Lunar Flashlight to seek ice on the moon

Artist’s concept of the Lunar Flashlight searching for ice deposits in deep, shadowed craters near the south pole of the moon. Image via NASA/ JPL-Caltech.

NASA is moving forward with its Artemis program, whose goal is to land the first woman and next man at the moon’s south pole by 2024. See this April 2020 report. When humans return to the moon this time, they’ll likely stay longer than their Apollo counterparts in the late 1960s and ’70s; the record stay during the Apollo missions was about 75 hours.

To accomplish future longer stays on the moon, lunar astronauts might utilize some natural resources from the moon itself, in particular water ice said to have been confirmed to exist in 2018, in deeply shadowed craters at the moon’s poles. This ice can be melted and purified for drinking; it can be used for rocket fuel. Enter Lunar Flashlight – a briefcase-sized satellite, also known as a CubeSat – with a projected launch date of 2021 and a specific mission of detecting naturally occurring surface ice in shadowed craters on the moon.

NASA’s Jet Propulsion Laboratory (JPL) described the innovative Lunar Flashlight technology on April 27, 2020. A new peer-reviewed paper about it was published in the April 2020 issue of IEEE Aerospace and Electronic Systems Magazine.

What is the Lunar Flashlight and what will it do?

View larger. | Scientists directly observed definitive evidence of water ice on the moon’s surface in 2018. The image shows the distribution of surface ice at the moon’s south pole (left) and north pole (right), detected by NASA’s Moon Mineralogy Mapper instrument. Blue represents the ice locations, plotted over an image of the lunar surface, where the gray scale corresponds to surface temperature (darker representing colder areas and lighter shades indicating warmer zones). The ice is concentrated at the darkest and coldest locations, in the shadows of craters. Image via NASA.

Basically, Lunar Flashlight acts like a spotlight. Lunar Flashlight will scan the surface with a near-infrared laser beam, shining down on the lunar surface to help scientists look for deposits of ice near the lunar south pole. Barbara Cohen, principal investigator of the mission at NASA’s Goddard Space Flight Center, said in the JPL statement:

Although we have a pretty good idea there’s ice inside the coldest and darkest craters on the moon, previous measurements have been a little bit ambiguous.

Scientifically, that’s fine, but if we’re planning on sending astronauts there to dig up the ice and drink it, we have to be sure it exists.

Mission profile and timeline for Lunar Flashlight. Image via Cohen et al./ IEEE.

Commercial and custom-built components of Lunar Flashlight. Image via Cohen et al./ IEEE.

From the paper:

Lunar Flashlight is a very small satellite [about 5 x 10 x 14 inches, or 12 × 24 × 36 cm], developed and managed by the Jet Propulsion Laboratory, that will search for water ice exposures and map their locations in the moon’s south polar region. The Lunar Flashlight mission will demonstrate technologies for NASA such as green propulsion and active laser spectroscopy while proving the capability of performing a planetary science investigation in the CubeSat form factor. Lunar Flashlight was selected in 2014 by the NASA Advanced Exploration Systems (AES) program … Lunar Flashlight will be one of 13 secondary payloads launched on Artemis-1, currently scheduled for 2020.

Water ice deposits have been found by orbiting spacecraft, but Lunar Flashlight would allow the exact locations of deposits to be determined, which could then be mined and used by astronauts staying on the moon for long periods of time. It will also be the first lunar mission to use lasers to find the ice. John Baker, Lunar Flashlight project manager at JPL, said:

A technology demonstration mission like Lunar Flashlight, which is lower cost and fills a specific gap in our knowledge, can help us better prepare for an extended NASA presence on the moon as well as test key technologies that may be used in future missions.

Because the moon is virtually airless, it gets very hot in the sunlight, but extremely cold in the darkness, especially within deep craters that are permanently in shadow at the poles. In those cold places, water ice molecules can accumulate and remain stable on the surface. As Cohen explained:

The sun moves around the crater horizon but never actually shines into the crater. Because these craters are so cold, these molecules never receive enough energy to escape, so they become trapped and accumulate over billions of years.

Artist’s concept of Lunar Flashlight seen from above. Image via NASA/ JPL-Caltech.

Such deposits on the moon are of much interest, and necessary, for future astronauts who will want to stay on the moon for long missions, or even eventually stay there permanently in bases. It would be expensive to continually transport water from Earth to the moon, so using the available resources of the already-existing ice deposits makes sense.

Lunar Flashlight will beam its lasers into some of these craters where the ice is either known or suspected to exist. It will do this for at least two months, and will be able to map out where these deposits are with great accuracy.

How does Lunar Flashlight identify ice?

The spacecraft’s four-laser reflectometer, which incorporates spectrophotometry, will use near-infrared wavelengths in the laser beams. Those wavelengths will be absorbed by water ice, but bare rock will simply reflect them back to the spacecraft. If there is a lot of absorption in a crater, that would be evidence for widespread ice deposits. Those findings can then be compared with those from other orbiters that have previously found ice on the moon. Cohen said:

We will also be able to compare the Lunar Flashlight data with the great data that we already have from other moon-orbiting missions to see if there are correlations in signatures of water ice, thereby giving us a global view of surface ice distribution.

Lunar Flashlight will also be the first planetary CubeSat mission to use “green” propulsion, propellant that is less toxic and safer than hydrazine, which is commonly used by most spacecraft.

Barbara Cohen at Goddard Space Flight Center, principal investigator for Lunar Flashlight. Image via NASA/ Science and Exploration Directorate.

While ice on the moon may sound rather unusual, it isn’t really too surprising to scientists. Asteroids and of course comets can also contain water ice. Even Mercury, which is much closer to the sun than the moon, has ice near its poles, found by the MESSENGER spacecraft in 2012.

There are also two other missions on the Artemis-1 launch that will complement Lunar Flashlight; Lunar IceCube and LunaH-Map will make additional measurements, looking for ice and other hydrogen deposits at the lunar south pole and on the near side of the moon. Results from all three missions will be synergistic, simultaneously exploring the nature and distribution of water ice on the moon in advance of human exploration.

Missions like Lunar Flashlight will help NASA astronauts not only continue to explore the moon, but also set the stage for long-term and then permanent human settlement on our nearest neighbor in space.

Bottom line: NASA has designed a new CubeSat spacecraft, the Lunar Flashlight, to search for ice on the moon using laser beams.

Source: Lunar Flashlight: Illuminating the Lunar South Pole

Via JPL

from EarthSky https://ift.tt/3dpmk04

Artist’s concept of the Lunar Flashlight searching for ice deposits in deep, shadowed craters near the south pole of the moon. Image via NASA/ JPL-Caltech.

NASA is moving forward with its Artemis program, whose goal is to land the first woman and next man at the moon’s south pole by 2024. See this April 2020 report. When humans return to the moon this time, they’ll likely stay longer than their Apollo counterparts in the late 1960s and ’70s; the record stay during the Apollo missions was about 75 hours.

To accomplish future longer stays on the moon, lunar astronauts might utilize some natural resources from the moon itself, in particular water ice said to have been confirmed to exist in 2018, in deeply shadowed craters at the moon’s poles. This ice can be melted and purified for drinking; it can be used for rocket fuel. Enter Lunar Flashlight – a briefcase-sized satellite, also known as a CubeSat – with a projected launch date of 2021 and a specific mission of detecting naturally occurring surface ice in shadowed craters on the moon.

NASA’s Jet Propulsion Laboratory (JPL) described the innovative Lunar Flashlight technology on April 27, 2020. A new peer-reviewed paper about it was published in the April 2020 issue of IEEE Aerospace and Electronic Systems Magazine.

What is the Lunar Flashlight and what will it do?

