Peer out our galaxy’s south window

Tonight, or any clear November evening, try using the Great Square of Pegasus to star-hop your way to a view out our galaxy’s south window. In other words, you’ll be looking away from the flat plane of our Milky Way – where most of our galaxy’s stars reside – and toward intergalactic space. You can do this no matter what part of Earth you’re standing on, by the way.

From the Northern Hemisphere: The Great Square of Pegasus appears high in the south to overhead each November, by around 8 p.m. local time in mid-November and 7 p.m. local time in late November/early December. This large asterism really does look like a large square pattern, with four medium-bright stars marking the corners. Draw a line through the Great Square’s two westernmost (or right-hand stars), and extend that line southward to land on the bright star Fomalhaut in the constellation Piscis Austrinus the Southern Fish.

From the Southern Hemisphere: Follow the directions above, but – instead of looking southward to overhead for the Great Square – you’ll be looking low in the north. You’ll still draw your line southward, but, in your sky – starting at the Great Square – that means you’ll draw the line upwards to Fomalhaut. Just take the chart at the top of this post, and turn it upside-down!

Why find Fomalhaut? When you look at this star – sometimes called the Loneliest Star – you are looking some 90 degrees from the plane of our galaxy’s equator.

Our Milky Way galaxy is round and flat, like a pancake. When you look toward Fomalhaut, you’re looking away from the pancake, and out the south window of the galaxy. In other words, we’re looking away from the star-packed disk of the galaxy, into extragalactic space and the realm of galaxies.

Want the exact location of the south galactic pole? It lies east of Fomalhaut, in the faint constellation Sculptor.

2017 EarthSky Lunar Calendar pre-sale…is happening NOW!

The south galactic pole lies in the direction of the constellation Sculptor.

Bottom line: Tonight, try using the Great Square of Pegasus to find the star Fomalhaut. Once you’ve found Fomalhaut, you’re on your way to visualizing looking out the south window of our Milky Way galaxy.

Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.

Donate: Your support means the world to us

from EarthSky http://ift.tt/1zTpz9j

Tonight, or any clear November evening, try using the Great Square of Pegasus to star-hop your way to a view out our galaxy’s south window. In other words, you’ll be looking away from the flat plane of our Milky Way – where most of our galaxy’s stars reside – and toward intergalactic space. You can do this no matter what part of Earth you’re standing on, by the way.

From the Northern Hemisphere: The Great Square of Pegasus appears high in the south to overhead each November, by around 8 p.m. local time in mid-November and 7 p.m. local time in late November/early December. This large asterism really does look like a large square pattern, with four medium-bright stars marking the corners. Draw a line through the Great Square’s two westernmost (or right-hand stars), and extend that line southward to land on the bright star Fomalhaut in the constellation Piscis Austrinus the Southern Fish.

From the Southern Hemisphere: Follow the directions above, but – instead of looking southward to overhead for the Great Square – you’ll be looking low in the north. You’ll still draw your line southward, but, in your sky – starting at the Great Square – that means you’ll draw the line upwards to Fomalhaut. Just take the chart at the top of this post, and turn it upside-down!

Why find Fomalhaut? When you look at this star – sometimes called the Loneliest Star – you are looking some 90 degrees from the plane of our galaxy’s equator.

Our Milky Way galaxy is round and flat, like a pancake. When you look toward Fomalhaut, you’re looking away from the pancake, and out the south window of the galaxy. In other words, we’re looking away from the star-packed disk of the galaxy, into extragalactic space and the realm of galaxies.

Want the exact location of the south galactic pole? It lies east of Fomalhaut, in the faint constellation Sculptor.

2017 EarthSky Lunar Calendar pre-sale…is happening NOW!

The south galactic pole lies in the direction of the constellation Sculptor.

Bottom line: Tonight, try using the Great Square of Pegasus to find the star Fomalhaut. Once you’ve found Fomalhaut, you’re on your way to visualizing looking out the south window of our Milky Way galaxy.

Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.

Donate: Your support means the world to us

from EarthSky http://ift.tt/1zTpz9j

An Inconvenient Sequel – the science, history, and politics of climate change

Al Gore’s new movie ‘An Inconvenient Sequel’ is, in some ways, similar to his groundbreaking Inconvenient Truth project, but different in other ways. Those key differences are why I recommend you watch it.

This movie successfully accomplishes a number of interweaving tasks. First, it gives some of the science of climate change. Gore gets his science right. I remember his first movie, which I thought was more steeped in science and data than this one, so based on my recollection this new picture is somewhat abbreviated. That’s a good thing because the science is settled on climate change. That is, the science is settled that humans are causing current climatic changes and the science is settled that we are observing these changes throughout the natural world. 

Readers of this column who venture into the comments below will likely find people claiming, “science is never settled.” But the people making those comments are not scientists. They don’t work in this field every day, they don’t see the data, and they don’t know what they’re talking about.

The opening of the new film shows a sample of the misguided attacks on Al Gore, exclusively from conservatives in the United States. It was so clear to me, when watching and listening, that these attacks are the same ones that we climate scientists constantly have to endure. Most scientists have not been attacked as consistently or for such a long duration as Mr. Gore, but the types of attacks he has had to handle are close cousins to what my colleagues and I experience on a regular basis. 

Many conservatives, and some progressives too, claim that Al Gore made climate change political. But I now realize he didn’t. Al Gore was simply the first major political figure that took a stand on climate change. He would have loved to have been joined by anyone of any political persuasion. I firmly believe that the denialism we see from conservatives in the USA is partly because they cannot bring themselves to admit he was right. 

In many people’s subconscious, it is better to deny the science and damn the world than admit a liberal former vice president was correct. And that failure is on them. Better people would rise above gut emotions and follow facts faithfully to where they lead. Instead, most US conservatives have tied their legacy to a climate denial movement that is causing and will cause irreparable harm to the planet, its biology, and human societies.

A party that calls itself “conservative” has acted out of accord with its stated values. And this fact should anger true conservatives. How could they allow an entire party to be tarred with this damning legacy? It isn’t Mr. Gore’s fault that conservatives have made climate denial a litmus test for their party. It isn’t Gore’s fault that conservative politicians have been bought by fossil fuel industries who have attacked climate science and climate scientists. It isn’t Al Gore’s fault that the Republican Party has stood in the way of the development of clean renewable fuels in the US. That is on them. It isn’t Mr. Gore’s fault that the very few conservatives who have taken a principled stand have been cast out from their party. The politicization of science is their scar.

With respect to the science, this new movie focuses on actual implications of climate change. Whether Mr. Gore is discussing Greenland’s crumbling ice sheet with scientists Eric Rignot or Konrad Steffen, or conversing with Miami city planners on ways to handle rising waters, the movie brings the implications of a changing climate home. Mr. Gore reminds us of projections for the future. For instance, South Florida may see 7 feet of sea level rise by 2100. City planners are considering ways to raise parts of the city to deal with this. Oh by the way, yes the best evidence shows we really may get 7 feet by 2100.

Later, Gore meets with people who have suffered through terrible and super-charged storms, such as recent typhoons in the Pacific. He lays clear the science that climate change is warming our oceans, providing extra fuel to make storms like Irma, Harvey, Sandy, and Maria more powerful. In these spots, his science is dead on.

This may make you wonder why I recommend people watch this movie. Isn’t it just more doom and gloom? Well, this is the exciting part. While the politics of climate change, at least in the USA (with a President and Congress in full denial mode, not only rolling back progress but sabotaging the science), what reason is there to be hopeful?

First, other countries are taking the lead from the US. I see this in my own work. Not only in basic science but in deployment of renewable energy. This is one area of great potential. Even though, as shown in the movie, fossil fuel companies and some conservative politicians are trying to sabotage clean energy markets, they cannot deny the economics. It just makes sense to use clean and renewable energy.

