arizona, which wasn't created until 1912.
I feel privileged to be able to use this piece of history several nights a week as part of my job at the observatory.
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]
In this activity, visitors examine the orbits of 5 asteroids to determine which one is in resonance with Jupiter.
Ideum collaborated with Lowell Observatory on an exhibition all about asteroid science. The entire exhibition is a fictional school, Space Guard Academy, where cadets learn all about asteroids and "rank up" as they participate in different interactive learning modules.
Ideum developed 5 connected interactives, as well as a student registration station, a system to track student scores and ranks, and a "hall of fame" displaying the pictures of recent graduates. To learn more about Ideum's Creative Services, visit our website.
I took this a few nights ago with the 24" Clark at Lowell Observatory when the seeing was pretty decent. Jupiter with three of the Galilean moons. From left to right, they are Europa, Io, and Ganymede. Notice how Jupiter doesn't appear as a perfect sphere--it is elongated at the equator due to its massive size and rapid rotation. This massive ball of gas does one rotation every 9 hours, 54 minutes.
Jupiter, the largest planet of the solar system, is currently at a distance of 4 AU (about 372 million miles) from the Earth. Its average distance from the sun is just under 500 million miles.
Europa is a little smaller than our own moon, has a thin but oxygenated atmosphere, and its rocky surface is covered with mostly water ice. It orbits Jupiter once every 3.5 days.
Io is slightly larger than our moon and is famous for its sulfur volcanoes, of which there are over 400. Some of them are taller than Mount Everest and can cause eruptions over 300 miles tall. It orbits Jupiter every 42.5 hours.
Ganymede is the largest moon in the solar system; it is 8% bigger than the planet Mercury, though it has much less mass. It orbits Jupiter once every 7 days. It is thought to be the only moon in the solar system that possesses a liquid core and its own magnetosphere.
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]
The 13-inch Astrograph built for the search for Pluto, that Clyde Tombaugh used to find the "new planet" in 1930. Tombaugh used this instrument, now an historic site at the Lowell Observatory, to take images of the sky on glass plates which he developed in the darkroom one floor below. He used the blink comparator to compare plates taken on different nights to look for objects that moved.
In this activity, visitors examine the orbits of 5 asteroids to determine which one is in resonance with Jupiter.
Ideum collaborated with Lowell Observatory on an exhibition all about asteroid science. The entire exhibition is a fictional school, Space Guard Academy, where cadets learn all about asteroids and "rank up" as they participate in different interactive learning modules.
Ideum developed 5 connected interactives, as well as a student registration station, a system to track student scores and ranks, and a "hall of fame" displaying the pictures of recent graduates. To learn more about Ideum's Creative Services, visit our website.
I'm burned out on Jupiter for a little while! This is the last of my archived photos. I took this on December 3rd through the Clark Telescope (see my photostream) at Lowell Observatory. The seeing was iffy, so this is a composite of 50 still exposures--scrubbed and stacked in Registax Pro and edited for detail and contrast in Photoshop CS4.
Io is off to the right by itself, Europa is the closest moon (the one at 8:00 left side) and Callisto is up above the limb at 11:00. Ganymede is just out of frame at image left--its orbital path around Jupiter sometimes makes it a little hard to get in frame with a 3x Barlow attached.
Mars (1895), Mars and its Canals (1906), Mars as the Abode of Life (1908), & The Evolution of Worlds (1909)
Percival Lowell (1855-1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars. In 1894, he chose Flagstaff, Arizona as the home of his new observatory, the now famous Lowell Observatory. For the next fifteen years, he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. Lowell published his views in three books: “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).
Lowell’s works include a full account of the “canals,” single and double, the “oases,” as he termed the dark spots at their intersections, and the varying visibility of both, depending partly on the Martian seasons. He theorized that an advanced but desperate culture had built the canals to tap Mars’ polar ice caps, the last source of water on an inexorably drying planet.
While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion. The existence of canal-like features was definitely disproved in the 1960s by NASA’s Mariner missions. Today, the surface markings taken to be canals are regarded as an optical illusion.
Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of Lowell's efforts, a stylized P-L monogram – the first two letters of the new planet's name and also Lowell's initials – was chosen as Pluto's astronomical symbol.
Although Lowell's theories of the Martian canals are now discredited, his building of an observatory at the position where it would best function has been adopted as a principle for all observatories. He also established the program and an environment which made the discovery of Pluto by Clyde Tombaugh possible. Craters on the Moon and on Mars have been named after Percival Lowell. He has been described by other planetary scientists as "the most influential popularizer of planetary science in America before Carl Sagan". Lowell is buried on Mars Hill near his observatory. [Source: Wikipedia]