Paradise

The Earth laughs in flowers.

montereybayaquarium:

Long-Distance Flyers
Think you travel a lot? The diminutive red knot probably has you beat, traveling from the Arctic Circle to Tierra del Fuego—a distance of 9,300 miles each way—each year. And it does it all under its own steam.
We just added two of these long distance flyers to our Aviary exhibit. You can also view them on our live web cam.
While red knots could put most business travelers to shame, ours have been forced to stick closer to home, due to permanent wing injuries. The pair (a male and female) flew here—in a plane—from the Florida Aquarium, which has hosted them for more than a decade.
Reading up on Red Knots
Red knots (Calidris canutus) are one of the larger sandpipers, and can live to a ripe age. Scientists recently discovered a 21-year-old. 
The birds, which grow to 10 inches, can occasionally be seen in local estuaries such as Elkhorn Slough. But these sightings are rare. These mileage champs breed in some of the coldest places in the world, and winter in some of the hottest. While they travel vast distances, red knots depend on certain stops along the way to fuel up, such as in Hudson Bay and Brazil. This can create challenges for the birds if food sources—particularly horseshoe crab eggs—are in short supply due to overharvesting.
“We’re really excited to have them,” says aviculturist Eric Miller. “Though they’re not technically endangered, red knots in some parts of the world are declining, and this is a great chance for people to see them.”

montereybayaquarium:

Long-Distance Flyers

Think you travel a lot? The diminutive red knot probably has you beat, traveling from the Arctic Circle to Tierra del Fuego—a distance of 9,300 miles each way—each year. And it does it all under its own steam.

We just added two of these long distance flyers to our Aviary exhibit. You can also view them on our live web cam.

While red knots could put most business travelers to shame, ours have been forced to stick closer to home, due to permanent wing injuries. The pair (a male and female) flew here—in a plane—from the Florida Aquarium, which has hosted them for more than a decade.

Reading up on Red Knots

Red knots (Calidris canutus) are one of the larger sandpipers, and can live to a ripe age. Scientists recently discovered a 21-year-old

The birds, which grow to 10 inches, can occasionally be seen in local estuaries such as Elkhorn Slough. But these sightings are rare. These mileage champs breed in some of the coldest places in the world, and winter in some of the hottest. While they travel vast distances, red knots depend on certain stops along the way to fuel up, such as in Hudson Bay and Brazil. This can create challenges for the birds if food sources—particularly horseshoe crab eggs—are in short supply due to overharvesting.

“We’re really excited to have them,” says aviculturist Eric Miller. “Though they’re not technically endangered, red knots in some parts of the world are declining, and this is a great chance for people to see them.”

dendroica:

Most detailed image of the Crab Nebula by europeanspaceagency on Flickr.

This new Hubble image - One among the largest ever produced with the Earth-orbiting observatory - shows gives the most detailed view so far of the entire Crab Nebula ever made. The Crab is arguably the single most interesting object, as well as one of the most studied, in all of astronomy. The image is the largest image ever taken with Hubble’s WFPC2 workhorse camera. The Crab Nebula is one of the most intricately structured and highly dynamical objects ever observed. The new Hubble image of the Crab was assembled from 24 individual exposures taken with the NASA/ESA Hubble Space Telescope and is the highest resolution image of the entire Crab Nebula ever made. Credit: ESA/Herschel/PACS/MESS Key Programme Supernova Remnant Team; NASA, ESA and Allison Loll/Jeff Hester (Arizona State University)

dendroica:

Most detailed image of the Crab Nebula by europeanspaceagency on Flickr.

This new Hubble image - One among the largest ever produced with the Earth-orbiting observatory - shows gives the most detailed view so far of the entire Crab Nebula ever made. The Crab is arguably the single most interesting object, as well as one of the most studied, in all of astronomy. The image is the largest image ever taken with Hubble’s WFPC2 workhorse camera. The Crab Nebula is one of the most intricately structured and highly dynamical objects ever observed. The new Hubble image of the Crab was assembled from 24 individual exposures taken with the NASA/ESA Hubble Space Telescope and is the highest resolution image of the entire Crab Nebula ever made.