Do you remember that iconic scene from his first movie, where he followed greenhouse gas data upward using a lift? The gas levels were literally off the screen? Well, that gloomy image is replaced in the new movie by an equally iconic but optimistic animation of how countries are installing clean energy. 

A large part of the story does deal with Al Gore’s personal journey.

Click here to read the rest

from Skeptical Science http://ift.tt/2zPXh3Q

Al Gore’s new movie ‘An Inconvenient Sequel’ is, in some ways, similar to his groundbreaking Inconvenient Truth project, but different in other ways. Those key differences are why I recommend you watch it.

This movie successfully accomplishes a number of interweaving tasks. First, it gives some of the science of climate change. Gore gets his science right. I remember his first movie, which I thought was more steeped in science and data than this one, so based on my recollection this new picture is somewhat abbreviated. That’s a good thing because the science is settled on climate change. That is, the science is settled that humans are causing current climatic changes and the science is settled that we are observing these changes throughout the natural world. 

Readers of this column who venture into the comments below will likely find people claiming, “science is never settled.” But the people making those comments are not scientists. They don’t work in this field every day, they don’t see the data, and they don’t know what they’re talking about.

The opening of the new film shows a sample of the misguided attacks on Al Gore, exclusively from conservatives in the United States. It was so clear to me, when watching and listening, that these attacks are the same ones that we climate scientists constantly have to endure. Most scientists have not been attacked as consistently or for such a long duration as Mr. Gore, but the types of attacks he has had to handle are close cousins to what my colleagues and I experience on a regular basis. 

Many conservatives, and some progressives too, claim that Al Gore made climate change political. But I now realize he didn’t. Al Gore was simply the first major political figure that took a stand on climate change. He would have loved to have been joined by anyone of any political persuasion. I firmly believe that the denialism we see from conservatives in the USA is partly because they cannot bring themselves to admit he was right. 

In many people’s subconscious, it is better to deny the science and damn the world than admit a liberal former vice president was correct. And that failure is on them. Better people would rise above gut emotions and follow facts faithfully to where they lead. Instead, most US conservatives have tied their legacy to a climate denial movement that is causing and will cause irreparable harm to the planet, its biology, and human societies.

A party that calls itself “conservative” has acted out of accord with its stated values. And this fact should anger true conservatives. How could they allow an entire party to be tarred with this damning legacy? It isn’t Mr. Gore’s fault that conservatives have made climate denial a litmus test for their party. It isn’t Gore’s fault that conservative politicians have been bought by fossil fuel industries who have attacked climate science and climate scientists. It isn’t Al Gore’s fault that the Republican Party has stood in the way of the development of clean renewable fuels in the US. That is on them. It isn’t Mr. Gore’s fault that the very few conservatives who have taken a principled stand have been cast out from their party. The politicization of science is their scar.

With respect to the science, this new movie focuses on actual implications of climate change. Whether Mr. Gore is discussing Greenland’s crumbling ice sheet with scientists Eric Rignot or Konrad Steffen, or conversing with Miami city planners on ways to handle rising waters, the movie brings the implications of a changing climate home. Mr. Gore reminds us of projections for the future. For instance, South Florida may see 7 feet of sea level rise by 2100. City planners are considering ways to raise parts of the city to deal with this. Oh by the way, yes the best evidence shows we really may get 7 feet by 2100.

Later, Gore meets with people who have suffered through terrible and super-charged storms, such as recent typhoons in the Pacific. He lays clear the science that climate change is warming our oceans, providing extra fuel to make storms like Irma, Harvey, Sandy, and Maria more powerful. In these spots, his science is dead on.

This may make you wonder why I recommend people watch this movie. Isn’t it just more doom and gloom? Well, this is the exciting part. While the politics of climate change, at least in the USA (with a President and Congress in full denial mode, not only rolling back progress but sabotaging the science), what reason is there to be hopeful?

First, other countries are taking the lead from the US. I see this in my own work. Not only in basic science but in deployment of renewable energy. This is one area of great potential. Even though, as shown in the movie, fossil fuel companies and some conservative politicians are trying to sabotage clean energy markets, they cannot deny the economics. It just makes sense to use clean and renewable energy.

Do you remember that iconic scene from his first movie, where he followed greenhouse gas data upward using a lift? The gas levels were literally off the screen? Well, that gloomy image is replaced in the new movie by an equally iconic but optimistic animation of how countries are installing clean energy. 

A large part of the story does deal with Al Gore’s personal journey.

Click here to read the rest

from Skeptical Science http://ift.tt/2zPXh3Q

New research, November 6-12, 2017

A selection of new climate related research articles is shown below.

The figure is from paper #32.

Climate change impacts

1. Nitrogen availability dampens the positive impacts of CO₂ fertilization on terrestrial ecosystem carbon and water cycles

"Results suggest that the rate of global GPP increase is overestimated by 85% during 2000-2015 without N limitation. This limitation is found to occur in many tropical and boreal forests, where a negative leaf N trend indicates a reduction in photosynthetic capacity, thereby suppressing the positive vegetation response to enhanced CO₂ fertilization."

2. Climatic variability and dengue risk in urban environment of Delhi (India)

"Findings reveal significant changes in weather across the year having significant and positive association with dengue cases at specified lags. Weeks in April and July to October with gaps have been identified as the high risk weeks based on the estimated relative risk. There has been intra-annual expansion in dengue risk period extending beyond monsoon and post-monsoon."

3. Introduction to Special Issue: Disciplinary Perspectives on Climate Change and Conflict

"These authors find little evidence for direct pathways from climate change to violence, especially for group-level violence and armed conflict. However, there is stronger evidence for indirect effects in agricultural and other vulnerable settings and for exacerbating ongoing violence rather than initiating new violence. The authors also emphasize the importance of governance and institutions, adaptive capacity, and potential cooperative behavior in moderating violence."

4. Flood vulnerability, local perception and gender role judgment using multivariate analysis: A problem-based “participatory action to Future Skill Management” to cope with flood impacts

5. Risk perception and adaptive responses to climate change and climatic variability in northeastern St. Vincent

6. Does weather forecasting relate to foraging productivity? An empirical test among three hunter-gatherer societies

7. Climate change impact on the potential yield of Arabicacoffee in southeast Brazil

8. Potential rice exposure to heat stress along the Yangtze River in China under RCP8.5 scenario

9. Influence of climate variability and length of rainy season on crop yields in semiarid Botswana

10. Increasing drought and diminishing benefits of elevated carbon dioxide for soybean yields across the US Midwest

11. The effects of projected climate and climate extremes on a winter and summer crop in the southeast USA

12. Irrigation offsets wheat yield reductions from warming temperatures

13. Temperature-mortality relationship in dairy cattle in France based on an iso-hygro-thermal partition of the territory

14. Impacts of temperature extremes on European vegetation during the growing season

15. Vegetation phenology on the Qinghai-Tibetan Plateau and its response to climate change (1982–2013)

16. Rapid responses of plants to temperature changes

17. Lags in the response of mountain plant communities to climate change

18. Emerging stress and relative resiliency of Giant Sequoia groves experiencing multi-year dry periods in a warming climate

19. Nitrogen limitation of decomposition and decay: how can it occur?

20. Impacts of warming and nitrogen addition on soil autotrophic and heterotrophic respiration in a semi-arid environment

21. Carbon cycle confidence and uncertainty: exploring variation among soil biogeochemical models

22. Multidecadal fCO₂ Increase Along the United States Southeast Coastal Margin

23. The fatty acid content of plankton is changing in subtropical coastal waters as a result of OA: Results from a mesocosm study

24. Ocean acidification does not impair predator recognition but increases juvenile growth in a temperate wrasse off CO2 seeps

25. Participatory scenario planning and climate change impacts, adaptation and vulnerability research in the Arctic

Climate change mitigation

26. How much do direct livestock emissions actually contribute to global warming?

"We find that direct livestock non-CO₂ emissions caused about 19% of the total modelled warming of 0.81°C from all anthropogenic sources in 2010. CO₂ from pasture conversions contributed at least another 0.03°C, bringing the warming directly attributable to livestock to 23% of the total warming in 2010."

