Tuesday, August 25, 2015

The Ellensburg WA sky for the week of 8/29/15

Saturday: School starts next week so it is time for a little geometry review. A square is a four-sided figure with four equal sides and four right angles. Go outside at 10 p.m. tonight with notebook in hand to sketch one. The Great Square of Pegasus is balancing on its corner two and a half fists held upright and at arm’s length above due east. The top corner of the square is two fists above the bottom corner. The other two corners are to the left and right of the line segment connecting the top and bottom corners. Hum. I guess that’s why it is called a square.

Sunday: Neptune is in opposition last night. But that doesn’t mean it is difficult to get along with. In fact, for a planet, being in opposition means it is easy to get along with.… Or, at least easy to observe. Opposition means that Neptune is on the opposite side of the Earth as the Sun. When an object is in opposition, it is at its highest point in the sky during the darkest time of the night. Neptune is three fists above the south-southeast horizon at midnight. You’ll need binoculars to see it but you can use the Moon and the bright star Fomalhaut as a guide. First find Fomalhaut, one fist above the south-southeast horizon. Then fine the moon. Next, draw an imaginary line straight up from Fomalhaut and straight to the right from the Moon.  Neptune will be found where those two lines cross.

Monday: Geometry review, part 2. Go outside at 10 p.m. tonight with notebook in hand. (Good teaching involves a little repetition.) You’ll have an easy time seeing your notebook because the moon is just a little past full. A triangle is a polygon with three corners and three line segments as sides. A good example is the Summer Triangle made up of the bright stars Vega, Deneb and Altair. Vega, the brightest star in the triangle, is a little bit southwest of straight overhead. Deneb is a little bit east of straight overhead and Altair is five fists held upright and at arm’s length above the south horizon.

Tuesday: Have you been excited to learn all of the new discoveries from the NASA spacecraft that traveled hundreds of millions of miles visit a dwarf planet that we knew little about and to return images of the surface that stunned astronomers and amateur space enthusiasts? And then have you been even more excited that this spacecraft continues to orbit the dwarf planet? Wait. What? Didn’t New Horizons fly by Pluto? Of course it did. I’m talking about the other dwarf planet mission: Dawn’s trip to the asteroid and dwarf planet called Ceres. If you have binoculars and a clear southern horizon, you will find Ceres one fist above due south at 10:15 p.m. Move your binoculars straight up from due south. On the way, you’ll encounter a line of three stars, each one getting successively dimmer than the one below it. With this line at the bottom of your binocular field of view, Ceres will be near the top of your field. If you are not sure which one is Ceres, visit that same spot a few nights in a row. Ceres will be the point of light that changes position from night to night. For more information about Ceres, go to http://goo.gl/Zsstrr.

Wednesday: The Ellensburg Rodeo is a “Top-25” rodeo. What does it take to be a “Top-25” star? There are many ways to rank stars. The most obvious way for a casual observer to rank stars is by apparent brightness. The apparent brightness is the brightness of a star as seen from Earth, regardless of its distance from the Earth. Shaula (pronounced Show’-la) is the 25th brightest star in the nighttime sky as seen from Earth. It represents the stinger of Scorpius the scorpion. In fact, Shaula means stinger in Arabic. Shaula has a visual brightness rating of 1.62. Sirius, the brightest star has a visual brightness rating of -1.46. (Smaller numbers mean brighter objects.) The dimmest objects that can be seen with the naked eye have a visual brightness rating of about 6. There are approximately 6,000 stars with a lower numbered visual brightness rating than 6 meaning there are 6,000 stars visible to the naked eye. Shaula is a blue sub-giant star that radiates 35,000 times more energy than the Sun. It is 700 light years away making it one of the most distant bright stars. Shaula is a challenge to find because it never gets more than a half a fist above the horizon. Look for it tonight about a half a fist above the south horizon, a little bit west of due south, at 8:30.

Thursday: Saturn is two fists above the south-southwest horizon at 8 p.m.

Friday: It’s Labor Day weekend. Time to go to the lake. A Martian lake. In 2010, astronomers found a chloride salt deposit on Mars. Geologists recently used images taken from spacecraft and models of the terrain to determine that the deposits sit at the bottom of a depression that has apparent inflow channels on the high side of the depression and an outflow channel on the low side. A salty deposit in a low-lying area does not automatically mean there was a lake there. But there are other lines of evidence that suggest that Mars was much warmer in the past. Get up at 5:30 a.m., put on your bathing suit and look for Mars one fist above the east-northeast horizon. It is a half a fist to the left of a much brighter Venus.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Wednesday, August 19, 2015

The Ellensburg WA sky for the week of 8/22/15

Saturday: Saturn is about a half a fist held out at arm’s length to the lower right of the first quarter moon at 9 p.m., low in the southwestern sky.

