Holiday Stargazing



December 24, 2013 at 11:13 am | Leave a Comment

Eyes to the Sky

This is the time of year when some of the loveliest constellations of the year show up in the nighttime sky. For many years I’ve shared those with family and friends via a star chart called the “Annual Family Stargaze”.  This year, I’m sharing it online so all my world wide group of friends and family can enjoy it. I’ve chosen a constellation that can be seen from pretty much anywhere in the world, although my friends in the far south will see it in a different rotation than it is in this image.

 

December 2013 skies around 10 p.m. or thereabouts! Click to get a larger version that will open in a separate window.

December 2013 skies around 10 p.m. or thereabouts! Click to get a larger version that will open in a separate window.

The most recognizable pattern of stars is in the middle—it’s the constellation Orion, the Hunter (oh-RYE-unn). The bright orange-red star in his shoulder is Betelgeuse (BEH-tell-jooze, although some say BEE-tell-juice)). His lower right knee (as we look at it) is called Rigel (RYE-jell). The three stars in a row mark his belt and point directly down to Sirius (SEER-ee-uss), which is the brightest star in our nighttime sky. Sirius is the brightest star in the constellation Canis Major (KAY-niss Major), the Great Dog. Below him is the star Canopus (Kan-OH-puss), visible to our more southerly family and friends. Just above Sirius is the bright star Procyon (PRO-see-onn), which is the brightest star in the tiny constellation of Canis Minor (CAY-niss Minor), the little dog. Above Orion is the constellation Taurus, the Bull (TAW-russ). You can make out the Vee-shaped face of the bull, with the bright star Aldebaran (al-DEB-ah-ron) as his eye. The V-shape is a cluster called the Hyades (HIGH-uh-deeze). Riding in the sky above the Bull’s back is the small star cluster called the Pleiades (PLEE-uh-deeze).

To the left of Taurus is the constellation Gemini (JEM-en-eye), with the bright planet Jupiter smack in the middle of it. The two stars to the upper left of Jupiter are Castor and Pollux (CASS-tore and PAHL-ucks), the heads of the twins that make up Gemini.

I hope that your weather will permit you to step outside tonight (or any nights during the holidays) to check out the stars. Dress for the weather, of course. Enjoy the sky, contemplate the peace stargazing can bring to your soul, and enjoy!

Happy Holidays (whatever you celebrate at this time of year)!





Give the Stars, Planets, Galaxies and More



December 20, 2013 at 20:25 pm | Leave a Comment

Last-minute Gifts for the Astronomy-minded

I’m at a point in my life where the prospect of gifts for the holidays leads me to wish for things like “world peace”, “less political animosity” and “a fully funded and operational space program”. Of course, I can’t buy all those things for people, and most of my friends can’t buy those things for me, but a person can have big dreams, right?

Still, it is the season of good cheer, holiday wishes, and traditional things like giving gifts to others. In that light, then, I realize that many folks are still out there trying to find a gift for a loved one. I’ve already suggested a few things, like my book Astronomy 101, and a wonderful astronomy app called Starmap, which runs on iPhone and iPad.  There’s even a free app called Starmap Media. It was just designated a 2014 Hot Product by the editors of Sky & Telescope, which is a great honor. To celebrate, the developer of Starmap and Starmap Media is giving away free Starmap Media stories. If you have the latest version of Starmap (Pro or HD), or Starmap Media, you can simply select “Media” and download all the stories you want.  Don’t have Starmap or Starmap Media?  Visit the developer’s web page above, get the free Starmap Media, or buy a copy of Starmap Pro (for iPhone) or HD (for iPad), and once you’ve got it installed, download all the stories you want. They’re free until January 31, 2014.

Just a few days ago I also got a nice calendar in the mail called The Year in Space, published in cooperation with the Planetary Society. It’s chock full of gorgeous images, space facts, and a lot more. I love this calendar and learn something from it every time I look at it.  The people behind this put a lot of time into it, so check out their work.

Often enough I get asked what to get for kids who are into space. I wish I could say, “A trip to Mars” but that’s still way off in the future. The next best thing might be a way for them to learn the sky, in book format. (Books?? As in, “tree-based knowledge delivery systems”?  Yeah, sure.  Why not?)  Sometimes there’s nothing like snuggling in with a good book. So, for the little folk in your life who are just learning the sky, I recommend Find the Constellations by H.A. Rey. It’s the book that generations of kids have used to learn the sky.  When they get a little older you can get them The Stars: A New Way to See Them, also by H.A. Rey.  Works well with adults, too. I’ve been recommending these books for years.

Over the years I’ve collected a number of astronomy books that I turn to again and again for helpful info. One of them is the Field Guide to the Stars and Planets by a valued colleague, Dr. Jay Pasachoff. It has very useful star charts, finder charts, some science bits and tids about specific objects in the sky, and very useful photographs of astronomical objects. I began using this book in the first edition, I’m now up to the 4th edition, and if another one comes out, I’ll get that one, too. It’s that good. Recommended for the reference shelf AND the field.

