Our milestones: A radical change that improved breast cancer surgery

This entry is part of 28 in the series Our milestones

In this post, we look at how a breast cancer clinical trial we helped fund in the 60s and 70s laid the foundations for improving surgery for women with early stage breast cancer. Its results allowed breast cancer surgeons to move away from ‘radical’ mastectomies towards kinder, less invasive surgeries.

Alex King, 52, is a volunteer on our London Cancer Awareness Roadshow. In 2009 she was diagnosed with early stage breast cancer after finding a pea-sized lump in her breast.

“When I was diagnosed I stayed positive and decided: ‘I’m going to fight this’. I got through it with amazing support from my son and daughter, my family and friends,” she says.

Alex’s treatment included surgery, chemotherapy and radiotherapy, which is given to kill any cancer cells left behind after surgery.

“My surgeon told me I was going to have a lumpectomy. He explained that during the surgery he would take just the tumour and a bit of healthy tissue from around it. The idea was to leave behind as much healthy breast tissue as possible, while at the same time removing the tumour.

“He described a lumpectomy as ‘breast-conserving surgery’, and I thought that sounded fantastic!”

Nowadays, lumpectomies are frequently used to treat women like Alex with early stage breast cancer.

But this wasn’t always the case.

Radical surgery, radical side effects

In the early 1900s the world was entering a new era. Women could compete in the Olympic Games, Einstein was proposing his theory of relativity, and King George V was ascending the throne in England.

But not everything was progressing.

Alex King, who was diagnosed with breast cancer in 2009.

Surgeons’ understanding of cancer at the time was limited, especially compared to what we know today.

This meant their approach to surgery as a treatment was to remove as much tissue as possible. They did this to try and get rid of all the cancer cells, in the hope that doing so would help more patients survive.

So for women diagnosed with breast cancer in the early 1900s, surgery took the form of a radical mastectomy, a type of surgery which lived up to its name.

Professor Arnie Purushotham, a breast cancer surgeon and senior clinical advisor at Cancer Research UK, explains: “These women were facing a severe operation. A radical mastectomy involved removing all of the breast tissue, the underlying muscles of the chest wall and lymph nodes from the armpit.”

After this difficult surgery, women experienced long recovery times and often, long-term side effects including swelling (lymphoedema) and difficulty moving their arms.

But the impact of the operation went far beyond just physical side effects.

This surgery was often very disfiguring for women, which caused many to experience psychological problems after the operation. These included poor body image, anxiety and depression as they tried to come to terms with the dramatic changes to their body.

So while these women were surviving breast cancer, it came at a high price.

Things had to change.

A changing focus

The mid-1900s were marked by the end of Second World War, with UK households facing rationing in the years that followed.

Amidst all of this, scientists, surgeons and doctors were considering rationing in a different sense: during breast surgery.

The desire to improve surgery was fuelled in part by a growing understanding of cancer and the biology of the disease.

But perhaps even more so, it was fuelled by the fact that doctors were seeing an increasing number of women who were reluctant – or completely refusing – to undergo radical mastectomies, because of the crippling physical side effects and emotional distress they caused.

To address these concerns, surgeons modified how they performed mastectomies, leaving behind the muscles of the chest wall.

Many surgeons were convinced this compromise was the best option. But many others disagreed.

“At the time, doctors were beginning to focus more on listening to patients, and were considering the psychological – not just physical – impact of radical and modified radical mastectomies,” says Purushotham.

Professor Arnie Purushotham, a breast cancer surgeon and senior clinical advisor at Cancer Research UK

To this end, some surgeons started to dial back surgery even further, performing what is now known as a lumpectomy.

“They were finding that women who had this less severe surgery often did better psychologically than those who had a more radical procedure,” says Purushotham.

But how did these women do physically? Did they still survive their cancer when they had a lumpectomy?

The answer was yes.

When surgeons studied the records of women who’d had radical mastectomies and compared them to those who had less severe surgery, there was very little difference between the groups in terms of how long patients lived after surgery.

This backed up the idea that a lumpectomy could be as good as a radical mastectomy as a treatment for breast cancer.

But because these findings had come from combining one off reports and medical records, many doctors and surgeons remained unconvinced.

The two approaches needed testing head to head. Clinical trials were needed.There was a lack of solid, scientific evidence to show a lumpectomy was as good as its more radical counterpart.

Testing times – the Guy’s Hospital trial

In 1961, at Guy’s Hospital in London, an important clinical trial was underway to help finally answer the question and which surgical approach was best.

Funded by Cancer Research Campaign (one of the forbearers of Cancer Research UK), the trial focused on women with early stage breast cancer.

It followed two groups – one had a radical mastectomy, the other a lumpectomy. Both groups received radiotherapy.

These trials finally put the radical mastectomy story to bed once and for all.

Professor Arnie Purushotham

In total, 370 women aged 50 and over took part in the trial and were randomly assigned to one of the surgeries.

The trial ran for 10 years, and the women were followed up with check-ups to see if there was any difference in survival between the groups.

They were also given questionnaires on a regular basis to assess and compare their quality of life following treatment.

The trial proved that for women with early stage breast cancer, the same positive survival outcome could be achieved with a lumpectomy as with the more severe, radical mastectomy.

But where lumpectomies shone was in reduced side-effects that women experienced along with better emotional and psychological wellbeing.

“There was a pressing need for this trial to be carried out, to make sure women with early stage breast cancer were getting the best treatment,” says Purushotham.

“The results marked a paradigm shift in how the medical community in the UK and globally saw lumpectomies – they were game changing. Women with early stage breast cancer could now choose to have a lumpectomy as part of their treatment.”

This small trial laid the foundations for further clinical trials comparing radical mastectomies and lumpectomies.

Encouragingly, its results were backed up by larger studies in the US and Europe that ran from the early ‘70s to the late ‘80s. These trials followed patients for 20 years and confirmed the findings of the UK trial.

As Purushotham recalls: “These trials finally put the radical mastectomy story to bed once and for all and showed that it’s not necessarily the best or only way to treat women with early stage breast cancer.”

Lumpectomy – small surgery, big impact

In 1990, based on the findings of these trials, including the one we helped fund, the National Institute of Health in the US released a statement.

I chose to have a lumpectomy because that’s what felt right for me.

Alex King

It recommended that lumpectomies followed by radiotherapy should be used “instead of mastectomies to treat early breast cancer, whenever possible”.

The UK soon followed suit, and lumpectomies became the recommended procedure for some women with early stage breast cancer, who met certain other criteria. This change offers many women a breast-conserving surgical option, without affecting their survival.

Patient choice is also now a major factor in selecting which of these treatments is best.

Some women feel a mastectomy is the best option for them, whereas others would rather have a lumpectomy.

“Nowadays, it is very much patient-led. I was always asked: ‘How do you feel about this? Are you happy for us to do this?” says Alex.

“I chose to have a lumpectomy because that’s what felt right for me.

“I’m super happy with how my body looks after my lumpectomy. I took part in the World Cancer Day 2016 naked photoshoot to show women that you can still be womanly even though you’ve had part of your breast removed – that was my motivation. The photos are lovely and tasteful, and when I look at them I just feel so empowered!”

It’s important to note that for some women, a mastectomy is still the best option. It depends on the person and their cancer. Every patient needs to discuss what’s best for them with their doctor so they can make an informed choice.

Looking to the future

Today, more people survive breast cancer than ever before. And research and improvements in surgery have been a big part of this.

But there’s still more we can do to help more women survive the disease. That’s why we continue to fund research into all aspects of the disease including how to prevent it, diagnose it earlier and improving treatments so they are tailored to each patient’s disease.

As Purushotham looks to the future, he highlights this last point: “As we continue to improve surgery, radiotherapy, drugs and combination treatments, we’re starting to offer patients treatment that’s more targeted to them and the specific faults in the tumour.”

And for Alex, having that option to do what was right for her made all the difference.

“My scar is amazing. I’m proud of my breasts as they are now and I feel that I have a lot to be thankful for!”