27. Role of e-reader adoption in life cycle greenhouse gas emissions of book reading activities

"Adopting e-readers was discovered to reduce both the GWP per person and the GWP per person-book of book reading activities. The GWP of e-books read with an e-reader and the GWP of paper books were found to break even at 4.7 books per year, provided consumers read less than 11 h a day. According to the web survey, e-reader users purchase more than seven e-books annually on average, which resulted in a smaller GWP per person-book relative to that of one paper book."

28. Climate change, future Arctic Sea ice, and the competitiveness of European Arctic offshore oil and gas production on world markets

"We find that under current hydrocarbon prices, oil and gas from the European offshore Arctic is not competitive on world markets."

29. Variability and correlation of renewable energy sources in the Portuguese electrical system

30. Diurnal and seasonal variations of greenhouse gas emissions from a naturally ventilated dairy barn in a cold region

31. Can abandoned peatland pasture sequestrate more carbon dioxide from the atmosphere than an adjacent pristine bog in Newfoundland, Canada?

32. Outdoor cooking prevalence in developing countries and its implication for clean cooking policies

33. An initial scoping of transitional justice for global climate governance

34. Climate Engagement in a Digital Age: Exploring the Drivers of Participation in Climate Discourse Online in the Context of COP21

35. Politicization of science: how climate change skeptics use experts and scientific evidence in their online communication

36. Uncertainties in modelling the climate impact of irrigation

37. Greenhouse Gas Emissions under Different Drainage and Flooding Regimes of Cultivated Peatlands

38. Reduction of solar photovoltaic resources due to air pollution in China

Climate change

39. Changing world extreme temperature statistics

"In contrast to this earlier work, we find that in every region except North America all-time high records were set at a rate significantly (at least 3σ) higher than in the null hypothesis of a stationary climate. Except in Antarctica, all-time low records were set at a rate significantly lower than in the null hypothesis. In Europe, North Africa and North Asia the rate of setting new all-time highs increased suddenly in the 1990s, suggesting a change in regional climate regime; in most other regions there was a steadier increase."

40. An energy balance model exploration of the impacts of interactions between surface albedo, cloud cover and water vapor on polar amplification

"We examine the effects of non-linear interactions between surface albedo, water vapor and cloud cover (referred to as climate variables) on amplified warming of the polar regions, using a new energy balance model. Our simulations show that the sum of the contributions to surface temperature changes due to any variable considered in isolation is smaller than the temperature changes from coupled feedback simulations. This non-linearity is strongest when all three climate variables are allowed to interact. Surface albedo appears to be the strongest driver of this non-linear behavior, followed by water vapor and clouds. This is because increases in longwave radiation absorbed by the surface, related to increases in water vapor and clouds, and increases in surface absorbed shortwave radiation caused by a decrease in surface albedo, amplify each other. Furthermore, our results corroborate previous findings that while increases in cloud cover and water vapor, along with the greenhouse effect itself, warm the polar regions, water vapor also significantly warms equatorial regions, which reduces polar amplification. Changes in surface albedo drive large changes in absorption of incoming shortwave radiation, thereby enhancing surface warming. Unlike high latitudes, surface albedo change at low latitudes are more constrained. Interactions between surface albedo, water vapor and clouds drive larger increases in temperatures in the polar regions compared to low latitudes. This is in spite of the fact that, due to a forcing, cloud cover increases at high latitudes and decreases in low latitudes, and that water vapor significantly enhances warming at low latitudes."

41. Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet System

"There have been dramatic increases in surface meltwater generation and runoff since the early 1990s, both due to increased air temperatures and decreasing surface albedo. Processes in the subglacial drainage system have similarities to valley glaciers and in a warming climate, the efficiency of meltwater routing to the ice sheet margin is likely to increase. The behaviour of the subglacial drainage system appears to limit the impact of increased surface melt on annual rates of ice motion, in sections of the ice sheet that terminate on land, while the large volumes of meltwater routed subglacially deliver significant volumes of sediment and nutrients to downstream ecosystems."

42. Unveiling aerosol–cloud interactions – Part 1: Cloud contamination in satellite products enhances the aerosol indirect forcing estimate

"We find that previous satellite-based radiative forcing estimates of aerosol–cloud interactions represented in key climate reports are likely exaggerated by up to 50 % due to including retrieval artefacts in the aerosols located near clouds. It is demonstrated that this retrieval artefact can be corrected in current products."

43. On the emergent constraints of climate sensitivity

"The relationships between the contrived metrics and ECS can also be linked statistically to shortwave cloud feedback. Thus any proposed or forthcoming ECS constraint based on the current generation of climate models should be viewed as a potential constraint on shortwave cloud feedback, and physical links with that feedback should be investigated to verify that the constraint is real. In addition, any proposed ECS constraint should not be taken at face value, since other factors influencing ECS besides shortwave cloud feedback could be systematically biased in the models."

44. A consistent sea-level reconstruction and its budget on basin and global scales over 1958-2014

"The global-mean sea-level reconstruction shows a trend of 1.5±0.2 mm/y over 1958-2014 (1σ), compared to 1.3±0.1 mm/y for the sum of contributors. Over the same period, the reconstruction shows a positive acceleration of 0.07±0.02 mm/y², which is also in agreement with the sum of contributors, which shows an acceleration of 0.07±0.01 mm/y²."

45. The impact of bias correction and model selection on passing temperature thresholds

46. Exceptional airmass transport and dynamical drivers of an extreme wintertime Arctic warm event

47. The role of humidity in determining scenarios of perceived temperature extremes in Europe

48. Warming across decades and deciles: minimum and maximum daily temperatures in China, 1955–2014

49. Variations in North Pacific sea surface temperature caused by Arctic stratospheric ozone anomalies

50. How uncertainty in field measurements of ice nucleating particles influences modeled cloud forcing

51. Simulated changes in aridity from the last glacial maximum to 4xCO 2

52. Comparison of various drought indices to monitor drought status in Pakistan

53. Seasonal predictability of Kiremt rainfall in coupled general circulation models

54. Scale dependency of regional climate modeling of current and future climate extremes in Germany

55. Regional Antarctic snow accumulation over the past 1000 years

56. Snow accumulation variability over the West Antarctic Ice Sheet since 1900: a comparison of ice core records with ERA-20C reanalysis

57. Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations

58. Heat flux distribution of Antarctica unveiled

59. Greenland Ice Sheet Surface Mass Loss: Recent Developments in Observation and Modeling

60. The modelled liquid water balance of the Greenland Ice Sheet

61. Algae drive enhanced darkening of bare ice on the Greenland ice sheet

62. The distribution and hydrological significance of rock glaciers in the Nepalese Himalaya

63. Simulated historical (1901–2010) changes in the permafrost extent and active layer thickness in the Northern Hemisphere

64. A new map of permafrost distribution on the Tibetan Plateau

65. Warmer spring conditions increase annual methane emissions from a boreal peat landscape with sporadic permafrost

66. Hemispheric asymmetry in stratospheric NO₂ trends

67. A two-year forecast for a 60-80% chance of La Niña in 2017-18

68. How predictable are the Arctic and North Atlantic Oscillations? Exploring the Variability and Predictability of the Northern Hemisphere

69. Regime shift of Indian summer monsoon rainfall to a persistent arid state: external forcing versus internal variability

70. Inflated uncertainty in multi-model based regional climate projections

71. Climate and anthropogenic controls of coastal deoxygenation on interannual to centennial timescales

72. Changes in terrestrial near-surface wind speed and their possible causes: an overview

73. Uncertainty in recent near-surface wind speed trends: a global reanalysis intercomparison

74. A Statistical Study of Unusual Tracks of Tropical Cyclones near Taiwan Island

75. Severity scale for tornadoes

76. Variations of climate, surface energy budget and minimum snow/ice extent over Canadian Arctic landmass for 2000-2016

77. Intrinsic and atmospherically-forced variability of the AMOC: insights from a large ensemble ocean hindcast

Other papers

78. Social Resilience to Climate-Related Disasters in Ancient Societies: A Test of Two Hypotheses

"The paper finds that societies allowing greater political participation appear to provide greater resilience to catastrophic climate-related disasters, generally supporting the predominant perspective in contemporary disaster response."