Many people have loved ones and friends who have trouble seeing well, and often wonder what to get for them. My friend Noreen Grice specializes in creating astronomy books for visually impaired and limited-vision people. One of her books, Touch the Universe, is available via Amazon and was created in cooperation with NASA. Noreen has founded a company called You Can Do Astronomy, and you can find more of her work there. Check it out!

Years ago, I attended a star party and we got into a big discussion about music and stargazing. When I mentioned that my husband composes space music, one guy whipped out a CD of Mark’s Geodesium music and said it went with him whenever he was stargazing. Small world and I didn’t even know the guy before that night. But, since then I’ve heard from others who like to use Mark’s relaxing space music as a part of their stargazing experience. Only now, in addition to CDs, they can download music (see the link for details) . So, if you’re in the mood for some space music, check out Mark’s work. It’s cosmic!

Well, those are a few gift suggestions. If you’re still stumped for ideas, check out your local planetarium or science center; if they have a gift shop, you’re sure to find something there to sate the space appetites of your friends and loved ones. If nothing else, get some advance tickets for a show and make it a party!

 

 

 





The Flippin’ Solar Magnetic Field



December 18, 2013 at 13:02 pm | Leave a Comment

Solar Magnetic Field About to Change

A Dec. 8 image of the Sun from the Solar Dynamics Observatory, showing regional magnetic field lines and plasma flowing along them in active regions. Courtesy SDO/NASA.

A Dec. 8 image of the Sun from the Solar Dynamics Observatory, showing regional magnetic field lines and plasma flowing along them in active regions. Courtesy SDO/NASA.

This is not “new” news, since it was announced earlier this year, but the Sun’s magnetic field is about to flip its polarity sometime in the next few weeks to a month. When this happens, the Sun’s polar magnetic fields weaken and then drop to zero.  Shortly thereafter, they emerge again, but with the opposite polarity. So, if one pole was “north”, it will be “south” after the flip, and the other will flip to “north”. This is really an outward effect of the Sun’s interior dynamo reorienting itself. This is a regular part of the solar cycle. The Sun does this every 11 years, regular as clockwork. Completely normal and nothing to be worried about.

It’s not completely clear yet WHY the Sun’s north pole flips south and the south pole flips north, although solar physicists are making great strides in understanding actions inside our star that cause this and other activity. They DO know that the new polarity builds up throughout the 11-year-long sunspot cycle. Sunspots are those dark spots that appear on the visible surface of the Sun. They’re regions where the temperatures are cooler than the surrounding surface and thus they appear darker. Astronomers at Stanford University, who are monitoring this regular magnetic field flip, described the process in a press story released last month.

“New polarity builds up throughout the 11-year solar cycle as sunspots – areas of intense magnetic activity – appear as dark blotches near the equator of the sun’s surface. Over the course of about a month, sunspots disintegrate, and gradually that magnetic field migrates from the equator to one of the sun’s poles.

As the surviving polarity moves toward the pole, it erodes the existing, opposite polarity, said Todd Hoeksema, a solar physicist at Stanford since 1978 and director of the Wilcox Solar Observatory. The magnetic field gradually reduces toward zero, and then rebounds with the opposite polarity.

“It’s kind of like a tide coming in or going out,” Hoeksema said. “Each little wave brings a little more water in, and eventually you get to the full reversal.”

When the Sun’s polarity flips, it does actually affect the rest of the solar system, but not in any psychic or alien way. And yes, there ARE people out there who interpret a magnetic field flip as some kind of paranormal thing. Nothing could be further from the truth, which is that the Sun is an active, evolving, magnetized sphere of plasma, and as such, it has constantly changing characteristics in ALL its magnetic fields. It has an overall magnetic field, and it also has localized magnetic fields which cluster around sunspots and are suspected to be involved in heating of the corona in some way. So, if you start to see hysterical ravings about the “mysterious” magnetic field flips of the Sun and how it will bring on a new age of psychic unity or something unlikely, put on your skeptic hat and turn to actual solar science for some answers.

Actually, the effects of a solar magnetic field flip are pretty cool to study. The changes propagate out to the “edge” of the heliosphere (the limit of the Sun’s influence in space).  Since these flips coincide with higher sunspot activity and more bursts of charged particles (through flares and coronal mass ejections), we can expect to see more auroral displays. The interactions with Earth’s magnetic field can affect our technology (how much it does so depends on the severity of any space weather “attack” fostered by the Sun’s activity), and might cause satellite operators to put their instruments into “safe mode” for a short while. We are currently in the middle of “solar max”, which is supposed to be the maximum amount of activity during a sunspot cycle. This has been a somewhat quiet solar max, so it will be interesting to see how the magnetic field reversal plays out.

If you want to read a more detailed description of what happens during a polarity flip, check out the Science Daily article from August 6th of this year or the recent press release from Stanford University, whose Wilcox Solar Observatory has been watching the Sun since the mid 1970s and is providing very good long-range looks at the Sun’s activity.





