Tuesday, January 22, 2013

The Ellensburg sky for the week of 1/26/13


Saturday: It’s cold. The snow is blowing in your face. Food is scarce. Packs of wild animals are wondering around howling. Does this describe your house after someone broke your window during your recent party? It also describes wolf packs around Native American villages. That’s why many tribes call January’s full moon, which occurs this evening, the Full Wolf Moon. It is also called the Moon after Yule. When the Moon is full, it is difficult to see dim objects in the sky because of the sky glow. But why struggle to find dim objects when there is so much to see on the big, bright object in front of you? The lunar crater called Tycho is best seen during a full Moon. Tycho was formed about 109 million years ago when an asteroid struck the Moon, leaving a crater over 50 miles in diameter and ejected dust trails that radiate out hundreds of miles in all directions. For more lunar highlights, go to http://nightsky.jpl.nasa.gov/docs/ObserveMoon.pdf, a resource of the Night Sky Network.

Sunday: Winter is the best season for finding bright stars. And if you only want to set aside a few minutes, 10 p.m. tonight just might be the best time because the winter hexagon is due south. Starting at the bottom, find Sirius, the brightest star in the night sky, two and a half fists held upright and at arm’s length above the south horizon. Going clockwise, Procyon (6th brightest star visible from Washington state) is about two and a half fists to the upper left of Sirius. Pollux (12th brightest) is about two and a half fists above Procyon. Capella (4th brightest) is about two and a half fists to the upper right of Procyon and close to straight overhead. Going back to Sirius at the bottom, Rigel (5th brightest) about two and a half fists to the upper right of Sirius. Aldebaran (9th brightest) is about three fists above Rigel. Betelgeuse (7th brightest) is in the center of the hexagon. Adhara (16th brightest) is a little more than a fist below Sirius and Castor (17th brightest) is right above Pollux. That’s nine of the 17 brightest stars visible in the northern United States in one part of the sky.

Monday: Jupiter is about six fists above the south horizon at 8 p.m.

Tuesday: The good news is the days are getting longer and the nights are getting shorter. The better news is the farther north you go in the United States, the longer the days get. Here in Ellensburg, there is one more hour of daylight than on the first day of winter. In the southern part of the US, there are only 30 more minutes of sunlight. Of course, on the North Pole, the day length goes from zero hours to 24 hours.

Wednesday: Saturn is almost exactly three fists above almost exactly due south at 6 a.m. How close to three fists? Try 3.02 fists. How close to due south? Try 0.01 degrees! That one earned an exclamation point.

Thursday: Three years ago, NASA’s Wide-field Infrared Survey Explorer, or WISE, spotted its first of many never-before-seen near Earth asteroids. While there is no danger of this asteroid hitting Earth in the foreseeable future, the United States’ government is worried about the threat of a rogue asteroid hitting Earth. So much so that Congress mandated that by 2020, NASA must find 90% of all potential Earth-impacting asteroids down to 140 meters across. I may write a book about this search patterned after Sarah Palin’s life called “Going Rogue – An Asteroid Life”. Here is an excerpt.
I’d rather “stand with our North Korean allies” than be in the path of even a small asteroid streaking towards Earth. Would it be dangerous? You betcha! The asteroid that created the mile-wide impact crater in Arizona was only 25 meters in diameter and packed a wallop about 150 times the force of the atomic bomb dropped on Hiroshima. I say “Thanks but no thanks” to that kind of risk, even if this size impact occurs only once every few hundred years.

Friday: Have you ever seen a bright light streaking through the sky and wondered if it was a meteor? Or, perhaps the mother ship coming to take you back home? Well, if you think it is a meteor, go to http://www.amsmeteors.org/ to see if others have reported seeing it. If you remember some details of your sighting, you may fill out a brief report online. Your report will help astronomers identify and possibly catalog celestial objects in Earth-crossing paths.

The positional information in this column about stars and planets is typically accurate for the entire week.