Fiona

from Cancer Research UK – Science blog http://ift.tt/2yQOgGP

This entry is part of 28 in the series Our milestones

In this post, we look at how a breast cancer clinical trial we helped fund in the 60s and 70s laid the foundations for improving surgery for women with early stage breast cancer. Its results allowed breast cancer surgeons to move away from ‘radical’ mastectomies towards kinder, less invasive surgeries.

Alex King, 52, is a volunteer on our London Cancer Awareness Roadshow. In 2009 she was diagnosed with early stage breast cancer after finding a pea-sized lump in her breast.

“When I was diagnosed I stayed positive and decided: ‘I’m going to fight this’. I got through it with amazing support from my son and daughter, my family and friends,” she says.

Alex’s treatment included surgery, chemotherapy and radiotherapy, which is given to kill any cancer cells left behind after surgery.

“My surgeon told me I was going to have a lumpectomy. He explained that during the surgery he would take just the tumour and a bit of healthy tissue from around it. The idea was to leave behind as much healthy breast tissue as possible, while at the same time removing the tumour.

“He described a lumpectomy as ‘breast-conserving surgery’, and I thought that sounded fantastic!”

Nowadays, lumpectomies are frequently used to treat women like Alex with early stage breast cancer.

But this wasn’t always the case.

Radical surgery, radical side effects

In the early 1900s the world was entering a new era. Women could compete in the Olympic Games, Einstein was proposing his theory of relativity, and King George V was ascending the throne in England.

But not everything was progressing.

Alex King, who was diagnosed with breast cancer in 2009.

Surgeons’ understanding of cancer at the time was limited, especially compared to what we know today.

This meant their approach to surgery as a treatment was to remove as much tissue as possible. They did this to try and get rid of all the cancer cells, in the hope that doing so would help more patients survive.

So for women diagnosed with breast cancer in the early 1900s, surgery took the form of a radical mastectomy, a type of surgery which lived up to its name.

Professor Arnie Purushotham, a breast cancer surgeon and senior clinical advisor at Cancer Research UK, explains: “These women were facing a severe operation. A radical mastectomy involved removing all of the breast tissue, the underlying muscles of the chest wall and lymph nodes from the armpit.”

After this difficult surgery, women experienced long recovery times and often, long-term side effects including swelling (lymphoedema) and difficulty moving their arms.

But the impact of the operation went far beyond just physical side effects.

This surgery was often very disfiguring for women, which caused many to experience psychological problems after the operation. These included poor body image, anxiety and depression as they tried to come to terms with the dramatic changes to their body.

So while these women were surviving breast cancer, it came at a high price.

Things had to change.

A changing focus

The mid-1900s were marked by the end of Second World War, with UK households facing rationing in the years that followed.

Amidst all of this, scientists, surgeons and doctors were considering rationing in a different sense: during breast surgery.

The desire to improve surgery was fuelled in part by a growing understanding of cancer and the biology of the disease.

But perhaps even more so, it was fuelled by the fact that doctors were seeing an increasing number of women who were reluctant – or completely refusing – to undergo radical mastectomies, because of the crippling physical side effects and emotional distress they caused.

To address these concerns, surgeons modified how they performed mastectomies, leaving behind the muscles of the chest wall.

Many surgeons were convinced this compromise was the best option. But many others disagreed.

“At the time, doctors were beginning to focus more on listening to patients, and were considering the psychological – not just physical – impact of radical and modified radical mastectomies,” says Purushotham.

Professor Arnie Purushotham, a breast cancer surgeon and senior clinical advisor at Cancer Research UK

To this end, some surgeons started to dial back surgery even further, performing what is now known as a lumpectomy.

“They were finding that women who had this less severe surgery often did better psychologically than those who had a more radical procedure,” says Purushotham.

But how did these women do physically? Did they still survive their cancer when they had a lumpectomy?

The answer was yes.

When surgeons studied the records of women who’d had radical mastectomies and compared them to those who had less severe surgery, there was very little difference between the groups in terms of how long patients lived after surgery.

This backed up the idea that a lumpectomy could be as good as a radical mastectomy as a treatment for breast cancer.

But because these findings had come from combining one off reports and medical records, many doctors and surgeons remained unconvinced.

The two approaches needed testing head to head. Clinical trials were needed.There was a lack of solid, scientific evidence to show a lumpectomy was as good as its more radical counterpart.

Testing times – the Guy’s Hospital trial

In 1961, at Guy’s Hospital in London, an important clinical trial was underway to help finally answer the question and which surgical approach was best.

Funded by Cancer Research Campaign (one of the forbearers of Cancer Research UK), the trial focused on women with early stage breast cancer.

It followed two groups – one had a radical mastectomy, the other a lumpectomy. Both groups received radiotherapy.

These trials finally put the radical mastectomy story to bed once and for all.

Professor Arnie Purushotham

In total, 370 women aged 50 and over took part in the trial and were randomly assigned to one of the surgeries.

The trial ran for 10 years, and the women were followed up with check-ups to see if there was any difference in survival between the groups.

They were also given questionnaires on a regular basis to assess and compare their quality of life following treatment.

The trial proved that for women with early stage breast cancer, the same positive survival outcome could be achieved with a lumpectomy as with the more severe, radical mastectomy.

But where lumpectomies shone was in reduced side-effects that women experienced along with better emotional and psychological wellbeing.

“There was a pressing need for this trial to be carried out, to make sure women with early stage breast cancer were getting the best treatment,” says Purushotham.

“The results marked a paradigm shift in how the medical community in the UK and globally saw lumpectomies – they were game changing. Women with early stage breast cancer could now choose to have a lumpectomy as part of their treatment.”

This small trial laid the foundations for further clinical trials comparing radical mastectomies and lumpectomies.

Encouragingly, its results were backed up by larger studies in the US and Europe that ran from the early ‘70s to the late ‘80s. These trials followed patients for 20 years and confirmed the findings of the UK trial.

As Purushotham recalls: “These trials finally put the radical mastectomy story to bed once and for all and showed that it’s not necessarily the best or only way to treat women with early stage breast cancer.”

Lumpectomy – small surgery, big impact

In 1990, based on the findings of these trials, including the one we helped fund, the National Institute of Health in the US released a statement.

I chose to have a lumpectomy because that’s what felt right for me.

Alex King

It recommended that lumpectomies followed by radiotherapy should be used “instead of mastectomies to treat early breast cancer, whenever possible”.

The UK soon followed suit, and lumpectomies became the recommended procedure for some women with early stage breast cancer, who met certain other criteria. This change offers many women a breast-conserving surgical option, without affecting their survival.

Patient choice is also now a major factor in selecting which of these treatments is best.

Some women feel a mastectomy is the best option for them, whereas others would rather have a lumpectomy.

“Nowadays, it is very much patient-led. I was always asked: ‘How do you feel about this? Are you happy for us to do this?” says Alex.

“I chose to have a lumpectomy because that’s what felt right for me.

“I’m super happy with how my body looks after my lumpectomy. I took part in the World Cancer Day 2016 naked photoshoot to show women that you can still be womanly even though you’ve had part of your breast removed – that was my motivation. The photos are lovely and tasteful, and when I look at them I just feel so empowered!”

It’s important to note that for some women, a mastectomy is still the best option. It depends on the person and their cancer. Every patient needs to discuss what’s best for them with their doctor so they can make an informed choice.

Looking to the future

Today, more people survive breast cancer than ever before. And research and improvements in surgery have been a big part of this.

But there’s still more we can do to help more women survive the disease. That’s why we continue to fund research into all aspects of the disease including how to prevent it, diagnose it earlier and improving treatments so they are tailored to each patient’s disease.

As Purushotham looks to the future, he highlights this last point: “As we continue to improve surgery, radiotherapy, drugs and combination treatments, we’re starting to offer patients treatment that’s more targeted to them and the specific faults in the tumour.”

And for Alex, having that option to do what was right for her made all the difference.

“My scar is amazing. I’m proud of my breasts as they are now and I feel that I have a lot to be thankful for!”

