Identify the Winter Circle and winter’s brightest stars

Tonight’s chart covers a wider area of sky than we typically show. It’s in answer to a reader in Nashville, who wrote:

I’ve heard mention of the Winter Circle of Stars. Could you list the stars in this circle?

If you’re in the Northern Hemisphere, you’ll find these stars at this time of year by looking southeast at early-to-mid evening, and more southward from mid-to-late evening. Although the almost-full waxing gibbous moon shines within the Winter Circle tonight, all the stars of the Winter Circle (sometimes called the Winter Hexagon) are first-magnitude stars, so they should be able to withstand tonight’s drenching moonlight. Note also that the Winter Triangle – formed by bright stars Sirius, Betelgeuse and Procyon – make up the southeast part of the Winter Circle.

By the way, in 2015, a super-brilliant starlike object sits outside the Winter Circle, low in the east at nightfall. That object is actually the king planet Jupiter. This world is far brighter than any Winter Circle star. Watch for the moon to leave the Winter Circle after a few more days, and to pair with the planet Jupiter around February 3.

Back to the Winter Circle. It’s a humongous pattern of stars and covers a wide area of sky, but it helps to start out small – in this case, by finding the prominent constellation Orion the Hunter. Orion is very noticeable on these winter evenings (see chart at top of page). If you pick out any pattern of stars in the southeast at nightfall, it’ll probably be part of Orion.

The Winter Circle stars surround Orion. They don’t form a perfect circle … is anything ever perfect? Try starting at Capella and moving clockwise to Aldebaran, Rigel, Sirius, Procyon, Pollux, and Castor.

This pattern of stars is not a constellation. It’s a lot of separate stars in different constellations. In other words, it’s what’s called an asterism. From our Northern Hemisphere locations, these same bright stars can be seen before dawn every late summer and early fall. And they can be seen in the evening every winter. Hence the name Winter Circle.

I wonder what these same stars are called in the Southern Hemisphere? They’re visible from there, but of course it’s summer there now. I don’t know if this particular collection of bright stars has some special name as seen from that part of the globe. If any of you do know … tell us in the comments!

By the way, the ruddy star Betelgeuse, in the shoulder of the constellation Orion, isn’t part of the Winter Circle. But it is part of the Winter Triangle, which is inside the Winter Circle.

Donate: Your support means the world to us

View larger. | The Winter Circle as photographed by EarthSky Facebook friend Zhean Peter Nacionales in the Philippines. Thank you, Zhean!

Bottom line: The stars of the Winter Circle may be found in the sky now. It can be seen on these cold winter nights until well after midnight.

Read more about the Winter Circle: Brightest winter stars

Live by the moon with your 2015 EarthSky lunar calendar!

from EarthSky http://ift.tt/1ySWuK2

Tonight’s chart covers a wider area of sky than we typically show. It’s in answer to a reader in Nashville, who wrote:

I’ve heard mention of the Winter Circle of Stars. Could you list the stars in this circle?

If you’re in the Northern Hemisphere, you’ll find these stars at this time of year by looking southeast at early-to-mid evening, and more southward from mid-to-late evening. Although the almost-full waxing gibbous moon shines within the Winter Circle tonight, all the stars of the Winter Circle (sometimes called the Winter Hexagon) are first-magnitude stars, so they should be able to withstand tonight’s drenching moonlight. Note also that the Winter Triangle – formed by bright stars Sirius, Betelgeuse and Procyon – make up the southeast part of the Winter Circle.

By the way, in 2015, a super-brilliant starlike object sits outside the Winter Circle, low in the east at nightfall. That object is actually the king planet Jupiter. This world is far brighter than any Winter Circle star. Watch for the moon to leave the Winter Circle after a few more days, and to pair with the planet Jupiter around February 3.

Back to the Winter Circle. It’s a humongous pattern of stars and covers a wide area of sky, but it helps to start out small – in this case, by finding the prominent constellation Orion the Hunter. Orion is very noticeable on these winter evenings (see chart at top of page). If you pick out any pattern of stars in the southeast at nightfall, it’ll probably be part of Orion.

The Winter Circle stars surround Orion. They don’t form a perfect circle … is anything ever perfect? Try starting at Capella and moving clockwise to Aldebaran, Rigel, Sirius, Procyon, Pollux, and Castor.

This pattern of stars is not a constellation. It’s a lot of separate stars in different constellations. In other words, it’s what’s called an asterism. From our Northern Hemisphere locations, these same bright stars can be seen before dawn every late summer and early fall. And they can be seen in the evening every winter. Hence the name Winter Circle.

I wonder what these same stars are called in the Southern Hemisphere? They’re visible from there, but of course it’s summer there now. I don’t know if this particular collection of bright stars has some special name as seen from that part of the globe. If any of you do know … tell us in the comments!

By the way, the ruddy star Betelgeuse, in the shoulder of the constellation Orion, isn’t part of the Winter Circle. But it is part of the Winter Triangle, which is inside the Winter Circle.

Donate: Your support means the world to us

View larger. | The Winter Circle as photographed by EarthSky Facebook friend Zhean Peter Nacionales in the Philippines. Thank you, Zhean!

Bottom line: The stars of the Winter Circle may be found in the sky now. It can be seen on these cold winter nights until well after midnight.

Read more about the Winter Circle: Brightest winter stars

Live by the moon with your 2015 EarthSky lunar calendar!

from EarthSky http://ift.tt/1ySWuK2

Temporary ecology/organismal biology position at UMM [Pharyngula]

We’re hiring! If you have skill in teaching, and want to hone those skills at a school with a reputation for excellence in teaching, apply!

Full-Time One-Year Position in Biology

University of Minnesota, Morris

The University of Minnesota, Morris seeks an individual committed to excellence in undergraduate education, to fill a full-time, one-year, possibly renewable, position in biology beginning August 17, 2015. Responsibilities include: teaching undergraduate biology courses including a 2000-level survey of organismal biology for majors (with labs), an introductory-level survey of biology for environmental studies/science students (with labs, including field trips to local habitats), and an upper-level organismal or ecological elective in the candidate’s area of expertise; contributing to other courses that support the biology curriculum; and sharing in the governance and advancement of the biology program as well as the campus at large.

Candidates must be at least A.B.D. in ecology, organismal biology, environmental biology, or a closely related field by August 17, 2015. Experience teaching undergraduate biology is required. (Graduate TA experience is acceptable).