View larger. | Scientists directly observed definitive evidence of water ice on the moon’s surface in 2018. The image shows the distribution of surface ice at the moon’s south pole (left) and north pole (right), detected by NASA’s Moon Mineralogy Mapper instrument. Blue represents the ice locations, plotted over an image of the lunar surface, where the gray scale corresponds to surface temperature (darker representing colder areas and lighter shades indicating warmer zones). The ice is concentrated at the darkest and coldest locations, in the shadows of craters. Image via NASA.

Basically, Lunar Flashlight acts like a spotlight. Lunar Flashlight will scan the surface with a near-infrared laser beam, shining down on the lunar surface to help scientists look for deposits of ice near the lunar south pole. Barbara Cohen, principal investigator of the mission at NASA’s Goddard Space Flight Center, said in the JPL statement:

Although we have a pretty good idea there’s ice inside the coldest and darkest craters on the moon, previous measurements have been a little bit ambiguous.

Scientifically, that’s fine, but if we’re planning on sending astronauts there to dig up the ice and drink it, we have to be sure it exists.

Mission profile and timeline for Lunar Flashlight. Image via Cohen et al./ IEEE.

Commercial and custom-built components of Lunar Flashlight. Image via Cohen et al./ IEEE.

From the paper:

Lunar Flashlight is a very small satellite [about 5 x 10 x 14 inches, or 12 × 24 × 36 cm], developed and managed by the Jet Propulsion Laboratory, that will search for water ice exposures and map their locations in the moon’s south polar region. The Lunar Flashlight mission will demonstrate technologies for NASA such as green propulsion and active laser spectroscopy while proving the capability of performing a planetary science investigation in the CubeSat form factor. Lunar Flashlight was selected in 2014 by the NASA Advanced Exploration Systems (AES) program … Lunar Flashlight will be one of 13 secondary payloads launched on Artemis-1, currently scheduled for 2020.

Water ice deposits have been found by orbiting spacecraft, but Lunar Flashlight would allow the exact locations of deposits to be determined, which could then be mined and used by astronauts staying on the moon for long periods of time. It will also be the first lunar mission to use lasers to find the ice. John Baker, Lunar Flashlight project manager at JPL, said:

A technology demonstration mission like Lunar Flashlight, which is lower cost and fills a specific gap in our knowledge, can help us better prepare for an extended NASA presence on the moon as well as test key technologies that may be used in future missions.

Because the moon is virtually airless, it gets very hot in the sunlight, but extremely cold in the darkness, especially within deep craters that are permanently in shadow at the poles. In those cold places, water ice molecules can accumulate and remain stable on the surface. As Cohen explained:

The sun moves around the crater horizon but never actually shines into the crater. Because these craters are so cold, these molecules never receive enough energy to escape, so they become trapped and accumulate over billions of years.

Artist’s concept of Lunar Flashlight seen from above. Image via NASA/ JPL-Caltech.

Such deposits on the moon are of much interest, and necessary, for future astronauts who will want to stay on the moon for long missions, or even eventually stay there permanently in bases. It would be expensive to continually transport water from Earth to the moon, so using the available resources of the already-existing ice deposits makes sense.

Lunar Flashlight will beam its lasers into some of these craters where the ice is either known or suspected to exist. It will do this for at least two months, and will be able to map out where these deposits are with great accuracy.

How does Lunar Flashlight identify ice?

The spacecraft’s four-laser reflectometer, which incorporates spectrophotometry, will use near-infrared wavelengths in the laser beams. Those wavelengths will be absorbed by water ice, but bare rock will simply reflect them back to the spacecraft. If there is a lot of absorption in a crater, that would be evidence for widespread ice deposits. Those findings can then be compared with those from other orbiters that have previously found ice on the moon. Cohen said:

We will also be able to compare the Lunar Flashlight data with the great data that we already have from other moon-orbiting missions to see if there are correlations in signatures of water ice, thereby giving us a global view of surface ice distribution.

Lunar Flashlight will also be the first planetary CubeSat mission to use “green” propulsion, propellant that is less toxic and safer than hydrazine, which is commonly used by most spacecraft.

Barbara Cohen at Goddard Space Flight Center, principal investigator for Lunar Flashlight. Image via NASA/ Science and Exploration Directorate.

While ice on the moon may sound rather unusual, it isn’t really too surprising to scientists. Asteroids and of course comets can also contain water ice. Even Mercury, which is much closer to the sun than the moon, has ice near its poles, found by the MESSENGER spacecraft in 2012.

There are also two other missions on the Artemis-1 launch that will complement Lunar Flashlight; Lunar IceCube and LunaH-Map will make additional measurements, looking for ice and other hydrogen deposits at the lunar south pole and on the near side of the moon. Results from all three missions will be synergistic, simultaneously exploring the nature and distribution of water ice on the moon in advance of human exploration.

Missions like Lunar Flashlight will help NASA astronauts not only continue to explore the moon, but also set the stage for long-term and then permanent human settlement on our nearest neighbor in space.

Bottom line: NASA has designed a new CubeSat spacecraft, the Lunar Flashlight, to search for ice on the moon using laser beams.

Source: Lunar Flashlight: Illuminating the Lunar South Pole

Via JPL

from EarthSky https://ift.tt/3dpmk04

This weekend, watch for a morning moon

Image at top via Buddy Puckhaper of Charleston, South Carolina.

Full moon was May 7, 2020, and by May 8 the moon is in a waning gibbous phase, rising later and later at night. For the mainland United States, the May 8 moon rises in the southeast nearly two hours after sunset. The days following full moon present the perfect time to catch a daytime moon over your western horizon after sunrise. Watch for it!

If you’re a night owl, you might see the moon and the bright star Antares before your bedtime on May 8 and 9, 2020.

View the moon in your eastern sky late in the evening this weekend, perhaps before going to bed. It’ll be ascending in the east later and later each evening. Then look for it low in your western sky right after sunrise. Day by day, the lighted portion of the waning gibbous moon will shrink. The half-lit last quarter moon will come on May 14, 2020.

The moon is up in the daytime much of the time. But, because it’s pale against the blue sky, it’s not as noticeable during the day as at night. However, there are certain times of the month when the daytime moon is more noticeable, and this weekend presents one of those times.

You’ll often miss the moon during the day because it’s so pale against the blue daytime sky. Look closely this weekend, especially in the hours after sunrise. Look west! You’ll see it. Our friend Jenney Disimon in Sabah, North Borneo, caught this daytime moon on January 4, 2018.

Why is the daytime moon most noticeable now? The moon is up during the day half the time. It must be, since it orbits around the whole Earth once a month. A crescent moon is hard to see, though, because it’s so near the sun in the sky. At the vicinity of last quarter moon about a week from now, you might have to crane your neck, looking up, to notice it after sunrise.

This weekend’s moon is noticeable simply because the moon is still showing us most of its lighted face; it appears large in our sky. Also, in the hours after sunrise, the moon is fairly near the western horizon, so people out and about early this weekend might catch sight of it.

At mid-northern latitudes in North America, the moon will set nearly two hours after sunrise on August 17. It’ll set roughly one hour later after sunrise each day thereafter.

These recommended almanacs can help you find the moon’s setting time in your sky

Daytime moon seen on December 18, 2010. Image by Brian Pate. Used with permission.

Bottom line: The moon is now in a waning gibbous phase. Beginning Friday or Saturday morning – May 8 or 9, 2020 – shortly after sunrise, you’ll see it floating pale and beautiful against a blue sky. Look west!

Donate: Your support means the world to us

from EarthSky https://ift.tt/2YPWZcR

Image at top via Buddy Puckhaper of Charleston, South Carolina.

