Wednesday, April 23, 2014
Saturday: 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 11:30 p.m.
Sunday: Venus is nearly a half a fist held upright and at arm’s length above the east horizon at 5 a.m.
Monday: You know Metis and Thebe and Adrastea and Amalthea. Io and Ganymede and Callisto and Europa. But do you recall? There are 67 Jovian moons in all. (As of July 2013.) Just 60 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 67 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 14, Mars with 2, and Earth with 1. Even dwarf planets have moons. Pluto has 5, 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 four fists above the west horizon at 9 p.m. Go to http://goo.gl/Xkoeq for more information about Solar System moons.
Tuesday: Tonight’s Moon is new. Don’t bother looking for it. The new moon is the phase where the Moon is directly between the Earth and the Sun. Hence the side of the Moon facing Earth is not receiving any sunlight and cannot be seen. However, if you are visiting Australia or Antarctica today, its effects can be seen. There will be an annular solar eclipse visible in part of Antarctica and a partial solar eclipse visible in all of Australia. For more information about this phenomenon, where the moon will block part of the Sun’s light, go to http://goo.gl/7Ecls0. If you are reading this from Australia, throw a shrimp on the Barbie and observe the Sun only through a proper solar filter.
Wednesday: 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.
Thursday: At 10 p.m., Saturn is one fist above the southeast horizon and Mars is nearly four fists above the south-southeast horizon.
Friday: Winter must be over because the winter constellations are becoming less visible. Orion is setting in the 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.
Thursday, April 17, 2014
Saturday: The first day of spring was March 20. The most recent full moon was last week. That means tomorrow is Easter. The standard way to determine the date of Easter for Western Christian churches is that it is the first Sunday after the full moon that occurs on or after the vernal equinox, also known as the first day of spring. Of course, the other standard way is to look for the date of church services celebrating the resurrection of Jesus. There is no Bible story of an “Easter star”. If there were, Spica would be a pretty good choice. The name Spica comes from the Latin “spica virginis” which means “Virgo’s ear of grain”. Spica represents life-giving sustenance rising after a long winter just like the risen Jesus represents life-giving redemption to Christians. Spica is one fist held upright and at arm’s length above the east-southeast horizon at 8:30 p.m. For an algorithm on how to calculate the exact date of Easter for any year, go to http://goo.gl/gFnepP.
Sunday: This week is International Dark Sky Week, a week to celebrate the night sky and think about how we can reduce light pollution. Because of an overabundance of inefficient outdoor lighting, the thick band of the Milky Way is not visible from even small cities such as Ellensburg. For more information about what you can do and to learn about the aesthetic, health, and environmental effects of light pollution, go to http://goo.gl/w6Hi7.
Monday: Mars is three and a half fists above the southeast horizon at 10 p.m.
Tuesday: 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 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 in the last quarter phase meaning it will be bright and be out for most of the prime viewing time. 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.
Wednesday: As the weather warms up, people start thinking about swimming in a nice cool body of water. Recently, astronomers have discovered evidence an ocean about 20 miles beneath the surface of Saturn’s moon Enceledas. NASA’s Cassini probe measured variations in how the moon’s gravity pulled on the orbiting spacecraft. These variations can be explained by a large amount of liquid water under one section of the ice because liquid water is denser than an equal volume of ice. While you need a very large telescope to see Enceledas, Saturn is visible to the naked eye tonight, one fist above the southeast horizon.
Thursday: Jupiter is four and a half fists above the west horizon at 9 p.m.
Friday: Venus is a half a fist below the moon, low in the eastern sky at 5:30 a.m. That’s right, 5:30 a.m. The Sun rises early now. You can’t waste the day sleeping.
Wednesday, April 9, 2014
Saturday: 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 one fist held upright ant at arm’s length above the southeast horizon. Mars is a fist above Spica.
Sunday: Tonight at 10 p.m., listen to an Eminem song. Next, eat some M & M candies. Finally, look three fists above the southeast horizon to see the Moon and Mars side by side for the entire night. That’s right. Watch the sky’s own M and M while eating M & Ms while listening to Eminem. You’ll have a great time or my name’s not (what?). My name’s not (who?). My name’s not… Slim Shady.
Monday: Last night, did you lose yourself in the music, the moment watching the Moon and Mars? Well, tonight’s even better. Tonight there will be a total lunar eclipse. Total lunar eclipses are not as noticeable as total solar eclipses because light still reaches the Moon even when it is completely blocked by the earth. That is because the Earth’s atmosphere acts like a lens and bends rays of light that would normally miss the moon towards the moon. That doesn’t mean the moon looks the same during a total lunar eclipse as it does during a normal full moon.