The University of Minnesota, Morris (UMM) is a residential public liberal arts college serving about 1900 undergraduate students. As one of five campuses of the University of Minnesota, the Morris campus is located 160 miles west of Minneapolis in the rural community of Morris, MN. UMM is consistently ranked by U.S. News & World Report as a Top 10 Best Public Liberal Arts College. The student body is talented, diverse and engaged. The UMM student body is one of the most ethnically diverse in the University of Minnesota system with 20% students of color (13% are American Indian students) and a growing international student population.

The college values diversity in its students, faculty, and staff. The college is especially interested in qualified candidates who can contribute to the diversity of our community through their teaching, research, and /or service because we believe that diversity enriches the classroom and research experience at the University

Applications must include a letter of application, resume, graduate and undergraduate transcripts, a teaching statement with evidence of teaching effectiveness, and three letters of reference. Applications may be sent to Ann Kolden, Administrative Assistant, at koldenal@morris.umn.edu, (320) 589-6301, or they may be sent to:

Biology Search Committee Chair

Division of Science and Mathematics

University of Minnesota, Morris

Morris, MN 56267-2128

Applications will be accepted until the position is filled. Screening begins February 16, 2015. Inquiries can be made to Professor Heather Waye, Search Committee Chair, at (320) 589-6304 (wayex001@morris.umn.edu).

The University of Minnesota shall provide equal access to and opportunity in its programs, facilities, and employment without regard to race, color, creed, religion, national origin, gender, age, marital status, disability, public assistance status, veteran status, sexual orientation, gender identity, or gender expression. To request disability accommodation or material in alternative formats contact: UMM Human Resources, (320)-589-6024, Room309, Behmler Hall, Morris, MN 56267.

from ScienceBlogs http://ift.tt/1JPietZ

We’re hiring! If you have skill in teaching, and want to hone those skills at a school with a reputation for excellence in teaching, apply!

Full-Time One-Year Position in Biology

University of Minnesota, Morris

The University of Minnesota, Morris seeks an individual committed to excellence in undergraduate education, to fill a full-time, one-year, possibly renewable, position in biology beginning August 17, 2015. Responsibilities include: teaching undergraduate biology courses including a 2000-level survey of organismal biology for majors (with labs), an introductory-level survey of biology for environmental studies/science students (with labs, including field trips to local habitats), and an upper-level organismal or ecological elective in the candidate’s area of expertise; contributing to other courses that support the biology curriculum; and sharing in the governance and advancement of the biology program as well as the campus at large.

Candidates must be at least A.B.D. in ecology, organismal biology, environmental biology, or a closely related field by August 17, 2015. Experience teaching undergraduate biology is required. (Graduate TA experience is acceptable).

The University of Minnesota, Morris (UMM) is a residential public liberal arts college serving about 1900 undergraduate students. As one of five campuses of the University of Minnesota, the Morris campus is located 160 miles west of Minneapolis in the rural community of Morris, MN. UMM is consistently ranked by U.S. News & World Report as a Top 10 Best Public Liberal Arts College. The student body is talented, diverse and engaged. The UMM student body is one of the most ethnically diverse in the University of Minnesota system with 20% students of color (13% are American Indian students) and a growing international student population.

The college values diversity in its students, faculty, and staff. The college is especially interested in qualified candidates who can contribute to the diversity of our community through their teaching, research, and /or service because we believe that diversity enriches the classroom and research experience at the University

Applications must include a letter of application, resume, graduate and undergraduate transcripts, a teaching statement with evidence of teaching effectiveness, and three letters of reference. Applications may be sent to Ann Kolden, Administrative Assistant, at koldenal@morris.umn.edu, (320) 589-6301, or they may be sent to:

Biology Search Committee Chair

Division of Science and Mathematics

University of Minnesota, Morris

Morris, MN 56267-2128

Applications will be accepted until the position is filled. Screening begins February 16, 2015. Inquiries can be made to Professor Heather Waye, Search Committee Chair, at (320) 589-6304 (wayex001@morris.umn.edu).

The University of Minnesota shall provide equal access to and opportunity in its programs, facilities, and employment without regard to race, color, creed, religion, national origin, gender, age, marital status, disability, public assistance status, veteran status, sexual orientation, gender identity, or gender expression. To request disability accommodation or material in alternative formats contact: UMM Human Resources, (320)-589-6024, Room309, Behmler Hall, Morris, MN 56267.

from ScienceBlogs http://ift.tt/1JPietZ

Iceberg sounds!

Distinctive underwater sounds announce the birth of an iceberg, say researchers. In a recent study, scientists used underwater microphones aboard buoys to record a variety of iceberg births at the Hans Glacier in Svalbard, Norway during three days in August 2013. These recordings were combined with time-lapse photos of the glacier during the same time period.

By synchronizing the sound recordings with the photographs, the researchers discovered that different types of ice loss are associated with distinct rumbles, snaps and splashes, according to a new study accepted for publication in Geophysical Research Letters.

Photo credit: Ryan Stanley

The scientists identified acoustic signatures for three different ways that ice ‘calves’ – that is, ice breaks away from a glacier:

– An ice chunk falls off the leading face of the glacier into the water below.

– An ice fragment cracks away from that face and slides down it into the water.

– Or, an underwater ice block detaches from the face beneath the water, then pops up to the sea surface.

The newly reported findings may give scientists a better understanding of how glaciers lose ice, the study’s authors write, even when icebergs detach underwater — a difficult-to-observe phenomenon. If inexpensive acoustic methods could be used to gain insight into various calving events, they add, that could be important as glaciers around the world continue to crumble and contribute to global sea level rise.

Photo credit: Mike Reyfman

Read more from the AGU

from EarthSky http://ift.tt/1tzh4Pc

Distinctive underwater sounds announce the birth of an iceberg, say researchers. In a recent study, scientists used underwater microphones aboard buoys to record a variety of iceberg births at the Hans Glacier in Svalbard, Norway during three days in August 2013. These recordings were combined with time-lapse photos of the glacier during the same time period.

By synchronizing the sound recordings with the photographs, the researchers discovered that different types of ice loss are associated with distinct rumbles, snaps and splashes, according to a new study accepted for publication in Geophysical Research Letters.

Photo credit: Ryan Stanley

The scientists identified acoustic signatures for three different ways that ice ‘calves’ – that is, ice breaks away from a glacier:

– An ice chunk falls off the leading face of the glacier into the water below.