Friday, January 18, 2013

The Ellensburg sky for the week of 1/19/13


Saturday: Draco Malfoy makes an appearance in all seven books of the Harry Potter series. Perhaps you’ve heard of these. But, the constellation Draco the dragon makes an appearance in the sky every night. It is a circumpolar constellation as viewed from Ellensburg meaning it never goes below the horizon. The head of the dragon is one fist held upright and at arm’s length above due north at 9 p.m. Eltanin, the brightest star in the constellation, is at one corner of the trapezoid-shaped head of Draco.

Sunday: Saturn is three fists above the south horizon at 7 a.m.

Monday: Jupiter is about a finger thickness from the moon throughout the night. At 7 p.m., Jupiter is just above the moon, six fists above the southeast horizon. In parts of the South Pacific, the moon will occult Jupiter. In musical language, that can be describes as “Some enchanted evening, you may see a planet, you may see a moon, across a crowded sky.”

Tuesday: You think wintertime weather is bad in Ellensburg. Astronomers have discovered storms and earth-sized clouds on a brown dwarf. These are cool, small stars that are not massive enough to fuse hydrogen atoms and fuse hydrogen. In fact, they are more similar to gas giant planets such as Jupiter that to the Sun. In this context, the discovery of storms similar to the giant Red Spot on Jupiter makes sense. For more information, go to http://goo.gl/jQS3k.

Wednesday: Let’s review three important sets of three cats. There’s Josie, Valerie, and Melody of Josie and the Pussycats. Felix, Tom, and Sylvester from old time cartoons. And, if you want to get away from the mind-numbing effects of television, there’s Leo the lion, Leo Minor, and Lynx in the night sky. Leo is by far the most prominent of these three constellations. Its brightest star called Regulus is nearly four fists above the east-southeast horizon at 11 p.m. The backwards question mark-shaped head of Leo is above Regulus and the trapezoid-shaped body is to the left of it. Leo Minor consists of a few dim stars right above Leo. Pretty wimpy. The long dim constellation spans from just above Leo Minor to nearly straight overhead. You and fellow stargazers won’t need to wear a long tail or ears for hats to enjoy these stellar cats.

Thursday: Are you looking for a vacation spot close by? One that is not to warm and not too cold. One that is “just right”. Last month, astronomers discovered that the star Tau Ceti, one of our closest neighbor at 12 light years away, may have five planets. One of those planets orbiting the Sun-like star is in the so-called Goldilocks Zone where the temperature is just right for having liquid water. You’ll want to do some research before you travel there. Tau Ceti is four and a half fists above the south-southwest horizon at 7 p.m. For more information about the discovery, go to http://goo.gl/jZ9xx.

Friday: Are you interested in participating in astronomy research? You don’t need to go back to school. You don’t need to spend thousands of dollars getting a fake degree from an online university. The scientists working on the High Resolution Imaging Science Experiment, or HiRISE, camera on NASA's Mars Reconnaissance Orbiter would like your input on which objects they should target for close-up pictures. While you may think the scientists are just trying to build interest in their project by having people look at pretty pictures, there is a real scientific benefit to having many eyes searching for interesting targets. There aren’t enough scientists to carefully inspect all of the low power images. And, surprisingly, computers are not nearly as effective as people in making educated judgments of images. So, go to http://www.uahirise.org/ and click on the HiWish button. You’ll be on your way to suggesting close-up targets for NASA's Mars Reconnaissance Orbiter.

The positional information in this column about stars and planets is typically accurate for the entire week.

Wednesday, January 9, 2013

The Ellensburg sky for the week of 1/12/13


Saturday: Who can forget that memorable song by Three Dog Constellations Night, “The sky is black. The stars are white. Together we learn to find the light.” Well, maybe it didn’t go like that. This is good because not all stars are white. Most stars are too dim to notice a color. But, the stars in the constellation Orion provide a noticeable contrast. Betelgeuse, five fists held upright and at arm’s length above due south at 10:30 p.m. is a red giant. Rigel, the bright star about two fists to the lower right of Betelgeuse, is a blue giant.
By the way, the three dog constellations are Canis Major, the greater dog; Canis Minor, the lesser dog; and Canes Venatici, the hunting dogs. Canis Major contains Sirius, the brightest star in the nighttime sky.

