The Ellensburg sky for the week of 9/29/12

Saturday: Tonight’s full moon is in the constellation. This morning’s other Moon is…. Wait a minute. The Earth has only one Moon. True. And it has always had only one Moon. Not necessarily true. According to the best existing model, about four billion years ago, a Mars-sized object collided with the young Earth. The resulting debris coalesced to form the Moon. However, this model left a mystery: why is the Moon so asymmetric? Hardened-lava lowlands dominate the near side while the far side is dominated by mountainous highlands. According to a recent revision of the prevailing model, the early collision formed a large Moon and a small Moon. Over the years, the small Moon caught up to and collided with the large Moon. The highlands are the material from the collided small Moon. For more information about this theory, go to http://goo.gl/6JlcA.

Sunday: Mnemonics are helpful for remembering astronomy facts. (Similarly, “Johnny Mnemonic”, the 1995 cyberpunk film, was helpful in getting Keanu Reeves’ career going.) After all, school children all around the country are learning the order of the planets by remembering, “My very excellent mother just served us nine….” Oops, I guess that one needs updating. Well, here’s one that will not need updating for nearly 100,000 years: the order of the stars in the Big Dipper. Because the nighttime stars are so far away from us, their actual motion through the sky, called their “proper motion” is not noticeable over even thousands of years. That is why the constellations have remained the same since ancient times. But two stars in the Big Dipper have a proper motion large enough such than in 100,000 years, the stars will no longer make a dipper shape. Until then, you can remember the names of the seven dipper stars in order from handle to cup by remembering this helpful advice for teens: “AM, ask mom. PM, dad”. The stars are Alkaid, Mizar, Alioth, Megrez, Phad, Merek, and Duhbe. The Big Dipper is one fist held upright and at arm’s length above the north horizon at 11 p.m.

Monday: Scandalous! The goddess of love will be cozying up to the little king. Venus will be about a pinky-width or less from the bright star Regulus, whose name mean “little king” in Latin. At 6:30 this morning, Regulus will be just to the lower left of Venus, three fists above the east horizon. Because Venus is so close to the Earth, it moves an easily noticeable amount in the sky each day. Compare its position to that of Regulus for the next few days.

Tuesday: The smoke is starting to clear so we can see objects in the sky better than we could a few weeks ago. Luckily the Big Bear Solar Observatory in California doesn’t have this problem. Astronomers have improved the optics of the telescope so much that it is able to resolve features on the surface of the Sun that are just a few miles across. Remember, never look at the Sun without proper eye protection. Instead, go to http://goo.gl/XIBh6 for images of the Sun and more information about the telescope.

Wednesday: Mars is less than a fist above the southeast horizon at 7:30 p.m.

Thursday: At 10:30 p.m., Jupiter is about one fist above the east-northeast horizon.

Friday: The constellation Orion is four fists above the south horizon at 6 a.m. The Orion is a cloud of gas and dust visible with binoculars about a half a fist below the “belt” of three stars. If you are feeling especially attracted to the nebula, that might be because astronomers think there may be a black hole in the middle. They have not directly observed the back hole, which would be the closest known one to Earth at a distance of 1,300 light years. But the motion of stars in the region is consistent with them being near a black hole 100 times the mass of the Sun. For more information, go to http://goo.gl/AGjFf.

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

The Ellensburg sky for the week of 9/22/12

Saturday: At precisely 7:47 a.m., the center of the Sun crosses the celestial equator and passes into the southern sky. The celestial equator is an imaginary line that divides the sky into a northern and southern half. When the Sun is in the southern half of the sky, it appears to take a shorter path from rising to setting. It also does not get as high in the sky at noon. This leads to shorter days and longer nights. Since the Sun crosses the celestial equator today, there is an instant when it is equally in the northern and southern sky, called the north and south celestial hemispheres. This so-called “equal night” is given by the Latin word equinox. Thus, today is known as the Autumnal Equinox. However, the day and night are not of equal duration today. The sun rises at 6:50 a.m. and sets at 6:58 p.m. Day and night are closest to equal duration on Tuesday.