– An ice fragment cracks away from that face and slides down it into the water.

– Or, an underwater ice block detaches from the face beneath the water, then pops up to the sea surface.

The newly reported findings may give scientists a better understanding of how glaciers lose ice, the study’s authors write, even when icebergs detach underwater — a difficult-to-observe phenomenon. If inexpensive acoustic methods could be used to gain insight into various calving events, they add, that could be important as glaciers around the world continue to crumble and contribute to global sea level rise.

Photo credit: Mike Reyfman

Read more from the AGU

from EarthSky http://ift.tt/1tzh4Pc

Explore Nanotechnology with Paper: Weekly Science Activity

In this week's spotlight: a materials science activity that gives families a hands-on look at nanotechnology. Materials coming out of nanotechnology research are often lighter and stronger than traditional materials. Nanotechnology scientists are working with matter at the nanoscale, which means they are working with individual atoms and molecules. By altering the structure and arrangement of particles, scientists are creating and discovering new materials that have exciting new qualities—some of these materials might even make you think of favorite science fiction or comic book characters! In this hands-on activity, students use paper to help model and visualize how different arrangements of the same matter can make a dramatic difference in the strength of the material made from that matter.

For both the science project and the shorter family-friendly science activity, students use everyday paper to represent carbon nanostructures used in nanotechnology. How does strength change when you stack, roll, fold, or otherwise manipulate the paper? Put it to the test for a better understanding of what it means for scientists to rearrange the structure of matter at the nanoscale!

• Exploring Nanotechnology: Fold, Roll, & Stack Your Way to Super-Strong Materials (full Science Buddies project idea)


• Super-Strong Science: Explore Nanotechnology Using Paper (science activity at Scientific American)

from Science Buddies Blog http://ift.tt/15WBKpf

In this week's spotlight: a materials science activity that gives families a hands-on look at nanotechnology. Materials coming out of nanotechnology research are often lighter and stronger than traditional materials. Nanotechnology scientists are working with matter at the nanoscale, which means they are working with individual atoms and molecules. By altering the structure and arrangement of particles, scientists are creating and discovering new materials that have exciting new qualities—some of these materials might even make you think of favorite science fiction or comic book characters! In this hands-on activity, students use paper to help model and visualize how different arrangements of the same matter can make a dramatic difference in the strength of the material made from that matter.

For both the science project and the shorter family-friendly science activity, students use everyday paper to represent carbon nanostructures used in nanotechnology. How does strength change when you stack, roll, fold, or otherwise manipulate the paper? Put it to the test for a better understanding of what it means for scientists to rearrange the structure of matter at the nanoscale!

• Exploring Nanotechnology: Fold, Roll, & Stack Your Way to Super-Strong Materials (full Science Buddies project idea)


• Super-Strong Science: Explore Nanotechnology Using Paper (science activity at Scientific American)

from Science Buddies Blog http://ift.tt/15WBKpf

Bad Faith Criticism of Science [Greg Laden's Blog]

I’ve recently written about the Serengeti Strategy, a coin termed by climate scientist Michael Mann to describe the anti-science strategy of personal attacks against individual scientists in an attempt to discredit valid scientific research one might find inconvenient. Science Careers (from Science Magazine) has a new item called “Science under the microscope” looking at bad faith criticism of science and scientist. Some of this comes from within science itself, where the term “torpedo” is sometimes used. Rival scientists do take shots at each other in the peer review or grant review process.

Whether it’s because they are overworked, lack training, vested in a particular theory or methodology, or just having a bad day, sometimes scientists write what Cornell University psychologist Robert Sternberg calls “savage reviews.” “A savage review is one that is either personalized—in other words, the criticisms are of the persons rather than of the works—or the criticisms are of the works but the language is excessive … for the gravity of the sins…”

Sometimes criticism from within science plays out outside the usual channels. Sometimes this criticism is quite valid, such as the widespread dislike of a paper on bacteria that seemed to be evolving in an American salt lake a few years ago. Remember that? The paper seemed to make claims about the significance of their findings that went beyond the results they reported, and the authors backed up those claims with a promise that they would be publishing a followup paper with the necessary proof. Never do that. A published scientific paper can include some speculation or suggestion of further findings, but highlighted findings, which in this case were highlighted in a major press event set up by NASA, should have been either not mentioned or backed up, perhaps in a later publication. In that case, the part of the scientific community that inhabits the science biosphere had a feeding frenzy. The criticisms being made in blogs were usually valid, but the tone was in some quarters way overdone. For my part, I took the opportunity of the paper coming out to write about a related topic, and I actually received some of the vitriol myself simply because I did not bother to address the original paper’s flaws. (I had decided not to because experts in the field had it covered!) The point is, sometimes the flak becomes so dense that the flack itself becomes the message. The Science Careers piece talks about a case of overlap between the scientific literature and the blogosphere that was less vitriolic but just as complex:

…cognitive psychologist Axel Cleeremans … attempted to replicate a classic study by John Bargh of Yale University, in which some participants were primed, without realizing it, with concepts associated with old age. Bargh’s study found that they walked more slowly from the exam room than subjects who had not been so primed. Cleeremans’s group found that they could not replicate the result …

The failed replication attempt…was picked up by science journalist Ed Yong at his Not Exactly Rocket Science blog and attracted a lot of attention. Bargh responded with a post on his own blog, at Psychology Today, where he spelled out the errors that he believed the Cleeremans group made. The post, titled “Nothing in their Heads,” used a tone Bargh later told The Chronicle of Higher Education that he now regrets; it has since been taken down. Yong described the post, in a subsequent blog post of his own, as “a mixture of critiques of the science within the paper, and personal attacks a…” Harsh words flew in Bargh’s direction, too, as Bargh’s critics accused him of ad hominem attacks and attacked him in turn, often via anonymous comments.

More recently, a reconstruction of a large and sexy dinosaur was heavily criticized in the blogosphere by individuals who probably knew their dinosaurs, but who had not seen the original fossils or casts. I’m pretty sure the criticisms were weak, and the language was strong, and no dinosaurs (or hypotheses) were harmed in the process. But it was yet another example of the bleed between traditional modalities of communication and newer on line and social networking based modalities, going at least a little bad.