Sunday: Mars is halfway between the crescent moon and the southwest horizon at 5 p.m. You may need binoculars to see it, even if the horizon is clear.

Monday: How do you study the life cycle of a dog? Easy. Get a dog from the animal shelter, care for it for 15 years and study it. How do you study the life cycle of a star? Easy. Pick a star, watch it for a few billion years, and…. Wait a minute. Astronomers can’t observe something for a few billion years. Instead, they study stars that are at different points in their long life cycle and piece together the information from those different stars. What they do is like studying a one-year-old dog for a few minutes, then studying a different two-year-old dog for a few minutes, and so on. The sky in and near the constellation Orion provides an example of four objects at different points of star life.
First, find Rigel, the bright star in the lower right corner of the constellation Orion. This star, rapidly burning its fuel for a high energy but short lived existence, is three and a half fists above due south at 9:30 p.m. About one fist up and to the left are the three objects of Orion’s sword holder. The middle “star” is really a star-forming region called the Orion nebula. There you’ll find baby Suns. Now, look about two fists to the right and a little below Rigel. You should be looking at a star that is about one tenth as bright as Rigel but still the brightest in its local region. The third star to the right of that star is Epsilon Eridani, the most Sun-like close and bright star. Betelgeuse, in the upper left corner of Orion, is a star at the end of its life that started out life a bit larger than the Sun.

Tuesday: Jupiter is six fists above the south horizon at 8 p.m.

Wednesday: What you see with the naked eye isn’t all that can be seen. While astronomers can learn a lot from observing the sky in the visible wavelengths, many celestial objects radiate more light, and more information, in wavelengths such as radio, microwave, infrared, ultraviolet, x-ray, and gamma ray. Last year, NASA launched the Wide-field Infrared Survey Explorer (WISE) to study objects that radiate in the infrared range such as asteroids, cool dim stars, and luminous galaxies. For an interesting comparison of how different wavelengths show different aspects of a galaxy, go to http://goo.gl/nvuax. If it weren’t for infrared telescopes such as WISE, astronomers would not know about the significant amount of dust in galaxies.

Thursday: January is the coldest month of the year so it is time to turn up the furnace. Fornax the furnace is one fist above due south at 7 p.m.

Friday: Tonight’s first quarter moon is in the constellation Aries the ram.

The positional information in this column about stars and planets is typically accurate for the entire week.

Thursday, January 3, 2013

The Ellensburg sky for the week of 1/5/13


Saturday: One Family Affair explored the trials of well-to-do civil engineer and bachelor Bill Davis as he attempted to raise his brother's orphaned children in his luxury New York City apartment (as described on Wikipedia). Another family affair explores how a well-to-do Solar System raises its constituents from birth, through growth, change, and death. Just like Buffy and Jody started off full of energy, planets start out hot and molten. Cissy got wrinkles as she approached middle age; planets become cratered as they age. We watched the TV show “Family Affair” to learn about a nontraditional Manhattan family grew and changed. Astronomers study other planets to learn how the Solar System will evolve. For more information about this Solar System Family Affair, go to http://goo.gl/G029D. Jupiter, the dad of the Solar System family, is about six fists held upright and at arm’s length above due south at 9 p.m.

Sunday: The waning crescent moon is between Saturn and the bright star Spica at 6 a.m. Saturn is about a fist to the upper left and Spica is a little more than a fist to the upper right of the moon. All three are low in the southeastern sky.

Monday: Venus is less than a half a fist above the southeast horizon at 7 a.m. Because Venus is the brightest point of light in the night sky, you should be able to find it despite its proximity to the nearly rising Sun.