79. The role of African dust in Atlantic climate during Heinrich events

80. Why artificial light at night should be a focus for global change research in the 21st century

from Skeptical Science http://ift.tt/2zPVH1G

A selection of new climate related research articles is shown below.

The figure is from paper #32.

Climate change impacts

1. Nitrogen availability dampens the positive impacts of CO₂ fertilization on terrestrial ecosystem carbon and water cycles

"Results suggest that the rate of global GPP increase is overestimated by 85% during 2000-2015 without N limitation. This limitation is found to occur in many tropical and boreal forests, where a negative leaf N trend indicates a reduction in photosynthetic capacity, thereby suppressing the positive vegetation response to enhanced CO₂ fertilization."

2. Climatic variability and dengue risk in urban environment of Delhi (India)

"Findings reveal significant changes in weather across the year having significant and positive association with dengue cases at specified lags. Weeks in April and July to October with gaps have been identified as the high risk weeks based on the estimated relative risk. There has been intra-annual expansion in dengue risk period extending beyond monsoon and post-monsoon."

3. Introduction to Special Issue: Disciplinary Perspectives on Climate Change and Conflict

"These authors find little evidence for direct pathways from climate change to violence, especially for group-level violence and armed conflict. However, there is stronger evidence for indirect effects in agricultural and other vulnerable settings and for exacerbating ongoing violence rather than initiating new violence. The authors also emphasize the importance of governance and institutions, adaptive capacity, and potential cooperative behavior in moderating violence."

4. Flood vulnerability, local perception and gender role judgment using multivariate analysis: A problem-based “participatory action to Future Skill Management” to cope with flood impacts

5. Risk perception and adaptive responses to climate change and climatic variability in northeastern St. Vincent

6. Does weather forecasting relate to foraging productivity? An empirical test among three hunter-gatherer societies

7. Climate change impact on the potential yield of Arabicacoffee in southeast Brazil

8. Potential rice exposure to heat stress along the Yangtze River in China under RCP8.5 scenario

9. Influence of climate variability and length of rainy season on crop yields in semiarid Botswana

10. Increasing drought and diminishing benefits of elevated carbon dioxide for soybean yields across the US Midwest

11. The effects of projected climate and climate extremes on a winter and summer crop in the southeast USA

12. Irrigation offsets wheat yield reductions from warming temperatures

13. Temperature-mortality relationship in dairy cattle in France based on an iso-hygro-thermal partition of the territory

14. Impacts of temperature extremes on European vegetation during the growing season

15. Vegetation phenology on the Qinghai-Tibetan Plateau and its response to climate change (1982–2013)

16. Rapid responses of plants to temperature changes

17. Lags in the response of mountain plant communities to climate change

18. Emerging stress and relative resiliency of Giant Sequoia groves experiencing multi-year dry periods in a warming climate

19. Nitrogen limitation of decomposition and decay: how can it occur?

20. Impacts of warming and nitrogen addition on soil autotrophic and heterotrophic respiration in a semi-arid environment

21. Carbon cycle confidence and uncertainty: exploring variation among soil biogeochemical models

22. Multidecadal fCO₂ Increase Along the United States Southeast Coastal Margin

23. The fatty acid content of plankton is changing in subtropical coastal waters as a result of OA: Results from a mesocosm study

24. Ocean acidification does not impair predator recognition but increases juvenile growth in a temperate wrasse off CO2 seeps

25. Participatory scenario planning and climate change impacts, adaptation and vulnerability research in the Arctic

Climate change mitigation

26. How much do direct livestock emissions actually contribute to global warming?

"We find that direct livestock non-CO₂ emissions caused about 19% of the total modelled warming of 0.81°C from all anthropogenic sources in 2010. CO₂ from pasture conversions contributed at least another 0.03°C, bringing the warming directly attributable to livestock to 23% of the total warming in 2010."

27. Role of e-reader adoption in life cycle greenhouse gas emissions of book reading activities

"Adopting e-readers was discovered to reduce both the GWP per person and the GWP per person-book of book reading activities. The GWP of e-books read with an e-reader and the GWP of paper books were found to break even at 4.7 books per year, provided consumers read less than 11 h a day. According to the web survey, e-reader users purchase more than seven e-books annually on average, which resulted in a smaller GWP per person-book relative to that of one paper book."

28. Climate change, future Arctic Sea ice, and the competitiveness of European Arctic offshore oil and gas production on world markets

"We find that under current hydrocarbon prices, oil and gas from the European offshore Arctic is not competitive on world markets."

29. Variability and correlation of renewable energy sources in the Portuguese electrical system

30. Diurnal and seasonal variations of greenhouse gas emissions from a naturally ventilated dairy barn in a cold region

31. Can abandoned peatland pasture sequestrate more carbon dioxide from the atmosphere than an adjacent pristine bog in Newfoundland, Canada?

32. Outdoor cooking prevalence in developing countries and its implication for clean cooking policies

33. An initial scoping of transitional justice for global climate governance

34. Climate Engagement in a Digital Age: Exploring the Drivers of Participation in Climate Discourse Online in the Context of COP21

35. Politicization of science: how climate change skeptics use experts and scientific evidence in their online communication

36. Uncertainties in modelling the climate impact of irrigation

37. Greenhouse Gas Emissions under Different Drainage and Flooding Regimes of Cultivated Peatlands

38. Reduction of solar photovoltaic resources due to air pollution in China

Climate change

39. Changing world extreme temperature statistics

"In contrast to this earlier work, we find that in every region except North America all-time high records were set at a rate significantly (at least 3σ) higher than in the null hypothesis of a stationary climate. Except in Antarctica, all-time low records were set at a rate significantly lower than in the null hypothesis. In Europe, North Africa and North Asia the rate of setting new all-time highs increased suddenly in the 1990s, suggesting a change in regional climate regime; in most other regions there was a steadier increase."

40. An energy balance model exploration of the impacts of interactions between surface albedo, cloud cover and water vapor on polar amplification

"We examine the effects of non-linear interactions between surface albedo, water vapor and cloud cover (referred to as climate variables) on amplified warming of the polar regions, using a new energy balance model. Our simulations show that the sum of the contributions to surface temperature changes due to any variable considered in isolation is smaller than the temperature changes from coupled feedback simulations. This non-linearity is strongest when all three climate variables are allowed to interact. Surface albedo appears to be the strongest driver of this non-linear behavior, followed by water vapor and clouds. This is because increases in longwave radiation absorbed by the surface, related to increases in water vapor and clouds, and increases in surface absorbed shortwave radiation caused by a decrease in surface albedo, amplify each other. Furthermore, our results corroborate previous findings that while increases in cloud cover and water vapor, along with the greenhouse effect itself, warm the polar regions, water vapor also significantly warms equatorial regions, which reduces polar amplification. Changes in surface albedo drive large changes in absorption of incoming shortwave radiation, thereby enhancing surface warming. Unlike high latitudes, surface albedo change at low latitudes are more constrained. Interactions between surface albedo, water vapor and clouds drive larger increases in temperatures in the polar regions compared to low latitudes. This is in spite of the fact that, due to a forcing, cloud cover increases at high latitudes and decreases in low latitudes, and that water vapor significantly enhances warming at low latitudes."

41. Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet System

"There have been dramatic increases in surface meltwater generation and runoff since the early 1990s, both due to increased air temperatures and decreasing surface albedo. Processes in the subglacial drainage system have similarities to valley glaciers and in a warming climate, the efficiency of meltwater routing to the ice sheet margin is likely to increase. The behaviour of the subglacial drainage system appears to limit the impact of increased surface melt on annual rates of ice motion, in sections of the ice sheet that terminate on land, while the large volumes of meltwater routed subglacially deliver significant volumes of sediment and nutrients to downstream ecosystems."

42. Unveiling aerosol–cloud interactions – Part 1: Cloud contamination in satellite products enhances the aerosol indirect forcing estimate

"We find that previous satellite-based radiative forcing estimates of aerosol–cloud interactions represented in key climate reports are likely exaggerated by up to 50 % due to including retrieval artefacts in the aerosols located near clouds. It is demonstrated that this retrieval artefact can be corrected in current products."

43. On the emergent constraints of climate sensitivity

"The relationships between the contrived metrics and ECS can also be linked statistically to shortwave cloud feedback. Thus any proposed or forthcoming ECS constraint based on the current generation of climate models should be viewed as a potential constraint on shortwave cloud feedback, and physical links with that feedback should be investigated to verify that the constraint is real. In addition, any proposed ECS constraint should not be taken at face value, since other factors influencing ECS besides shortwave cloud feedback could be systematically biased in the models."

44. A consistent sea-level reconstruction and its budget on basin and global scales over 1958-2014

"The global-mean sea-level reconstruction shows a trend of 1.5±0.2 mm/y over 1958-2014 (1σ), compared to 1.3±0.1 mm/y for the sum of contributors. Over the same period, the reconstruction shows a positive acceleration of 0.07±0.02 mm/y², which is also in agreement with the sum of contributors, which shows an acceleration of 0.07±0.01 mm/y²."

45. The impact of bias correction and model selection on passing temperature thresholds

46. Exceptional airmass transport and dynamical drivers of an extreme wintertime Arctic warm event

47. The role of humidity in determining scenarios of perceived temperature extremes in Europe

48. Warming across decades and deciles: minimum and maximum daily temperatures in China, 1955–2014

49. Variations in North Pacific sea surface temperature caused by Arctic stratospheric ozone anomalies

50. How uncertainty in field measurements of ice nucleating particles influences modeled cloud forcing

51. Simulated changes in aridity from the last glacial maximum to 4xCO 2

52. Comparison of various drought indices to monitor drought status in Pakistan

53. Seasonal predictability of Kiremt rainfall in coupled general circulation models

54. Scale dependency of regional climate modeling of current and future climate extremes in Germany

55. Regional Antarctic snow accumulation over the past 1000 years

56. Snow accumulation variability over the West Antarctic Ice Sheet since 1900: a comparison of ice core records with ERA-20C reanalysis

57. Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations

58. Heat flux distribution of Antarctica unveiled

59. Greenland Ice Sheet Surface Mass Loss: Recent Developments in Observation and Modeling

60. The modelled liquid water balance of the Greenland Ice Sheet

61. Algae drive enhanced darkening of bare ice on the Greenland ice sheet

62. The distribution and hydrological significance of rock glaciers in the Nepalese Himalaya

63. Simulated historical (1901–2010) changes in the permafrost extent and active layer thickness in the Northern Hemisphere

64. A new map of permafrost distribution on the Tibetan Plateau

65. Warmer spring conditions increase annual methane emissions from a boreal peat landscape with sporadic permafrost

66. Hemispheric asymmetry in stratospheric NO₂ trends

67. A two-year forecast for a 60-80% chance of La Niña in 2017-18

68. How predictable are the Arctic and North Atlantic Oscillations? Exploring the Variability and Predictability of the Northern Hemisphere

69. Regime shift of Indian summer monsoon rainfall to a persistent arid state: external forcing versus internal variability

70. Inflated uncertainty in multi-model based regional climate projections

71. Climate and anthropogenic controls of coastal deoxygenation on interannual to centennial timescales

72. Changes in terrestrial near-surface wind speed and their possible causes: an overview

73. Uncertainty in recent near-surface wind speed trends: a global reanalysis intercomparison

74. A Statistical Study of Unusual Tracks of Tropical Cyclones near Taiwan Island

75. Severity scale for tornadoes

76. Variations of climate, surface energy budget and minimum snow/ice extent over Canadian Arctic landmass for 2000-2016

77. Intrinsic and atmospherically-forced variability of the AMOC: insights from a large ensemble ocean hindcast

Other papers

78. Social Resilience to Climate-Related Disasters in Ancient Societies: A Test of Two Hypotheses

"The paper finds that societies allowing greater political participation appear to provide greater resilience to catastrophic climate-related disasters, generally supporting the predominant perspective in contemporary disaster response."

79. The role of African dust in Atlantic climate during Heinrich events

80. Why artificial light at night should be a focus for global change research in the 21st century

from Skeptical Science http://ift.tt/2zPVH1G

5 discoveries we owe to twins

Image via University of Melbourne.

By Catriona May, University of Melbourne

Twins have long held a fascination in our popular imagination.

And while stories about telepathy are intriguing, says Director of Twins Research Australia John Hopper, twins hold the key to a more important mystery: nature versus nurture.

Hopper has been leading the University of Melbourne based research facility since 1990. He said:

Twins allow us to control perfectly for one of the main variables in our health – genetics. Then we can drill down on the role that environmental factors are playing.

For example, studying twin pairs where one smoked and the other didn’t revealed tobacco use is a major cause of osteoporosis.

Twin research helps scientists translate new knowledge in genomics into public health advances. Image via Eye for Ebony/Unsplash/University of Melbourne.

Launched in 1982, the facility has more than 35,000 pairs of twins on its database and is the largest volunteer twin registry in the world. To mark their 35th anniversary, Professor Hopper listed five of the most significant discoveries to come from its more than 230 twin studies.

1. Identifying the genetic and epigenetic risk of breast cancer

Hopper said:

Through studying twin pairs we identified the first gene that influences both mammographic density (the amount of white areas on a mammogram) and risk of breast cancer, called LSP1.

His team found monozygotic (identical) twins were highly similar for mammographic density, which predicts future risk of breast cancer. Dizygotic (non-identical) twins were half as similar, suggesting a major genetic role underlying this risk factor. Hopper said:

Incredibly, we also found a new epigenetic risk factor for breast cancer that is determined in the uterus – a finding we could only have discovered by studying twin pairs.

The next step, he says, is to find out why the environment in the womb influences the risk of breast cancer.

Ultimately, this work could change breast screening and breast cancer prevention across the world.

in research is revealing how the environment in the womb can impact health outcomes later in life. Image via University of Melbourne/iStock.

2. Epilepsy can be inherited

Twenty years ago the medical profession thought epilepsy was an acquired disease, caused by head injuries or a difficult birth.

But Professors Sam Berkovic and Ingrid Scheffer from the University of Melbourne found a genetic basis to specific forms of epilepsy, transforming how epilepsy is defined and treated. Hopper said:

Twin research was really fundamental in these discoveries. It revealed which of the many types of epilepsy had a genetic basis, and which didn’t, so as to better target their gene discovery studies.

The team also studied twin pairs in which one had epilepsy and the other didn’t, and looked at data on any injuries or complications at birth.

There was no evidence to suggest obstetric complications caused epilepsy – a huge relief for so many parents.

3. The environment in the womb impacts our future health

The relatively new field of epigenetics studies the effect of the environment on how our genes work. An important area is methylation, the process by which genes are switched on and off.

The field is helping researchers better understand the impacts of lifestyle factors like diet and stress on our health, and how these are possibly passed down through generations.

By comparing the level of epigenetic differences in identical and non-identical twins, Associate Professor Jeff Craig from the Murdoch Children’s Research Institute and his team showed that experiences in the womb help determine the epigenetic profile we are born with.