The Science Careers piece also talks about attacks on science, and scientists, from outside the population of scientists and deeply interested and informed parties, such as attacks on climate scientists by those who insist on denying the reality of anthropogenic global warming. My piece on the Serengeti Strategy, which was a commentary on Michael Mann’s paper on that topic, covers that area. See also these posts on the Recursive Fury maneno.

Michael Mann, a climate scientist at Pennsylvania State University, University Park, has experienced many attacks since his “hockey stick” curve was published in the 2001 report of the Intergovernmental Panel on Climate Change. Mann has since become an outspoken defender of climate science…and been the victim of many vilifying media reports, campaigns aimed at discrediting him, the misuse of open-records laws, e-mail hacking (in the so-called “Climategate”), and threats to his and his family’s safety.

Such attacks can be “very stressful, it can take a lot of a scientist’s time. … Unfortunately if their institution doesn’t support them, it’s potentially very expensive” in legal costs, says Lauren Kurtz, executive director of the Climate Science Legal Defense Fund. It can detract from your ability to do research, Kurtz adds. There also is a danger that it will derail your career, especially for young scientists who don’t have the security of tenure, Mann writes in an e-mail. “[T]here is always a fear that your colleagues and bosses (chairs, deans, provosts, presidents) will believe the scurrilous accusations made against you.”

Some of this is not so much about science (or anti science) but just plain harassment. Or, a combination of both, especially if the scientist under attack is a woman. It seems that one of the main roles of the blogosphere is to give misogynists their own private shooting gallery.

“For the longest time, the only people reacting to academic research were either academics or people who were very interested in a particular field,” says Whitney Phillips, a media studies scholar at Humboldt State University in Arcata, California. But “Things are … so visible now that anybody … can say something on a blog and then suddenly find themselves on the receiving end of lots of weird commentary.”

There are lots of different kinds of nasty behaviors online, and how they are perceived largely depends on the receiver, Phillips says. Online nastiness can go all the way from potentially offensive general comments to personal attacks directed at you. Sometimes it can even “reac[h] the legal criteria for harassment, so someone is not just saying rude things to you but is … potentially even threatening you or trying to wiggle their way into your life,” Phillips says.

Women and minorities are disproportionately exposed to online antagonism and may also be more sensitized because they already confront it in real life, Phillips says…

Phillips suggests limiting the power of “Internet trolls”…by deleting anything they (the trolls) post on your blog, banning them from your site, and using word filters. Try not to get sucked in, as what they want most is a response and an audience, she says….

One of my favorite quotes by me (if I may be allowed) is, “It is important to be hated by the right people.” This is obvious. If Ghandi hates you and Hitler loves you, you are probably doing something wrong. When sadistic internet trolls and anti-science activists go after you, you are a victim but you are also a symbol of something good. Truly, a mixed bag, but worth keeping in mind. The Science Career piece also makes this point. And other points. Go read it.

(I’m assuming it is not behind a firewall but I’m not sure. If you find it so let me know and I’ll change that last sentence to “Go don’t read it.”)

from ScienceBlogs http://ift.tt/1ERXCyo

I’ve recently written about the Serengeti Strategy, a coin termed by climate scientist Michael Mann to describe the anti-science strategy of personal attacks against individual scientists in an attempt to discredit valid scientific research one might find inconvenient. Science Careers (from Science Magazine) has a new item called “Science under the microscope” looking at bad faith criticism of science and scientist. Some of this comes from within science itself, where the term “torpedo” is sometimes used. Rival scientists do take shots at each other in the peer review or grant review process.

Whether it’s because they are overworked, lack training, vested in a particular theory or methodology, or just having a bad day, sometimes scientists write what Cornell University psychologist Robert Sternberg calls “savage reviews.” “A savage review is one that is either personalized—in other words, the criticisms are of the persons rather than of the works—or the criticisms are of the works but the language is excessive … for the gravity of the sins…”

Sometimes criticism from within science plays out outside the usual channels. Sometimes this criticism is quite valid, such as the widespread dislike of a paper on bacteria that seemed to be evolving in an American salt lake a few years ago. Remember that? The paper seemed to make claims about the significance of their findings that went beyond the results they reported, and the authors backed up those claims with a promise that they would be publishing a followup paper with the necessary proof. Never do that. A published scientific paper can include some speculation or suggestion of further findings, but highlighted findings, which in this case were highlighted in a major press event set up by NASA, should have been either not mentioned or backed up, perhaps in a later publication. In that case, the part of the scientific community that inhabits the science biosphere had a feeding frenzy. The criticisms being made in blogs were usually valid, but the tone was in some quarters way overdone. For my part, I took the opportunity of the paper coming out to write about a related topic, and I actually received some of the vitriol myself simply because I did not bother to address the original paper’s flaws. (I had decided not to because experts in the field had it covered!) The point is, sometimes the flak becomes so dense that the flack itself becomes the message. The Science Careers piece talks about a case of overlap between the scientific literature and the blogosphere that was less vitriolic but just as complex:

…cognitive psychologist Axel Cleeremans … attempted to replicate a classic study by John Bargh of Yale University, in which some participants were primed, without realizing it, with concepts associated with old age. Bargh’s study found that they walked more slowly from the exam room than subjects who had not been so primed. Cleeremans’s group found that they could not replicate the result …

The failed replication attempt…was picked up by science journalist Ed Yong at his Not Exactly Rocket Science blog and attracted a lot of attention. Bargh responded with a post on his own blog, at Psychology Today, where he spelled out the errors that he believed the Cleeremans group made. The post, titled “Nothing in their Heads,” used a tone Bargh later told The Chronicle of Higher Education that he now regrets; it has since been taken down. Yong described the post, in a subsequent blog post of his own, as “a mixture of critiques of the science within the paper, and personal attacks a…” Harsh words flew in Bargh’s direction, too, as Bargh’s critics accused him of ad hominem attacks and attacked him in turn, often via anonymous comments.

More recently, a reconstruction of a large and sexy dinosaur was heavily criticized in the blogosphere by individuals who probably knew their dinosaurs, but who had not seen the original fossils or casts. I’m pretty sure the criticisms were weak, and the language was strong, and no dinosaurs (or hypotheses) were harmed in the process. But it was yet another example of the bleed between traditional modalities of communication and newer on line and social networking based modalities, going at least a little bad.

The Science Careers piece also talks about attacks on science, and scientists, from outside the population of scientists and deeply interested and informed parties, such as attacks on climate scientists by those who insist on denying the reality of anthropogenic global warming. My piece on the Serengeti Strategy, which was a commentary on Michael Mann’s paper on that topic, covers that area. See also these posts on the Recursive Fury maneno.