Tuesday: You never see a giraffe on the ground in Ellensburg. But you can look for one every night in the sky. The constellation Camelopardalis the giraffe is circumpolar from Ellensburg’s latitude of 47 degrees north meaning it is always above the horizon. Don’t expect to be overwhelmed by the appearance of the stars in Camelopardalis. The brightest star in the constellation appears only about half as bright as the dimmest star in the Big Dipper. However, the actual luminosities of the three brightest stars in Camelopardalis are very high, each at least 3,000 times more luminous than the Sun. Alpha Camelopardalis, a mind boggling 600,000 times more luminous than the Sun, is seven fists above due north at 10 p.m.

Wednesday: Have you ever looked down on the ground and spotted a penny? In Yakima? While you were standing in Ellensburg? If you have, then you may be able to see the star Hamal as more than just a point of light. Hamal, the brightest star in the constellation Aries the ram, has an angular diameter that can be directly measured from Earth. It appears to be the same size as a penny as seen from 37 miles away. (For comparison, the moon is about half the diameter of a penny held at arm’s length.) Hamal is six and a half fists above due south at 7 p.m.

Thursday: The rapper Lil Bow Wow, now known by his adult name, Bow Wow, has had the same new album coming out “soon” for the past two years. The sky has its own lil bow wow dependably coming out every night this winter. Procyon, the brightest star in Canis Minor, the lesser dog, is about three and a half fists above the east-southeast horizon at 10 p.m. As the seventh brightest star in the night sky, Procyon is definitely not “Underrated”.

Friday: Orion stands tall in the southern sky. At 10 p.m., the middle of Orion’s belt is four fists above due south. And talk about belt tightening! Alnilam, the middle star in the belt, is losing mass at a rate of about 100 thousand trillion tons a day. That’s a 1 followed by 17 zeros tons per day.

The positional information in this column about stars and planets is typically accurate for the entire week.

Thursday, December 27, 2012

The Ellensburg sky for the week of 12/29/12


Saturday: Did you get a new telescope for Christmas? Skyandtelescope.com has a good article on how to get started using it. Go to http://goo.gl/2cJwo. Any observing tip to the night sky should include Jupiter. Jupiter is six fists held upright and at arm’s length above due south at 10 p.m. tonight. A small telescope should reveal Jupiter’s cloud belts and its four largest moons. These are called the Galilean moons because Galileo Galilei discovered them about 400 years ago.

Sunday: Mars is a half a fist above the southwest horizon at 5:30 p.m.

Monday: Forget about that big bright ball in Times Square. You can mark the start of the new year with one of the sky’s own big bright balls. That perennial favorite New Year’s Day marker, Sirius, the brightest star in the night sky, rises to its highest point in the sky a little after midnight on January 1. Thus, when Sirius starts to “fall”, the new year has begun. Look for Sirius about two and a half fists above due south at midnight.

Tuesday: Today is the day we celebrate the anniversary of something new – a new classification of celestial objects. Giuseppe Piazzi discovered Ceres [pronounced sear’-ease], the first of what are now called “asteroids”, on January 1, 1801. Ceres is the largest asteroid in the belt between Mars and Jupiter. At first, Piazzi thought it was a star that didn’t show up on his charts. But, he noted its position changed with respect to the background stars from night to night. This indicated to him that it had to be orbiting the Sun. The International Astronomical Union promoted Ceres to the status of “dwarf planet” in August of 2006.
If the Sun looks big today, your eyes are not playing tricks on you. The Earth is at perihelion at about 9 p.m. tonight. If you dig out your Greek language textbook, you’ll see that peri- means “in close proximity” and helios means “Sun”. So, perihelion is when an object is closest to the Sun in its orbit, about 1.5 million miles closer than its average distance of 93 million miles. Since it is winter in the Northern Hemisphere now, the seasonal temperature changes must not be caused by the Earth getting farther from and closer to the Sun. Otherwise, we’d have summer when the Earth is closest to the Sun. The seasons are caused by the angle of the sunlight hitting the Earth. In the winter, sunlight hits the Earth at a very low angle, an angle far from perpendicular or straight up and down. This means that a given “bundle” of sunlight is spread out over a large area and does not warm the surface as much as the same bundle in the summer.

