Wednesday, April 25, 2012

The Ellensburg Sky for the week of 4/28/12

Saturday: Jupiter is rapidly disappearing from view as it moves closer and closer to the Sun in the evening sky. At 8:30, Jupiter is a half a fist held upright and at arm’s length above the west-northwest horizon. By next week, it will be lost in the glare of the Sun. A few weeks later, it will be visible in the morning sky.

Sunday: Many ancient philosophers thought the pattern of movement in the heavenly bodies represented a “musica universalis” ore “universal music”. For example, Pythagoras, the right triangle guy, hypothesized that the Sun, Moon, and planets emitted their own characteristic hum based on their orbital motion. Of course we now know that it not the case. But that does not mean astronomy and music are unrelated. At 1:00 Pacific Daylight Time today, Italian pianist and composer Giovanni Renzo will give an online Cosmic Concert with music to accompany beautiful pictures and videos of the night sky. Go to http://goo.gl/hAz1h for more information about the concert and http://goo.gl/QUuLI for a live stream of the concert.

Monday: In honor of the mentioning of Pythagoras yesterday, Mars, the bright star Regulus, and the Moon make a right triangle in the southern sky at 9 p.m. Regulus is at the right angle.

Tuesday: Winter must be over because the winter constellations are becoming less visible. Orion is setting due west starting at about 9 p.m. At this time, Orion’s belt is a little more than half a fist above the west horizon and Betelgeuse is nearly two fists above the west horizon. By mid-May, Orion will be lost in the glare of the Sun.

Wednesday: Do people think you have a magnetic personality? The star Cor Caroli understands how you feel. Cor Caroli has one of the strongest magnetic fields among main sequence stars similar to our Sun. This strong magnetic field is thought to produce large sunspots that cause the brightness of Cor Caroli to vary. Cor Caroli is nearly straight overhead at 10:30 p.m.

Thursday: Venus is two and a half fists above the west horizon at 9 p.m.

Friday: This is just a Pythagorean week. At 9 p.m. Saturn, the bright star Spica, and the Moon make a right triangle low in the southeast sky. If you are already regretting watching boring golf on Sunday rather than listening to the Cosmic Concert, go to http://goo.gl/P6Lgw and watch nearly two minutes of real footage of Saturn and Jupiter from NASA’s Voyager and Cassini spacecraft.
The positional information in this column about stars and planets is typically accurate for the entire week. This column is also available online at http://theellensburgsky.blogspot.com/.

Sunday, April 15, 2012

The Ellensburg Sky for the week of 4/21/12

Saturday: Remember the old saying: April showers bring… meteors. The Lyrid meteor shower peaks tonight. The meteors appear to come from a point to the right of the bright bluish star Vega in the constellation Lyra the lyre. This point is about three fists held upright and at arm’s length above the east-northeast horizon at midnight tonight and close to straight overhead near dawn. The best time to look is just before dawn since that is when the radiant, or point from which the meteors appear to come, is high in the sky. This year, the Moon is new so expect to see up to 20 bright meteors per hour. Typically, this is one of the least interesting major meteor showers of the year. However, it is also one of the most unpredictable. As recently as 1982, there were 90 meteors visible during a single hour. In addition, the Lyrid meteor shower has historical interest because it was one of the first ones observed. Chinese records say “stars fell like rain” in the shower of 687 B.C. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere.

Sunday: You know Metis and Thebe and Adrastea and Amalthea. Io and Ganymede and Callisto and Europa. But do you recall? There are 65 Jovian moons in all. Less than 50 years ago, Jupiter was thought to have only 12 moons. But, astronomers are red-nosed with delight that the advent of supersensitive electronic cameras has caused the number of discovered moons to rapidly increase. Jupiter’s 65 moons range in size from Ganymede, with a diameter of 5,262 kilometers, to S/2002 J12 and S/2003 J9, with a diameter of only one kilometer. Our moon has a diameter of 3,475 kilometers. (One kilometer is 0.62 miles.) Saturn is second place in the moon race with 62. Uranus is next with 27. Then comes Neptune with 13, Mars with 2, and Earth with 1. Even dwarf planets have moons. Pluto has 4, Eris has 1, and Haumea has 2. Eris is an outer solar system object that was discovered in 2005 and named in September of 2006. Because astronomers thought it was larger than Pluto, people called it the tenth planet for a while. (More recent measurements show Eris to be a little smaller than Pluto.) Haumea, the newest dwarf planet with a moon, was discovered in 2004 and officially named a dwarf planet on September 17, 2008. Jupiter, the “mooning” champ, is a half a fist above the west horizon at 9 p.m. Go to http://goo.gl/Xkoeq for more information about Solar System moons.

