Wednesday, March 25, 2009

The Ellensburg sky for the week of 3/28/09

Saturday: 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://astronomy2009.nasa.gov/observe.htm 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, in the northeast sky. The Whirlpool Galaxy is two fingers to the upper right of Alkaid.

Sunday: The moon is spending a fun-filled Monday morning and afternoon with seven sisters. (Don’t tell Mrs. Moon.) At 9 p.m. tonight, the open star cluster called the Pleiades, or the seven sisters, is a half a fist to the upper left of the moon. During the night and into tomorrow, the moon will move to being right next to the Pleiades. By tomorrow night, the Pleiades will be below the moon. Expect the moon to sleep on the couch tomorrow night.

Monday: April’s “Hot Topic” for the International Year of Astronomy is galaxies and the distant universe. When Galileo turned his telescope to the seemingly continuous band of light in the sky, he discovered it consisted of countless faint stars. This extended our celestial neighborhood from a few thousand stars to millions of stars. This neighborhood configuration lasted until the 1920’s when Edwin Hubble discovered that there are other galaxies with millions, or even billions, of stars just like our own galaxy. Go to http://astronomy2009.nasa.gov/topics.htm for more information about the April “Hot Topic”.

Tuesday: Jupiter is about a fist held upright and at arm’s length above the southeast horizon at 6 a.m.

Wednesday: After a long journey through space, there is nothing will quench your thirst better than a few drops of refreshing Mars water. Wait! Is this an April Fool’s Day joke? No. After analyzing photos taken by the Mars Phoenix Lander, a group of astronomers discovered drops of very salty liquid water on one of the Lander’s legs. Because Mars is so cold and has such a thin atmosphere, astronomers thought water could exist in solid and vapor form only. But, temperature fluctuations in the Mars polar region and the saltiness of the soil where Phoenix landed probably created a pocket of water too salty to freeze. Salt water freezes at a lower temperature than fresh water, no matter what planet it is found on. Scientists think that ice was melted by the Lander’s exhaust and splashed on the leg at impact. Furthermore, some of the muddy, salty water drops seem to have grown by absorbing water vapor from the atmosphere. This is similar to how water droplets form and grow on the outside of a cool glass. You’ll need binoculars to see Mars this morning. It is less than a half a fist above the east-southeast horizon at 6:15. As the weeks go by, Mars will move higher and high in the morning sky. For more information about liquid water on Mars, go to http://www.skyandtelescope.com/news/41728642.html.

Thursday: Tonight’s first quarter moon is in the constellation Gemini the twins.

Friday: Saturn is four fists above the southeast horizon at 9 p.m. Saturn’s largest moon, Titan, is visible with binoculars to the right of Saturn. Astronomers studying Titan’s spin assumed that its rotation rate (spin on its axis) was the same as its rate of revolution around Saturn. This is the case for our moon. But, data from the Cassini mission shows that Titan’s rotation seems to be increasing. Some astronomers hypothesize that Titan’s high winds are contributing to the increase.

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

Tuesday, March 17, 2009

The Ellensburg sky for the week of 3/21/09

Saturday: How many stars can you see in the constellation Orion? This week, you can help answer that question. The organization called GLOBE at Night is looking for people all over the world to count how many stars they can see in the constellation Orion. Participants use star charts found at http://www.globe.gov/GaN/ to observe Orion and compare what they see to the charts. After making the observations, participants can go to the website and add their findings to those of thousands of other observers. The main goal of GLOBE at Night is to research the pattern of light pollution across the globe. A secondary goal is to increase interest in observing and awareness of the night sky. You can find Orion four fists held upright and at arm’s length above the south-southwest horizon at 8 p.m. In Orion, you’ll see four of the 30 brightest stars (Rigel, Betelgeuse, Bellatrix, and Alnilam) in the night sky.

Sunday: Jupiter is less than a half a fist to the lower left of the Moon at 6 a.m.

Monday: According to the latest count, there are over 444,000 asteroids in the asteroid belt. Ceres, the largest one, is closer to Earth this year than is has been 1857. You can spot it with binoculars in the constellation Leo Minor. First find the bright star Regulus. It is nearly five fists above the southeast horizon at 9 p.m., at the bottom of a backwards question mark. Count three bright stars up the question mark. Put that star on the right hand edge of your binocular field of view. Ceres will be a fairly dim point of light on the left-hand side of your field of view. Go back to that same portion of the sky for the next few nights. The point of light that moved from your first observation is Ceres.

Tuesday: Ours isn’t the only solar system with planets. Near the top of the constellation Cancer the crab at the extreme limit of naked eye visibility is 55 Cancri, a binary star system 41 light years from Earth and the star with the most known planets other than our Sun. There are five known planets in orbit around 55 Cancri, seven fists above the south-southeast horizon at 9 pm. Four of the planets are similar in size to Jupiter and one is similar in size to Neptune. It is unlikely that any of these planets have life and almost certainly not complex life as it exists on Earth. For more information about planets orbiting stars other than our Sun, called extrasolar planets, go to http://planetquest.jpl.nasa.gov/.

Wednesday: Saturn is four fists above the southeast horizon at 10 p.m.

Thursday: 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. This is why some people call this phase the “dark moon” and reserve the name “new moon” for the first visible waxing crescent after the Moon moves out from directly between the Earth and Sun.

Friday: Spica, the brightest star in the constellation Virgo, is one fist above the east-southeast horizon at 10 p.m.

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

Friday, March 13, 2009

The Ellensburg sky for the week of 3/14/09

Saturday: Sirius, the brightest star in the nighttime sky, is two and a half fists held upright and at arm’s length above due south at 8 p.m.