Michael Mann, a climate scientist at Pennsylvania State University, University Park, has experienced many attacks since his “hockey stick” curve was published in the 2001 report of the Intergovernmental Panel on Climate Change. Mann has since become an outspoken defender of climate science…and been the victim of many vilifying media reports, campaigns aimed at discrediting him, the misuse of open-records laws, e-mail hacking (in the so-called “Climategate”), and threats to his and his family’s safety.

Such attacks can be “very stressful, it can take a lot of a scientist’s time. … Unfortunately if their institution doesn’t support them, it’s potentially very expensive” in legal costs, says Lauren Kurtz, executive director of the Climate Science Legal Defense Fund. It can detract from your ability to do research, Kurtz adds. There also is a danger that it will derail your career, especially for young scientists who don’t have the security of tenure, Mann writes in an e-mail. “[T]here is always a fear that your colleagues and bosses (chairs, deans, provosts, presidents) will believe the scurrilous accusations made against you.”

Some of this is not so much about science (or anti science) but just plain harassment. Or, a combination of both, especially if the scientist under attack is a woman. It seems that one of the main roles of the blogosphere is to give misogynists their own private shooting gallery.

“For the longest time, the only people reacting to academic research were either academics or people who were very interested in a particular field,” says Whitney Phillips, a media studies scholar at Humboldt State University in Arcata, California. But “Things are … so visible now that anybody … can say something on a blog and then suddenly find themselves on the receiving end of lots of weird commentary.”

There are lots of different kinds of nasty behaviors online, and how they are perceived largely depends on the receiver, Phillips says. Online nastiness can go all the way from potentially offensive general comments to personal attacks directed at you. Sometimes it can even “reac[h] the legal criteria for harassment, so someone is not just saying rude things to you but is … potentially even threatening you or trying to wiggle their way into your life,” Phillips says.

Women and minorities are disproportionately exposed to online antagonism and may also be more sensitized because they already confront it in real life, Phillips says…

Phillips suggests limiting the power of “Internet trolls”…by deleting anything they (the trolls) post on your blog, banning them from your site, and using word filters. Try not to get sucked in, as what they want most is a response and an audience, she says….

One of my favorite quotes by me (if I may be allowed) is, “It is important to be hated by the right people.” This is obvious. If Ghandi hates you and Hitler loves you, you are probably doing something wrong. When sadistic internet trolls and anti-science activists go after you, you are a victim but you are also a symbol of something good. Truly, a mixed bag, but worth keeping in mind. The Science Career piece also makes this point. And other points. Go read it.

(I’m assuming it is not behind a firewall but I’m not sure. If you find it so let me know and I’ll change that last sentence to “Go don’t read it.”)

from ScienceBlogs http://ift.tt/1ERXCyo

The Problem with (and Promise of) Word Problems [Uncertain Principles]

Math with Bad Drawings has a post about “word problems” that will sound very familiar to anyone who’s taught introductory physics. As he notes, the problem with “word problems” for math-phobic students is that it requires translating words into symbols, and then using the symbols to select a procedure. It adds a step to what at a lower level is a simple turn-the-crank algorithm: given this set of symbols, do these abstract operations, and write down the answers.

This is a very familiar problem in intro physics, where I regularly have struggling students tell me “I can do the math just fine, I just don’t know how to set up the problems.” And, you know, that’s true, because the math is far and away the least difficult part of intro physics– it’s all arithmetic and algebra, with a tiny bit of trigonometry sprinkled in. We very occasionally use stuff from calculus, but almost never at a level above the routine algorithms for differentiation and integration.

All of the problems in intro physics are word problems, because that’s where all the action is. The hard part is figuring out how to translate a real-world situation into symbols, and where to make approximations and idealizations to make that process easier. Once you have all the symbols, there are simple heuristics to figure out what procedures to try, but it’s getting the right symbols in the right places that’s a problem.

And there’s always a tension here, when it comes to writing homework and exam questions. On the one hand, we want to be testing students’ understanding of the concepts and procedures of intro physics, which argues for very abstract, very plainly stated problems– blocks sliding on inclined planes, uniformly charged spherical shells, etc. But on the other hand, I think probably the most important thing physics has to offer is the idea that sometimes the spherical cow is good enough, that very translation and abstraction process that you find in “word problems.” Which argues for much more rich-context stuff.

And, in the end, the only way to get that process down is to do it– to work a whole bunch of different “word problems” until you get comfortable with the idea of translating and abstracting. Because sooner or later, students who go on in physics will need that. The alternative is to give clearly stated problems and explicitly teach the heuristics for making decisions, but that just kicks the can down the road to the next class.

One way to ease this, though, is to move some of that translation and abstraction process up a bit, to earlier ages. which is where this pivots to become another Thanks, Common Core post, based on a conversation I had last night with SteelyKid, after sparring class at taekwondo. We were at Panera, and I asked her a math question (as one does with one’s first-grader…): “What’s 27 minus 19?”

“Ummm… Can you write that down?” she asked. So I wrote the top lines in this picture:

Working two-digit subtraction with SteelyKid.

(OK, technically, this is my re-creation of what we drew on the back of a Panera receipt last night, but roll with it…)

“OK, I’m going to re-write that as a number sentence,” she said, and produced the second line. “27 take away 19 equals what?”

Then she went on to the third line, saying “So, what I do is, I break the 27 up, so it’s a 2 and a 7, which means 20 and 7…” and though she stumbled for a second at this point, she quickly got that 20 minus 19 leaves 1, which you combine with the 7 to make 8, the correct answer.

That’s not by any means the traditional algorithm I learned (which would start from the top-line format), but it works, and she was very pleased with herself. What I like about it, though, is that this is already getting across the idea of translating between representations. These are all the same problem, stated in words and translated into symbols, but she recognizes that you can write the same problem in different ways, and that that’s a useful thing to do. It’s turning a numbers-and-symbols problem into a “word problem” and back again, and I think that’s great.

That doesn’t mean this will automatically translate to being able to turn rich-context physics problems about real bodies in motion into abstract collections of point masses connected by massless springs, but this kind of thing is a good start. Carry it on up through the curriculum, and teaching intro physics to incoming college students who learned math this way could get a lot more pleasant.