Full moon was May 7, 2020, and by May 8 the moon is in a waning gibbous phase, rising later and later at night. For the mainland United States, the May 8 moon rises in the southeast nearly two hours after sunset. The days following full moon present the perfect time to catch a daytime moon over your western horizon after sunrise. Watch for it!

If you’re a night owl, you might see the moon and the bright star Antares before your bedtime on May 8 and 9, 2020.

View the moon in your eastern sky late in the evening this weekend, perhaps before going to bed. It’ll be ascending in the east later and later each evening. Then look for it low in your western sky right after sunrise. Day by day, the lighted portion of the waning gibbous moon will shrink. The half-lit last quarter moon will come on May 14, 2020.

The moon is up in the daytime much of the time. But, because it’s pale against the blue sky, it’s not as noticeable during the day as at night. However, there are certain times of the month when the daytime moon is more noticeable, and this weekend presents one of those times.

You’ll often miss the moon during the day because it’s so pale against the blue daytime sky. Look closely this weekend, especially in the hours after sunrise. Look west! You’ll see it. Our friend Jenney Disimon in Sabah, North Borneo, caught this daytime moon on January 4, 2018.

Why is the daytime moon most noticeable now? The moon is up during the day half the time. It must be, since it orbits around the whole Earth once a month. A crescent moon is hard to see, though, because it’s so near the sun in the sky. At the vicinity of last quarter moon about a week from now, you might have to crane your neck, looking up, to notice it after sunrise.

This weekend’s moon is noticeable simply because the moon is still showing us most of its lighted face; it appears large in our sky. Also, in the hours after sunrise, the moon is fairly near the western horizon, so people out and about early this weekend might catch sight of it.

At mid-northern latitudes in North America, the moon will set nearly two hours after sunrise on August 17. It’ll set roughly one hour later after sunrise each day thereafter.

These recommended almanacs can help you find the moon’s setting time in your sky

Daytime moon seen on December 18, 2010. Image by Brian Pate. Used with permission.

Bottom line: The moon is now in a waning gibbous phase. Beginning Friday or Saturday morning – May 8 or 9, 2020 – shortly after sunrise, you’ll see it floating pale and beautiful against a blue sky. Look west!

Donate: Your support means the world to us

from EarthSky https://ift.tt/2YPWZcR

As the climate shifts, a border moves

Mount Similaun glacier, where the border between Italy and Austria drifts with the ice. Image via Delfino Sisto Legnani/ Italian Limes.

This article – written by Elza Bouhassira – is republished with permission from GlacierHub.

Rifugio Guide del Cervino, a small mountain restaurant, opened in 1984 at a location high in the Italian Alps; now it might be in Switzerland. The restaurant has become the subject of a dispute between the two states due to a legal agreement which allows Italy’s northern border to move with the natural, morphological boundaries of glaciers’ frontiers, which largely follow the watersheds on either side of the ridges. The moving border has shifted over the last fifteen years since its creation as glaciers retreat and the restaurant may now be in Swiss territory. If decided to be in Switzerland, the restaurant would be subject to Swiss law, taxes, and potentially even customs; Swiss inspectors would need to approve every box of pasta and package of coffee brought up to the restaurant by cable car from Italy.

Rifugio Guide Del Cervino. Image via Franco56/ Wikimedia Commons.

Borders can follow artificial paths, like those on maps forming perfectly straight lines, independent of the physical and cultural landscapes they may be mincing. Others are fixed by natural boundaries like the Niagara River separating the US and Canada.

However, not all natural boundaries are as stable as they might appear. Italy, Austria, and Switzerland’s shared borders depend on the limits of the glaciers and they have been melting at increased rates due to climate change. This has caused the border to shift noticeably in recent years. The border lies primarily at high altitudes, among tall mountain peaks where it crosses white snowfields and icy blue glaciers.

Installation on the Similaun glacier. Image via Sisto Legnani/ Italian Limes.

The moving border is an unprecedented legal concept. It was established through an agreement between Italy and Austria in 2006 and another between Italy and Switzerland in 2009. France did not sign such an agreement because of post World War II territorial gains on the Italian side of the watershed it did not want to risk losing.

The moving border’s flexibility is a highly unusual case in a world where many borders serve to mark defined lines of inclusion and exclusion. International lawyer and Roma Tre University human rights professor Alice Riccardi told GlacierHub:

Borders today move following the policies of exclusion from/inclusion in pursued by States. For instance, when it comes to migration, EU South external borders happen to be already in Africa, where migrants are prevented from embarking towards Europe.

Since 2008, the Istituto Geografico Militare (IGM), which has defined and maintained Italy’s state borders since 1865, has conducted high-altitude survey expeditions every two years to search for shifts in the border and subsequently to update official maps. The collaborative team that conducts the survey is composed of an equal number of experts from IGM and representatives from cartographic institutes of neighboring states.

The concept of the moving border captured the attention of Marco Ferrari, an architect, and Dr. Elisa Pasqual, a visual designer. In 2014, they launched a research project and interactive installation called Italian Limes focused on the moving border. The word limes comes from Latin and was used by the Romans to describe a nebulous, unfixed fringe zone on the edge of their territorial control. The Romans viewed limes as ebbing and flowing as the Roman army advanced and retreated similar to how today the border moves as the ice drifts.

The project, featured in the 2014 Venice Biennale, explores the limits of natural borders when they are tested by long-term ecological processes and reveals how climate change has begun to wear on Western ideas of territory and borders. Ferrari told GlacierHub:

The project makes the speed of climate change visible because we are used to thinking of borders, glaciers, and mountains as things that stay fixed.

Climate change changes our conception of territory in a way that is not just material, it’s not just a disruption of infrastructure, but also of the geographical imagery of the planet itself. So the very idea of the border is put into crisis by climate change in this sense, it almost contradicts the possibility of being able to trace a border.

One of the high-precision GPS measurement tools used by the project at Grafferner Glacier. Image via Delfino Sisto Legnani/ Italian Limes.

The Italian Limes project takes measurements at the 1.5-kilometer (.9 mile) long Grafferner Glacier near Mount Similaun in the Ötztal Alps at the border of Italy and Austria. GPS measurement units were installed at the site to track changes to the glacier and watershed which broadcast their data to a machine, which prints a real-time representation of the moving border. Ferrari explained to GlacierHub:

By looking at the history of the border we came across this specific moment in time of the mobile border that was initially presented to us as an anecdote, as a funny curiosity, a weird glitch in the normal diplomatic management of the relationship between countries. Because of how it was presented to us, we almost didn’t focus on it, but on second thought we saw that this was the nexus that could allow us to talk about all the things we wanted to talk about; it could allow us to reveal the contradiction in this idea of a natural border–how even the mountains, even the watershed, even glaciers aren’t something that is forever, the fact that they are chosen to be borders is a clear political act and when these things move the contradiction gets exposed.

The installation showing a live representation of the border at ZKM, Karlsruhe. Image via Delfino Sisto Legnani/ Italian Limes.

The project grew to the point that Ferrari and Pasqual teamed up with architect and editor Andrea Bagnato to create A Moving Border: Alpine Cartographies of Climate Change, a 2019 book which builds on Italian Limes to map out the effects of climate change on geopolitical understandings of the border. Bagnato told GlacierHub:

I saw the project at the Venice Biennale 2014, it was a fantastic installation, and that’s when I proposed to Marco and Elisa to turn it into a book because I thought that after the work they had done physically going up on the glacier and producing these devices to visualize the movements of the glacier, there were a lot of issues to explore in more detail, historical and political issues. The book was a way to do that..