Sunday: Ask someone on which day in March the day becomes longer than the night. Go ahead, ask someone. Why are you still reading this? I can wait. If they said the first or second day of spring, they are wrong. Today, five days before the first day of spring, is the day in which there are more minutes of daylight than night. There are two main reasons for this. First, the atmosphere acts like a lens, bending light from the Sun above the horizon when the Sun is below the horizon. Thus, the Sun appears to rise before it actually rises and it appears to set after is actually sets. Second, spring starts when the center of the Sun passes through the point called the vernal equinox. But, the Sun is not a point. The upper edge of the Sun rises about a minute before the center of the Sun and the lower edge sets a minute after the center of the Sun. Thus, even if we didn’t have an atmosphere that bent the sunlight, daytime on the first day of spring would still be longer than 12 hours.

Monday: Venus is one fist above the west horizon at 8 p.m.

Tuesday: The bright star Antares in the constellation Scorpius is less than a half a fist to the upper right of the Moon at 6 a.m. Certain regions of South America and Africa will see the Moon block, or occult, Antares. Is an occultation such as this a once in a lifetime event? Should you consider spending your retirement saving to gaze at the wonder of a lunar occultation? Hardly. The moon occulted Antares as recently as September of 2008 and January 2009. Antares is just below the ecliptic, the imaginary line in the sky that the Sun follows throughout the year. Since the moon follows that path, as well, it passes near Antares in the sky a few times a year. Oh, and, by the way, sorry to bring up your retirement savings. I know that’s a sore subject now days.

Wednesday: This morning’s last quarter moon is in the constellation Ophiuchus the serpent bearer.

Thursday: Saturn is three and a half fists above the southeast horizon at 10 p.m.

Friday: Look up in the sky. It’s a plane. It’s a bird. No, it’s the vernal equinox. The vernal equinox!? Spring starts at 4:45 a.m. Pacific Daylight Time The first day of spring is often called the vernal equinox. This label for the day is misleading. The vernal equinox is actually the point in the sky where the Sun’s apparent path with respect to the background stars (called the ecliptic) crosses the line that divides the stars into north and south (celestial equator). This point is in the constellation Pisces the fishes. At the vernal equinox, the Sun is moving from the southern region of background stars to the northern region. This marks the beginning of six months of days being longer than nights in the northern hemisphere. Since the Sun crosses the vernal equinox in the evening, tomorrow will be the first full day of spring.
You can’t see the vernal equinox. But you can see Jupiter this morning, less than a half a fist above the southeast horizon at 6:30 a.m.
Because the Earth slowly wobbles like a spinning top, the vernal equinox is slowly moving into the constellation Aquarius. By the year 2597, the vernal equinox will reach the constellation Aquarius and the “Age of Aquarius” will begin. Until then, we’ll be in “the age of Pisces”.

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

Wednesday, March 4, 2009

The Ellensburg sky for the week of 3/7/09

Saturday: Don't forget to set you clocks ahead one hour tonight for the annual ritual called daylight savings. Daylight savings originated in the United States during World War I to save energy for the war effort. But a recent study by two economists shows that switching to daylight savings time may actually lead to higher utility bills. When the economists compared the last three years of energy bills in the section of Indiana that just started observing daylight savings, they discovered that switching to daylight savings cost Indiana utility customers $8.6 million in electricity. In an even more important consequence of daylight savings, Stanley Coren of the University of British Columbia discovered a 7% jump in traffic accidents on the Monday after we "spring ahead". Blame it on the lost hour of sleep. And, sky watchers lose even more sleep because the sky does not get dark for an additional hour.

Sunday: Tonight is one of the best nights of the year to observe Saturn because it is at opposition. That doesn’t mean that Saturn is now a teenager. Opposition means that Saturn is on the opposite side of the Earth as the Sun. In this case, Saturn is also at its biggest and brightest of the year. When an object is in opposition, it is at its highest point in the sky during the darkest time of the day. Saturn is about four and a half fists held upright and at arm’s length above the south southeast horizon at midnight.

Monday: Tonight, the Moon is between two bright objects in the sky. Regulus is about a fist to the upper right of the Moon and Saturn is about a fist to the lower left. Look for them in the southeast sky at 10 p.m.

Tuesday: Tonight’s full moon is in the constellation Leo the lion. While we may refer to the moon tonight by the boring title, “a full moon in March”, Native Americans in the eastern United States called this moon the Full Worm Moon. By March, the temperature has increased enough so the ground starts to thaw and earthworms make their first appearance. Earthworms attract birds. Northern tribes thought of the bird connection when they referred to the March full moon as the Full Crow Moon. Tribes in parts of the country with maple trees call this full moon the Full Sap Moon For more full moon names, go to http://www.farmersalmanac.com/full-moon-names.

Wednesday: Venus is about a fist and a half above the west horizon at 8 p.m.

Thursday: Jupiter is less than a fist above the southeast horizon at 6:30 a.m.

Friday: Today’s sunrise is at 7:14 Pacific Daylight Time. Enjoy the sunrises while you can because you have only 7.6 billion more years of them. As the Sun ages, it slowly expands. The latest estimate is that the outer layer of the Sun will have expanded out to the Earth’s orbital path in 7.6 billion years. Of course, long before then – perhaps about a billion years from now – the Sun would have expanded enough to boil off all of the Earth’s water and burn off the atmosphere making Earth an unpleasant place to watch the next 6.6 billion years of sunrises. Isn’t that a happy thought for this Friday the 13th?

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