This may explain why identical twins, despite sharing the same DNA, often experience different health conditions. Hopper said:

Again, twin research is showing our health is shaped by the environment right from the time of conception, and especially in early life.

tudying older twins helps reveal the impact of decades of particular lifestyle choices, like engaging (or not) in regular exercise. Image via University of Melbourne/Shutterstock.

4. Healthy brain aging

The longitudinal Older Australian Twins Study, led by neuro-psychiatrist Professor Perminder Sachdev from the University of New South Wales, is following twins over the age of 65 to investigate healthy brain aging.

By comparing identical and non-identical twins, researchers are learning what genes and lifestyle factors are causing cognitive decline, or cognitive resilience, in later life. Hopper said:

By studying older twins, the researchers are uncovering novel findings about what causes brains to age faster, or slower, by comparing their lifetime of experiences in exercise, diet, smoking and so on.

By controlling perfectly for genetic factors, the results are much more compelling than if the researchers had studied a random sample of the general population, given how much underlying genetic risk of cognitive decline differs across people.

5. Math and reading skills are largely genetic

Professor Brian Byrne from the University of New England analyzed the NAPLAN scores of about 3,000 sets of twins in Years 3, 5, 7 and 9.

[The National Assessment Program – Literacy and Numeracy (NAPLAN) is a series of tests focused on basic skills that are administered annually to Australian students.]

His team discovered that up to 75 percent of differences in children’s abilities in maths, reading and spelling, and up to 50 percent of their differences in writing skills, could be due to genetic differences. Hopper said:

There tends to be an argument that if genes are important, then the environment doesn’t matter.

In fact the opposite is true. Environmental and genetic factors multiply on one another. Whether children are genetically inclined to be academic or not, they need an environment that supports them to maximize their talents.

If you are an identical or non-identical twin, please consider joining Twins Research Australia here.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Donate to EarthSky: Your support means the world to us

Bottom line: Five of the most significant discoveries to come from 35 years of twin studies.

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

Image via University of Melbourne.

By Catriona May, University of Melbourne

Twins have long held a fascination in our popular imagination.

And while stories about telepathy are intriguing, says Director of Twins Research Australia John Hopper, twins hold the key to a more important mystery: nature versus nurture.

Hopper has been leading the University of Melbourne based research facility since 1990. He said:

Twins allow us to control perfectly for one of the main variables in our health – genetics. Then we can drill down on the role that environmental factors are playing.

For example, studying twin pairs where one smoked and the other didn’t revealed tobacco use is a major cause of osteoporosis.

Twin research helps scientists translate new knowledge in genomics into public health advances. Image via Eye for Ebony/Unsplash/University of Melbourne.

Launched in 1982, the facility has more than 35,000 pairs of twins on its database and is the largest volunteer twin registry in the world. To mark their 35th anniversary, Professor Hopper listed five of the most significant discoveries to come from its more than 230 twin studies.

1. Identifying the genetic and epigenetic risk of breast cancer

Hopper said:

Through studying twin pairs we identified the first gene that influences both mammographic density (the amount of white areas on a mammogram) and risk of breast cancer, called LSP1.

His team found monozygotic (identical) twins were highly similar for mammographic density, which predicts future risk of breast cancer. Dizygotic (non-identical) twins were half as similar, suggesting a major genetic role underlying this risk factor. Hopper said:

Incredibly, we also found a new epigenetic risk factor for breast cancer that is determined in the uterus – a finding we could only have discovered by studying twin pairs.

The next step, he says, is to find out why the environment in the womb influences the risk of breast cancer.

Ultimately, this work could change breast screening and breast cancer prevention across the world.

in research is revealing how the environment in the womb can impact health outcomes later in life. Image via University of Melbourne/iStock.

2. Epilepsy can be inherited

Twenty years ago the medical profession thought epilepsy was an acquired disease, caused by head injuries or a difficult birth.

But Professors Sam Berkovic and Ingrid Scheffer from the University of Melbourne found a genetic basis to specific forms of epilepsy, transforming how epilepsy is defined and treated. Hopper said:

Twin research was really fundamental in these discoveries. It revealed which of the many types of epilepsy had a genetic basis, and which didn’t, so as to better target their gene discovery studies.

The team also studied twin pairs in which one had epilepsy and the other didn’t, and looked at data on any injuries or complications at birth.

There was no evidence to suggest obstetric complications caused epilepsy – a huge relief for so many parents.

3. The environment in the womb impacts our future health

The relatively new field of epigenetics studies the effect of the environment on how our genes work. An important area is methylation, the process by which genes are switched on and off.

The field is helping researchers better understand the impacts of lifestyle factors like diet and stress on our health, and how these are possibly passed down through generations.

By comparing the level of epigenetic differences in identical and non-identical twins, Associate Professor Jeff Craig from the Murdoch Children’s Research Institute and his team showed that experiences in the womb help determine the epigenetic profile we are born with.

This may explain why identical twins, despite sharing the same DNA, often experience different health conditions. Hopper said:

Again, twin research is showing our health is shaped by the environment right from the time of conception, and especially in early life.

tudying older twins helps reveal the impact of decades of particular lifestyle choices, like engaging (or not) in regular exercise. Image via University of Melbourne/Shutterstock.

4. Healthy brain aging

The longitudinal Older Australian Twins Study, led by neuro-psychiatrist Professor Perminder Sachdev from the University of New South Wales, is following twins over the age of 65 to investigate healthy brain aging.

By comparing identical and non-identical twins, researchers are learning what genes and lifestyle factors are causing cognitive decline, or cognitive resilience, in later life. Hopper said:

By studying older twins, the researchers are uncovering novel findings about what causes brains to age faster, or slower, by comparing their lifetime of experiences in exercise, diet, smoking and so on.

By controlling perfectly for genetic factors, the results are much more compelling than if the researchers had studied a random sample of the general population, given how much underlying genetic risk of cognitive decline differs across people.

5. Math and reading skills are largely genetic

Professor Brian Byrne from the University of New England analyzed the NAPLAN scores of about 3,000 sets of twins in Years 3, 5, 7 and 9.

[The National Assessment Program – Literacy and Numeracy (NAPLAN) is a series of tests focused on basic skills that are administered annually to Australian students.]

His team discovered that up to 75 percent of differences in children’s abilities in maths, reading and spelling, and up to 50 percent of their differences in writing skills, could be due to genetic differences. Hopper said:

There tends to be an argument that if genes are important, then the environment doesn’t matter.

In fact the opposite is true. Environmental and genetic factors multiply on one another. Whether children are genetically inclined to be academic or not, they need an environment that supports them to maximize their talents.

If you are an identical or non-identical twin, please consider joining Twins Research Australia here.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Donate to EarthSky: Your support means the world to us

Bottom line: Five of the most significant discoveries to come from 35 years of twin studies.

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

Almach is a quadruple star system

Through even a modest telescope, the star Almach (Gamma Andromedae) appears as one of the finest double stars in all the heavens. EarthSky friend Scott MacNeill captured this shot with the aid of a 12″ Newtonian telescope. Thank you, Scott!

The constellation Andromeda the Princess is renowned for the Andromeda galaxy, but anyone with even a modest telescope would be remiss to overlook Andromeda’s star Almach (Gamma Andromedae), which appears in a telescope as one of the finest double stars in all the heavens. One component of this telescopic double appears golden, and the other component appears indigo blue. What’s more, further research has shown that Almach is really four stars. Follow the links below to learn more about this beautiful star.

How to find the star Almach

Almach looks single, but is really four stars

Almach looks like a single star to the unaided eye. In skylore, Almach marks the Princess Andromeda’s left foot.

How to find the star Almach. In skylore, Almach marks the Princess Andromeda’s left foot. Star-hop to Almach from the Great Square of Pegasus, the signature star formation of Northern Hemisphere autumn.

Two streamers of stars fly outward from the Great Square, starting at the star Alpheratz. These streamers of stars are the constellation Andromeda.