Wednesday: Venus is a half a fist above the southeast horizon at 7 a.m.

Thursday: Today’s early morning weather forecast: showers. Meteor showers, that is. The Quadrantid meteor shower peaks this morning between midnight and dawn. Meteor showers are named after the constellation from which the meteors appear to originate. That makes this shower mysterious because there isn’t any constellation with this name now. The shower was named after Quadrans Muralis, an obsolete constellation found in some early 19th century star atlases. These meteors appear to come from a point in the modern constellation Draco the dragon. This point is about three fists above the northeast horizon at 1 a.m. This year, the waning moon will be rising just before the peak observation time so the dimmer meteors will be obscured by moonlight. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere. Most meteors are associated with the path of a comet. This shower consists of the debris from an asteroid discovered in 2003. Keeping with the comet-origin paradigm, astronomers think the asteroid is actually an “extinct” comet, a comet that lost all of its ice as it passed by the Sun during its many orbits.

Friday: Has it been tough to wake up this past week? It should have been because the sunrise has been getting a little later since summer started. I know. I know. December 22 was the shortest day of the year. But, because the Earth’s orbit around the Sun is elliptical and not circular, the Earth does not travel at a constant speed. It moves faster when it is closer to the Sun and slower when it is farther away. This leads to the latest sunrise occurring during the first week in January and the earliest sunset occurring in early December, not on the first day of winter, the shortest day of the year. On the first day of winter, however, the interval between sunrise and sunset is the shortest. For more information, go to http://goo.gl/SJC5r. 

The positional information in this column about stars and planets is typically accurate for the entire week.

Monday, December 10, 2012

The Ellensburg sky for the week of 12/15/12


Saturday: Listen, do you want to know a secret? Do you promise not to tell? Whoa oh, oh. The Beatles certainly didn’t write this song about the Barringer meteorite crater in Arizona. Astronomers are studying this 50,000-year-old impact to learn more about our planet’s violent history as well as the physics of impacts throughout the solar system. If you’d like to be let in on some of these secrets, go to http://goo.gl/sqbBe.

Sunday: I know you’re staying up late to train yourself to wait up for Santa. So look out a south-facing window at 1 a.m. and see Sirius, the brightest star in the nighttime sky, as high as it ever gets in the sky. It is two and a half fists held upright and at arm’s length above due south.

Monday: Today is Saturnalia, an ancient Roman festival in honor of their god Saturn, the god of agriculture and time. The holiday featured a break from work and school, a public banquet, and private gift giving. Some of these customs influenced the secular aspects of Christmas celebrations. Celebrate Saturnalia at 6 a.m.-alia by viewing the planet Saturn, two fists above due southeast.

Tuesday: Jupiter is nearly two fists above the east-northeast horizon at 5 p.m. Wow – night sky observations at 5 p.m. It must be getting close to winter.

Wednesday: Venus is one fist above due southeast at 7 a.m. Even though the sky is fairly well lit by the nearly rising Sun, Venus is bright enough to be easily seen. The bigger challenge is Mercury, a half a fist to the lower left of Venus and just above the horizon.

Thursday: Tonight’s first quarter moon is in the constellation Pisces the fish.

Friday: At 3:12 a.m., the Sun reaches its lowest point in the sky with respect to the background stars. This point is called the Winter Solstice. During the day that the Sun reaches this point, your noontime shadow is longer than any other day of the year. Also, the Sun spends less time in the sky on the day of the Winter Solstice than any other day making this the shortest day of the year. Even though it is the shortest day of the year, it is not the day with the latest sunrise or the earliest sunset. The latest sunrise is during the first week in January and the earliest sunset is during the second week in December. The Sun is at its southernmost point with respect to the background stars on the day of the winter solstice. This means the Sun spends the least amount of time above the horizon on that day. But, the Sun rise and set time depends on more than its apparent vertical motion. It also depends on where the Sun is on the analemma, that skinny figure-8 you see on globes and world maps. During the second week in December, the Sun is not quite to the bottom of the analemma.  But, it is on the first part of the analemma to go below the horizon. During the first week in January, it is on the last part of the analemma to rise above the horizon. For more information on this, go to http://goo.gl/wE9nP.