Congratulations to China



December 16, 2013 at 23:02 pm | 2 Comments

A Successful Lunar Landing

The Chinese Chang'e-3 mission rover called "Yutu" (Jade Rabbit) as shown after the soft lunar landing. Courtesy Chinese National Space Agency and CCTV.

The Chinese Chang’e-3 mission rover called “Yutu” (Jade Rabbit) as shown after the soft lunar landing. Courtesy Chinese National Space Agency and CCTV.

I’ve been on travel the past three weeks, speaking about astronomy on board a cruise ship. I get a lot of questions from my fellow passengers, and usually somebody asks me when we’ll go back to the Moon. Well, folks, “we” in the form of the Chinese space agency, have returned to the Moon this week. Not necessarily a crew of humans walking around, but a spectacularly beautiful mission called Chang’e-3 and its Yutu rover.

If you haven’t checked out the mission, it’s part of the Chinese Lunar Exploration mission, designed to explore the lunar surface, and eventually bring back samples for study. If this sounds familiar, the Apollo missions did similar studies in the 1970s, but no one has been back to the Moon to continue those studies. The Chinese missions are taking up where the U.S. left off and I expect they will take lunar studies to the next level very soon. I wish them much luck — the exploration of the Moon, or that of any solar system object, is a complex task and requires the best and brightest to accomplish it. It also requires national and political will to see the positive opportunities in extending our scientific understanding beyond the surface of our home world.

The study of the Moon and other objects in the solar system is an increasingly multi-national process. Doing such exploration is expensive, and individual countries such as India, Japan, and China are making their mark in planetary science. But, in the future, I suspect that many missions will continue to be conducted by collaborations of scientists from many countries, such as with the Cassini Mission to Saturn. Not only was NASA involved, but the European Space Agency provided Huygens lander for Titan exploration, and scientists from 17 countries participate in science acquisition and data analysis. The Chinese and Russians have explored joint collaboration for future lunar missions, and there are many other joint projects between various countries under consideration.

While the Chinese bask in the glory of achievement, and received laudatory comments from many of us in the U.S. (including a nice set of comments by my good friend Greg Redfern (the SkyGuy)) I’ve noticed (and unfortunately expected) a tide of whining from some people in the U.S. (not all of us, mind you), about how it’s the Chinese going to the Moon now. We should be congratulating our fellow humans on their brilliant work, not pissing and moaning about it. I’m not sure what to say to the whinging contingent except, “Stop complaining and do something. Support NASA, support science research in our country, support science education, and if your representative in Congress or your Senator don’t support these things, let them know that they are undermining our future. Find new ones who will take us forward, not hold us back. If you don’t take action at your level, you’re part of the problem.”

You know, we once had a forward-looking space policy in the U.S., and it has been undermined. The laundry list of those who seek to gut our future is long, and it stretches from the halls of government to the apathetic voters who don’t give a damn. That’s all got to change. Otherwise, we’ll see more missions with “others” going where we in the U.S. thought we were going. There’s room in space for everybody, and the U.S. doesn’t have a monopoly on space travel. We certainly got it going, and it inspired many people to look to the skies for technological achievements. That’s great. I think it’s great that other humans on our home planet are taking to the skies. I hope sincerely that in the U.S. our best days are still ahead of us.  But, we need to make it happen. Just as the Chinese and Indians and Europeans and Iranians and Japanese have done.





Black Hole Jets Determine a Galaxy’s Fate



December 9, 2013 at 8:30 am | Leave a Comment

They Pack a Huge Punch

Blackhole_1920

An artist’s conception of a black hole with a bipolar jet streaming away from it. These jets could carry away heavy atoms of iron and other elements.

I haven’t talked about black holes lately, so let’s take a look at the latest in what these suckers are doing. Astronomers have been watching the jets streaming out from the neighborhood of supermassive black holes (in the centers of galaxies) and found out that these high-speed streams are packed with heavy atoms of material that somehow don’t get swallowed up into the black hole. Instead, these jets act as cosmic recycling barges, sending matter and energy out to space.  If the jets are strong enough, and have enough influence, they can actually influences where and when a galaxy forms its stars.

So, what kind of heavy atoms are we talking about here?  Most black hole jets only carry electrons, which are quite l0w in mass. It turns out that astronomers using the European Space Agency’s XMM-Newton mission and a compact array radio telescope in Australia have found evidence of some unusual stuff — like iron and nickel — racing away from the black holes inside these superheated jets. They studied the black hole called 4U1630-47, which is a small black hole perhaps only a few times the mass of the Sun. Even though it’s small, the effects it has can be scaled up to larger black holes like the ones that hide in the cores of galaxies.

Jets carrying iron atoms away from a black hole must be very strong jets indeed. That’s because it takes a lot more energy to move iron than it does other, lighter particles such as electrons. The jets strong enough to carry iron and other heavy atoms are moving quite fast and are very powerful. When they smash into matter in space, they could annihilate it, thus destroying the material that a galaxy needs to create stars (and planets).

Black holes are implicated in the formation and ongoing evolution of galaxies, and this study shows one way in which they influence their surroundings.  I wonder what we’ll learn next about these pesky guys?





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