Fiona

from Cancer Research UK – Science blog http://ift.tt/2yQOgGP

5 myths about the moon

Myth 1 is that moon has a permanent dark side. This is the far side of the moon, as photographed by Apollo 16 in 1972. See? It isn’t dark. Image via NASA.

We have full moons, blue moons, Harvest moons, supermoons and any number of culturally relevant references to the moon. Maybe it’s time to unearth a few moon myths and misconceptions. Follow the links below to learn more about the moon.

Myth 1. The moon has a permanent dark side.

Myth 2. The moon is perfectly round.

Myth 3. The moon is bright white.

Myth 4. There is no gravity on the moon.

Myth 5. The moon raises tides in people.

EarthSky tees are back! Learn how your purchase helps support worthy causes, and use code ESFRIENDS for $5 off.

The eighth studio album by the English progressive rock band Pink Floyd – released in March 1973 – was titled Dark Side of the Moon and probably helped perpetuate the myth. Here’s original album artwork by Hipgnosis and George Hardie. Via Wikimedia Commons.

Myth 1. The moon has a permanent dark side. Most grammar school students know that the moon presents only one face or side to the Earth. This is (roughly) true and gives rise to the idea that there is a permanently dark side of the moon, a thought immortalized in Pink Flyod’s music and elsewhere.

In fact, the side of the moon that is perpetually turned away from Earth is no more dark than the side we see. It is fully illuminated by the sun just as often (lunar daytime), and is in shade just as often (lunar night), as is the familiar Man in the Moon face we see.

The Earth-facing side of the moon gives rise to another misconception that many people share, namely that we see only 50% of the moon from Earth. In fact, only about 41 percent of the moon’s far side (a much more accurate and preferable term than dark side) is perpetually hidden from earthly observers. A diligent observer on Earth can, over time, observe about 59% of the moon’s surface. This is because a phenomenon called libration causes the moon’s viewing angle, relative to Earth, to change slightly over its orbit.

Lunar libration is due to the fact that the moon’s orbit around Earth isn’t a perfect circle. Instead, it’s a slightly elongated circle called an ellipse. Imagine a race car on an elliptical track. At each elliptical end of the racecourse, the car is flung out slightly due to the change in angle. It is a bit like rounding a corner. The result for the moon is that it occasionally exposes slightly more of its surface on the eastern or western extreme (depending on the location in the orbit). That’s why, as viewed from Earth, about 59% of the moon’s surface is exposed over the course of the moon’s (roughly) monthly orbit around the Earth.

Near side of the moon, as seen through a telescope. The moon looks round, but it isn’t. In a dark sky, the moon looks bright white, but this image captures its true asphalt gray color. Notice that the moon’s near side has dark “maria” or “seas,” while the moon’s far side (photo at top of post) lacks these features. Image via Wikimedia Commons.

Myth 2. The moon is perfectly round. To the eye, the moon appears round, and it’s natural to assume that it is actually spherical in shape – with every point on its surface equidistant from its center – like a big ball. Not so. The shape of the moon is that of an oblate spheroid, meaning it has the shape of a ball that is slightly flattened. Look at a photo of Jupiter and you will see a good example of this. The moon exhibits very slight oblateness, but more important is the fact that the “side” of the moon that faces Earth is bit larger than the side turned away from us. This makes it slightly similar to the shape of typical bird egg that is larger on one “end” than on other. You might think of it as “gumdrop” shaped. So the moon is not exactly spherical. The deviation is small, but real.

Myth 3. The moon is bright white. Anyone who has seen a full moon high in a clear sky late at night has a right to believe this. Comparatively speaking, however, the moon is neither particularly bright nor actually white. It appears very bright relative to the dark sky, and ordinarily looks white to the eye. Remember the old-style incandescent light bulbs? Now imagine a 100-watt light bulb located about 150 feet away, and shining in an otherwise completely dark night. That is approximately how bright the full moon is. Really.

And the color? Well, as with brightness, color is a subjective thing. The moon emits no light of its own, but rather shines by reflecting sunlight. Sunlight is composed of all colors, but peaks in the yellow-green range of the spectrum. The sun looks white when high in the sky, as does the moon, because of the way our eye-brain connection mixes all the colors together. The moon’s color varies somewhat according to its phase and position in the sky, although this color variation generally is too subtle for human eyes. However, the moon is actually gray rather than pure white, on average much like the well-worn asphalt on most streets.

This isn’t a real photo. It’s from a television commercial for Nike footwear, called “Moon Jump.” The idea of zero gravity on the moon is equally imaginary. Read more about this image here.

Myth 4. There is no gravity on the moon. But of course the moon does have gravity. The idea that the moon has no gravity is frankly so ludicrous that I would not even mention it were it not so prevalent. Shown an image of one of the Apollo astronauts jumping high or seemingly floating across the lunar surface, some of my college students will reply that it is because there is no gravity on the moon. In reality, the force of gravity on the moon is only about one-sixth what it is on Earth, but it is still there.

I think that this moon myth, widespread though it may be, is simply a misunderstanding of what the word gravity means in physics. Every physical body, whether it be the sun, the Earth, the moon, a human body or a subatomic particle – everything that has substance – has a gravitational pull. While the practicality of measuring your weight (the pull of gravity) on tiny objects, such as a grain of sand, can be debated, the force exists and can be calculated. Even photons of light and other forms of energy exhibit gravity. Gravity holds galaxy clusters, galaxies, stars, planets and moons together and/or in orbit about each other. If every physical thing did not exhibit gravity, the universe as we know it could not exist.

The moon may tug your heartstrings, but its tidal effect on the human body is negligible. Image is a still from a beautiful video called Full Moon Silhouettes by Mark Gee. View the video here.

Myth 5. The moon raises significant tides in people. There is no question that the moon, or rather its gravity, is the major cause of oceans tides on Earth. The sun’s gravity raises tides, too, by the way, but its effect is smaller. Some folks use the indisputable fact of the moon’s effect on the tides to argue that the moon raises tides in the human body. However, to believe that ocean tides and human tides both are caused by the moon betrays a major misunderstanding about how gravity works to produce ocean tides.

In short, gravity depends on two things: mass and distance. Tides are produced only when the two objects involved (say, the Earth and the moon) are both of astronomical size (far larger than a human!), and also close (astronomically) in distance. The moon is roughly 30 Earth diameters away from our planet, and roughly 1/80th of the Earth’s mass. Given that, the moon helps raise tides, which on average, are a couple of meters high in the fluid oceans.

If tidal effects were even measurable in the human body, which they aren’t, they would be on the order of a ten-millionth of a meter, or about one-thousandth the thickness of a piece of paper. Those are still tides, you say? Perhaps. But they are far, far smaller tides than are raised within your body when a truck passes you on the highway … or even when another person walks past you on the street.

So while the moon’s gravity can power the tides on Earth, its effect on a human body is utterly inconsequential.

By the way, we often hear people say that nurses in hospitals report an increase in birth rate at times of the month when the moon is full. But studies don’t bear out this correlation. There’s a concise summary of moon / birth rate studies at Wikipedia. Be sure to click into the references to see that they were published in bonafide science journals, such as the New England Journal of Medicine, American Journal of Obstetrics and Gynecology, and so on.

On the other hand, women’s menstrual cycles do appear to correlate with the cycle of the moon’s monthly orbit around Earth. If it is a true correlation, and not a coincidence, it has yet to be explained. We’re not saying a correlation doesn’t exist … just that gravity doesn’t cause it.

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Bottom line: Common myths about Earth’s moon explained.

from EarthSky http://ift.tt/16tcP67

Myth 1 is that moon has a permanent dark side. This is the far side of the moon, as photographed by Apollo 16 in 1972. See? It isn’t dark. Image via NASA.

We have full moons, blue moons, Harvest moons, supermoons and any number of culturally relevant references to the moon. Maybe it’s time to unearth a few moon myths and misconceptions. Follow the links below to learn more about the moon.

Myth 1. The moon has a permanent dark side.

Myth 2. The moon is perfectly round.

Myth 3. The moon is bright white.