So, as with last week’s post: Thanks, Common Core. More like this, please.

from ScienceBlogs http://ift.tt/1Llnx6b

Math with Bad Drawings has a post about “word problems” that will sound very familiar to anyone who’s taught introductory physics. As he notes, the problem with “word problems” for math-phobic students is that it requires translating words into symbols, and then using the symbols to select a procedure. It adds a step to what at a lower level is a simple turn-the-crank algorithm: given this set of symbols, do these abstract operations, and write down the answers.

This is a very familiar problem in intro physics, where I regularly have struggling students tell me “I can do the math just fine, I just don’t know how to set up the problems.” And, you know, that’s true, because the math is far and away the least difficult part of intro physics– it’s all arithmetic and algebra, with a tiny bit of trigonometry sprinkled in. We very occasionally use stuff from calculus, but almost never at a level above the routine algorithms for differentiation and integration.

All of the problems in intro physics are word problems, because that’s where all the action is. The hard part is figuring out how to translate a real-world situation into symbols, and where to make approximations and idealizations to make that process easier. Once you have all the symbols, there are simple heuristics to figure out what procedures to try, but it’s getting the right symbols in the right places that’s a problem.

And there’s always a tension here, when it comes to writing homework and exam questions. On the one hand, we want to be testing students’ understanding of the concepts and procedures of intro physics, which argues for very abstract, very plainly stated problems– blocks sliding on inclined planes, uniformly charged spherical shells, etc. But on the other hand, I think probably the most important thing physics has to offer is the idea that sometimes the spherical cow is good enough, that very translation and abstraction process that you find in “word problems.” Which argues for much more rich-context stuff.

And, in the end, the only way to get that process down is to do it– to work a whole bunch of different “word problems” until you get comfortable with the idea of translating and abstracting. Because sooner or later, students who go on in physics will need that. The alternative is to give clearly stated problems and explicitly teach the heuristics for making decisions, but that just kicks the can down the road to the next class.

One way to ease this, though, is to move some of that translation and abstraction process up a bit, to earlier ages. which is where this pivots to become another Thanks, Common Core post, based on a conversation I had last night with SteelyKid, after sparring class at taekwondo. We were at Panera, and I asked her a math question (as one does with one’s first-grader…): “What’s 27 minus 19?”

“Ummm… Can you write that down?” she asked. So I wrote the top lines in this picture:

Working two-digit subtraction with SteelyKid.

(OK, technically, this is my re-creation of what we drew on the back of a Panera receipt last night, but roll with it…)

“OK, I’m going to re-write that as a number sentence,” she said, and produced the second line. “27 take away 19 equals what?”

Then she went on to the third line, saying “So, what I do is, I break the 27 up, so it’s a 2 and a 7, which means 20 and 7…” and though she stumbled for a second at this point, she quickly got that 20 minus 19 leaves 1, which you combine with the 7 to make 8, the correct answer.

That’s not by any means the traditional algorithm I learned (which would start from the top-line format), but it works, and she was very pleased with herself. What I like about it, though, is that this is already getting across the idea of translating between representations. These are all the same problem, stated in words and translated into symbols, but she recognizes that you can write the same problem in different ways, and that that’s a useful thing to do. It’s turning a numbers-and-symbols problem into a “word problem” and back again, and I think that’s great.

That doesn’t mean this will automatically translate to being able to turn rich-context physics problems about real bodies in motion into abstract collections of point masses connected by massless springs, but this kind of thing is a good start. Carry it on up through the curriculum, and teaching intro physics to incoming college students who learned math this way could get a lot more pleasant.

So, as with last week’s post: Thanks, Common Core. More like this, please.

from ScienceBlogs http://ift.tt/1Llnx6b

Star of the week: Betelgeuse will explode someday

There has been a lot of excitement this month about the supernova in the distant galaxy M82. It is the closest supernova in many years, despite the fact that it’s some 11-12 million light-years away. On a January or February evening, come to know the red star Betelgeuse in the constellation Orion. It’s not only one of Orion’s brightest stars. It’s also a star that astronomers know will one day explode as a supernova. And it’s only 430 light-years away! Follow the links below to learn more about Betelgeuse and its explosive destiny.

Betelgeuse will explode someday.

Will Betelgeuse become a second sun?

Will the explosion of Betelgeuse destroy earthly life?

What will happen when Betelgeuse goes supernova?

How to see the star Betelgeuse in the night sky.

Betelgeuse in pop culture, history and mythology.

Red Betelgeuse, also known as Alpha Orionis, is the ninth-brightest star in the night sky and second-brightest in the constellation of Orion. Photo taken February 18, 2014 by Thomas Wildoner.

Betelgeuse imaged in ultraviolet light by the Hubble Space Telescope and subsequently enhanced by NASA. The bright white spot is likely one of this star's poles. Image via NASA/ESA.

View larger. | Thomas Wildoner captured these before-and-after images of the supernova that erupted in January 2014, in the galaxy M82. See the supernova? Astronomers sometimes say that a supernova can outshine the galaxy in which it resides. This photo makes me believe it! Read more about the supernova in M82.

Betelgeuse will explode someday Betelgeuse lies some 430 light-years from Earth. Yet it’s already one of the brightest stars in Earth’s sky. The reason is that Betelgeuse is a supergiant star. It is intrinsically very brilliant.

Such brilliance comes at a price, however. Betelgeuse is one of the most famous stars in the sky because it’s due to explode someday. Betelgeuse’s enormous energy requires that the fuel be expended quickly (relatively speaking), and in fact Betelgeuse is now near the end of its lifetime. Someday soon (astronomically speaking), it will run out of fuel, collapse under its own weight, and then rebound in a spectacular supernova explosion. When this happens, Betelgeuse will brighten enormously for a few weeks or months, perhaps as bright as the full moon and visible in broad daylight.

When will it happen? Probably not in our lifetimes. But, in fact, no one really knows. It could be tomorrow or a million years in the future.

Images of closest supernova in years, in galaxy M82

Cool image, but we won't see this from Earth when Betelgeuse goes supernova sometime in the next thousand - or million - years. Image via Geekosystem

Will Betelgeuse become a second sun? Short answer: no. That rumor was flying around in 2012. Remember 2012? The year the world was supposed to end? Anyway, when it does go supernova, Betelgeuse won’t be bright enough to appear as a second sun in our sky.

Instead, anyone alive on Earth when it happens will be treated to an amazingly beautiful sight in the night sky – a very, very, very bright star.