The book provides a kind of historical perspective of the border and also of climate change. Although we don’t address them directly in the book, I think it opens up to a lot of different geopolitical scenarios. Of course there are many situations in the world where borders pass on glaciers like in Chile/Argentina, India/Pakistan, and so on, where the geopolitics are far more heated than in Italy or Austria.

The Alps in the Trentino province of Italy. Image via Nawarona/ Flickr.

Ultimately, the effects of climate change will introduce stresses that borders cannot keep under control. The new, quick changes to the moving border are only one such instance. The U.S. state of Louisiana is rapidly losing ground to the waters on its coast. India and Bangladesh were involved in a dispute over who controlled an uninhabited sandbar that vanished beneath the rising seas. The province of Kashmir has long been a point of contention between Pakistan and India. If its glaciers melt and regional freshwater supply is put under great stress, conflict for control of the province could escalate significantly.

In an interview with Vice, Ferrari said:

Even the biggest and most stable things, like glaciers, mountains—these huge objects, they can change in a few years. We live on a planet that changes, and we try to make rules, to give meaning, but this meaning is completely artificial because nature, basically, doesn’t give a s**t.

Bottom line: Italy’s northern border with Switzerland is what’s known as a moving border, This is, it depends on the natural, morphological boundaries of glaciers’ frontiers. But in recent years, glaciers have been melting at increased rates due to climate change, causing much more dramatic – and controversial – border shifts.

from EarthSky https://ift.tt/3dsNsvf

Mount Similaun glacier, where the border between Italy and Austria drifts with the ice. Image via Delfino Sisto Legnani/ Italian Limes.

This article – written by Elza Bouhassira – is republished with permission from GlacierHub.

Rifugio Guide del Cervino, a small mountain restaurant, opened in 1984 at a location high in the Italian Alps; now it might be in Switzerland. The restaurant has become the subject of a dispute between the two states due to a legal agreement which allows Italy’s northern border to move with the natural, morphological boundaries of glaciers’ frontiers, which largely follow the watersheds on either side of the ridges. The moving border has shifted over the last fifteen years since its creation as glaciers retreat and the restaurant may now be in Swiss territory. If decided to be in Switzerland, the restaurant would be subject to Swiss law, taxes, and potentially even customs; Swiss inspectors would need to approve every box of pasta and package of coffee brought up to the restaurant by cable car from Italy.

Rifugio Guide Del Cervino. Image via Franco56/ Wikimedia Commons.

Borders can follow artificial paths, like those on maps forming perfectly straight lines, independent of the physical and cultural landscapes they may be mincing. Others are fixed by natural boundaries like the Niagara River separating the US and Canada.

However, not all natural boundaries are as stable as they might appear. Italy, Austria, and Switzerland’s shared borders depend on the limits of the glaciers and they have been melting at increased rates due to climate change. This has caused the border to shift noticeably in recent years. The border lies primarily at high altitudes, among tall mountain peaks where it crosses white snowfields and icy blue glaciers.

Installation on the Similaun glacier. Image via Sisto Legnani/ Italian Limes.

The moving border is an unprecedented legal concept. It was established through an agreement between Italy and Austria in 2006 and another between Italy and Switzerland in 2009. France did not sign such an agreement because of post World War II territorial gains on the Italian side of the watershed it did not want to risk losing.

The moving border’s flexibility is a highly unusual case in a world where many borders serve to mark defined lines of inclusion and exclusion. International lawyer and Roma Tre University human rights professor Alice Riccardi told GlacierHub:

Borders today move following the policies of exclusion from/inclusion in pursued by States. For instance, when it comes to migration, EU South external borders happen to be already in Africa, where migrants are prevented from embarking towards Europe.

Since 2008, the Istituto Geografico Militare (IGM), which has defined and maintained Italy’s state borders since 1865, has conducted high-altitude survey expeditions every two years to search for shifts in the border and subsequently to update official maps. The collaborative team that conducts the survey is composed of an equal number of experts from IGM and representatives from cartographic institutes of neighboring states.

The concept of the moving border captured the attention of Marco Ferrari, an architect, and Dr. Elisa Pasqual, a visual designer. In 2014, they launched a research project and interactive installation called Italian Limes focused on the moving border. The word limes comes from Latin and was used by the Romans to describe a nebulous, unfixed fringe zone on the edge of their territorial control. The Romans viewed limes as ebbing and flowing as the Roman army advanced and retreated similar to how today the border moves as the ice drifts.

The project, featured in the 2014 Venice Biennale, explores the limits of natural borders when they are tested by long-term ecological processes and reveals how climate change has begun to wear on Western ideas of territory and borders. Ferrari told GlacierHub:

The project makes the speed of climate change visible because we are used to thinking of borders, glaciers, and mountains as things that stay fixed.

Climate change changes our conception of territory in a way that is not just material, it’s not just a disruption of infrastructure, but also of the geographical imagery of the planet itself. So the very idea of the border is put into crisis by climate change in this sense, it almost contradicts the possibility of being able to trace a border.

One of the high-precision GPS measurement tools used by the project at Grafferner Glacier. Image via Delfino Sisto Legnani/ Italian Limes.

The Italian Limes project takes measurements at the 1.5-kilometer (.9 mile) long Grafferner Glacier near Mount Similaun in the Ötztal Alps at the border of Italy and Austria. GPS measurement units were installed at the site to track changes to the glacier and watershed which broadcast their data to a machine, which prints a real-time representation of the moving border. Ferrari explained to GlacierHub:

By looking at the history of the border we came across this specific moment in time of the mobile border that was initially presented to us as an anecdote, as a funny curiosity, a weird glitch in the normal diplomatic management of the relationship between countries. Because of how it was presented to us, we almost didn’t focus on it, but on second thought we saw that this was the nexus that could allow us to talk about all the things we wanted to talk about; it could allow us to reveal the contradiction in this idea of a natural border–how even the mountains, even the watershed, even glaciers aren’t something that is forever, the fact that they are chosen to be borders is a clear political act and when these things move the contradiction gets exposed.

The installation showing a live representation of the border at ZKM, Karlsruhe. Image via Delfino Sisto Legnani/ Italian Limes.

The project grew to the point that Ferrari and Pasqual teamed up with architect and editor Andrea Bagnato to create A Moving Border: Alpine Cartographies of Climate Change, a 2019 book which builds on Italian Limes to map out the effects of climate change on geopolitical understandings of the border. Bagnato told GlacierHub:

I saw the project at the Venice Biennale 2014, it was a fantastic installation, and that’s when I proposed to Marco and Elisa to turn it into a book because I thought that after the work they had done physically going up on the glacier and producing these devices to visualize the movements of the glacier, there were a lot of issues to explore in more detail, historical and political issues. The book was a way to do that..

The book provides a kind of historical perspective of the border and also of climate change. Although we don’t address them directly in the book, I think it opens up to a lot of different geopolitical scenarios. Of course there are many situations in the world where borders pass on glaciers like in Chile/Argentina, India/Pakistan, and so on, where the geopolitics are far more heated than in Italy or Austria.

The Alps in the Trentino province of Italy. Image via Nawarona/ Flickr.

Ultimately, the effects of climate change will introduce stresses that borders cannot keep under control. The new, quick changes to the moving border are only one such instance. The U.S. state of Louisiana is rapidly losing ground to the waters on its coast. India and Bangladesh were involved in a dispute over who controlled an uninhabited sandbar that vanished beneath the rising seas. The province of Kashmir has long been a point of contention between Pakistan and India. If its glaciers melt and regional freshwater supply is put under great stress, conflict for control of the province could escalate significantly.

In an interview with Vice, Ferrari said:

Even the biggest and most stable things, like glaciers, mountains—these huge objects, they can change in a few years. We live on a planet that changes, and we try to make rules, to give meaning, but this meaning is completely artificial because nature, basically, doesn’t give a s**t.