Myth 4. There is no gravity on the moon.

Myth 5. The moon raises tides in people.

EarthSky tees are back! Learn how your purchase helps support worthy causes, and use code ESFRIENDS for $5 off.

The eighth studio album by the English progressive rock band Pink Floyd – released in March 1973 – was titled Dark Side of the Moon and probably helped perpetuate the myth. Here’s original album artwork by Hipgnosis and George Hardie. Via Wikimedia Commons.

Myth 1. The moon has a permanent dark side. Most grammar school students know that the moon presents only one face or side to the Earth. This is (roughly) true and gives rise to the idea that there is a permanently dark side of the moon, a thought immortalized in Pink Flyod’s music and elsewhere.

In fact, the side of the moon that is perpetually turned away from Earth is no more dark than the side we see. It is fully illuminated by the sun just as often (lunar daytime), and is in shade just as often (lunar night), as is the familiar Man in the Moon face we see.

The Earth-facing side of the moon gives rise to another misconception that many people share, namely that we see only 50% of the moon from Earth. In fact, only about 41 percent of the moon’s far side (a much more accurate and preferable term than dark side) is perpetually hidden from earthly observers. A diligent observer on Earth can, over time, observe about 59% of the moon’s surface. This is because a phenomenon called libration causes the moon’s viewing angle, relative to Earth, to change slightly over its orbit.

Lunar libration is due to the fact that the moon’s orbit around Earth isn’t a perfect circle. Instead, it’s a slightly elongated circle called an ellipse. Imagine a race car on an elliptical track. At each elliptical end of the racecourse, the car is flung out slightly due to the change in angle. It is a bit like rounding a corner. The result for the moon is that it occasionally exposes slightly more of its surface on the eastern or western extreme (depending on the location in the orbit). That’s why, as viewed from Earth, about 59% of the moon’s surface is exposed over the course of the moon’s (roughly) monthly orbit around the Earth.

Near side of the moon, as seen through a telescope. The moon looks round, but it isn’t. In a dark sky, the moon looks bright white, but this image captures its true asphalt gray color. Notice that the moon’s near side has dark “maria” or “seas,” while the moon’s far side (photo at top of post) lacks these features. Image via Wikimedia Commons.

Myth 2. The moon is perfectly round. To the eye, the moon appears round, and it’s natural to assume that it is actually spherical in shape – with every point on its surface equidistant from its center – like a big ball. Not so. The shape of the moon is that of an oblate spheroid, meaning it has the shape of a ball that is slightly flattened. Look at a photo of Jupiter and you will see a good example of this. The moon exhibits very slight oblateness, but more important is the fact that the “side” of the moon that faces Earth is bit larger than the side turned away from us. This makes it slightly similar to the shape of typical bird egg that is larger on one “end” than on other. You might think of it as “gumdrop” shaped. So the moon is not exactly spherical. The deviation is small, but real.

Myth 3. The moon is bright white. Anyone who has seen a full moon high in a clear sky late at night has a right to believe this. Comparatively speaking, however, the moon is neither particularly bright nor actually white. It appears very bright relative to the dark sky, and ordinarily looks white to the eye. Remember the old-style incandescent light bulbs? Now imagine a 100-watt light bulb located about 150 feet away, and shining in an otherwise completely dark night. That is approximately how bright the full moon is. Really.

And the color? Well, as with brightness, color is a subjective thing. The moon emits no light of its own, but rather shines by reflecting sunlight. Sunlight is composed of all colors, but peaks in the yellow-green range of the spectrum. The sun looks white when high in the sky, as does the moon, because of the way our eye-brain connection mixes all the colors together. The moon’s color varies somewhat according to its phase and position in the sky, although this color variation generally is too subtle for human eyes. However, the moon is actually gray rather than pure white, on average much like the well-worn asphalt on most streets.

This isn’t a real photo. It’s from a television commercial for Nike footwear, called “Moon Jump.” The idea of zero gravity on the moon is equally imaginary. Read more about this image here.

Myth 4. There is no gravity on the moon. But of course the moon does have gravity. The idea that the moon has no gravity is frankly so ludicrous that I would not even mention it were it not so prevalent. Shown an image of one of the Apollo astronauts jumping high or seemingly floating across the lunar surface, some of my college students will reply that it is because there is no gravity on the moon. In reality, the force of gravity on the moon is only about one-sixth what it is on Earth, but it is still there.

I think that this moon myth, widespread though it may be, is simply a misunderstanding of what the word gravity means in physics. Every physical body, whether it be the sun, the Earth, the moon, a human body or a subatomic particle – everything that has substance – has a gravitational pull. While the practicality of measuring your weight (the pull of gravity) on tiny objects, such as a grain of sand, can be debated, the force exists and can be calculated. Even photons of light and other forms of energy exhibit gravity. Gravity holds galaxy clusters, galaxies, stars, planets and moons together and/or in orbit about each other. If every physical thing did not exhibit gravity, the universe as we know it could not exist.

The moon may tug your heartstrings, but its tidal effect on the human body is negligible. Image is a still from a beautiful video called Full Moon Silhouettes by Mark Gee. View the video here.

Myth 5. The moon raises significant tides in people. There is no question that the moon, or rather its gravity, is the major cause of oceans tides on Earth. The sun’s gravity raises tides, too, by the way, but its effect is smaller. Some folks use the indisputable fact of the moon’s effect on the tides to argue that the moon raises tides in the human body. However, to believe that ocean tides and human tides both are caused by the moon betrays a major misunderstanding about how gravity works to produce ocean tides.

In short, gravity depends on two things: mass and distance. Tides are produced only when the two objects involved (say, the Earth and the moon) are both of astronomical size (far larger than a human!), and also close (astronomically) in distance. The moon is roughly 30 Earth diameters away from our planet, and roughly 1/80th of the Earth’s mass. Given that, the moon helps raise tides, which on average, are a couple of meters high in the fluid oceans.

If tidal effects were even measurable in the human body, which they aren’t, they would be on the order of a ten-millionth of a meter, or about one-thousandth the thickness of a piece of paper. Those are still tides, you say? Perhaps. But they are far, far smaller tides than are raised within your body when a truck passes you on the highway … or even when another person walks past you on the street.

So while the moon’s gravity can power the tides on Earth, its effect on a human body is utterly inconsequential.

By the way, we often hear people say that nurses in hospitals report an increase in birth rate at times of the month when the moon is full. But studies don’t bear out this correlation. There’s a concise summary of moon / birth rate studies at Wikipedia. Be sure to click into the references to see that they were published in bonafide science journals, such as the New England Journal of Medicine, American Journal of Obstetrics and Gynecology, and so on.

On the other hand, women’s menstrual cycles do appear to correlate with the cycle of the moon’s monthly orbit around Earth. If it is a true correlation, and not a coincidence, it has yet to be explained. We’re not saying a correlation doesn’t exist … just that gravity doesn’t cause it.

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Bottom line: Common myths about Earth’s moon explained.

from EarthSky http://ift.tt/16tcP67

2017 SkS Weekly Climate Change & Global Warming Digest #39

Story of the Week... Toon of the Week... Coming Soon on SkS... Poster of the Week... Climate Feedback Reviews... SkS Week in Review... 97 Hours of Consensus...

Story of the Week...

September is the most energetic month for hurricanes ever recorded in the Atlantic

 

Satellite image of Hurricane Maria making landfall on Puerto Rico on Sep 20, 2017 

The 2017 hurricane season has certainly been one for the record books. Whether it be Harvey’s scale-tipping rains, Irma’s off-the-chart winds, or the sheer number of storms that have spun up, this year is clearly anything but normal.

But how wacky has the weather in the tropics been? For that, meteorologists refer to a figure known as ACE, a measure of every hurricane’s energy put together during its life span. September produced the most ACE in any month on record in the Atlantic Ocean.

ACE, or Accumulated Cyclone Energy, is manifest in stirred-up oceans, steamy downpours, crackling lightning and ferocious winds. The force to instigate these nasty conditions is extracted from the roasting waters of the tropical Atlantic and Caribbean, and transformed into motion through a hurricane’s natural “heat engine.”