Jump three stars over on the lower streamer to locate Almach. At second-magnitude brightness, Almach shines pretty much on a par with the stars of the Big Dipper.

This star – or we should say star system – is located an estimated 350 light-years away.

Notice the star Almach in the upper right of this photo, almost directly above the Pleiades star cluster. Photo via aquinoktium on Flickr.

Almach looks single, but is really four stars. Look through the telescope to see Almach transform into two colorful suns. The larger sun appears golden, and the smaller one appears blue.

Practiced telescope users recommend a magnification of 75X or so for the most vivid view of this colorful double.

Some double star aficionados believe Almach’s vibrancy of color even surpasses that of the star Albireo in the constellation Cygnus, generally regarded as the sky’s finest double star. In autumn, both Almach and Albireo are there for the viewing, so check them out and decide for yourself.

The colorful telescopic double star Almach is really four stars. The fainter blue component is actually triple.

The double nature of Almach has been known since 1778, when the astronomer Johann Tobias Mayer viewed them through one of the early telescopes.

Today, it’s known that the smaller blue star is also a triple star system, making Almach four stars in all.

Almach shines relatively close to the famous variable star Algol in the constellation Perseus. When Algol shines at maximum brilliance, it matches Almach in brilliance.

Enjoying EarthSky? Sign up for our free daily newsletter today!

Bottom line: The star Almach (Gamma Andromedae) looks single to the eye. But astrononomical research has revealed that one component is a triple system, with four stars in all.

Mirfak: Perseus’ brightest star

Capella: Golden Goat Star

from EarthSky http://ift.tt/1N9HbRS

Through even a modest telescope, the star Almach (Gamma Andromedae) appears as one of the finest double stars in all the heavens. EarthSky friend Scott MacNeill captured this shot with the aid of a 12″ Newtonian telescope. Thank you, Scott!

The constellation Andromeda the Princess is renowned for the Andromeda galaxy, but anyone with even a modest telescope would be remiss to overlook Andromeda’s star Almach (Gamma Andromedae), which appears in a telescope as one of the finest double stars in all the heavens. One component of this telescopic double appears golden, and the other component appears indigo blue. What’s more, further research has shown that Almach is really four stars. Follow the links below to learn more about this beautiful star.

How to find the star Almach

Almach looks single, but is really four stars

Almach looks like a single star to the unaided eye. In skylore, Almach marks the Princess Andromeda’s left foot.

How to find the star Almach. In skylore, Almach marks the Princess Andromeda’s left foot. Star-hop to Almach from the Great Square of Pegasus, the signature star formation of Northern Hemisphere autumn.

Two streamers of stars fly outward from the Great Square, starting at the star Alpheratz. These streamers of stars are the constellation Andromeda.

Jump three stars over on the lower streamer to locate Almach. At second-magnitude brightness, Almach shines pretty much on a par with the stars of the Big Dipper.

This star – or we should say star system – is located an estimated 350 light-years away.

Notice the star Almach in the upper right of this photo, almost directly above the Pleiades star cluster. Photo via aquinoktium on Flickr.

Almach looks single, but is really four stars. Look through the telescope to see Almach transform into two colorful suns. The larger sun appears golden, and the smaller one appears blue.

Practiced telescope users recommend a magnification of 75X or so for the most vivid view of this colorful double.

Some double star aficionados believe Almach’s vibrancy of color even surpasses that of the star Albireo in the constellation Cygnus, generally regarded as the sky’s finest double star. In autumn, both Almach and Albireo are there for the viewing, so check them out and decide for yourself.

The colorful telescopic double star Almach is really four stars. The fainter blue component is actually triple.

The double nature of Almach has been known since 1778, when the astronomer Johann Tobias Mayer viewed them through one of the early telescopes.

Today, it’s known that the smaller blue star is also a triple star system, making Almach four stars in all.

Almach shines relatively close to the famous variable star Algol in the constellation Perseus. When Algol shines at maximum brilliance, it matches Almach in brilliance.

Enjoying EarthSky? Sign up for our free daily newsletter today!

Bottom line: The star Almach (Gamma Andromedae) looks single to the eye. But astrononomical research has revealed that one component is a triple system, with four stars in all.

Mirfak: Perseus’ brightest star

Capella: Golden Goat Star

from EarthSky http://ift.tt/1N9HbRS

Keep watching for Leonid meteors

Between midnight and dawn on Saturday, November 18, watch for meteors in the annual Leonid meteor shower. Maybe you saw some meteors on the morning of November 17, too? In 2017, the peak stretches over two mornings, and a new moon on November 18 guarantees darkness (from rural locations) on both nights.

The Leonids are famous for storming at various times in recent history. The first great meteor storm of modern times was nearly 200 years ago; it was the Leonid shower of November 1833. That famous shower had a major effect on the development of the scientific study of meteors. It’s one reason the Leonids are so famous.

Previously, meteors were thought to be atmospheric phenomena, like rain or snow. But scientists were curious. Why was the 1833 shower so strong? In 1865, astronomers discovered a comet, which was named Comet Tempel-Tuttle for its discoverers. The comet’s orbit around the sun was found to be about 33 years. Some predicted that there would be another Leonid meteor storm in November 1866 – and so there was!

Thus the Leonid meteor storm of 1833 helped prove that meteors in annual shower originate in comets.

Leonid meteor storm, as seen over North America on the night of November 12-13, 1833. This woodcut was published in 1888 by E. Weib in his Bilderatlas der Sternenwelt (Illustrated Atlas of the Stars). Image via Wikimedia Commons.

Now we know that Earth crosses the orbital path of Comet Tempel-Tuttle every year. Debris from this comet burns up in the Earth’s upper atmosphere to create the annual Leonid shower. It’s only when the comet is near that we see a Leonid storm.

The illustration above depicts the 1833 Leonid meteor shower, said to have produced from 100,000 to 200,000 meteors per hour! This old woodcut, published in 1888, shows what the Leonid shower might look like in a year that this shower erupts into storm, bombarding the sky with hundreds of thousands of meteors.

That happened last in 1966, when North Americans enjoyed a Leonid storm numbering 100,000 shooting stars per hour. Since then, the Leonids have put on some stunning displays, but nothing to match the 1966 shower.

Will there be a Leonid storm in 2017? That’s one prediction we can make with a fair amount of certainty, and the answer is no. No storm or heightened meteor activity is anticipated for the Leonid meteor shower in 2017. That’s because the parent comet of the Leonid shower is not nearby.

The comet takes just over 33 years to orbit the sun. Its last perihelion (closest point to the sun) was February 28, 1998. Its next expected perihelion is May 20, 2031. So we’ve got awhile to wait for the next Leonid storm!

When they’re not storming, the Leonids are a modest, though reliable, shower. In a dark, moonless sky, you might see up to 10 to 15 meteors per hour. The absence of moonlight will undoubtedly enhance the view of this shower in 2017.

Even watching just one meteor flying across the sky can count as a big thrill. A good percentage of these swift-moving meteor leave persistent trains – glowing trails of ionized gas that last for a few moments are the meteor has gone!

On a dark night, we typically see the most Leonid meteors streaking the sky in the hour before before dawn because that’s when the constellation Leo the Lion – the radiant point of the shower – is found highest in the sky. In 2017, those wanting to make a night of it can observe Mars rising in the east around 3 a.m. local time, and then Jupiter and Venus coming up as the predawn darkness gives way to morning twilight. Click here for an almanac telling you when these planets will rise into your sky.

The planetary line-up shortly before sunrise November 18, 2017. Mars and Spica rise before dawn. Jupiter rises just as the predawn darkness is beginning to give way to morning twilight. Venus rises after dawn’s first light. Click here for an almanac.