Will the explosion of Betelgeuse destroy earthly life? When Betelgeuse does blow up, our planet Earth is too far away for this explosion to harm, much less destroy, life on Earth. Astrophysicists say we’d have to be within 50 light-years of a supernova for it to harm us. Betelgeuse is nearly 10 times this distance.

So we’re safe from Betelgeuse. And, in fact, if there are any astronomers around when it does blow, they will be extremely thrilled to have a relatively nearby supernova to study.

Artist’s concept showing star Betelgeuse (center), with a series of arcs immediately to the left of the star. The arcs are thought to be material ejected from Betelgeuse as it evolved into a red supergiant. Notice the faint linear bar of dust on the left side of the image. It represents a dusty filament connected to our galaxy’s magnetic field, or the edge of an interstellar cloud. If this filament, or wall, exists – as some astronomers believe – the arcs ejected from Betelgeuse will hit the wall 5,000 years from now. Betelgeuse itself will collide with the wall 12,500 years later. Image via ESA/Herschel/PACS/L. Decin et al. Read more about this image here.

What will happen when Betelgeuse goes supernova? Fortunately for us, it appears that there will be few, if any, adverse affects to Earth when Betelgeuse goes supernova.

If Betelgeuse were side by side with our sun, you’d find it 10,000 times brighter than the sun in visible light. It might be surprising then to learn that the surface temperature of Betelgeuse is only about 6,000 degrees F (3,600K) in contrast to the sun’s 10,000 degrees F.

In terms of mass, Betelgeuse is thought to be about 15 times the mass of the sun, but 600 times wider and more than 200 million times its volume! When you consider its size, as well as the infrared and other radiations it pumps out, Betelgeuse probably outshines our sun by at least 50,000 times.

Betelgeuse is one of two very bright stars in the constellation Orion the Hunter. The other bright star is Rigel. Notice Betelgeuse and Rigel on either side of the short, straight row of three medium-bright stars. That row of stars represents Orion’s Belt. Betelgeuse is said to represent the right shoulder of the Hunter.

How to see the star Betelgeuse in the night sky. At mid-northern latitudes, around the first of every year, Betelgeuse rises around sunset. The star is very well placed for viewing on January and February evenings.

By the beginning of March, this star is due south in early evening. By mid-May, it can be glimpsed briefly in the west after sunset. Betelgeuse is traveling behind the sun in early summer, but it returns to the east before dawn by about mid-July.

Betelgeuse – in the famous constellation Orion – is easy to spot. See our sky chart to learn the pattern of the constellation Orion the Hunter. Orion itself is noticeable for the short, straight row of three medium-bright stars in its mid-section. Betelgeuse is in the upper left corner of the large rectangle forming Orion.

The star Betelgeuse has a distinctive color: somber orange-red. It’s ideal for convincing non-believers that stars do, in fact, come in colors.

Stars designated as Alpha are typically brightest in their constellations. But Betelgeuse is Alpha Orionis, despite the fact that it’s fainter than Orion’s other bright star, Rigel. Betelgeuse is the 10th brightest star in the sky overall, and it’s the 7th brightest star visible from most of the U.S., Canada, Europe and the majority of the northern hemisphere.

Betelgeuse is often said to represent the right shoulder of the Orion the Hunter. Diagram via stardate.org.

Betelgeuse in pop culture, history and mythology. Remember the movie Beetlejuice? This star’s name is similar.

The proper names of many bright stars are Arabic in origin. This fact reflects the dominance of Arabic astronomers and astrologers during Europe’s Dark Ages. The name Betelgeuse apparently is derived from an Arabic phrase that is usually translated as The Armpit of the Giant. Of course the Giant refers to Orion, but – rather than an armpit – some authors see Betelgeuse as representing a hand or sometimes a shoulder. While it is not entirely clear what the name means, in any event, Betelgeuse marks the right shoulder of Orion in many old star maps.

In the ancient myths, Orion is most often associated with a giant, a warrior, a hunter, a god or some other anthropomorphic or animal figure, so it is not surprising that most depictions of Betelgeuse have an anatomical connection. The Sanskrit name signified an arm, too, for example, although it likely was really the leg of a stag. In parts of Brazil Betelgeuse was seen as the hind leg of a cayman (crocodilian) or the foreleg of a turtle. On the other hand, in ancient Japan, Betelgeuse was considered to be part of the rim of a ceremonial drum. In Peru, it was one of four vultures about the devour a criminal.

Bottom line: The star Betelgeuse is destined to explode someday as a supernova. But don’t worry. The chances of it exploding in our lifetimes are … well, astronomically small. Even if it did explode, it would not destroy or even harm earthly life. It would not add a second sun to Earth’s sky. It would most likely simply be a wonderful natural event. If, when it happens, people are still watching the skies, then they’ll have something awesome to tell their grandchildren.

The position of Betelgeuse is RA 05h 55m 10.3053s, dec +07° 24′ 25.4″.

Do you live by the moon? Order your EarthSky Lunar Calendar!

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!

from EarthSky http://ift.tt/13RT78I

There has been a lot of excitement this month about the supernova in the distant galaxy M82. It is the closest supernova in many years, despite the fact that it’s some 11-12 million light-years away. On a January or February evening, come to know the red star Betelgeuse in the constellation Orion. It’s not only one of Orion’s brightest stars. It’s also a star that astronomers know will one day explode as a supernova. And it’s only 430 light-years away! Follow the links below to learn more about Betelgeuse and its explosive destiny.

Betelgeuse will explode someday.

Will Betelgeuse become a second sun?

Will the explosion of Betelgeuse destroy earthly life?

What will happen when Betelgeuse goes supernova?

How to see the star Betelgeuse in the night sky.

Betelgeuse in pop culture, history and mythology.

Red Betelgeuse, also known as Alpha Orionis, is the ninth-brightest star in the night sky and second-brightest in the constellation of Orion. Photo taken February 18, 2014 by Thomas Wildoner.

Betelgeuse imaged in ultraviolet light by the Hubble Space Telescope and subsequently enhanced by NASA. The bright white spot is likely one of this star's poles. Image via NASA/ESA.

View larger. | Thomas Wildoner captured these before-and-after images of the supernova that erupted in January 2014, in the galaxy M82. See the supernova? Astronomers sometimes say that a supernova can outshine the galaxy in which it resides. This photo makes me believe it! Read more about the supernova in M82.