To quantify this measure, scientists take into account the strength of the winds within each and every storm, as well as their duration. ACE is calculated every six hours, and a running tally is kept for each storm so long as it sticks around. The measure does not take into account a storm’s size. 

September is the most energetic month for hurricanes ever recorded in the Atlantic by Matthew Cappucci, Capital Weather Gang, Washington Post, Sep 27, 2017

---

Toon of the Week...

 

Hat tip to Stop Science Denial Facebook page. 

---

Coming Soon on SkS...

• Why the 97% climate consensus is important (Dana, John Cook, Sander van der Linden, Ed Maibach, Tony Lieserowitz)
• Factcheck: Mail on Sunday’s ‘astonishing evidence’ about global temperature rise (Zeke Hausfather)
• Global climate impacts of a potential volcanic eruption of Mount Agung (Flavio Lehner & John Fasullo)
• Guest Post (John Abraham)
• New research, Sep - Oct 1 2017 (Ari)
• 2017 SkS Weekly Climate Change & Global Warming News Roundup #40 (John Hartz)
• 2017 SkS Weekly Climate Change & Global Waming Digest #40 (John Hartz)

---

Poster of the Week...

 

---

Climate Feedback Reviews...

Climate Feedback asked its network of scientists to review the article, Climate Change Is Complex. We’ve Got Answers to Your Questions by Justin Gillis, New York Times, Sep 19, 2017.

Thirteen scientists analyzed the article and estimated its overall scientific credibility to be ‘high’ to ‘very high’.

A majority of reviewers tagged the article as: Accurate

Review Summary

This article in The New York Times serves as a primer by briefly answering seventeen basic questions about the cause and consequences of—and possible solutions to—climate change.

Thirteen scientists reviewed the article, and generally found the answers to be highly accurate distillations of the research on that topic. There are only a few instances where answers—mainly to questions about efforts to reduce greenhouse gas emissions—are worded in an imprecise way that could lead to readers misunderstanding the state of scientific knowledge.

New York Times’ “straightforward answers” to common climate questions are accurate, too, Climate Feedback, Sep 28, 2017

---

SkS Week in Review... 

• 2017 SkS Weekly Climate Change & Global Warming News Roundup #39 by John Hartz
• New research, September 18-24, 2017 by Ari Jokimäki
• Climate and energy are becoming focal points in state political races by John Abraham (Climate Consenus - the 97%, Guardian)
• Right-wing media could not be more wrong about the 1.5°C carbon budget paper by Dana Nuccitelli (Climate Consenus - the 97%, Guardian)
• Potholer on the 1.5C carbon budget paper controversy by Guest Author
• The Mail's censure shows which media outlets are biased on climate change by Dana Nuccitelli (Climate Consenus - the 97%, Guardian)
• 2017 SkS Weekly Climate Change & Global Warming Digest #38 by John Hartz

---

97 Hours of Consensus...

 

 

Chris Forest's bio page

Quote derived with author's permission from:

"[I]t's very clear from the observations that the climate system has warmed over the past century, and that these results are then consistent with human causes having forced the climate system over the past century." 

High resolution JPEG (1024 pixels wide)

from Skeptical Science http://ift.tt/2g2qz6B

Story of the Week... Toon of the Week... Coming Soon on SkS... Poster of the Week... Climate Feedback Reviews... SkS Week in Review... 97 Hours of Consensus...

Story of the Week...

September is the most energetic month for hurricanes ever recorded in the Atlantic

 

Satellite image of Hurricane Maria making landfall on Puerto Rico on Sep 20, 2017 

The 2017 hurricane season has certainly been one for the record books. Whether it be Harvey’s scale-tipping rains, Irma’s off-the-chart winds, or the sheer number of storms that have spun up, this year is clearly anything but normal.

But how wacky has the weather in the tropics been? For that, meteorologists refer to a figure known as ACE, a measure of every hurricane’s energy put together during its life span. September produced the most ACE in any month on record in the Atlantic Ocean.

ACE, or Accumulated Cyclone Energy, is manifest in stirred-up oceans, steamy downpours, crackling lightning and ferocious winds. The force to instigate these nasty conditions is extracted from the roasting waters of the tropical Atlantic and Caribbean, and transformed into motion through a hurricane’s natural “heat engine.”

To quantify this measure, scientists take into account the strength of the winds within each and every storm, as well as their duration. ACE is calculated every six hours, and a running tally is kept for each storm so long as it sticks around. The measure does not take into account a storm’s size. 

September is the most energetic month for hurricanes ever recorded in the Atlantic by Matthew Cappucci, Capital Weather Gang, Washington Post, Sep 27, 2017

---

Toon of the Week...

 

Hat tip to Stop Science Denial Facebook page. 

---

Coming Soon on SkS...

• Why the 97% climate consensus is important (Dana, John Cook, Sander van der Linden, Ed Maibach, Tony Lieserowitz)
• Factcheck: Mail on Sunday’s ‘astonishing evidence’ about global temperature rise (Zeke Hausfather)
• Global climate impacts of a potential volcanic eruption of Mount Agung (Flavio Lehner & John Fasullo)
• Guest Post (John Abraham)
• New research, Sep - Oct 1 2017 (Ari)
• 2017 SkS Weekly Climate Change & Global Warming News Roundup #40 (John Hartz)
• 2017 SkS Weekly Climate Change & Global Waming Digest #40 (John Hartz)

---

Poster of the Week...

 

---

Climate Feedback Reviews...

Climate Feedback asked its network of scientists to review the article, Climate Change Is Complex. We’ve Got Answers to Your Questions by Justin Gillis, New York Times, Sep 19, 2017.

Thirteen scientists analyzed the article and estimated its overall scientific credibility to be ‘high’ to ‘very high’.

A majority of reviewers tagged the article as: Accurate

Review Summary

This article in The New York Times serves as a primer by briefly answering seventeen basic questions about the cause and consequences of—and possible solutions to—climate change.

Thirteen scientists reviewed the article, and generally found the answers to be highly accurate distillations of the research on that topic. There are only a few instances where answers—mainly to questions about efforts to reduce greenhouse gas emissions—are worded in an imprecise way that could lead to readers misunderstanding the state of scientific knowledge.

New York Times’ “straightforward answers” to common climate questions are accurate, too, Climate Feedback, Sep 28, 2017

---

SkS Week in Review... 

• 2017 SkS Weekly Climate Change & Global Warming News Roundup #39 by John Hartz
• New research, September 18-24, 2017 by Ari Jokimäki
• Climate and energy are becoming focal points in state political races by John Abraham (Climate Consenus - the 97%, Guardian)
• Right-wing media could not be more wrong about the 1.5°C carbon budget paper by Dana Nuccitelli (Climate Consenus - the 97%, Guardian)
• Potholer on the 1.5C carbon budget paper controversy by Guest Author
• The Mail's censure shows which media outlets are biased on climate change by Dana Nuccitelli (Climate Consenus - the 97%, Guardian)
• 2017 SkS Weekly Climate Change & Global Warming Digest #38 by John Hartz

---

97 Hours of Consensus...

 

 

Chris Forest's bio page

Quote derived with author's permission from:

"[I]t's very clear from the observations that the climate system has warmed over the past century, and that these results are then consistent with human causes having forced the climate system over the past century." 

High resolution JPEG (1024 pixels wide)

from Skeptical Science http://ift.tt/2g2qz6B

Scientists reveal secrets of lost continent Zealandia

A rainbow seen from the research ship JOIDES Resolution, during the Zealandia expedition. Image by Tim Fulton via International Ocean Discovery Program/ JRSO/ NSF.

A team of 32 scientists from 12 countries returned last week from a nine-week voyage to study the once-lost continent of Zealandia in the South Pacific. This mostly submerged or hidden continent is an elevated part of the ocean floor, about two-thirds the size of Australia, located between New Zealand and New Caledonia. Scientists said earlier this year they thought Zealandia should be recognized as a full-fledged Earth continent. This was one of the first extensive surveys of the region, and the scientists who carried it out – affiliated with the International Ocean Discovery Program (IODP) at Texas A&M University – have just arrived back in Hobart, Tasmania, aboard the research vessel JOIDES Resolution. They said their work has already revealed that Zealandia might once have been much closer to land level than previously thought, providing pathways for animals and plants to cross between continents.