Sunday: “You know Aries and Cancer and Draco and Libra. Leo and Pisces and Virgo and Hydra. But, do you recall, the pointiest asterism of all? Triangulum, the three sided asterism, had a very pointy edge….” Sorry. Some stores have started putting up their Christmas decorations and that has put me in the mood to modify some Christmas songs. Anyway, Triangulum is a small constellation between the more prominent Andromeda and Aries. Its main feature is a skinny triangle oriented parallel to and nearly four fists held upright and at arm’s length above the east horizon at 10 p.m.

Monday: Jupiter is one fist above the east-northeast horizon at 11 p.m. By 6 a.m., it is more than six fists above due south. Venus, the brightest point of light in the sky, is nearly three fists above the east horizon at 6 a.m.

Tuesday: Did you time the exact length of the day and night on Saturday, the first day of autumn? They were not equal in duration. Many people think that the day and night are the same duration on the autumnal equinox. The day is a little longer than the night for two reasons. First, the Sun is an extended object so even when the middle part has set, the upper half is still above the horizon lighting the sky. The second, and more influential reason is that the atmosphere acts like a lens, bending light from the Sun above the horizon when the Sun is really still below the horizon. Day and night are closest in duration today.

Wednesday: It has been dry in Ellensburg. But for a few days each month, the moon often spends time in the watery part of the sky. Tonight is one of those nights. At 10 p.m., Capricornus, the sea goat is one to two fists to the lower right of the moon. Aquarius, the water bearer, is just above and to the right of the moon. Piscis Austrinus, the southern fish, is three fists below the moon. This constellation features the bright star Fomalhaut.

Thursday: The bright bluish star Vega is nearly straight overhead at 8 p.m.

Friday: The cloudy season is coming to Ellensburg. Don’t feel bad. According to astronomers from the European Southern Observatory, it is always cloudy season on HD 85512b, a newly discovered planet orbiting the star called… wait for it… wait for it… called HD 85512. These astronomers developed a method to estimate the cloud cover on planets orbiting distant stars. They think HD 85512b may be cloudy enough to have liquid water on its surface even though it is fairly close to its host star. While the presence of surface water does not guarantee finding life, it is a critical component. For more information, go to http://goo.gl/bGxMD.

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

The Ellensburg sky for the week of 9/15/12

Saturday: “Excuse me, do you have the time?”

“No, but the Big Dipper does.”

You can use the orientation of the Big Dipper to tell time with a precision of about 15-30 minutes. First, find the two stars at the far end of the Big Dipper cup, the stars that do not touch the handle. Draw an imaginary line segment starting at the North Star and passing through the two Big Dipper cup stars. Now, draw a big circle around the North Star. Your circle is a 24-hour clock. Number the circle from 0 hours at the top, counterclockwise to 12 hours at the bottom of the circle, and back up to 24 hours at the top. (O hours and 24 hours are the same on this clock because the day is 24 hours long.) The hour number on the big circle closest to where your imaginary line intersects this circle is called your raw time. Due to the location of the Big Dipper compared to the rest of the stars, the time nearest the intersection (the raw time) is correct for March 6. For any other night, subtract two times the number of months the current date is after March 6 from the raw time. For example, let’s say the imaginary line between the North Star and the Dipper stars is pointed to the right. That means the raw time is 18 hours or 6 p.m. If you made this observation on October 6, which is seven months after March 6, you would subtract two times seven or 14 hours from the raw time.  Thus, the time for November 6 is 18 hours minus 14 hours or 4 hours. In other words, 4 a.m. Don’t forget to convert for daylight savings time if needed. For a more complete set of instructions, go to http://goo.gl/02HmA. There is a simple “star clock” template and instructions at http://goo.gl/SFKrE. Use this paper star clock whenever you watch is broken.

Sunday: Saturn is about a half a fist above the west-southwest horizon at 8 p.m.