Bottom line: Italy’s northern border with Switzerland is what’s known as a moving border, This is, it depends on the natural, morphological boundaries of glaciers’ frontiers. But in recent years, glaciers have been melting at increased rates due to climate change, causing much more dramatic – and controversial – border shifts.

from EarthSky https://ift.tt/3dsNsvf

Sunset over the canyons of NYC

View at EarthSky Community Photos. | New York City, looking west toward Times Square from 6th Ave and 43rd Street. Around 7:30 p.m. on May 4, 2020. Lawrence Scott wrote: “Often looking west down the canyons of skyscrapers one can see fantastic colors and formations. Sunsets in NYC can be really spectacular. Now with the empty Covid-19 streets, it adds a another dynamic.” Thank you, Lawrence, and stay safe!

from EarthSky https://ift.tt/35IvBhl

View at EarthSky Community Photos. | New York City, looking west toward Times Square from 6th Ave and 43rd Street. Around 7:30 p.m. on May 4, 2020. Lawrence Scott wrote: “Often looking west down the canyons of skyscrapers one can see fantastic colors and formations. Sunsets in NYC can be really spectacular. Now with the empty Covid-19 streets, it adds a another dynamic.” Thank you, Lawrence, and stay safe!

from EarthSky https://ift.tt/35IvBhl

The mysterious yellow skies of WASP-79b

Artist’s concept of WASP-79b, a hot Jupiter-like exoplanet 780 light-years from Earth. New research shows the planet has a yellow sky instead of blue as expected. Image via NASA/ ESA/ L. Hustak (STScI)/ Hubblesite.

Earth is beautiful, and we might sometimes take it for granted that we can look up and see a deep blue sky. But what about other planets? A planet’s particular sky depends, of course, on its unique atmosphere. For example, we here on Earth have a blue sky because the blue component of our sun’s light is scattered in all directions by air molecules in Earth’s atmosphere. Mars, on the other hand, has a more pinkish sky due to ever-present dust lofted from Mars surface by winds. Now, scientists have announced results of a study of a distant exoplanet, orbiting a star hotter and brighter than our sun. This planet – called WASP-79b – doesn’t have a blue or pink sky, but instead a yellow one!

The finding was made by researchers combining data from the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite (TESS) and the ground-based Magellan telescopes at the Las Campanas Observatory in Chile.

The intriguing results were first published December 10, 2019, in The Astrophysical Journal and later published in the January 2020 issue of the journal.

WASP-79b is a large gas giant planet of the type known as a hot Jupiter, which orbits very close to its star and completes an orbit in only 3 1/2 days. Its star, WASP-79, is about 780 light-years away in the constellation Eridanus the River.

Scientists had expected that the planet would experience Rayleigh scattering, where certain colors of light are dispersed by very fine dust particles in the upper atmosphere. This is what makes Earth’s skies blue, since shorter (bluer) wavelengths of sunlight are dispersed.

Schematic of an exoplanet atmosphere in relation to the visible light that passes through it. Top: cloudless, distended atmospheres (top) scatter mostly blue light through Rayleigh scattering, while longer wavelengths like red light pass through. Bottom: cloudy atmospheres equally prevent all wavelengths of visible light from passing through. Middle: if the atmosphere is less extended and cloudless, all visible light passes through about equally. Image via National Astronomical Observatory of Japan/ JHUAPL.

But that is not what the researchers found. The lack of Rayleigh scattering is unexpected and “weird” according to the scientists involved. It may be evidence for currently unknown atmospheric process on the planet. As a result, the planet’s skies are probably yellow in color. The researchers also found that the planet’s atmosphere is a humid and sizzling 3,000 degrees Fahrenheit (1,648 degrees Celsius). Hot! There might be molten iron rain coming down from its scattered manganese sulfide or silicate clouds.

WASP-79b is definitely a world very unlike Earth and not a place you would want to go to for a vacation. As lead study author Kristin Showalter Sotzen of the Johns Hopkins University Applied Physics Laboratory (JHUAPL) said in a statement:

This is a strong indication of an unknown atmospheric process that we’re just not accounting for in our physical models. I’ve shown the WASP-79b spectrum to a number of colleagues, and their consensus is ‘that’s weird.’

Because this is the first time we’ve see this, we’re really not sure what the cause is. We need to keep an eye out for other planets like this because it could be indicative of unknown atmospheric processes that we don’t currently understand. Because we only have one planet as an example we don’t know if it’s an atmospheric phenomenon linked to the evolution of the planet.

Comparison of the sizes of WASP-79b, Jupiter and Earth. Image via WASP Planets.

So how did the researchers determine the color of WASP-79b’s sky?

They did it by using a spectrograph on the Magellan telescopes. Spectrographs analyze the different wavelengths of light, and by doing so, in this case, can find clues as to the chemical composition of the exoplanet’s atmosphere. It was anticipated that the atmosphere of WASP-79b would have Rayleigh scattering like in Earth’s atmosphere, resulting in a blue sky. But – surprise – they found the opposite instead. There was less absorption and scattering in the atmosphere, meaning that the planet probably has a yellow sky instead of blue. The findings by the Magellan telescopes were also confirmed by TESS.

WASP-79 is now one of the largest stars known to have a planet, which makes this study even more interesting. So far, most exoplanets have been discovered orbiting red dwarfs, the most common stars in the galaxy, or around stars similar to our sun.

WASP-79b is huge, about 1.7 times the radius of Jupiter. Its deep, extended atmosphere, due to it being so hot, makes it an ideal exoplanet for study by the telescopes used in this study. It’s also interesting in other ways as well.

WASP-79 as compared in size to the sun. It is one of the largest stars known to have an exoplanet. Image via WASP Planets.

Previous studies of the planet by Hubble showed that it has water vapor in its atmosphere. This isn’t really too surprising in itself, despite the heat, but the finding may also help scientists better understand just what is going on in WASP-79b’s exotic atmosphere.

The newest unusual results will keep scientists busy, and should help shed light on how hot Jupiters and other giant planets form and evolve. In another press release from JHUAPL, Sotzen said:

We’re really not sure what’s going on here. But if similar features are found on other such worlds, it’s going to provoke questions about current theories on atmospheric processes and evolution. We’re trying to look at a lot of different hot Jupiters because they’re easier to analyze. What we learn from them will help us make predictions about the atmospheres of other exoplanets, like whether they have clouds or not.

Kristin Showalter Sotzen at JHUAPL, lead author of the new study. Image via STARGATE.

Kathleen Mandt, a planetary scientist at JHUAPL, also said:

In our own solar system, we don’t know how much solid material contributed to the formation of the giant planets, how quickly they formed and by what processes, and even more importantly how they migrated after forming. As we obtain new results about exoplanets like WASP-79b, we’re collecting critical information about the formation of giant planets around other stars to better understand fundamental processes of planet formation and evolution.

The upcoming James Webb Space Telescope – tentatively scheduled to launch in 2021 – will be able to take an even better look at WASP-79b and analyze its chemical composition in more detail. This might help solve the mysteries of this intriguing, yellow-hued world.

Bottom line: Using three different telescopes, scientists have found that a huge, hot exoplanet has yellow skies instead of blue.

Source: Transmission Spectroscopy of WASP-79b from 0.6 to 5.0 um

Via Hubblesite

Via JHUAPL

from EarthSky https://ift.tt/35EROfU

Artist’s concept of WASP-79b, a hot Jupiter-like exoplanet 780 light-years from Earth. New research shows the planet has a yellow sky instead of blue as expected. Image via NASA/ ESA/ L. Hustak (STScI)/ Hubblesite.