Little is known about Zealandia because it’s submerged about two-thirds of a miles (more than a kilometer) under the sea. Until now, the region has been sparsely surveyed and sampled.

Scientists taking part in the 2017 expedition drilled deep into Zealandia’s seabed at six sites in water depths of more than 4,000 feet (1,250 meters). They collected 8,000 feet (2,500 meters) of sediment cores from layers that record how the geography, volcanism and climate of the region have changed over millions of years.

EarthSky tees are back! Learn how your purchase helps support worthy causes, and use code ESFRIENDS for $5 off.

A global view of the submerged continent of Zealandia, via GNS Science.

View larger. | Detailed map of Zealandia … once lost, now found. Image via IODP/ NSF.

According to expedition co-chief scientist Gerald Dickens of Rice University in Houston, Texas, Zealandia expedition scientists made significant new fossil discoveries, proving that Zealandia was not always as deep beneath the waves as it is today. He said:

More than 8,000 specimens were studied, and several hundred fossil species were identified.

The discovery of microscopic shells of organisms that lived in warm shallow seas, and of spores and pollen from land plants, reveal that the geography and climate of Zealandia were dramatically different in the past.

He also said that the new discoveries show that the Pacific Ocean’s encircling Ring of Fire – where there are frequent earthquakes and powerful volcanic eruptions – had a role in causing Zealandia’s submersion beneath the ocean waves. That is, he said, the formation of the Ring of Fire caused dramatic changes in ocean depth and volcanic activity, which buckled the seabed of Zealandia.

Researchers explored deep under Zealandia’s sea floor, obtaining samples of the continent. Image via IODP/ NSF.

A sediment core obtained through deep-sea drilling. It’ll be pored over by scientists long after the expedition’s end. Image by Tim Fulton via IODP JRSO/ NSF.

Expedition co-chief scientist Rupert Sutherland of Victoria University of Wellington in New Zealand said researchers had believed that Zealandia was submerged when it separated from Australia and Antarctica about 80 million years ago:

That is still probably accurate, but it is now clear that dramatic later events shaped the continent we explored on this voyage.

Big geographic changes across northern Zealandia, which is about the same size as India, have implications for understanding questions such as how plants and animals dispersed and evolved in the South Pacific.

The discovery of past land and shallow seas now provides an explanation. There were pathways for animals and plants to move along.

The sediment cores obtained during the expedition will be studied by scientists long after the expedition’s end. The scientists said they expect the cores to help them understand how Earth’s tectonic plates move and how the global climate system works.

These scientists also said that records of Zealandia’s history will provide a sensitive test for computer models used to predict future changes in climate.

The JOIDES Resolution – which carried scientists on the Zealandia expendition – at the dock in Townsville, Australia. Image by Tim Fulton via IODP JRSO/ NSF.

Bottom line: An international team of scientists has just returned from the first major expedition to Zealandia, which some believed should be recognized as a full-fledged Earth continent, now submerged beneath the ocean in the South Pacific.

from EarthSky http://ift.tt/2yQ3con

A rainbow seen from the research ship JOIDES Resolution, during the Zealandia expedition. Image by Tim Fulton via International Ocean Discovery Program/ JRSO/ NSF.

A team of 32 scientists from 12 countries returned last week from a nine-week voyage to study the once-lost continent of Zealandia in the South Pacific. This mostly submerged or hidden continent is an elevated part of the ocean floor, about two-thirds the size of Australia, located between New Zealand and New Caledonia. Scientists said earlier this year they thought Zealandia should be recognized as a full-fledged Earth continent. This was one of the first extensive surveys of the region, and the scientists who carried it out – affiliated with the International Ocean Discovery Program (IODP) at Texas A&M University – have just arrived back in Hobart, Tasmania, aboard the research vessel JOIDES Resolution. They said their work has already revealed that Zealandia might once have been much closer to land level than previously thought, providing pathways for animals and plants to cross between continents.

Little is known about Zealandia because it’s submerged about two-thirds of a miles (more than a kilometer) under the sea. Until now, the region has been sparsely surveyed and sampled.

Scientists taking part in the 2017 expedition drilled deep into Zealandia’s seabed at six sites in water depths of more than 4,000 feet (1,250 meters). They collected 8,000 feet (2,500 meters) of sediment cores from layers that record how the geography, volcanism and climate of the region have changed over millions of years.

EarthSky tees are back! Learn how your purchase helps support worthy causes, and use code ESFRIENDS for $5 off.

A global view of the submerged continent of Zealandia, via GNS Science.

View larger. | Detailed map of Zealandia … once lost, now found. Image via IODP/ NSF.

According to expedition co-chief scientist Gerald Dickens of Rice University in Houston, Texas, Zealandia expedition scientists made significant new fossil discoveries, proving that Zealandia was not always as deep beneath the waves as it is today. He said:

More than 8,000 specimens were studied, and several hundred fossil species were identified.

The discovery of microscopic shells of organisms that lived in warm shallow seas, and of spores and pollen from land plants, reveal that the geography and climate of Zealandia were dramatically different in the past.

He also said that the new discoveries show that the Pacific Ocean’s encircling Ring of Fire – where there are frequent earthquakes and powerful volcanic eruptions – had a role in causing Zealandia’s submersion beneath the ocean waves. That is, he said, the formation of the Ring of Fire caused dramatic changes in ocean depth and volcanic activity, which buckled the seabed of Zealandia.

Researchers explored deep under Zealandia’s sea floor, obtaining samples of the continent. Image via IODP/ NSF.

A sediment core obtained through deep-sea drilling. It’ll be pored over by scientists long after the expedition’s end. Image by Tim Fulton via IODP JRSO/ NSF.

Expedition co-chief scientist Rupert Sutherland of Victoria University of Wellington in New Zealand said researchers had believed that Zealandia was submerged when it separated from Australia and Antarctica about 80 million years ago:

That is still probably accurate, but it is now clear that dramatic later events shaped the continent we explored on this voyage.

Big geographic changes across northern Zealandia, which is about the same size as India, have implications for understanding questions such as how plants and animals dispersed and evolved in the South Pacific.

The discovery of past land and shallow seas now provides an explanation. There were pathways for animals and plants to move along.

The sediment cores obtained during the expedition will be studied by scientists long after the expedition’s end. The scientists said they expect the cores to help them understand how Earth’s tectonic plates move and how the global climate system works.

These scientists also said that records of Zealandia’s history will provide a sensitive test for computer models used to predict future changes in climate.

The JOIDES Resolution – which carried scientists on the Zealandia expendition – at the dock in Townsville, Australia. Image by Tim Fulton via IODP JRSO/ NSF.

Bottom line: An international team of scientists has just returned from the first major expedition to Zealandia, which some believed should be recognized as a full-fledged Earth continent, now submerged beneath the ocean in the South Pacific.

from EarthSky http://ift.tt/2yQ3con

What’s the birthstone for October?

Opalized fossils. Image via Cobalt123

Opal

The opal is a fragile hydrated silica material, made of submicroscopic silica spheres held together by more silica and water. It is a soft stone, easily altered in appearance by changes in heat and pressure. This mineral contains varying amounts of water within it that determine the appearance of the gemstone. When water evaporates out of an opal, the stone appears slightly smaller and the stress of the evaporation creates cracks on it.

Opals are formed in near-surface volcanic rocks, within cavities and cracks. In sedimentary volcanic ash rock, percolating water in the ground dissolves silica that eventually precipitates to form the opal, sometimes becoming the replacement material for fossils – shells, bones, wood – whose original material had dissolved away.