Credit: ESA/Herschel/PACS/MESS Key Programme Supernova Remnant Team; NASA, ESA and Allison Loll/Jeff Hester (Arizona State University)

libutron:

Colombian frogs are affected by illegal coca cultivation … and also because of crop eradication
A report prepared since 2009 by scientists from the Institute of Natural Sciences, National University of Colombia, recognized that both coca cultivation and its eradication by the government with the herbicide glyphosate (Glyphos ®), may be affecting the biodiversity of amphibians, especially frogs, in the lowlands of Colombia.
In Colombia, coca plants Erythroxylum coca (Erythroxylaceae) grow in areas where there was previously tropical rainforest. In most cases, the coca plants are grown in deforested areas; but to avoid detection, the illicit cultivation can also be found among other crops such as banana plantations. The most obvious feature of coca cultivation is ecosystem degradation, since producers remove all vegetation, from the canopy to the bed of leaves.
According to assessments, coca cultivation is likely to cause reduction of frog populations in approximately 90% in the affected areas. Sometimes, however, habitat alterations and crops seem to favor some species of frogs that are better adapted to the changes and benefit from having less inter-specific competition.
Furthermore, the coca eradication programs through the aerial spraying of glyphosate is risky, since the larvae of frogs are sensitive to the substance when they are within the radius of spraying (because their skin is permeable).
This report indicate that 193 frog species occur within 10 km of the areas where coca is grown, many of which are endangered, so this situation is especially complex and is a serious dilemma between programs to eradicate coca crops and conservation of amphibian diversity in a country that is characterized by its high diversity of anurans (over 700 species).
The photo shows a Babbling Torenteer, Hyloscirtus alytolylax (Hylidae), a species native to Colombia and Ecuador, and one of the 49 species of the Hylidae family, which in Colombia is found within the radius of 10 km around the areas of coca cultivation and herbicide spraying.
Reference: [1]
Photo credit: ©Andreas Kay | Locality: Ecuador

libutron:

Colombian frogs are affected by illegal coca cultivation … and also because of crop eradication

A report prepared since 2009 by scientists from the Institute of Natural Sciences, National University of Colombia, recognized that both coca cultivation and its eradication by the government with the herbicide glyphosate (Glyphos ®), may be affecting the biodiversity of amphibians, especially frogs, in the lowlands of Colombia.

In Colombia, coca plants Erythroxylum coca (Erythroxylaceae) grow in areas where there was previously tropical rainforest. In most cases, the coca plants are grown in deforested areas; but to avoid detection, the illicit cultivation can also be found among other crops such as banana plantations. The most obvious feature of coca cultivation is ecosystem degradation, since producers remove all vegetation, from the canopy to the bed of leaves.

According to assessments, coca cultivation is likely to cause reduction of frog populations in approximately 90% in the affected areas. Sometimes, however, habitat alterations and crops seem to favor some species of frogs that are better adapted to the changes and benefit from having less inter-specific competition.

Furthermore, the coca eradication programs through the aerial spraying of glyphosate is risky, since the larvae of frogs are sensitive to the substance when they are within the radius of spraying (because their skin is permeable).

This report indicate that 193 frog species occur within 10 km of the areas where coca is grown, many of which are endangered, so this situation is especially complex and is a serious dilemma between programs to eradicate coca crops and conservation of amphibian diversity in a country that is characterized by its high diversity of anurans (over 700 species).

The photo shows a Babbling Torenteer, Hyloscirtus alytolylax (Hylidae), a species native to Colombia and Ecuador, and one of the 49 species of the Hylidae family, which in Colombia is found within the radius of 10 km around the areas of coca cultivation and herbicide spraying.

Reference: [1]

Photo credit: ©Andreas Kay | Locality: Ecuador

libutron:

Red foxes may use Earth’s magnetic field to enhance hunting success

Red foxes, Vulpes vulpes (Carnivora - Canidae) hunting rodents show a specific behavior known as ‘mousing’. The fox jumps high, so that it surprises its prey by striking from above. Prior to an attack, foxes move forward very slowly and deliberately, with ears erect, cocking their heads from side to side indicating that they are paying careful attention to auditory cues. However, the body direction of foxes as they attack are non-random.

Field research observing mousing behavior in wild red foxes, and recording the body orientation of foxes while preparing for a jump, showed that a large majority of successful attacks in high cover were north-east-oriented jumps, while attacks in other directions were largely unsuccessful. 