Earth is beautiful, and we might sometimes take it for granted that we can look up and see a deep blue sky. But what about other planets? A planet’s particular sky depends, of course, on its unique atmosphere. For example, we here on Earth have a blue sky because the blue component of our sun’s light is scattered in all directions by air molecules in Earth’s atmosphere. Mars, on the other hand, has a more pinkish sky due to ever-present dust lofted from Mars surface by winds. Now, scientists have announced results of a study of a distant exoplanet, orbiting a star hotter and brighter than our sun. This planet – called WASP-79b – doesn’t have a blue or pink sky, but instead a yellow one!

The finding was made by researchers combining data from the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite (TESS) and the ground-based Magellan telescopes at the Las Campanas Observatory in Chile.

The intriguing results were first published December 10, 2019, in The Astrophysical Journal and later published in the January 2020 issue of the journal.

WASP-79b is a large gas giant planet of the type known as a hot Jupiter, which orbits very close to its star and completes an orbit in only 3 1/2 days. Its star, WASP-79, is about 780 light-years away in the constellation Eridanus the River.

Scientists had expected that the planet would experience Rayleigh scattering, where certain colors of light are dispersed by very fine dust particles in the upper atmosphere. This is what makes Earth’s skies blue, since shorter (bluer) wavelengths of sunlight are dispersed.

Schematic of an exoplanet atmosphere in relation to the visible light that passes through it. Top: cloudless, distended atmospheres (top) scatter mostly blue light through Rayleigh scattering, while longer wavelengths like red light pass through. Bottom: cloudy atmospheres equally prevent all wavelengths of visible light from passing through. Middle: if the atmosphere is less extended and cloudless, all visible light passes through about equally. Image via National Astronomical Observatory of Japan/ JHUAPL.

But that is not what the researchers found. The lack of Rayleigh scattering is unexpected and “weird” according to the scientists involved. It may be evidence for currently unknown atmospheric process on the planet. As a result, the planet’s skies are probably yellow in color. The researchers also found that the planet’s atmosphere is a humid and sizzling 3,000 degrees Fahrenheit (1,648 degrees Celsius). Hot! There might be molten iron rain coming down from its scattered manganese sulfide or silicate clouds.

WASP-79b is definitely a world very unlike Earth and not a place you would want to go to for a vacation. As lead study author Kristin Showalter Sotzen of the Johns Hopkins University Applied Physics Laboratory (JHUAPL) said in a statement:

This is a strong indication of an unknown atmospheric process that we’re just not accounting for in our physical models. I’ve shown the WASP-79b spectrum to a number of colleagues, and their consensus is ‘that’s weird.’

Because this is the first time we’ve see this, we’re really not sure what the cause is. We need to keep an eye out for other planets like this because it could be indicative of unknown atmospheric processes that we don’t currently understand. Because we only have one planet as an example we don’t know if it’s an atmospheric phenomenon linked to the evolution of the planet.

Comparison of the sizes of WASP-79b, Jupiter and Earth. Image via WASP Planets.

So how did the researchers determine the color of WASP-79b’s sky?

They did it by using a spectrograph on the Magellan telescopes. Spectrographs analyze the different wavelengths of light, and by doing so, in this case, can find clues as to the chemical composition of the exoplanet’s atmosphere. It was anticipated that the atmosphere of WASP-79b would have Rayleigh scattering like in Earth’s atmosphere, resulting in a blue sky. But – surprise – they found the opposite instead. There was less absorption and scattering in the atmosphere, meaning that the planet probably has a yellow sky instead of blue. The findings by the Magellan telescopes were also confirmed by TESS.

WASP-79 is now one of the largest stars known to have a planet, which makes this study even more interesting. So far, most exoplanets have been discovered orbiting red dwarfs, the most common stars in the galaxy, or around stars similar to our sun.

WASP-79b is huge, about 1.7 times the radius of Jupiter. Its deep, extended atmosphere, due to it being so hot, makes it an ideal exoplanet for study by the telescopes used in this study. It’s also interesting in other ways as well.

WASP-79 as compared in size to the sun. It is one of the largest stars known to have an exoplanet. Image via WASP Planets.

Previous studies of the planet by Hubble showed that it has water vapor in its atmosphere. This isn’t really too surprising in itself, despite the heat, but the finding may also help scientists better understand just what is going on in WASP-79b’s exotic atmosphere.

The newest unusual results will keep scientists busy, and should help shed light on how hot Jupiters and other giant planets form and evolve. In another press release from JHUAPL, Sotzen said:

We’re really not sure what’s going on here. But if similar features are found on other such worlds, it’s going to provoke questions about current theories on atmospheric processes and evolution. We’re trying to look at a lot of different hot Jupiters because they’re easier to analyze. What we learn from them will help us make predictions about the atmospheres of other exoplanets, like whether they have clouds or not.

Kristin Showalter Sotzen at JHUAPL, lead author of the new study. Image via STARGATE.

Kathleen Mandt, a planetary scientist at JHUAPL, also said:

In our own solar system, we don’t know how much solid material contributed to the formation of the giant planets, how quickly they formed and by what processes, and even more importantly how they migrated after forming. As we obtain new results about exoplanets like WASP-79b, we’re collecting critical information about the formation of giant planets around other stars to better understand fundamental processes of planet formation and evolution.

The upcoming James Webb Space Telescope – tentatively scheduled to launch in 2021 – will be able to take an even better look at WASP-79b and analyze its chemical composition in more detail. This might help solve the mysteries of this intriguing, yellow-hued world.

Bottom line: Using three different telescopes, scientists have found that a huge, hot exoplanet has yellow skies instead of blue.

Source: Transmission Spectroscopy of WASP-79b from 0.6 to 5.0 um

Via Hubblesite

Via JHUAPL

from EarthSky https://ift.tt/35EROfU

Virgo? Here’s your constellation

Classical illustration of the constellation Virgo the Maiden, via constellationsofwords.com.

The constellation Virgo the Maiden fully returns to sky at nightfall – with her feet planted on the eastern horizon – by late April and early May. Virgo appears in the evening sky on late May, June and July evenings, too. Then by late August or September, Virgo begins her descent into the glow of evening twilight.

How to find the constellation Virgo. It’s easy to see why early stargazers named this pattern of stars for the goddess of the harvest.

Virgo ranks as the largest constellation of the zodiac and the second-largest constellation overall (after Hydra). Yet Virgo’s long and rambling group of stars doesn’t lend itself to a well-defined pattern. It’s very difficult for most people to make out the winged maiden holding an ear of wheat in her left hand.

You can always follow the curve in the handle of the Big Dipper to the bright orange star Arcturus, then extend that line to Spica, Virgo's brightest star.

Fortunately, Virgo’s first-magnitude star, sparkling blue-white Spica, makes this constellation fairly easy to locate in the night sky. If you live in the Northern Hemisphere, and are familiar with the Big Dipper asterism, you can star-hop to this gem of a star from the handle of the Big Dipper. Moreover, since the Big Dipper is quite high in the sky on May and June evenings, even people at tropical and subtropical regions in the Southern Hemisphere can use the Big Dipper at this time of year to locate Spica, Virgo’s brightest star.

View larger. | The constellation Virgo. Image via Wikipedia.

The mnemonic goes like this: arc to Arcturus and spike Spica. In other words, follow the arc in the handle of the Big Dipper until you see an orange star. That is Arcturus in the constellation Boötes. Then continue that line to Spica.

So if the easy-to-recognize Big Dipper is visible in your sky, use it to star-hop to Spica, Virgo’s brightest star. You can be sure you’ve found Spica if you notice a lopsided square pattern nearby. That little pattern is another constellation, Corvus the Crow.