Sunday: In most parts of the country, a mixture of tasty carbon-based material and healthy minerals is called a casserole. In Minnesota, it is called a hot dish. (Uffdah, you betcha!) In space, it is called a supergiant. Antares, a supergiant in the constellation Scorpius, is forging lighter elements into carbon, oxygen, silicon, and iron in its core. It is the main course, about one fist above the south-southwest horizon at 9 p.m. The moon represents a half a meatball a fist above Antares. Make sure it cools off before you take a bite.

Monday: Had the script been written a little differently for a well-known Robin Williams movie, we might have heard Mr. Williams shout, “Goooood Morning Orion the hunter”. Orion is typically thought of as a winter constellation. But, it makes its first appearance in the summer sky. The lowest corner of Orion’s body, represented by the star Saiph (pronounced “safe”), rises at 3:30 a.m., well before the Sun. By 5 a.m., Orion’s belt is three fists above the southeast horizon.

Tuesday: In 1987, the rock group Def Leppard sang “Pour some sugar on me, in the name of love. Pour some sugar on me, come on fire me up”. In 2012, some European astronomers “found some sugar near stars, they were very young. Found some sugar near stars, out where planets formed.” Astronomers observed molecules of glycolaldehyde, a simple form of sugar, in the disk of gas and dust orbiting young binary stars. This is the first time astronomers have found this simple sugar so close to a star indicating that organic molecules can be found in planet-forming regions of stars. For more information, go to http://goo.gl/tfwy1.

Wednesday: Do you wish you could travel to Mars? Your name can… on InSight, the NASA probe that will study the interior of Mars. InSight is scheduled to launch in March of 2016. Go to http://go.usa.gov/3Aj3G to send your name to Mars on a tiny chip. Check out your destination this morning at 5:30, one fist above the east horizon.

Thursday: You think the Ellensburg wind is bad. Some of the Jovian planets have winds of over 1000 miles per hour. Jupiter and Saturn have belts of rapidly moving clouds that can be observed with back yard telescopes. To learn more about windy worlds, go to http://goo.gl/GLWAi. Jupiter is line with the Sun and won’t be visible in the morning sky until the second week of September.

Friday: Deneb is about seven fists above the east horizon at 9 p.m. When you look at Deneb, you are seeing light that left Deneb about 1,800 years ago.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Thursday, August 13, 2015

The Ellensburg WA sky for the week of 8/15/15

Saturday: Sometimes you find a quarter on the ground. Maybe you find a dollar in the lining of your jacket. But how often do you find a galaxy in a well-known part of the sky? The Hubble Space Telescope discovered a face-on spiral galaxy in the Coma Cluster of galaxies about 320 million light years away. This galaxy, called NGC 4911, contains regions of gas and dust as well as glowing newborn star clusters. The Coma Star cluster is in the constellation Coma Berenices, found two and a half fists held upright and at arm’s length above the west-northwest horizon at 10 p.m. For more information about this newly discovered galaxy, plus a zoomable image, go to http://goo.gl/5OXUX.

Sunday: Mercury and the young waxing crescent moon are less than a half a fist above due west at 8:30 p.m. Obviously, the moon will be easier to find so use it to guide you to Mercury, less than a half a fist to the right of the moon.

Monday: The Pleiades is less than one fist above the east-northeast horizon at midnight.

Tuesday: Need a caffeine pick-me-up? Make it a double. Need an astronomy pick-me-up? Make it a double-double. Find Vega, in the constellation Lyra the lyre, nearly straight overhead at 10:00 tonight. Less than half a fist to the east (or left if you are facing south) of the bright bluish star Vega is the “star” Epsilon Lyra. If you look at Epsilon Lyra through binoculars, it looks like two stars. If you look at Epsilon Lyra through a large enough telescope, you will notice that each star in the pair is itself a pair of stars.  Each star in the double is double. Hence, Epsilon Lyra is known as the double-double. The stars in each pair orbit a point approximately in the center of each respective pair. The pairs themselves orbit a point between the two pairs.