This north-east preferred attack directions cannot be explained by an effect of light cues since observations were carried out at different times of day, at different seasons of the year, under overcast and clear skies. Nor was this clustering a response to wind direction, which varied from observation to observation.

When hunting for prey in high cover or under snow, foxes are unable to use visual cues to augment auditory cues to target prey. So, directional heading has a profound effect on hunting success under such conditions. In low vegetation, where the prey can be spotted also by sight, directional heading seems to play a less decisive role.

In the absence of any other source of directional information that can explain the non-random alignment of fox predatory attacks and, in particular, the precise alignment of successful attacks on prey in high cover and under snow, it was proposed that these responses are a case of alignment with respect to the geomagnetic field (GMF). 

Furthermore, a fox that approaches an unseen prey along a northward compass bearing could estimate the distance of its prey by moving forward until the sound source is in a fixed relationship to the magnetic field, e.g. it coincides with the inclination of the magnetic field.

Thus, when visual information is limited, using the magnetic compass to provide a more accurate estimate of distance from the prey could account for the dramatic increase in predatory success of attacks aligned to the north and south field. If so, this would be the first documented case of an animal using magnetic compass input to estimate distance, rather than direction.

Reference: ČervenýJ.BegallS.KoubekP.NovákováP. and BurdaH. (2011). Directional preference may enhance hunting accuracy in foraging foxes. Biol. Lett. 7355-357.  Abstract/FREE Full Text

Photo credit: ©Eric Megnuson | Locality: Colorado, US - [Top] - [Bottom]

libutron:

Sharpshooter
Sharpshooter is a term used colloquially to refer to a highly diverse group of leafhoppers of the family Cicadellidae. Oncometopia nigricans (Hemiptera - Cicadellidae), pictured, is one of nearly 20,000 described species in that taxonomic family.
Like all true bugs, this species has piercing-sucking mouthparts, which are used to tap into and feed upon xylem or phloem (sap) tissue of plants. It also has large eyes and excellent visual acuity to avoid detection and capture by potential predators.
Oncometopia nigricans is an American species which as other ones, is considered a pest of several crops, because they can disperse relatively long distances, feed on a great variety of plants, and more importantly, they have the ability to vector (transmit) infectious pathogens from plant to plant. 
Reference: [1]
Photo credit: ©Kim Fleming | Locality: unknown

libutron:

Sharpshooter

Sharpshooter is a term used colloquially to refer to a highly diverse group of leafhoppers of the family Cicadellidae. Oncometopia nigricans (Hemiptera - Cicadellidae), pictured, is one of nearly 20,000 described species in that taxonomic family.

Like all true bugs, this species has piercing-sucking mouthparts, which are used to tap into and feed upon xylem or phloem (sap) tissue of plants. It also has large eyes and excellent visual acuity to avoid detection and capture by potential predators.

Oncometopia nigricans is an American species which as other ones, is considered a pest of several crops, because they can disperse relatively long distances, feed on a great variety of plants, and more importantly, they have the ability to vector (transmit) infectious pathogens from plant to plant. 

Reference: [1]

Photo credit: ©Kim Fleming | Locality: unknown

libutron:

Blue Tortoise beetle

Incredible dorsal (top photo) and ventral (bottom photo) macro views of an unidentified blue tortoise beetle (Chrysomelidae - Cassidinae).

Tortoise beetles are almost world-wide in distribution, though they have a much greater diversity in the tropics, especially tropical South America. They are scarce in temperate regions of North America and Australia and abundand in temperate Euroasia. 

Reference: [1]

Photo credit: ©Maxwel Rocha [Top] - [Bottom] | Locality: Brazil

neurosciencestuff:

Quick Getaway: How Flies Escape Looming Predators
When a fruit fly detects an approaching predator, the fly can launch itself into the air and soar gracefully to safety in a fraction of a second. But there’s not always time for that. Some threats demand a quicker getaway. New research from scientists at Howard Hughes Medical Institute’s Janelia Research Campus reveals how a quick-escape circuit in the fly’s brain overrides the fly’s slower, more controlled behavior when a threat becomes urgent.
“The fly’s rapid takeoff is, on average, eight milliseconds faster than its more controlled takeoff,” says Janelia group leader Gwyneth Card. “Eight milliseconds could be the difference between life and death.”
Card studies escape behaviors in the fruit fly to unravel the circuits and processes that underlie decision making, teasing out how the brain integrates information to respond to a changing environment. Her team’s new study, published online June 8, 2014, in the journal Nature Neuroscience, shows that two neural circuits mediate fruit flies’ slow-and-stable or quick-but-clumsy escape behaviors. Card, postdoctoral researcher Catherine von Reyn, and their colleagues find that a spike of activity in a key neuron in the quick-escape circuit can override the slower escape, prompting the fly to spring to safety when a threat gets too near.
A pair of neurons—called giant fibers—in the fruit fly brain has long been suspected to trigger escape. Researchers can provoke this behavior by artificially activating the giant fiber neurons, but no one had actually demonstrated that those neurons responded to visual cues associated with an approaching predator, Card says. She was curious how the neurons could be involved in the natural behavior if they didn’t seem to respond to the relevant sensory cues, so she decided to test their role.
Genetic tools developed in the lab of Janelia executive director Gerald Rubin enabled Card’s team to switch the giant fiber neurons on or off, and then observe how flies responded to a predator-like stimulus. They conducted their experiments in an apparatus developed in Card’s lab that captures videos of individual flies as they are exposed to a looming dark circle. The image is projected onto a hemispheric surface and expands rapidly to fill the fly’s visual field, simulating the approach of a predator. “It’s really like a domed IMAX for the fly,” Card explains. A high-speed camera records the response at 6,000 frames per second, allowing Card and her colleagues to examine in detail the series of events that make up the fly’s escape.
To ensure their experiments were relevant to fruit flies’ real-world experiences, Card teamed with fellow Janelia group leader Anthony Leonardo to record and analyze the trajectories and acceleration of damselflies—natural predators of the fruit fly—as they attacked. They designed their looming stimulus to mimic these features. “We wanted to make sure we were really challenging the animal with something that was like a predator attack,” Card says.
By analyzing more than 4,000 flies, Card and her colleagues discovered two distinct responses to the simulated predator: long and short escapes. To prepare for a steady take-off, flies took the time to raise their wings fully. Quicker escapes, in contrast, eliminated this step, shaving time off the take-off but often causing the fly to tumble through the air. 
When the scientists switched off the giant fiber neurons, preventing them from firing, flies still managed to complete their escape sequence. “On a surface level evaluation, silencing the neuron had absolutely no effect,” Card says. “You can do away with this neuron that people thought was fundamental to this escape behavior, and flies still escape.” Shorter escapes, however, were completely eliminated. Flies without active giant fiber neurons invariably opted for the slower, steadier escape. In contrast, when the scientists switched giant fiber neurons on in the absence of a predator-like stimulus, flies enacted their quick-escape behavior. The evidence suggested the giant fiber neurons were involved only in short escapes, while a separate circuit mediated the long escapes.
Card and her colleagues wanted to understand how flies decide when to sacrifice stability in favor of a quicker response. To learn more, Catherine von Reyn, a postdoctoral researcher in Card’s lab, set up experiments in which she could directly monitor activity in the giant fiber neurons. Surprisingly, she discovered that the giant fibers were not only active in short-mode escape, but also during some of the long-mode escapes. The situation was more complicated than their genetic experiments had suggested. “Seeing the dynamics of the electrophysiology allowed us to understand that the timing of the spike is important is determining the fly’s choice of escape behavior,” Card says.  
Based on their data, Card and von Reyn propose that a looming stimulus first activates a circuit in the brain that initiates a slow escape, beginning with a controlled lift of the wings. When the object looms closer, filling more of the fly’s field of view, the giant fiber activates, prompting a more urgent escape. “What determines whether a fly does a long-mode or a short-mode escape is how soon after the wings go up the fly kicks its legs and it starts to take off,” Card says. “The giant fiber can fire at any point during that sequence. It might not fire at all—in which case you get this nice long, beautifully choreographed takeoff. It might fire right away, in which case you get an abbreviated escape.” The more quickly an object approaches, the sooner the giant fiber is likely to fire, increasing the probability of a short escape.
Card remains curious about many aspects of escape behavior. How does a fly calculate the orientation of a threat and decide in which direction to flee, she wonders. What makes a fly decide to initiate a takeoff as opposed to other evasive maneuvers? The relatively compact circuits that control these sensory-driven behaviors provide a powerful system for exploring the mechanisms that animals use to selecting one behavior over another, she says. “We think that you can really ask these questions at the level of individual neurons, and even individual spikes in those neurons.”