Spica climbs highest for the night – as seen from both the Northern and the Southern Hemispheres – at roughly local midnight (1 a.m. daylight saving time) in middle April. Because the stars return to the same place in the sky about two hours earlier with each passing month, look for Spica to be highest up at mid-May around 10 p.m. (11 p.m. daylight saving time), and at mid-June at about 8 p.m. (9 p.m. daylight saving time). These times refer to your local time.

We are surrounded by stars. Because Earth orbits in a flat plane around the sun, we see the sun against the same stars again and again throughout the year. Those constellations, which have been special to people throughout the ages, are the constellations of the Zodiac. Image via Professor Marcia Rieke.

Sun in front of Virgo on your birthday? The sun passes in front of the constellation Virgo each year from about September 16 to October 30. Because Virgo is such a large constellation, the sun stays in front of Virgo for longer than one month.

Dates of sun’s entry into each constellation of the zodiac

The dates of the sun’s passage through Virgo may conflict with what you read on the horoscope page, which probably says from about August 23 to September 22. Keep in mind that astrologers are referring to the sign – not the constellation – Virgo. Yes, there is a difference between a constellation and a sign!

A constellation of the zodiac refers to certain section of the starry sky. On the other hand, a sign of the zodiac refers to the seasonal position of the sun, irrespective of what constellation backdrops the sun at a given season.

For instance, the March equinox marks the first point of (the sign) Aries, the June solstice marks the first point of (the sign) Cancer, the September equinox marks the first point of (the sign) Libra, and the December solstice marks the first point of (the sign) Capricorn.

By definition, the first point of (the sign) Libra always coincides with the sun’s position on the September equinox. This is in spite of the fact that the sun shines in front of the constellation Virgo on the September equinox nowadays. The sun resides in the sign Libra for one month, starting on or near September 23, yet the sun also shines in front of the constellation Virgo during this period of time.

Constellations are less abstract than signs, so astronomers and stargazers who directly observe the night sky find it easier to refer to constellations. It’s not incorrect to list the star Spica’s position as Libra 23^o 50’ but that bit of information won’t help many people to locate Spica, the constellation Virgo’s brightest star.

The Virgo galaxy cluster, via Wikimedia Commons.

The famous Sombrero Galaxy (M104) is thought by some to belong to the Virgo cluster. Image via mini82.

Virgo galaxy cluster. In mythology, Virgo represents fruitfulness and fertility, but this wondrous constellation has also proven its fruitfulness in ways undreamed of by the ancients. This constellation is the home of the great Virgo galaxy cluster, a conglomeration made up of thousands of galaxies. A few of these galaxies are actually visible as faint smudges of light through a small telescope. That in itself is pretty amazing, given that the Virgo cluster of galaxies lies some 65 million light-years distant.

Perhaps the most famous galaxy residing within Virgo’s borders is the Sombrero galaxy (M104). There seems to be disagreement, though, on whether this galaxy is a member of the Virgo galaxy cluster.

The Return of Persephone by Frederic Leighton. Image via Wikipedia.

Virgo in ancient mythology. The constellation Virgo is often said to personify Persephone, the daughter of Demeter, the harvest goddess. According to the famous Greek myth, eternal spring once reigned upon the Earth, until that fateful day when the god of the underworld abducted Persephone, the radiant maiden of spring.

Her mother Demeter was so overcome with grief over the loss of her only child that she abandoned her role as the goddess of fruitfulness and fertility. In some parts of the globe, the winter cold turned the once-verdant Earth in to a frigid wasteland, while elsewhere the summer heat scorched the Earth and gave rise to pestilence and disease. The Earth would not bear fruit again until Demeter was reunited with her daughter.

Humanity would have died altogether had not Zeus, the king of the gods, intervened. Zeus insisted that the god of the underworld return Persephone back to Demeter, but also proclaimed that Persephone abstain from food until her return. Alas, the god of the underworld purposely gave Persephone a pomegranate, knowing she would suck on a pomegranate seed on her way home.

Persephone was given back to her mother, but Persephone – because of the pomegranate – has to return to the underworld for four months every year. To this day, spring returns to the Northern Hemisphere when Persephone is reunited with Demeter, but the winter season reigns when Persephone dwells in the underworld.

That’s why, according to myth, it’s spring when the constellation Virgo is above the horizon at early evening but why it’s winter when she’s not. From the perspective of the Northern Hemisphere, Virgo is absent from early evening sky in late autumn, winter and early spring. Virgo’s return to sky at nightfall coincides with the verdant season of spring.

Virgo the winged harvest goddess. Image via Hubble Source.

Bottom line: The constellation Virgo the Maiden fully returns to sky at nightfall – with her feet planted on the eastern horizon – by late April or early May. This post has information about how to find the constellation Virgo, its brightest star, interesting things to see within its boundaries, and its mythology.

from EarthSky https://ift.tt/3dvgPgB

Classical illustration of the constellation Virgo the Maiden, via constellationsofwords.com.

The constellation Virgo the Maiden fully returns to sky at nightfall – with her feet planted on the eastern horizon – by late April and early May. Virgo appears in the evening sky on late May, June and July evenings, too. Then by late August or September, Virgo begins her descent into the glow of evening twilight.

How to find the constellation Virgo. It’s easy to see why early stargazers named this pattern of stars for the goddess of the harvest.

Virgo ranks as the largest constellation of the zodiac and the second-largest constellation overall (after Hydra). Yet Virgo’s long and rambling group of stars doesn’t lend itself to a well-defined pattern. It’s very difficult for most people to make out the winged maiden holding an ear of wheat in her left hand.

You can always follow the curve in the handle of the Big Dipper to the bright orange star Arcturus, then extend that line to Spica, Virgo's brightest star.

Fortunately, Virgo’s first-magnitude star, sparkling blue-white Spica, makes this constellation fairly easy to locate in the night sky. If you live in the Northern Hemisphere, and are familiar with the Big Dipper asterism, you can star-hop to this gem of a star from the handle of the Big Dipper. Moreover, since the Big Dipper is quite high in the sky on May and June evenings, even people at tropical and subtropical regions in the Southern Hemisphere can use the Big Dipper at this time of year to locate Spica, Virgo’s brightest star.

View larger. | The constellation Virgo. Image via Wikipedia.

The mnemonic goes like this: arc to Arcturus and spike Spica. In other words, follow the arc in the handle of the Big Dipper until you see an orange star. That is Arcturus in the constellation Boötes. Then continue that line to Spica.

So if the easy-to-recognize Big Dipper is visible in your sky, use it to star-hop to Spica, Virgo’s brightest star. You can be sure you’ve found Spica if you notice a lopsided square pattern nearby. That little pattern is another constellation, Corvus the Crow.

Spica climbs highest for the night – as seen from both the Northern and the Southern Hemispheres – at roughly local midnight (1 a.m. daylight saving time) in middle April. Because the stars return to the same place in the sky about two hours earlier with each passing month, look for Spica to be highest up at mid-May around 10 p.m. (11 p.m. daylight saving time), and at mid-June at about 8 p.m. (9 p.m. daylight saving time). These times refer to your local time.

We are surrounded by stars. Because Earth orbits in a flat plane around the sun, we see the sun against the same stars again and again throughout the year. Those constellations, which have been special to people throughout the ages, are the constellations of the Zodiac. Image via Professor Marcia Rieke.

Sun in front of Virgo on your birthday? The sun passes in front of the constellation Virgo each year from about September 16 to October 30. Because Virgo is such a large constellation, the sun stays in front of Virgo for longer than one month.

