Thursday, March 24, 2011

The Ellensburg sky for the week of 3/26/11

Saturday: Say good bye to Jupiter. It is just above the west horizon at 7:45 p.m. You may need binoculars to find it hiding in the glare of the setting Sun. Over the next few weeks, Jupiter will move behind the Sun and show up in the early morning sky.

Sunday: Venus, the brightest planet, is a half a fist held upright and at arm's length above the southeast horizon at 6:15 a.m. Neptune, the dimmest planet, is just to the upper right of Venus. But, you'll need binoculars to find it. When Venus is at the center of your field of view, Neptune will be the dim point of light at the 2 o'clock position.

Monday: Mercury and its human-made moon are one fist above the west horizon at 8 p.m. The "moon", also known as MESSENGER or MErcury Surface, Space ENvironment, GEochemistry, and Ranging, orbits Mercury once every 12 hours, getting as close as 124 miles from the surface of the planet. For comparison, the International Space Station orbits about 200 miles above the Earth's surface. For more information about the MESSENGER mission, go to

Tuesday: Leo the lion prowls the sky in the late winter and early spring. Regulus, the brightest star in the constellation, is five fists above the southeast horizon at 9 p.m.

Wednesday: So far this week, I have written about Mercury, Venus, Jupiter, and Neptune. Do you even care about these planets or does another planet really catch your fancy? If you’d like to learn what certain people’s favorite planet is, go to 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's merits or simply “Pick Uranus”, go to “The Pluto Files” and vote. Saturn will be holding a campaign rally tonight at 11 p.m., two fists above the southeast horizon.

Thursday: Venus is about a half a fist to the lower right of the Moon in the eastern sky at 6 a.m.

Friday: 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. Last year, after analyzing photos taken by the Mars Phoenix Lander, a group of astronomers discovered what they interpreted as drops of very salty liquid water on one of the Lander’s legs. But we are not going to travel 18 months to Mars just to lick a few drops of water off a metal leg. We want waterfront property if we are going all that way. The high resolution camera aboard the Mars Reconnaissance Orbiter has taken images of dark rivulets form, grow, and fade in the Martian southern hemisphere. Even though Mars is very cold, this liquid could contain enough salt to lower its freezing point by more than 100 degrees Fahrenheit. Mars and that refreshing water rises due east just before the Sun. For more information about liquid water on Mars, go to

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

Tuesday, March 8, 2011

The Ellensburg sky for the week of 3/12/11

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 will lose even more sleep because the sky does not get dark for an additional hour.

Sunday: Jupiter, the largest planet in the Solar System, is a half a fist above the west horizon at 8 p.m. Mercury, the smallest planet in the Solar System, is a couple finger widths to the lower right of Jupiter.

Monday: The Moon is midway between the twin stars in Gemini and the little Dog Star. Procyon, the brightest star in the constellation Canis Minor, or the lesser dog, is one and a half fists below the Moon. Pollux and Castor are about a fist above the Moon. All of these objects are in the southern sky at 9 p.m.

Tuesday: Vega is a little more than a half a fist above the northeast horizon at 11:30 p.m.

Wednesday: This Saturday is Earth Sun day. For more information, go to

Thursday: Mercury is the naked eye planet we know the least about. That may soon change because NASA’s Messenger probe is scheduled to start orbiting Mercury today. It will be the first visitor to the planet one Messenger scientist called the most under-appreciated planet since 1974. The number one question scientists hope to answer is why Mercury has such a large iron core compared to its size. The number one question you may be asking is “Why is Mercury in a different location with respect to Jupiter since Sunday?”. It is now about a finger width to the upper right of Jupiter. Since mercury is so close to the Sun, it moves very fast in its orbit so it changes positions in the sky much faster than an outer planet such as Jupiter.

Friday: 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, two 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 actually below the horizon. This makes the Sun appear to rise before it actually rises and appear 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.

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

Tuesday, March 1, 2011

The Ellensburg sky for the week of 3/5/11

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: Jupiter is about a half a fist to the lower left of the Moon at 7 p.m. Enjoy Jupiter while you can because it is moving toward the Sun in the evening sky. Within a couple of weeks, it will be lost in the glare of the setting Sun.

Monday: 2009 was the International Year of Astronomy. Even though 2009 is long gone, 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. For the past 50 years, astronomers have started gathering gamma ray, x-ray, ultraviolet, infrared, and microwave radiation. Finally, the entire symphony of wavelengths rather than just 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 for more information about the March “Hot Topic”.

Tuesday: Some people dream of moving into a high-rise. Craters on Mars dream of being photographed by HiRISE, the High-Resolution Imaging Science Experiment, the largest telescope ever flown to another planet. It can see details down to one foot across. But, it didn't need much resolution on January 10 when it snapped a picture of twin craters, each about one mile across, connected on their side. The object that made the craters probably broke into two nearly equal sized objects in the thin Martian atmosphere and hit the ground at nearly the same time. For more information, go to

Wednesday: In this busy world, it is important to know what time it is. We have many devises that give us the time. Our phone, a computer, a watch. But who has time to build a phone, computer or evan a watch. Not you. But everyone has enough time to build a simple Sun Clock. All you need is a pencil, a compass and a print out of the clock template. Go to for more information.

Thursday: Seven sisters are hanging out with the Moon tonight. The open star cluster known as the Pleiades, or the Seven Sisters, is less than a half a fist above the Moon at 7 p.m. Since the Moon is so much brighter than the stars in the cluster, it will be very difficult to see the sisters with the naked eye. Instead, aim your binoculars so the Moon is just below your field of view. The Pleiades will be near or below the middle of your field of view.

Friday: Saturn is three fists above the southeast horizon at 11 p.m. The bright star Spica is below it. Note the difference in the colors of the two objects. Saturn is a yellowish-orange color because of the material in its atmosphere. Spica is a whiteish-blue color because it is glowing like an extra hot light bulb filament. Star color os related to the temperature of the star. Red stars have smaller energy level transitions so they are cool. Blue and whiteish-blue stars have larger energy level transitions so they are hot.

Wait a minute. We got all the way to the end of the week with no Moon phase summary? How can that be? There are 29.5 days between the same Moon phase in two different cycles. That means about 7.5 days between the phases new, first quarter, full and last quarter. Since a week is seven days, there are some weeks in which none of the main phases occur. This week, the Moon was always in the waxing crescent phase.

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