Image via Aramgutang

Opals are famous for their “play of colors” – many stones flash the colors of the rainbow when moved, due to the interference of light on small cracks and other internal structural differences. Opals also have characteristic colors due to impurities within the stone. The milky or pearly appearance of some opals are due to inclusions of tiny gas bubbles. Yellows and reds betray the presence of iron oxides. The spectacular black opals that sometimes flash green, blue and red get their color from magnesium oxides and organic carbon within the stone. Perhaps the most valuable opal pattern is the “harlequin,” large angular patches of red, yellow and green resembling the checks on a clown’s costume.

The principal source of opals is Australia, noted for its magnificent black opals. Fire opals were first mined in Mexico, and continue to be produced today. In the United States, brilliant fire opals are also found in Nevada. Other commercial sources of opal are Brazil, Honduras, Nicaragua, Guatemala, Japan and Ireland.

The name opal is derived from the Sanskrit word “upala,” as well as the Latin “opalus,” meaning “precious stone.” Opal is a gemstone of much variety; the ancient Roman natural historian Pliny once described it in the following way:

It is made up of the glories of the most precious stones. To describe it is a matter of inexpressive difficulty: There is in it the gentler fire of the ruby, the brilliant purple of the amethyst, the sea-green of the emerald, all shining together in an incredible union.

There is an Indian legend about the origin of the opal. Quoted from Gemstones by Willard Heaps:

The gods Brahma, Vishnu and Shiva once vied in jealous love for a beautiful woman. This angered the Eternal, who changed the fair mortal into a creature made of mist. Thereupon each of the three gods endowed her with his own color so as to be able to recognize her. Brahma gave her the glorious blue of the heavens, Vishnu enriched her with the splendor of gold, and Shiva lent her his flaming red. But all this was in vain, since the lovely phantom was whisked away by the winds. Finally, the Eternal took pity on her and transformed her into a stone, the opal, that sparkles in all the colors of the rainbow.

To ancient Romans, the opal was a symbol of love and hope. Orientals called it the “anchor of hope.” Arabs say it fell from the heavens in flashes of lightning. It was believed to make its wearer invisible, hence the opal was the talisman of thieves and spies.

During the Medieval period, a change in color intensity of an opal was believed to indicated if its wearer was ill or in good health. The opal was supposed to maintain a strong heart, prevent fainting, protect against infection, and cleanse foul-smelling air. The stone, as in ancient times, was still regarded as a symbol of hope.

But the opal’s reputation changed in the mid-14th century. The Black Death swept across Europe, killing one quarter of its population. The gem was believed to be the cause of death. When worn by someone struck with the deadly plague, it would appear brilliant only until the person died. Then it would change in appearance, losing its luster. In reality, it was the sensitivity of this stone to changes in temperature that altered its appearance, as the heat from a burning fever gave way to the chill of death.

In Elizabethan England, the opal was treasured for its beauty. Shakespeare wrote of it in the Twelfth Night as the “queen of gems.” Queen Victoria presented her children with opal jewelry, thus making the the stone popular. But the stone continued to have a mixed reputation, chiefly due to a novel written by Sir Walter Scott in 1887 that depicted it as a stone of evil.

In Australia, there is a legend of a huge opal that governs the stars and guides human love, as well as controls the gold in mines. But Australian aborigines see it in a different light – to them, the opal is the devil that lurks in the ground, a half-serpent and half-human with flashes of wicked magic that lures men to destruction.

Tourmaline via Orbital Joe

Tourmaline
The alternate birthstone for October is the tourmaline, a gemstone that exhibits the broadest spectrum of gemstone colors. Gem-quality forms of this mineral have in the past been misidentified as rubies, emeralds and sapphires. In fact, a famous tourmaline-the size of a pigeon’s egg-belonging to the Russian Empress Catherine the Great was long thought to be a ruby. The name of this gemstone is believed to derive from the Singhalese (Sri Lankan) word “toramalli,” a term applied to yellow, green or brown stones, that means “something little out of the earth.”

Tourmaline is a complex aluminous borosilicate mineral built of crystals with complicated aggregations of sodium, aluminum, boron, oxygen, hydrogen and silicon atoms. Other metals are also present within the crystal structure, and are responsible for the characteristic colors of the gemstones. Pink, for example, is due to the presence of manganese, while ferrous iron, chromium or vanadium betray their presence as green gemstones.

Most tourmalines are found in a myriad of colors: yellow, green, red, blue, pink, brown, black. Some even have bi-colored properties. A valued bi-colored variety of tourmaline, found in Brazil, is called the “watermelon.” The outer edges of the gem are green, transitioning to a transparent white zone that gives way to a pink or light red interior.

Tourmaline has an unusual property. When it is warmed or rubbed, it attracts small bits of paper, lint and ash. This occurs because the gem becomes charged with static electricity. In fact, Benjamin Franklin used this gem in his studies of electricity. Maintaining a tourmaline exhibit at museums requires frequent cleaning of the gemstone because heat from lights of the display case create a charge in the stone that attracts dust.

Compared with other gemstones, tourmalines are a relatively recent discovery. Hence, it lacks the rich lore that accompanies many other precious gems. However, among some people, the stone is known as the “peace stone,” believed to dispel fear and make its wearer calm.

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Find out about the birthstones for the other months of the year:

January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

from EarthSky http://ift.tt/2hFAz9q

Opalized fossils. Image via Cobalt123

Opal

The opal is a fragile hydrated silica material, made of submicroscopic silica spheres held together by more silica and water. It is a soft stone, easily altered in appearance by changes in heat and pressure. This mineral contains varying amounts of water within it that determine the appearance of the gemstone. When water evaporates out of an opal, the stone appears slightly smaller and the stress of the evaporation creates cracks on it.

Opals are formed in near-surface volcanic rocks, within cavities and cracks. In sedimentary volcanic ash rock, percolating water in the ground dissolves silica that eventually precipitates to form the opal, sometimes becoming the replacement material for fossils – shells, bones, wood – whose original material had dissolved away.

Image via Aramgutang

Opals are famous for their “play of colors” – many stones flash the colors of the rainbow when moved, due to the interference of light on small cracks and other internal structural differences. Opals also have characteristic colors due to impurities within the stone. The milky or pearly appearance of some opals are due to inclusions of tiny gas bubbles. Yellows and reds betray the presence of iron oxides. The spectacular black opals that sometimes flash green, blue and red get their color from magnesium oxides and organic carbon within the stone. Perhaps the most valuable opal pattern is the “harlequin,” large angular patches of red, yellow and green resembling the checks on a clown’s costume.

The principal source of opals is Australia, noted for its magnificent black opals. Fire opals were first mined in Mexico, and continue to be produced today. In the United States, brilliant fire opals are also found in Nevada. Other commercial sources of opal are Brazil, Honduras, Nicaragua, Guatemala, Japan and Ireland.

The name opal is derived from the Sanskrit word “upala,” as well as the Latin “opalus,” meaning “precious stone.” Opal is a gemstone of much variety; the ancient Roman natural historian Pliny once described it in the following way:

It is made up of the glories of the most precious stones. To describe it is a matter of inexpressive difficulty: There is in it the gentler fire of the ruby, the brilliant purple of the amethyst, the sea-green of the emerald, all shining together in an incredible union.

There is an Indian legend about the origin of the opal. Quoted from Gemstones by Willard Heaps:

The gods Brahma, Vishnu and Shiva once vied in jealous love for a beautiful woman. This angered the Eternal, who changed the fair mortal into a creature made of mist. Thereupon each of the three gods endowed her with his own color so as to be able to recognize her. Brahma gave her the glorious blue of the heavens, Vishnu enriched her with the splendor of gold, and Shiva lent her his flaming red. But all this was in vain, since the lovely phantom was whisked away by the winds. Finally, the Eternal took pity on her and transformed her into a stone, the opal, that sparkles in all the colors of the rainbow.

To ancient Romans, the opal was a symbol of love and hope. Orientals called it the “anchor of hope.” Arabs say it fell from the heavens in flashes of lightning. It was believed to make its wearer invisible, hence the opal was the talisman of thieves and spies.