Dates of sun’s entry into each constellation of the zodiac

The dates of the sun’s passage through Virgo may conflict with what you read on the horoscope page, which probably says from about August 23 to September 22. Keep in mind that astrologers are referring to the sign – not the constellation – Virgo. Yes, there is a difference between a constellation and a sign!

A constellation of the zodiac refers to certain section of the starry sky. On the other hand, a sign of the zodiac refers to the seasonal position of the sun, irrespective of what constellation backdrops the sun at a given season.

For instance, the March equinox marks the first point of (the sign) Aries, the June solstice marks the first point of (the sign) Cancer, the September equinox marks the first point of (the sign) Libra, and the December solstice marks the first point of (the sign) Capricorn.

By definition, the first point of (the sign) Libra always coincides with the sun’s position on the September equinox. This is in spite of the fact that the sun shines in front of the constellation Virgo on the September equinox nowadays. The sun resides in the sign Libra for one month, starting on or near September 23, yet the sun also shines in front of the constellation Virgo during this period of time.

Constellations are less abstract than signs, so astronomers and stargazers who directly observe the night sky find it easier to refer to constellations. It’s not incorrect to list the star Spica’s position as Libra 23^o 50’ but that bit of information won’t help many people to locate Spica, the constellation Virgo’s brightest star.

The Virgo galaxy cluster, via Wikimedia Commons.

The famous Sombrero Galaxy (M104) is thought by some to belong to the Virgo cluster. Image via mini82.

Virgo galaxy cluster. In mythology, Virgo represents fruitfulness and fertility, but this wondrous constellation has also proven its fruitfulness in ways undreamed of by the ancients. This constellation is the home of the great Virgo galaxy cluster, a conglomeration made up of thousands of galaxies. A few of these galaxies are actually visible as faint smudges of light through a small telescope. That in itself is pretty amazing, given that the Virgo cluster of galaxies lies some 65 million light-years distant.

Perhaps the most famous galaxy residing within Virgo’s borders is the Sombrero galaxy (M104). There seems to be disagreement, though, on whether this galaxy is a member of the Virgo galaxy cluster.

The Return of Persephone by Frederic Leighton. Image via Wikipedia.

Virgo in ancient mythology. The constellation Virgo is often said to personify Persephone, the daughter of Demeter, the harvest goddess. According to the famous Greek myth, eternal spring once reigned upon the Earth, until that fateful day when the god of the underworld abducted Persephone, the radiant maiden of spring.

Her mother Demeter was so overcome with grief over the loss of her only child that she abandoned her role as the goddess of fruitfulness and fertility. In some parts of the globe, the winter cold turned the once-verdant Earth in to a frigid wasteland, while elsewhere the summer heat scorched the Earth and gave rise to pestilence and disease. The Earth would not bear fruit again until Demeter was reunited with her daughter.

Humanity would have died altogether had not Zeus, the king of the gods, intervened. Zeus insisted that the god of the underworld return Persephone back to Demeter, but also proclaimed that Persephone abstain from food until her return. Alas, the god of the underworld purposely gave Persephone a pomegranate, knowing she would suck on a pomegranate seed on her way home.

Persephone was given back to her mother, but Persephone – because of the pomegranate – has to return to the underworld for four months every year. To this day, spring returns to the Northern Hemisphere when Persephone is reunited with Demeter, but the winter season reigns when Persephone dwells in the underworld.

That’s why, according to myth, it’s spring when the constellation Virgo is above the horizon at early evening but why it’s winter when she’s not. From the perspective of the Northern Hemisphere, Virgo is absent from early evening sky in late autumn, winter and early spring. Virgo’s return to sky at nightfall coincides with the verdant season of spring.

Virgo the winged harvest goddess. Image via Hubble Source.

Bottom line: The constellation Virgo the Maiden fully returns to sky at nightfall – with her feet planted on the eastern horizon – by late April or early May. This post has information about how to find the constellation Virgo, its brightest star, interesting things to see within its boundaries, and its mythology.

from EarthSky https://ift.tt/3dvgPgB

Happy Buddha Purnima

View at EarthSky Community Photos. | Composite image via Swami Krishnananda in Ranchi, Jharkhand, India.

Our friend Swami Krishnananda captured an image of last night’s moon (May 6, 2020) – and created this composite – and wrote:

I was able to shoot the supermoon with clear skies. We will be celebrating Buddha Purnima i.e. Lord Buddha’s birthday. So I felt it would be nice to greet all the EarthSky community and wish them all a Happy Buddha Purnima by superimposing the face of Lord Buddha on the supermoon.

Thank you, Swami Krishnananda!

According to the May 7, 2020 HindustanTimes:

The birth anniversary of Gautam Buddha, the founder of Buddhism, is celebrated as Buddha Purnima or Buddha Jayanti with much fervour across the world. It falls on a full moon day in the month of Vaisakh (April/May) according to the Hindu calendar. This year Buddha Purnima will be celebrated on May 7. In Theravada Buddhism, it is also observed as the day when Buddha, born as Prince Siddhartha Gautama (c. 563-483 BCE) attained Nirvana (salvation) under the Mahabodhi tree at Bodh Gaya, Bihar, as well as his death anniversary. The Vesak full moon day is the most important day in the Buddhist calendar. Several Buddhists go to the pagodas to pour water at the foot of the sacred tree in remembrance of the Buddha’s Enlightenment.

Buddha Purnima is a major festival celebrated with great pomp and fervor in countries like Sri Lanka (where it is called Vesak), India, Nepal, Bhutan, Burma, Thailand, Tibet, China, Korea, Laos, Vietnam, Mongolia, Cambodia, Singapore and Indonesia, though celebrations vary from country to country.

Read more from HindustanTimes … Buddha Purnima 2020: Here’s everything you need to know about Gautam Buddha’s birth anniversary

Bottom line: A composite photo and some information about the May 7, 2020 Buddha Purnima.

from EarthSky https://ift.tt/3fsagwO

View at EarthSky Community Photos. | Composite image via Swami Krishnananda in Ranchi, Jharkhand, India.

Our friend Swami Krishnananda captured an image of last night’s moon (May 6, 2020) – and created this composite – and wrote:

I was able to shoot the supermoon with clear skies. We will be celebrating Buddha Purnima i.e. Lord Buddha’s birthday. So I felt it would be nice to greet all the EarthSky community and wish them all a Happy Buddha Purnima by superimposing the face of Lord Buddha on the supermoon.

Thank you, Swami Krishnananda!

According to the May 7, 2020 HindustanTimes:

The birth anniversary of Gautam Buddha, the founder of Buddhism, is celebrated as Buddha Purnima or Buddha Jayanti with much fervour across the world. It falls on a full moon day in the month of Vaisakh (April/May) according to the Hindu calendar. This year Buddha Purnima will be celebrated on May 7. In Theravada Buddhism, it is also observed as the day when Buddha, born as Prince Siddhartha Gautama (c. 563-483 BCE) attained Nirvana (salvation) under the Mahabodhi tree at Bodh Gaya, Bihar, as well as his death anniversary. The Vesak full moon day is the most important day in the Buddhist calendar. Several Buddhists go to the pagodas to pour water at the foot of the sacred tree in remembrance of the Buddha’s Enlightenment.

Buddha Purnima is a major festival celebrated with great pomp and fervor in countries like Sri Lanka (where it is called Vesak), India, Nepal, Bhutan, Burma, Thailand, Tibet, China, Korea, Laos, Vietnam, Mongolia, Cambodia, Singapore and Indonesia, though celebrations vary from country to country.

Read more from HindustanTimes … Buddha Purnima 2020: Here’s everything you need to know about Gautam Buddha’s birth anniversary

Bottom line: A composite photo and some information about the May 7, 2020 Buddha Purnima.

from EarthSky https://ift.tt/3fsagwO