Wednesday: Have you ever gone to a family reunion, looked around and asked, “How in the world are we related to each other?”. Astronomers look around the Solar System and wonder if there is life anywhere else that we are related to. The Mars Science Laboratory landed on Mars in 2012 to investigate whether it ever had conditions favorable for life. The Cassini Mission continues to study the plume of complex organic chemicals streaming from Saturn’s moon Enceladus. NASA and the European Space Agency are planning a trip to study Europa, the Jovian moon with an ice-covered ocean. And many astronomers consider the methane haze in the atmosphere in Saturn’s moon Titan similar to that of the early Earth. To learn more about the search for life in the Solar System and beyond, go to http://goo.gl/ewtfr. While you won’t see anyone waving back, you can see Saturn one fist above due southwest at 10 p.m. and Mars one fist above the east-northeast horizon at 5:30 a.m.

Thursday: Arcturus is two and a half fists above due west at 10:30 p.m. This star, whose name means bear watcher, is the brightest in the sky’s northern hemisphere. It follows Ursa Major, the Great Bear, around the North Star. Arcturus is the closest giant star to Earth and is one of the few stars whose diameter can be measured directly.

Friday: Hercules stands six fists above the southwest horizon at 10:00 this evening. Four moderately bright stars form a lopsided square that represents his body, while his head points southward.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Wednesday, August 5, 2015

The Ellensburg WA sky for the week of 8/8/15

Saturday: The Perseid meteor shower hits its peak late for the next few nights with Wednesday night and early Thursday morning being the peak of the peak. The meteors appear to come from a point just below the W of the constellation Cassiopeia. This point is about two and a half fists held upright and at arm’s length above the northeast horizon at 11 p.m. By dawn, this point is about seven fists above the northeast horizon. If you fall asleep or forget to set your alarm, you will be able to observe this shower from about 11 p.m. to dawn for the next few nights in about the same location in the sky. The Perseid shower is one of the longest lasting showers. With dark skies owing to the new or nearly new moon for the whole week, you can see up to 100 meteors per hour in the late night and early morning hours all week. For tips about optimizing your viewing this year, go to http://goo.gl/Ylk9jA. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. These meteors are sand to pea-sized bits of rock that fell off of Comet Swift-Tuttle. They are traveling about 40 miles per second as they collide with the Earth and burn up in the atmosphere. 

Sunday: Jupiter and the bright star Regulus are about a pinky-width above the west-northwest horizon at 8:45 p.m. Slightly less challenging is the planet Mercury, two finger widths above the west horizon at this time. 

Monday: The bright star Betelgeuse is about one fist to the lower right of the waning crescent moon at 5 a.m. 

Tuesday: Let’s all sing the galactic black hole monster song: “D is for dusty, that’s good enough for me. D is for dusty that’s good enough for me. D is for dusty that’s good enough for me. Oh dusty, dusty, dusty starts with D.” Astronomers know that spiral galaxies such as our own have super massive black holes in the center, black holes that are billions of times the mass of the Sun. They thought they got to be this massive by mergers where two galaxies collide and the gas, dust and black holes at the center of each colliding galaxy form a larger central black hole. But many distant galaxies show no signs of galactic mergers. Astronomers think the black holes at the center of these galaxies grew simply by snacking on the gas and dust that comes from supernova explosions and normal star formation. Just like the Cookie Monster gains weight by snacking on individual cookies rather than eating a cookie factory. Cookie crumbs, I mean dust, block your view of the center of our galaxy.  It is about one fist above due south at 10 p.m., between the constellations Sagittarius and Scorpius. For more information, go to http://goo.gl/L9ppJf. 

Wednesday: Saturn is two fists above the south-southwest horizon at 9 p.m. 

Thursday: Altair, at one corner of the Summer Triangle, is four fists above the southeast horizon at 11 p.m. Altair is one of the closest bright stars, so close that fictional astronauts visited a planet orbiting Altair in the 1956 movie “Forbidden Planet”. 

Friday: Many big city dwellers never see the milky white, nearly continuous band of stars known as the Milky Way. As cities grow and add more lights, it has become harder to see the bulk of the Milky Way galaxy, our home in the universe. But, there are two easy ways to see the Milky Way. The first way is to look in the mirror. You are part of the Milky Way. The second way is to look from due north through the point straight overhead (called the zenith) to due south from 10:30 p.m. to 1 a.m. for the next two weeks. This is the time of year when the Milky Way is highest in the sky and away from the city lights on the horizon. 

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm