Wednesday, March 31, 2010

The Ellensburg sky for the week of 4/3/10

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 astronomy2009.nasa.gov/observe_apr.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, 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.

Sunday: Mercury and Venus are about a fist and a half above the west horizon at 8 p.m. Venus is the brighter object. They’ll be neighbors in the sky for the next few nights.

Monday: Mars is about six and a half fists above the south horizon at 9 p.m.

Tuesday: This morning’s last quarter moon is in the constellation Sagittarius the archer.

Wednesday: This April, the hot topic in the tabloids is Sandra Bullock and Jesse James. (No, not that Jesse James.) Last April, the “Hot Topic” for the International Year of Astronomy was galaxies and the distant universe (astronomy2009.nasa.gov/topics_apr.htm). 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. We may lose interest in celebrity break-ups but galaxies are always hot.

Thursday: This evening, Mercury is as far away from the Sun in the sky as it will get this orbital cycle and at its most favorable viewing position of the whole year. This "farthest away" point is known as the planet's greatest elongation. Since Mercury is in evening sky, it is east of the Sun. Thus, this evening’s elongation is known as the greatest eastern elongation. (If you care to remember this in general, remember both eastern and evening start with the letter "e".) Mercury is about a fist and a half above the west horizon at 8 p.m. Over the next few weeks, Mercury will move toward the Sun and into the morning sky.

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

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

Wednesday, March 24, 2010

The Ellensburg sky for the week of 3/27/10

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. Hopefully there won’t be as much light pollution as usual because this is in the middle of Earth Hour. Earth Hour, which goes from 8:30-9:30 p.m. local time, is the World Wildlife Fund's global program where individuals and organizations turn off unnecessary lights for one hour to support climate change initiatives.

Sunday: Saturn is about a fist to the left of the moon at 10 p.m. They are three fists above the southeast horizon.

Monday: 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.

Tuesday: Venus is a half a fist above the west horizon at 8:30 p.m. A much dimmer Mercury is a finger width to the lower right of Venus.

Wednesday: Orion is getting lower and lower in the nighttime sky. Its brightest star Rigel is only two fists above the southwest horizon at 9 p.m.

Thursday: 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. Look for Mars and those refreshing drops of water six fists above the southwest horizon at 10 p.m. For more information about liquid water on Mars, go to http://www.skyandtelescope.com/news/41728642.html.

Friday: Give me a “W”. Cassiopeia, a W-shaped group of stars is two fists above the north horizon at midnight.

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

Sunday, March 14, 2010

The Ellensburg sky for the week of 3/20/10

Saturday: 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 12:33 p.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 (called the 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. Since the Sun crosses the vernal equinox in the middle of the day, tomorrow will actually be the first full day of spring.
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”.

Sunday: Saturn is opposition tonight. That doesn’t mean that Saturn is in the minority party in the senate. 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 four and a half fists held upright and at arm’s length above the south horizon at 1 a.m. It is two fists above the east-southeast horizon at 9 p.m.
If you remember this column from March 7, 2009, you know that Saturn was also in opposition on March 8, 2009. Thus, it was in opposition about two weeks earlier last 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: Look very low due north at 9:45 p.m. It’s a plane. It’s a bird. It’s the vernal equinox. (Oops, I already used that joke.) It’s a spotlight on the ridge. No, it’s not a spotlight on the ridge. It is the star Deneb of the constellation Cygnus the swan. Deneb is the second brightest circumpolar star. Circumpolar stars never rise or set. They are always above the horizon.

Tuesday: This morning’s first quarter moon is in the constellation Gemini the twins.

Wednesday: Mars is less than a half a fist to the upper left of the Moon at 10 p.m.

Thursday: Do you ever stare off into space and wonder if there is life out there? Your search may be successful if you stare in the direction of Orion for the next billion years or so. The Herschel Space Observatory has discovered signs of such life-enabling molecules as water, carbon monoxide, and methanol, among others in the Orion Nebula, a star forming region about 1,500 light years away. This does not mean life will definitely form there, just that the conditions are more favorable there than many other places in the galaxy. The Orion Nebula is about three fists above the southwest horizon at 9 p.m. For more information about the Herschel discovery, go to http://www.portaltotheuniverse.org/news/view/48403/.

Friday: Tomorrow night at 8:30 p.m. local time hundreds of millions of people around the world will come together to call for action on climate change by turning off unnecessary lights and other electric devices for one hour. To find out more about this event, called Earth Hour, go to https://www.myearthhour.org/.

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

Thursday, March 11, 2010

The Ellensburg sky for the week of 3/13/10

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: Mars is six and a half fists above the south horizon at 10 p.m.

Monday: 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.