neurosciencestuff:

Quick Getaway: How Flies Escape Looming Predators

When a fruit fly detects an approaching predator, the fly can launch itself into the air and soar gracefully to safety in a fraction of a second. But there’s not always time for that. Some threats demand a quicker getaway. New research from scientists at Howard Hughes Medical Institute’s Janelia Research Campus reveals how a quick-escape circuit in the fly’s brain overrides the fly’s slower, more controlled behavior when a threat becomes urgent.

“The fly’s rapid takeoff is, on average, eight milliseconds faster than its more controlled takeoff,” says Janelia group leader Gwyneth Card. “Eight milliseconds could be the difference between life and death.”

Card studies escape behaviors in the fruit fly to unravel the circuits and processes that underlie decision making, teasing out how the brain integrates information to respond to a changing environment. Her team’s new study, published online June 8, 2014, in the journal Nature Neuroscience, shows that two neural circuits mediate fruit flies’ slow-and-stable or quick-but-clumsy escape behaviors. Card, postdoctoral researcher Catherine von Reyn, and their colleagues find that a spike of activity in a key neuron in the quick-escape circuit can override the slower escape, prompting the fly to spring to safety when a threat gets too near.

A pair of neurons—called giant fibers—in the fruit fly brain has long been suspected to trigger escape. Researchers can provoke this behavior by artificially activating the giant fiber neurons, but no one had actually demonstrated that those neurons responded to visual cues associated with an approaching predator, Card says. She was curious how the neurons could be involved in the natural behavior if they didn’t seem to respond to the relevant sensory cues, so she decided to test their role.

Genetic tools developed in the lab of Janelia executive director Gerald Rubin enabled Card’s team to switch the giant fiber neurons on or off, and then observe how flies responded to a predator-like stimulus. They conducted their experiments in an apparatus developed in Card’s lab that captures videos of individual flies as they are exposed to a looming dark circle. The image is projected onto a hemispheric surface and expands rapidly to fill the fly’s visual field, simulating the approach of a predator. “It’s really like a domed IMAX for the fly,” Card explains. A high-speed camera records the response at 6,000 frames per second, allowing Card and her colleagues to examine in detail the series of events that make up the fly’s escape.

To ensure their experiments were relevant to fruit flies’ real-world experiences, Card teamed with fellow Janelia group leader Anthony Leonardo to record and analyze the trajectories and acceleration of damselflies—natural predators of the fruit fly—as they attacked. They designed their looming stimulus to mimic these features. “We wanted to make sure we were really challenging the animal with something that was like a predator attack,” Card says.

By analyzing more than 4,000 flies, Card and her colleagues discovered two distinct responses to the simulated predator: long and short escapes. To prepare for a steady take-off, flies took the time to raise their wings fully. Quicker escapes, in contrast, eliminated this step, shaving time off the take-off but often causing the fly to tumble through the air. 

When the scientists switched off the giant fiber neurons, preventing them from firing, flies still managed to complete their escape sequence. “On a surface level evaluation, silencing the neuron had absolutely no effect,” Card says. “You can do away with this neuron that people thought was fundamental to this escape behavior, and flies still escape.” Shorter escapes, however, were completely eliminated. Flies without active giant fiber neurons invariably opted for the slower, steadier escape. In contrast, when the scientists switched giant fiber neurons on in the absence of a predator-like stimulus, flies enacted their quick-escape behavior. The evidence suggested the giant fiber neurons were involved only in short escapes, while a separate circuit mediated the long escapes.

Card and her colleagues wanted to understand how flies decide when to sacrifice stability in favor of a quicker response. To learn more, Catherine von Reyn, a postdoctoral researcher in Card’s lab, set up experiments in which she could directly monitor activity in the giant fiber neurons. Surprisingly, she discovered that the giant fibers were not only active in short-mode escape, but also during some of the long-mode escapes. The situation was more complicated than their genetic experiments had suggested. “Seeing the dynamics of the electrophysiology allowed us to understand that the timing of the spike is important is determining the fly’s choice of escape behavior,” Card says.  

Based on their data, Card and von Reyn propose that a looming stimulus first activates a circuit in the brain that initiates a slow escape, beginning with a controlled lift of the wings. When the object looms closer, filling more of the fly’s field of view, the giant fiber activates, prompting a more urgent escape. “What determines whether a fly does a long-mode or a short-mode escape is how soon after the wings go up the fly kicks its legs and it starts to take off,” Card says. “The giant fiber can fire at any point during that sequence. It might not fire at all—in which case you get this nice long, beautifully choreographed takeoff. It might fire right away, in which case you get an abbreviated escape.” The more quickly an object approaches, the sooner the giant fiber is likely to fire, increasing the probability of a short escape.

Card remains curious about many aspects of escape behavior. How does a fly calculate the orientation of a threat and decide in which direction to flee, she wonders. What makes a fly decide to initiate a takeoff as opposed to other evasive maneuvers? The relatively compact circuits that control these sensory-driven behaviors provide a powerful system for exploring the mechanisms that animals use to selecting one behavior over another, she says. “We think that you can really ask these questions at the level of individual neurons, and even individual spikes in those neurons.”

distant-traveller:

Astronomers confounded by massive rocky world


Astronomers have discovered a rocky planet that weighs 17 times as much as Earth and is more than twice as large in size. This discovery has planet formation theorists challenged to explain how such a world could have formed.
"We were very surprised when we realized what we had found," said astronomer Xavier Dumusque of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, who led the analysis using data originally collected by NASA’s Kepler space telescope.
Kepler-10c, as the planet had been named, had a previously measured size of 2.3 times larger than Earth, but its mass was not known until now. The team used the HARPS-North instrument on the Telescopio Nazionale Galileo in the Canary Islands to conduct follow-up observations to obtain a mass measurement of the rocky behemoth.
It was thought worlds such as this could not possibly exist. The enormous gravitational force of such a massive body would accrete a gas envelope during formation, ballooning the planet to a gas giant the size of Neptune or even Jupiter. However, this planet is thought to be solid, composed primarily of rock.
"Just when you think you’ve got it all figured out, nature gives you a huge surprise — in this case, literally," said Natalie Batalha, Kepler mission scientist at NASA’s Ames Research Center in Moffett Field, California. "Isn’t science marvelous?"
Kepler-10c orbits a sun-like star every 45 days, making it too hot to sustain life as we know it. It is located about 560 light-years from Earth in the constellation Draco. The system also hosts Kepler-10b, the first rocky planet discovered in the Kepler data.


Image credit: Harvard-Smithsonian Center for Astrophysics/David Aguilar

distant-traveller:

Astronomers confounded by massive rocky world

Astronomers have discovered a rocky planet that weighs 17 times as much as Earth and is more than twice as large in size. This discovery has planet formation theorists challenged to explain how such a world could have formed.

"We were very surprised when we realized what we had found," said astronomer Xavier Dumusque of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, who led the analysis using data originally collected by NASA’s Kepler space telescope.

Kepler-10c, as the planet had been named, had a previously measured size of 2.3 times larger than Earth, but its mass was not known until now. The team used the HARPS-North instrument on the Telescopio Nazionale Galileo in the Canary Islands to conduct follow-up observations to obtain a mass measurement of the rocky behemoth.

It was thought worlds such as this could not possibly exist. The enormous gravitational force of such a massive body would accrete a gas envelope during formation, ballooning the planet to a gas giant the size of Neptune or even Jupiter. However, this planet is thought to be solid, composed primarily of rock.

"Just when you think you’ve got it all figured out, nature gives you a huge surprise — in this case, literally," said Natalie Batalha, Kepler mission scientist at NASA’s Ames Research Center in Moffett Field, California. "Isn’t science marvelous?"

Kepler-10c orbits a sun-like star every 45 days, making it too hot to sustain life as we know it. It is located about 560 light-years from Earth in the constellation Draco. The system also hosts Kepler-10b, the first rocky planet discovered in the Kepler data.

Image credit: Harvard-Smithsonian Center for Astrophysics/David Aguilar

sci-universe:

Different cities seen at night from the International Space Station.
Click images to see which cities are shown. Credit: ESA/NASA

sci-universe:

Astrophotography from 1908 – 1919
Image courtesy: Yerkes Observatory, Royal Observatory of Greenwich, Mount Wilson Observatory