During the Medieval period, a change in color intensity of an opal was believed to indicated if its wearer was ill or in good health. The opal was supposed to maintain a strong heart, prevent fainting, protect against infection, and cleanse foul-smelling air. The stone, as in ancient times, was still regarded as a symbol of hope.

But the opal’s reputation changed in the mid-14th century. The Black Death swept across Europe, killing one quarter of its population. The gem was believed to be the cause of death. When worn by someone struck with the deadly plague, it would appear brilliant only until the person died. Then it would change in appearance, losing its luster. In reality, it was the sensitivity of this stone to changes in temperature that altered its appearance, as the heat from a burning fever gave way to the chill of death.

In Elizabethan England, the opal was treasured for its beauty. Shakespeare wrote of it in the Twelfth Night as the “queen of gems.” Queen Victoria presented her children with opal jewelry, thus making the the stone popular. But the stone continued to have a mixed reputation, chiefly due to a novel written by Sir Walter Scott in 1887 that depicted it as a stone of evil.

In Australia, there is a legend of a huge opal that governs the stars and guides human love, as well as controls the gold in mines. But Australian aborigines see it in a different light – to them, the opal is the devil that lurks in the ground, a half-serpent and half-human with flashes of wicked magic that lures men to destruction.

Tourmaline via Orbital Joe

Tourmaline
The alternate birthstone for October is the tourmaline, a gemstone that exhibits the broadest spectrum of gemstone colors. Gem-quality forms of this mineral have in the past been misidentified as rubies, emeralds and sapphires. In fact, a famous tourmaline-the size of a pigeon’s egg-belonging to the Russian Empress Catherine the Great was long thought to be a ruby. The name of this gemstone is believed to derive from the Singhalese (Sri Lankan) word “toramalli,” a term applied to yellow, green or brown stones, that means “something little out of the earth.”

Tourmaline is a complex aluminous borosilicate mineral built of crystals with complicated aggregations of sodium, aluminum, boron, oxygen, hydrogen and silicon atoms. Other metals are also present within the crystal structure, and are responsible for the characteristic colors of the gemstones. Pink, for example, is due to the presence of manganese, while ferrous iron, chromium or vanadium betray their presence as green gemstones.

Most tourmalines are found in a myriad of colors: yellow, green, red, blue, pink, brown, black. Some even have bi-colored properties. A valued bi-colored variety of tourmaline, found in Brazil, is called the “watermelon.” The outer edges of the gem are green, transitioning to a transparent white zone that gives way to a pink or light red interior.

Tourmaline has an unusual property. When it is warmed or rubbed, it attracts small bits of paper, lint and ash. This occurs because the gem becomes charged with static electricity. In fact, Benjamin Franklin used this gem in his studies of electricity. Maintaining a tourmaline exhibit at museums requires frequent cleaning of the gemstone because heat from lights of the display case create a charge in the stone that attracts dust.

Compared with other gemstones, tourmalines are a relatively recent discovery. Hence, it lacks the rich lore that accompanies many other precious gems. However, among some people, the stone is known as the “peace stone,” believed to dispel fear and make its wearer calm.

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Find out about the birthstones for the other months of the year:

January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

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Minnesota northern lights

Photo via Judy Allen.

Judy Allen wrote:

Northern lights early this morning in southwestern Minnesota! It was an awesome show!

Thanks for sharing this with us Judy.

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Photo via Judy Allen.

Judy Allen wrote:

Northern lights early this morning in southwestern Minnesota! It was an awesome show!

Thanks for sharing this with us Judy.

EarthSky tees are back! Check out the styles and colors

from EarthSky http://ift.tt/2xM9ENm

Can you find the Big Dipper?

Tonight … can you find the Big Dipper at nightfall and early evening? It’s perhaps the most famous of all star patterns, and – for those at latitudes 41 degrees North or farther north – it’s circumpolar, or always above the northern horizon. For the rest of us, though, during the coming months, the Big Dipper sinks below the horizon during the evening hours. The pattern is visible all night from northerly latitudes, albeit low in the sky. It’s tough (or impossible) to spot from the southern half of the United States, during the evening hours. Want to see it? You’ll want to wait until the hours before dawn. At this time of year, before dawn, you’ll easily see the Big Dipper ascending in the northeast.

To remember the best times to view the Big Dipper in the evening, remember the phrase: spring up and fall down. That’s because the Big Dipper shines way high in the sky on spring evenings but close to the horizon on autumn evenings.

View larger. | Big Dipper on the horizon while getting set up at the Astronomical Society of New Haven‘s Connecticut Star Party, October, 2015. Photo by Kurt Zeppetello.

The distances of the stars in the Dipper reveal something interesting about them: five of these seven stars have a physical relationship in space. That’s not always true of patterns on our sky’s dome. Most star patterns are made up of unrelated stars at vastly different distances.

But Merak, Mizar, Alioth, Megrez and Phecda are part of a single star grouping. They probably were born together from a single cloud of gas and dust, and they’re still moving together as a family.

The other two stars in the Dipper – Dubhe and Alkaid – are unrelated to each other and to the other five. They are moving in an entirely different direction. Thus millions of years from now the Big Dipper will have lost its familiar dipper-like shape.

Big Dipper is part of Ursa Major, the Big Bear constellation. Image via Old Book Art Image Gallery

Here are the star distances to the Dipper’s stars:

Alkaid 101 light-years
Mizar 78 light-years
Alioth 81 light-years
Megrez 81 light-years
Phecda 84 light-years
Dubhe 124 light-years
Merak 79 light-years

View larger. | This beautiful photo is from EarthSky Facebook friend John Michael Mizzi on the island of Gozo, south of Italy.

Bottom line: Sure, it’s easy to recognize, but sometimes the Big Dipper is low in the northern sky. That’s the case now, in the evening. How to spot it.

Donate: Your support means the world to us

from EarthSky http://ift.tt/1iT0Snt

Tonight … can you find the Big Dipper at nightfall and early evening? It’s perhaps the most famous of all star patterns, and – for those at latitudes 41 degrees North or farther north – it’s circumpolar, or always above the northern horizon. For the rest of us, though, during the coming months, the Big Dipper sinks below the horizon during the evening hours. The pattern is visible all night from northerly latitudes, albeit low in the sky. It’s tough (or impossible) to spot from the southern half of the United States, during the evening hours. Want to see it? You’ll want to wait until the hours before dawn. At this time of year, before dawn, you’ll easily see the Big Dipper ascending in the northeast.

To remember the best times to view the Big Dipper in the evening, remember the phrase: spring up and fall down. That’s because the Big Dipper shines way high in the sky on spring evenings but close to the horizon on autumn evenings.

View larger. | Big Dipper on the horizon while getting set up at the Astronomical Society of New Haven‘s Connecticut Star Party, October, 2015. Photo by Kurt Zeppetello.

The distances of the stars in the Dipper reveal something interesting about them: five of these seven stars have a physical relationship in space. That’s not always true of patterns on our sky’s dome. Most star patterns are made up of unrelated stars at vastly different distances.

But Merak, Mizar, Alioth, Megrez and Phecda are part of a single star grouping. They probably were born together from a single cloud of gas and dust, and they’re still moving together as a family.

The other two stars in the Dipper – Dubhe and Alkaid – are unrelated to each other and to the other five. They are moving in an entirely different direction. Thus millions of years from now the Big Dipper will have lost its familiar dipper-like shape.

Big Dipper is part of Ursa Major, the Big Bear constellation. Image via Old Book Art Image Gallery

Here are the star distances to the Dipper’s stars:

Alkaid 101 light-years
Mizar 78 light-years
Alioth 81 light-years
Megrez 81 light-years
Phecda 84 light-years
Dubhe 124 light-years
Merak 79 light-years

View larger. | This beautiful photo is from EarthSky Facebook friend John Michael Mizzi on the island of Gozo, south of Italy.

Bottom line: Sure, it’s easy to recognize, but sometimes the Big Dipper is low in the northern sky. That’s the case now, in the evening. How to spot it.

Donate: Your support means the world to us

from EarthSky http://ift.tt/1iT0Snt