Monday: Are you thirsty. I’ll wait while you get some water. I will NOT wait while Corvus the crow gets you some water. The Greco-Roman god Apollo made this mistake. He sent Corvus the crow to get some water in the cup known as Crater. Some figs distracted Corvus and he waited for them to ripen so he could eat them. When Corvus got back late, Apollo put Corvus and Crater in the sky with the gently tipping cup just out of the reach of the perpetually thirsty crow. Corvus is a trapezoid-shaped constellation about two fists above due south at 11 p.m. Crater is just to the right of Corvus.

Tuesday: Venus is about a half a fist to the upper right of the Moon at 9 p.m. Both objects are low in the western sky.

Wednesday: “Water, water everywhere nor any drop to drink” is from The Rime of the Ancient Mariner. (No not Ichiro.) But is could be the slogan of our solar system. Astronomers used to think that the solar system was dry with earth being the only place to find water. It turns out that the solar system has an abundance of water; Comets are made of water ice. Some astronomers think they be the source of some, or even most, of Earth’s water. Jupiter’s Moon Europa has a crust of frozen water covering a large ocean containing more water than all of the Earth’s oceans. Even the Moon, thought to be dry as a bone, has frozen ice deep in its polar craters. Take a swim in the watery last quarter Moon this morning. Once you dry off, visit http://goo.gl/BZqbL to read more about solar system water.

Thursday: At 10 p.m., Mars is about five and a half fists above the south horizon and Saturn is about two and a half fists above the southeast horizon. Saturn is slightly brighter and orange compared to the bluish star Spica to its lower right.

Friday: How many of you know your 12 nearest neighbors? I thought so. Why don’t you go out and meet them right now. I’ll wait. Yes, of course bring them cookies. No, not those stale ones you hate.
Are you back already? That means you didn’t really go out and meet your 12 nearest stellar neighbors, did you? Including the Sun, there are 12 stars within 10 light years of Earth. The most well known are the Sun (obviously); Proxima Centauri, the nearest star other than the Sun; Alpha Centauri, a bright binary star visible from the tropics and the Southern Hemisphere; and Sirius, the brightest star in the nighttime sky. Sirius is the largest and most luminous star in our neighborhood. It is one and a half fists above the southwest horizon at 9 p.m.

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

Thursday, April 12, 2012

The Ellensburg Sky for the week of 4/14/12

Saturday: This week is International Dark Sky week, a time during which people around the world are encouraged to turn off any unnecessary outdoor lights in order to temporarily reduce light pollution. Light pollution is the adverse effect of unwanted light including sky glow, glare, and light clutter. If you think that there is not much sky glow, or wasted light, in the world, look at the nighttime image of the Earth at http://www.cc.gatech.edu/~pesti/night/. While turning off a few unnecessary outdoor lights for one week will not solve the problem of light pollution, International Dark Sky Week will raise awareness of the issue. You can do your own dark sky test. At 10 p.m., look in the sky starting at the southwest horizon, moving to about halfway up in the western sky and back down to due north. If you can see the faint glow of the Milky Way Galaxy, you are observing from a dark site. And if you can force yourself to stay awake or if you get up before sunrise or stay up very late any night this week, be on the lookout for meteors coming from nearly straight overhead near dawn. The Lyrid meteor shower is active for the next two weeks.

Sunday: Saturn is opposition tonight. That doesn’t mean that Saturn is a teenager. Opposition means that Saturn 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 day. Thus, opposition is typically the best time to observe a planet. Saturn is about three and a half fists above the south horizon at 1 a.m. It is one fist above the east-southeast horizon at 9 p.m.
If you remember this column from 2/23/2008, 3/8/2009, 3/21/2010, and 4/4/11, you know that Saturn was also in opposition on those dates. Thus, it is in opposition about two weeks later each year. Two weeks is about one twenty-fourth of a year. This implies that it takes Saturn about 24 years to make one orbit around the Sun and get back in line with the same stars again. Saturn’s actual orbital period of 30 years matches this approximation quite well.