Many ask about the radiant points of meteor showers. Please know that you don’t have to locate the radiant point to watch the Leonid shower, for these meteors fly all through the starry heavens. But it’s fun to know where the radiant lies in the sky. When tracing the paths of the Leonid meteors backward, they appear to radiate from the constellation Leo the Lion. Therefore, the meteors in this annual shower are named for this constellation. As seen from mid-northern latitudes, Leo rises over eastern horizon around 1 a.m. After rising, Leo then climbs upward and westward, soaring to its highest point in the southern sky around 6:30 a.m. local time.

Bottom line: On the night of November 17-18, find a dark sky away from pesky artificial lights, enjoy the comfort of a reclining lawn chair and sleeping bag, and enjoy watching the swift-moving and often bright Leonid meteor shower. The new moon on November 18 guarantees a dark sky.

Never miss another full moon. Order your 2017 EarthSky moon calendar today! Supplies limited.

How high up are meteors when they begin to glow?

Do you love stargazing? Order your EarthSky Planisphere today

from EarthSky http://ift.tt/1BBnII2

Between midnight and dawn on Saturday, November 18, watch for meteors in the annual Leonid meteor shower. Maybe you saw some meteors on the morning of November 17, too? In 2017, the peak stretches over two mornings, and a new moon on November 18 guarantees darkness (from rural locations) on both nights.

The Leonids are famous for storming at various times in recent history. The first great meteor storm of modern times was nearly 200 years ago; it was the Leonid shower of November 1833. That famous shower had a major effect on the development of the scientific study of meteors. It’s one reason the Leonids are so famous.

Previously, meteors were thought to be atmospheric phenomena, like rain or snow. But scientists were curious. Why was the 1833 shower so strong? In 1865, astronomers discovered a comet, which was named Comet Tempel-Tuttle for its discoverers. The comet’s orbit around the sun was found to be about 33 years. Some predicted that there would be another Leonid meteor storm in November 1866 – and so there was!

Thus the Leonid meteor storm of 1833 helped prove that meteors in annual shower originate in comets.

Leonid meteor storm, as seen over North America on the night of November 12-13, 1833. This woodcut was published in 1888 by E. Weib in his Bilderatlas der Sternenwelt (Illustrated Atlas of the Stars). Image via Wikimedia Commons.

Now we know that Earth crosses the orbital path of Comet Tempel-Tuttle every year. Debris from this comet burns up in the Earth’s upper atmosphere to create the annual Leonid shower. It’s only when the comet is near that we see a Leonid storm.

The illustration above depicts the 1833 Leonid meteor shower, said to have produced from 100,000 to 200,000 meteors per hour! This old woodcut, published in 1888, shows what the Leonid shower might look like in a year that this shower erupts into storm, bombarding the sky with hundreds of thousands of meteors.

That happened last in 1966, when North Americans enjoyed a Leonid storm numbering 100,000 shooting stars per hour. Since then, the Leonids have put on some stunning displays, but nothing to match the 1966 shower.

Will there be a Leonid storm in 2017? That’s one prediction we can make with a fair amount of certainty, and the answer is no. No storm or heightened meteor activity is anticipated for the Leonid meteor shower in 2017. That’s because the parent comet of the Leonid shower is not nearby.

The comet takes just over 33 years to orbit the sun. Its last perihelion (closest point to the sun) was February 28, 1998. Its next expected perihelion is May 20, 2031. So we’ve got awhile to wait for the next Leonid storm!

When they’re not storming, the Leonids are a modest, though reliable, shower. In a dark, moonless sky, you might see up to 10 to 15 meteors per hour. The absence of moonlight will undoubtedly enhance the view of this shower in 2017.

Even watching just one meteor flying across the sky can count as a big thrill. A good percentage of these swift-moving meteor leave persistent trains – glowing trails of ionized gas that last for a few moments are the meteor has gone!

On a dark night, we typically see the most Leonid meteors streaking the sky in the hour before before dawn because that’s when the constellation Leo the Lion – the radiant point of the shower – is found highest in the sky. In 2017, those wanting to make a night of it can observe Mars rising in the east around 3 a.m. local time, and then Jupiter and Venus coming up as the predawn darkness gives way to morning twilight. Click here for an almanac telling you when these planets will rise into your sky.

The planetary line-up shortly before sunrise November 18, 2017. Mars and Spica rise before dawn. Jupiter rises just as the predawn darkness is beginning to give way to morning twilight. Venus rises after dawn’s first light. Click here for an almanac.

Many ask about the radiant points of meteor showers. Please know that you don’t have to locate the radiant point to watch the Leonid shower, for these meteors fly all through the starry heavens. But it’s fun to know where the radiant lies in the sky. When tracing the paths of the Leonid meteors backward, they appear to radiate from the constellation Leo the Lion. Therefore, the meteors in this annual shower are named for this constellation. As seen from mid-northern latitudes, Leo rises over eastern horizon around 1 a.m. After rising, Leo then climbs upward and westward, soaring to its highest point in the southern sky around 6:30 a.m. local time.

Bottom line: On the night of November 17-18, find a dark sky away from pesky artificial lights, enjoy the comfort of a reclining lawn chair and sleeping bag, and enjoy watching the swift-moving and often bright Leonid meteor shower. The new moon on November 18 guarantees a dark sky.

Never miss another full moon. Order your 2017 EarthSky moon calendar today! Supplies limited.

How high up are meteors when they begin to glow?

Do you love stargazing? Order your EarthSky Planisphere today

from EarthSky http://ift.tt/1BBnII2

Crossing Phobos 2.0

We received an update from Robert Guilanya, flight dynamics lead for ExoMars/TGO, earlier today. He provided a short explanation of the Phobos orbit crossing that happened, for the first times, at 14:30 UTC and 20:00 UTC.

The crossing of the TGO orbit by the other Mars satellites is a normal situation that we monitor. During the last two weeks, we have been controlling the progress of the aerobraking campaign such that at the time Phobos crosses the TGO orbit, TGO is as far away as possible.

For today’s orbit, see below a series of plot that shows the Phobos orbit (blue line) and the TGO orbit (black line). The red dot shows Phobos’ position, and the black dot, TGO’s position.

To give you some numbers with the orbit of today:

1. Today at 06:44 UTC Phobos crossed the TGO orbit
   

   Phobos orbit & TGO trajectory 06:44 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

2. 259 min later, TGO crossed Phobos orbit, at 11:03Z
   

   Phobos orbit & TGO trajectory 11:03 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

3. 200 min later, Phobos crossed again the TGO orbit, at 14:23Z
   

   Phobos orbit & TGO trajectory 14:23 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

As you can see, both satellites (Phobos, too, is a ‘satellite’) had a large phase difference at the time they were crossing the orbits.

 

from Rocket Science http://ift.tt/2AM5Snu
v

We received an update from Robert Guilanya, flight dynamics lead for ExoMars/TGO, earlier today. He provided a short explanation of the Phobos orbit crossing that happened, for the first times, at 14:30 UTC and 20:00 UTC.

The crossing of the TGO orbit by the other Mars satellites is a normal situation that we monitor. During the last two weeks, we have been controlling the progress of the aerobraking campaign such that at the time Phobos crosses the TGO orbit, TGO is as far away as possible.

For today’s orbit, see below a series of plot that shows the Phobos orbit (blue line) and the TGO orbit (black line). The red dot shows Phobos’ position, and the black dot, TGO’s position.

To give you some numbers with the orbit of today:

1. Today at 06:44 UTC Phobos crossed the TGO orbit
   

   Phobos orbit & TGO trajectory 06:44 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

2. 259 min later, TGO crossed Phobos orbit, at 11:03Z
   

   Phobos orbit & TGO trajectory 11:03 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

3. 200 min later, Phobos crossed again the TGO orbit, at 14:23Z
   

   Phobos orbit & TGO trajectory 14:23 UTC 16 Nov 2017 Credit: ESA/R. Guilanya

As you can see, both satellites (Phobos, too, is a ‘satellite’) had a large phase difference at the time they were crossing the orbits.

 

from Rocket Science http://ift.tt/2AM5Snu
v