Sunlight is white. White light is the sum of all of the colors in the visible spectrum (red, orange, yellow, green, blue, indigo and violet). Our atmosphere scatters the blue component of the Sun’s white light. That is why our sky is blue. (If our atmosphere consisted of different gasses, we would likely have a different colored sky.) When the Sun or moon is near the horizon, the light passes through a lot of the atmosphere meaning a lot of the blue light is scattered and the Sun or moon looks redder than when it is high in the sky. During a total lunar eclipse, sunlight passes through a large slice of the Earth’s atmosphere. The remaining light that reaches the moon is reddish. Thus, the moon looks red during a total lunar eclipse.
From our perspective in central Washington, the moon will begin the partial eclipse stage at 10:59 p.m. The moon will slowly move into the Earth’s shadow and get dark from left to right. At 12:08 a.m., the moon will be fully eclipsed. The total eclipse lasts until 1:23 a.m. The moon will be moving out of the earth’s darkest shadow or umbra until 2:32 a.m. After that, the moon will look white, just like a normal full moon. Thus, during the entire eclipse, the moon looks white, then black, then red all over. For more information, go to NASA Science News at http://goo.gl/q19W5E.
Tuesday: The Lyrid meteor shower peaks next week. But there will be increased meteor activity for the next two weeks in the vicinity of the constellation Lyre. 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 above the east-northeast horizon at midnight and close to straight overhead near dawn.
Wednesday: Saturn is about a finger width to the upper left of the Moon in the southeast sky at 10 p.m. By sunrise tomorrow at 6 a.m., they are about twice as far apart and are in the southwest sky. The main east to west motion of objects in the sky is due to the rotation of the Earth. The actual motion of objects really far away such as stars, and even planets, does not affect what we can observe with the naked eye over one night. But the Moon is so close to us, its actual motion can be observed over a few hours. Its actual is best observed on a night like tonight when there is another bright object next to the Moon throughout the night.
Thursday: Venus is one fist above the east-southeast horizon at 6 a.m.
Friday: Jupiter is nearly five fists above the west-southwest horizon at 9 p.m.
Thursday, April 3, 2014
Saturday: Some people in town today for the Yakima River Canyon Marathon may be looking for a little running inspiration. While nothing can take the place of a 20+ mile long run for marathon preparation (I know), certain objects in the night sky are inspiring. In the Bible, Job specifically mentions the star Arcturus, or the bear keeper, to his friend as a sign of God's majesty. He describes God as that "Which maketh Arcturus, Orion, and Pleiades, and the chambers (constellations) of the south" (Job 9:9, King James Version). Whatever your religious beliefs, it is clear that Job was impressed with this very bright star. See the star that inspired Job about one and a half fists held upright and at arm’s length above the east horizon at 9 p.m.
Sunday: If you ran far yesterday, you don’t want to stay up late looking at the stars. So do something during the day that will help you and other night sky enthusiasts: make sure your outdoor light fixtures are shielded or at least facing down. This will cut down on light pollution, stray light that obscures the stars, and give you a head start in celebrating International Dark Sky week, which occurs later in the month. Go to http://goo.gl/w6Hi7 for more information on how to do an outdoor lighting audit and get more information about International Dark Sky week.
Monday: NASA is inviting you to take the plunge with a laddie. Not ready for that level of commitment? Against your religion? You should, at least, “Take the Plunge” with LADEE, NASA’s Lunar Atmosphere and Dust Environment Explorer satellite. Within the next two weeks, it will run out of fuel and crash into the moon. NASA is sponsoring a contest for people to predict the exact date and time it will happen. Winners will receive a personalized certificate from the LADEE team. The deadline to enter the contest is 3 p.m., PDT on Friday April 11. http://goo.gl/exguh0.
Tuesday: Mars is at opposition tonight. No, that doesn’t mean that Mars refuses to eat his vegetables. (Please eat your vegetables, children.) Opposition means that Mars is on the opposite side of the Earth as the Sun. An object is in opposition when it is due south 12 hours after the Sun. When an object is in opposition, it is at its highest point in the sky during the darkest time of the night. A planet in opposition shines brighter and appears larger in a telescope than any other night. And since Mars is also relatively close, it is exceptionally bright tonight. Mars is three and a half fists above due south at 1 a.m.
Wednesday: If you are more of a morning person, you’ll find Mars about one fist above the west-southwest horizon at 6 a.m. At this same time, Venus is one fist above the east-southeast horizon.
Thursday: 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 and a half fists above the northeast horizon. The Whirlpool Galaxy is two fingers to the upper right of Alkaid.
Friday: Saturn is one fist above the southeast horizon at 11:30 p.m.