The positional information in this column about stars and planets is typically accurate for the entire week.

Wednesday, December 5, 2012

The Ellensburg sky for the week of 12/8/12


Saturday: The earliest sunsets of the year occur all this week – 4:13 p.m. That seems counterintuitive because the shortest day of the year in the Northern Hemisphere isn’t until December 21. Since the Earth’s orbit is elliptical, the Sun does not appear to move across the sky at the same rate from day to day throughout the year. That means some parts of the year the Sun is “fast” and sometimes “slow”. Today, the Sun reaches the noontime position of due south at 11:52 a.m. meaning it will also reach the setting position a few minutes earlier than the expected time. For more information on this, go to http://goo.gl/kjnHP. Or just go watch the sunset. But don’t stare at the Sun.

Monday: Okay boys and girls. Let’s follow along with the moon this week as it tours the bright objects in the southeastern sky. At 6:30 a.m., the bright star Spica is less than a half a fist above the moon. Spica is believed to be the star that provided the ancient astronomer Hipparchus with the data to show that the Earth precesses like a spinning, wobbling top.

Tuesday: On these cold mornings, it is difficult to get going. You just want to plop into a chair and sit still. But, are you really sitting still? You’re moving at about 700 miles per hour due to the rotation of the Earth on its axis and 66,000 miles per hour due to the revolution of the Earth around the Sun. If that’s not enough, the entire solar system is orbiting the center of the galaxy at a whopping 480,000 miles per hour! So while you may be sitting still with respect to your living room (and all of the over achievers in your house), you are NOT sitting still with respect to the center of the galaxy. For more information about this concept, go to http://goo.gl/lPVPS. Before you barf from all of that motion, go outside at 6:30 a.m. and observe Saturn, less than a fist above the moon in the southeast sky. Because of Saturn’s rapid rotation, only 10.5 hours, it appears visible flattened.

Tuesday: At 6:30 this morning, the moon marks the right angle corner of a right triangle with the very bright Venus above it and Mercury to its lower left.

Wednesday: Just like during last month’s new moon, people are humming the astronomy version of 1981 Blondie hit The Tide is High: “The tide is high ‘cause the moon is new. Higher still when the moon’s close, too.” Tonight's moon is new. The new moon is the phase where the Moon is directly between the Earth and the Sun. That means the moon and Sun are both stretching the Earth in the same direction causing the ocean water in line with the Sun and moon to be pulled upward. In addition, the moon is at perigee so this is the day of the month when the moon is closest to the Earth. This accentuates the upward pull on the water and makes the tides really high.

Thursday: The Geminid meteor shower peaks late tonight and early tomorrow morning. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Gemini the twins. This point is about three fists held upright and at arm’s length above the east-northeast horizon at 9 p.m. tonight. You can follow this point throughout the night, as it will remain near the bright star Castor, the right hand star of the “twin” stars Pollux and Castor. This shower is typically one of the best ones of the year producing bright, medium speed meteors with up to 80 meteors per hour near the peak. This year, the moon will be new during the peak night ensuring dark skies.
Most meteor showers occur when the Earth passes through the orbital trail of a comet. The broken off comet fragments collide with the earth and burn up in the atmosphere. Astronomers had searched for a comet source for this shower since 1862 when the shower was first observed. Finally, in 1983, astronomers discovered the object that created the fragments that cause the meteor shower. To their surprise, it was a dark, rock that looked like an asteroid, not a shiny icy comet. Astronomers named this object Asteroid 3200 Phaethon. But, they still don’t know if it an asteroid or if it is a comet with all of its ice sublimated away by many close passes by the Sun. For more information about 3200 Phaethon, go to http://goo.gl/LuwGW.

Friday: Mars is less than a fist to the left of the thin crescent moon, low in the southwest sky.

The positional information in this column about stars and planets is typically accurate for the entire week.