Monday: Let me tell you the story of the ghostly white figure that rises early in the morning around Halloween. It appears to be a huge dim glow of white light that rises up from the east in the pre-dawn sky. No, I’m not writing about the ROTC student who has early morning physical training. I’m describing an effect called the zodiacal light. This light comes from sunlight reflecting off dust grains in our solar system. The effect is the most visible when the band of constellations called the zodiac makes a steep angle with the horizon. You need a clear sky with no haze or light pollution to see the zodiacal light that will be visible for the next week or so. At its brightest, the zodiacal light rivals the light of the central Milky Way.

Tuesday: To celebrate the start of school at CWU tomorrow, let’s sing a song of the season. “Oh the weather outside is grand. And the fire is rightfully banned. There is really no place to go. Let it snow, let it snow, let it snow. On Mars.” The Mars Reconnaissance Orbiter has discovered evidence of carbon dioxide snow clouds high above the surface of Mars.  Carbon dioxide, also called “dry ice”, exists in Mars south polar ice cap and requires temperatures of nearly 200 degrees below zero Fahrenheit to form. Astronomers were not sure how this polar cap gets replenished but the discovery of carbon dioxide clouds may provide an answer. For more information, go to http://goo.gl/shMTf. Mars is less than one fist held upright and at arm’s length above the southwest horizon at 8 p.m.

Wednesday: Venus is three fists above the east horizon at 6 a.m.

Thursday: “One world, group hug, love everyone” philosophy: political borders are human-made and can’t be seen from space. Real world, pragmatic discovery: some human-made political borders CAN be seen from space. Since 2003, India has illuminated its border with Pakistan to prevent illegal crossings. In August, astronaut Ron Garan took a picture of the boarder from the International Space Station. For more information, including the photo, go to http://goo.gl/mY8xG.

Friday: Jupiter is a half a fist above the east-northeast horizon at 11 p.m.

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

The Ellensburg sky for the week of 9/8/12

Saturday: In the movie The Terminator, Arnold said “Hasta la vista, baby”. Today you can join NASA scientists and many other people around the world in saying “Hasta la vista, Vesta”. The Dawn probe has studied the asteroid Vesta for the past year. Soon it will head over to the dwarf planet Ceres. Before it goes, Dawn scientists and engineers will host a Google+ Hangout from noon-2:00 p.m. Pacific Daylight Time this afternoon. You can also get mission updates throughout the mission on Facebook or Twitter. For more information, go to http://goo.gl/fKorW.

Sunday: If you sat up late Saturday night or get up very early this morning, you can say “Hasta la vista, Ceres” for an hour. At about 12:25 this morning, the Moon will pass between the Earth and Ceres. This is called an occultation of Ceres because the word “occult” means to block. At about 1:20 a.m., the Moon will have moved far enough in its orbit such that Ceres will emerge out from behind the dark part of the Moon. You’ll need binoculars or a small telescope to see Ceres.

Monday: Science is Central! This week, faculty, staff, and students in the College of the Sciences at CWU will kick off the start of the academic year by hosting a series of evening science lectures and demonstrations geared for all ages. All events are taking place on the CWU Ellensburg campus and all are free. The series kicks off tonight with CWU professor, astronomy club advisor and columnist extraordinaire Bruce Palmquist at 7:00 – 8:00 pm in Lind Hall 215 on the CWU campus. He’ll be giving an interactive lecture about the probability of finding intelligent life on other planets followed by a guided tour of the night sky with several telescopes. Go to http://www.cwu.edu/newmap.html for a map of campus. Parking is free after 4:30 p.m. For more information about the week's events, go to http://goo.gl/6Gseh.

Tuesday: 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 on the main course table one fist above the southwest horizon at 7:30. Make sure it cools off before you take a bite.

Wednesday: Venus is less than a half a fist to the upper left of the Moon at 6 a.m. Jupiter is over six fists above the south-southeast horizon. If you don’t want to get up early to see Jupiter, it is less than a half a fist above the east-northeast horizon at 11 p.m.

Thursday: As Jupiter moves into the evening sky, Mars and Saturn are moving out of the evening sky by moving closer to being in line with the Sun. At 8 p.m., Saturn is half a fist above the west-southwest horizon and Mars is a little less than a fist above the southwest horizon.

Friday: 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.

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