Betelgeuse will explode someday Betelgeuse lies some 430 light-years from Earth. Yet it’s already one of the brightest stars in Earth’s sky. The reason is that Betelgeuse is a supergiant star. It is intrinsically very brilliant.

Such brilliance comes at a price, however. Betelgeuse is one of the most famous stars in the sky because it’s due to explode someday. Betelgeuse’s enormous energy requires that the fuel be expended quickly (relatively speaking), and in fact Betelgeuse is now near the end of its lifetime. Someday soon (astronomically speaking), it will run out of fuel, collapse under its own weight, and then rebound in a spectacular supernova explosion. When this happens, Betelgeuse will brighten enormously for a few weeks or months, perhaps as bright as the full moon and visible in broad daylight.

When will it happen? Probably not in our lifetimes. But, in fact, no one really knows. It could be tomorrow or a million years in the future.

Images of closest supernova in years, in galaxy M82

Cool image, but we won't see this from Earth when Betelgeuse goes supernova sometime in the next thousand - or million - years. Image via Geekosystem

Will Betelgeuse become a second sun? Short answer: no. That rumor was flying around in 2012. Remember 2012? The year the world was supposed to end? Anyway, when it does go supernova, Betelgeuse won’t be bright enough to appear as a second sun in our sky.

Instead, anyone alive on Earth when it happens will be treated to an amazingly beautiful sight in the night sky – a very, very, very bright star.

Will the explosion of Betelgeuse destroy earthly life? When Betelgeuse does blow up, our planet Earth is too far away for this explosion to harm, much less destroy, life on Earth. Astrophysicists say we’d have to be within 50 light-years of a supernova for it to harm us. Betelgeuse is nearly 10 times this distance.

So we’re safe from Betelgeuse. And, in fact, if there are any astronomers around when it does blow, they will be extremely thrilled to have a relatively nearby supernova to study.

Artist’s concept showing star Betelgeuse (center), with a series of arcs immediately to the left of the star. The arcs are thought to be material ejected from Betelgeuse as it evolved into a red supergiant. Notice the faint linear bar of dust on the left side of the image. It represents a dusty filament connected to our galaxy’s magnetic field, or the edge of an interstellar cloud. If this filament, or wall, exists – as some astronomers believe – the arcs ejected from Betelgeuse will hit the wall 5,000 years from now. Betelgeuse itself will collide with the wall 12,500 years later. Image via ESA/Herschel/PACS/L. Decin et al. Read more about this image here.

What will happen when Betelgeuse goes supernova? Fortunately for us, it appears that there will be few, if any, adverse affects to Earth when Betelgeuse goes supernova.

If Betelgeuse were side by side with our sun, you’d find it 10,000 times brighter than the sun in visible light. It might be surprising then to learn that the surface temperature of Betelgeuse is only about 6,000 degrees F (3,600K) in contrast to the sun’s 10,000 degrees F.

In terms of mass, Betelgeuse is thought to be about 15 times the mass of the sun, but 600 times wider and more than 200 million times its volume! When you consider its size, as well as the infrared and other radiations it pumps out, Betelgeuse probably outshines our sun by at least 50,000 times.

Betelgeuse is one of two very bright stars in the constellation Orion the Hunter. The other bright star is Rigel. Notice Betelgeuse and Rigel on either side of the short, straight row of three medium-bright stars. That row of stars represents Orion’s Belt. Betelgeuse is said to represent the right shoulder of the Hunter.

How to see the star Betelgeuse in the night sky. At mid-northern latitudes, around the first of every year, Betelgeuse rises around sunset. The star is very well placed for viewing on January and February evenings.

By the beginning of March, this star is due south in early evening. By mid-May, it can be glimpsed briefly in the west after sunset. Betelgeuse is traveling behind the sun in early summer, but it returns to the east before dawn by about mid-July.

Betelgeuse – in the famous constellation Orion – is easy to spot. See our sky chart to learn the pattern of the constellation Orion the Hunter. Orion itself is noticeable for the short, straight row of three medium-bright stars in its mid-section. Betelgeuse is in the upper left corner of the large rectangle forming Orion.

The star Betelgeuse has a distinctive color: somber orange-red. It’s ideal for convincing non-believers that stars do, in fact, come in colors.

Stars designated as Alpha are typically brightest in their constellations. But Betelgeuse is Alpha Orionis, despite the fact that it’s fainter than Orion’s other bright star, Rigel. Betelgeuse is the 10th brightest star in the sky overall, and it’s the 7th brightest star visible from most of the U.S., Canada, Europe and the majority of the northern hemisphere.

Betelgeuse is often said to represent the right shoulder of the Orion the Hunter. Diagram via stardate.org.

Betelgeuse in pop culture, history and mythology. Remember the movie Beetlejuice? This star’s name is similar.

The proper names of many bright stars are Arabic in origin. This fact reflects the dominance of Arabic astronomers and astrologers during Europe’s Dark Ages. The name Betelgeuse apparently is derived from an Arabic phrase that is usually translated as The Armpit of the Giant. Of course the Giant refers to Orion, but – rather than an armpit – some authors see Betelgeuse as representing a hand or sometimes a shoulder. While it is not entirely clear what the name means, in any event, Betelgeuse marks the right shoulder of Orion in many old star maps.

In the ancient myths, Orion is most often associated with a giant, a warrior, a hunter, a god or some other anthropomorphic or animal figure, so it is not surprising that most depictions of Betelgeuse have an anatomical connection. The Sanskrit name signified an arm, too, for example, although it likely was really the leg of a stag. In parts of Brazil Betelgeuse was seen as the hind leg of a cayman (crocodilian) or the foreleg of a turtle. On the other hand, in ancient Japan, Betelgeuse was considered to be part of the rim of a ceremonial drum. In Peru, it was one of four vultures about the devour a criminal.

Bottom line: The star Betelgeuse is destined to explode someday as a supernova. But don’t worry. The chances of it exploding in our lifetimes are … well, astronomically small. Even if it did explode, it would not destroy or even harm earthly life. It would not add a second sun to Earth’s sky. It would most likely simply be a wonderful natural event. If, when it happens, people are still watching the skies, then they’ll have something awesome to tell their grandchildren.

The position of Betelgeuse is RA 05h 55m 10.3053s, dec +07° 24′ 25.4″.

Do you live by the moon? Order your EarthSky Lunar Calendar!

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!

from EarthSky http://ift.tt/13RT78I