Tuesday: Venus is about as half a fist to the left of the young crescent Moon at 8 p.m. They are both less than a half a fist above the west horizon.

Wednesday: 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, three 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 bends the sunlight, daytime on the first day of spring would still be longer than 12 hours.

Thursday: So far this week, I have written about Mars and Venus. Do you even care about these planets or does another planet really catch your fancy? If you’d like to know what most people’s favorite planet is, go to http://www.pbs.org/wgbh/nova/pluto/favorite.html and click on “Launch Interactive”. The public TV special called “The Pluto Files” has set up a website in which astronomers give a 30-second pitch for why a certain planet might be their favorite. After listening to the pitch, you may vote for your favorite planet. Of course, you may also do what most people do for political elections: vote for the candidate with the best name or the one with the most interesting campaign slogan. So whether you carefully consider each planet or simply “Swoon for Neptune”, go to “The Pluto Files” and vote. Saturn will be holding a campaign rally tonight at 11 p.m., three and a half fists above the southeast horizon.

Friday: The bright star Arcturus is three fists above due east at 11 p.m.

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

Tuesday, March 2, 2010

The Ellensburg sky for the week of 3/6/10

Saturday: “The crow rises in the southeast” said spy number one. “I’m sorry. I don’t recognize that code” replied spy number two. Spy one exclaimed, “That’s because it’s not a code, you idiot. I’m talking about the constellation Corvus the crow.” This very bad spy movie dialogue is to remind you that Corvus had a very bad life. According to one myth, Corvus brought the god Apollo the news that his girlfriend was seeing someone else. In a classic case of punishing the messenger, Apollo turned the formerly beautifully colored crow black. The box-shaped Corvus is one fist held upright and at arm’s length above the southeast horizon at 10 p.m.

Sunday: This morning’s last quarter Moon is in the constellation Ophiuchus the serpent bearer. At 6 a.m., the bright star Antares is about a half a fist to the right of the Moon.

Monday: 2009 was the International Year of Astronomy. Even though 2009 was over, astronomy lives on in the “Hot Topic” of the month. For March, the hot topic is observing at night… and in the day. Technology has expanded the amount of information astronomers can learn from observing the sky. Up until the mid 1900s, we studied the sky using a very narrow portion of the electromagnetic spectrum – visible light waves. It was like studying music by listening only to notes of medium pitch. The invention of the radio telescope opened up a new source of information, long wavelength radiation. It also opened a new time to observe the sky – the day time. Radio waves from outer space are not blocked by the sunlit sky like visible light from outer space is. Since then, astronomers have started gathering gamma ray, x-ray, ultraviolet, infrared, and microwave radiation. Finally, the entire symphony rather than a few notes. But technology has also negatively impacted our view of the nighttime sky through light pollution. The dim light of a distant galaxy is facing more and more competition from businesses that use inefficient lighting that lights the sky as much as it lights the ground. Many communities, including Ellensburg, have passed or are working on ordinances to reduce this costly and sky-robbing stray lighting. Go to http://astronomy2009.nasa.gov/topics_mar.htm for more information about the March “Hot Topic”.

Tuesday: Saturn is three fists above the southeast horizon at 10 a.m.

Wednesday: Venus is a half a fist above the west horizon at 6:30 p.m.

Thursday: How many of you will be stationary at 1 a.m. this morning? You. And you. And Mars, too. The Earth is closer to the Sun than Mars is. Thus, the Earth moves faster in its orbit around the Sun. About once every year and a half, the Earth passes Mars as Mars lollygags in its orbit. As the Earth passes Mars, Mars appears to move backwards in the sky. You notice a similar occurrence while driving. When you pass a car, it appears to be moving backwards with respect to you. On a nearly circular “track” like the solar system, as a fast inner planet passes a slow outer planet, the outer planet appears to move backward, or westward, with respect to the background stars. Once the Earth has passed Mars by a sufficient amount, after about two months, Mars starts moving forward, or eastward, again. When something goes from moving backward to moving forward, it is stationary for a moment. That moment for Mars comes at 1 a.m. today. This backward motion with respect to the stars is called retrograde motion. If you are stationary and looking up at the sky at this time, Mars is three and a half fists above the west horizon.

Friday: Sunspot activity on the Sun is starting to increase. On the Sun-like star Corot-2a, there is always a lot of sunspot activity. Amazing as it may seem, astronomers can measure sunspot activity on stars that are dozens of light years away. They do so by measuring how much the Corot-2a’s light dips when the close-in planet Corot-2b passes in front of it. Sunspots are relatively cool and dark portions of a star. When the planet passes in front of a region of high sunspot activity, Corot-2a’s light dims less because the planet is blocking a relatively dark portion of the star.

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