Monday: Avast ye matey. Swab the poop deck. Pirates love astronomy. In fact, the term “poop” in poop deck comes from the French word for stern (poupe) which comes for the Latin word Puppis. Puppis is a constellation that represents the raised stern deck of Argo Navis, the ship used by Jason and the Argonauts in Greek mythology. Argo Nevis was an ancient constellation that is now divided between the constellations Puppis, Vela and Carina. The top of Puppis is about a fist and a half to the left of the bright star Sirius in the south-southwest sky at 9 p.m. Rho Puppis, one of the brightest stars in the constellation, is about one and a half fists above the south-southwest horizon at this time.

Tuesday: The nighttime stars take little more than an instant to rise. The Moon takers about two minutes to rise. That’s absolutely speedy compared to the constellation Virgo which takes four hours to rise. The first star in Virgo rises at 4:30 in the afternoon today. Spica, the brightest star in the constellation, rises at 7:30. By 9 p.m., Spica is a fist and a half above the southeast horizon.

Wednesday: Mercury will be as far away from the Sun in the sky as it will get this orbital cycle. This "farthest away" point is known as the planet's greatest elongation. Since Mercury is in morning sky, it is west of the Sun and this occurrence is called the greatest western elongation. This morning will be the best mornings to observe Mercury for the next few weeks. Mercury is about a half a fist above the east horizon at 6 a.m., between the horizon and the Moon Over the next few weeks, Mercury will move toward the Sun in the sky. By early June, it will be visible in the evening sky.

Thursday: Jupiter is fading in the evening sky. It is less than half a fist above the west-northwest horizon at 9 p.m.

Friday: At 10 p.m., Venus, the brightest point of light in the night sky, is two fists above the west-northwest horizon and Mars is five and a half fists above the south horizon.

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

Wednesday, April 4, 2012

The Ellensburg Sky for the week of 4/7/12

Saturday: This month is Global Astronomy Month (www.gam-awb.org). Astronomers around the world want to reconnect people with the night sky, thus their slogan: One People, One Sky. For a summary of Global Astronomy Month events, click on “Events” at the middle of the right-hand column. One of the feature events for this week is a video entitled “Space Trip” featuring new works by the Austrian artist Thomas Riess. His work is abstract yet there is a certain familiarity to it. Go to http://goo.gl/EffgU either today or tomorrow to read more about his work and for a link to the video.

Sunday: The Big Dipper is nearly straight overhead at 11 p.m., spilling its contents all over the north horizon.

Monday: On March 31, over 600 people ran a real road marathon from Ellensburg to Selah. Today at 1 p.m. Pacific Daylight time there will be a virtual Messier Marathon. In a road marathon, you run far and look at the backs of the people ahead of you. In a Messier Marathon, you look at objects that are far away. The Messier Object Catalogue consists of 110 fuzzy objects that were difficult to distinguish from comets in late 18th century telescopes. These can be a challenge to find on your own. That’s why you should participate in the virtual marathon at http://virtualtelescope.bellatrixobservatory.org/mm2012.html. Astronomers on the nighttime side of the Earth will point their telescope at the Messier objects and stream the images live in the internet.

Tuesday: Antares is a half a fist to the lower right of the Moon at 5 a.m.

Wednesday: You probably didn’t know this but several British New Wave bands were really into astronomy. Take the band “Dead or Alive” (please). The original lyrics to their song “You Spin my Round (Like a Record) were thought to be: “ You spin me right round, baby, right round, like the Whirlpool Galaxy, right round, round, round.” (Well, that’s what I thought them to be.) The Whirlpool Galaxy was the first galaxy observed to have a spiral shape. Since then, astronomers have discovered many galaxies, including our own Milky Way Galaxy, have a spiral shape. Go to http://www.spacetelescope.org/images/heic0506a/ for more information about the Whirlpool Galaxy. Go to your small telescope to find the Whirlpool Galaxy in the night sky. It is in the constellation Canes Venatici, the hunting dogs. At 10 p.m., find Alkaid, the end star of the Big Dipper handle, five fists held upright and at arm’s length above the northeast horizon. The Whirlpool Galaxy is two fingers to the upper right of Alkaid.

Thursday: Mars is five and a half fists above the south horizon and Saturn is two fists above the southeast horizon at 10 p.m.

Friday: If Friday the 13th is supposed to be unlucky, then this is your unlucky year. There are three Fridays that fall on the 13th this year! And they occur 13 weeks apart! And the government is charging an extra $13 tax those Fridays! Okay, I made up that last one. But I’m not making up that Aldebaran is the 13th brightest star in the nighttime sky. At 9 p.m. tonight, it is about a fist to the lower left of Venus and two fists above due west. At this time, Jupiter is about a half a fist above the west-northwest horizon.

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