Tuesday, July 10, 2018

The Ellensburg sky for the week of 7/14/18

Saturday: The Moon starts its night sky Solar System tour tonight. It is less than a half a fist held upright and at arm's length above Mercury, low in the west-northwest sky at 9:30 p.m. 

Sunday: Fresh off of a successful appearance with the innermost planet, the Moon passes over Venus in the sky tonight. You'll barely be able to fit a finger between Venus and the Moon at 9:30 p.m., low in the western sky. 

Monday: At 11:45 p.m., Saturn is almost exactly two fists above due south and Mars is one fist above the south-southeast horizon. 

Tuesday: Say "Cheese". 167 years ago today, Vega, in the constellation Lyra the lyre, became the first star ever photographed. The photograph was taken at the Harvard Observatory using the daguerreotype process. Vega is the third brightest nighttime star we can see in Ellensburg, behind Sirius and Arcturus. Vega is nearly straight overhead at 11:00 tonight.  

Wednesday: What you see with the naked eye isn’t all that can be seen. While astronomers can learn a lot from observing the sky in the visible wavelengths, many celestial objects radiate more light, and more information, in wavelengths such as radio, microwave, infrared, ultraviolet, x-ray, and gamma ray. In 2012, NASA launched the Wide-field Infrared Survey Explorer (WISE) to study objects that radiate in the infrared range such as asteroids, cool dim stars, and luminous galaxies. For an interesting comparison of how different wavelengths show different aspects of celestial objects, go to http://goo.gl/nvuax. For example, if it weren’t for infrared telescopes such as WISE, astronomers would not know about the significant amount of dust in galaxies.  

Thursday: Last week marked the three-year anniversary of NASA’s New Horizons probe passing by Pluto. If the band Nirvana was still together, they’d probably rewrite one of their hit songs to be called Heart-Shaped Spot, after one of Pluto’s most distinctive features. “She eyes me like a dwarf planet when I am weak. I’ve been imaging your heart-shaped spot for weeks.” Astronomers think this heart-shaped spot is a large plain of nitrogen ice that consists of convective cells 10-30 miles across. Solid nitrogen is warmed in the interior of Pluto, becomes buoyant, and bubbles up to the surface like a lava lamp. You will find great pictures and information about what New Horizons found this past year at http://pluto.jhuapl.edu/. Hey, wait, I’ve got a new complaint. People should be more interested in astronomy. 

Friday: Take a two and a half hour walk. Too long, you say? Forty-nine years ago today, Neil Armstrong and Buzz Aldrin took the first ever walk by humans on another world. They spend two and a half hours setting up scientific instruments and collecting rocks for study back on Earth. Michael Collins orbited the Moon in the spacecraft the astronauts would use to return to Earth. The Moon is celebrating this event with Jupiter tonight. They are about two fists above the southwest horizon at 10 p.m. with Jupiter being less than a half a fist below the Moon. 

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.  

Friday, July 6, 2018

The Ellensburg WA sky for the week of 7/7/18


Saturday: The CWU Physics Department and the College of the Sciences is hosting its first Saturday planetarium show today from noon to 1 pm. CWU physics professor Tony Smith will give a show called Space: The Fun and the Fiction. Have Scotty beam you aboard and come to the presentation. There will be a show at noon on the first Saturday of every month hosted by different CWU astronomers and astronomy educators. These shows are free and open to all ages. The planetarium is room 101 in Science Phase II, just off the corner of 11th and Wildcat Way, H-11 on the campus map found at https://www.cwu.edu/facility/campus-map.

Sunday: Venus is within a fingerwidth of the bright star Regulus for the next few days. They are about one and a half fists held upright and at arm’s length above due west at 9:30 p.m. Venus is the brighter of the two. Mercury is lower, about a half a fist above the west-northwest horizon at this time.

Monday: Look straight up at midnight. The head of Draco the dragon will be looking straight down on you. The brightest star in the head is called Eltanin. If you chose to wait a VERY long time, Eltanin will be the brightest star in the night sky. Currently 154 light years away, it is moving towards Earth and will be only 28 light years away in about 1.3 million years, claiming the title as brightest star.

Tuesday: Being in a coma is a bad thing. Looking at the Coma Star Cluster is a good thing. The Coma Star Cluster is an open cluster of about 50 stars that takes up more space in the sky than 10 full Moons. It looks like a fuzzy patch with the naked eye. Binoculars reveal dozens of sparkling stars. A telescope actually diminishes from the spectacle because the cluster is so big and the telescope’s field of view is so small. The Coma Star Cluster is in the faint constellation Coma Berenices (ba-ron-ice’-ez) or Queen Berenice’s hair. Queen Berenice of Egypt cut off her beautiful hair as a sacrifice to the gods for the safe return of her husband Ptolemy III from battle. The Coma Star Cluster is about four fists held upright and at arm’s length above the west horizon at 11:00 p.m

Wednesday: It is Wednesday so you want to go to bed early fo focus on the early evening (for summer, anyway) planets. At 10 p.m., Jupiter is two and a half fists above the southwest horizon. It is the brightest point of light in its part of the sky. Saturn is about five fists to the left of Jupiter, about one and a half fists above the southeast horizon. The star Antares is halfway between the two in the night sky.

Thursday: Mizar is a star in the middle of the Big Dipper handle. Don’t confuse Mizar with its rhyming brother Izar in the constellation Bootes. Izar is also a binary star with about the same apparent brightness. And both were featured in different episodes of Star Trek. Izar was featured in the Star Trek episode “Whom Gods Destroy” from the original series. It is the base of Fleet Captain Garth, a former big shot in the federation and one of Kirk’s heroes before he went insane. Garth kidnaps Kirk and Spock before eventually being out smarted. Mizar doesn’t play as big a role in its episode. It is the star of the home world of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and seven fists above the south horizon at 10 p.m. Mizar is seven fists above the northwest horizon at this time.

Friday: It is Friday so you don’t mind staying up late. Mars is one fist above the southeast horizon at midnight.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.

Thursday, June 28, 2018

The Ellensburg WA sky for the week of 6/30/18


Saturday:  Happy Asteroid Day (http://www.asteroidday.org/), the day we celebrate avoiding the destruction of the Earth by an undiscovered asteroid. There are a million asteroids in the Solar System with the potential to strike Earth and destroy a city. Astronomers have discovered only 1% of them. Asteroid Day is an effort to educate the public and encourage policy makers to fund this important effort. King Tut may have celebrated an ancient Asteroid Day by asking his assistants to make a dagger out of a broken-off asteroid that landed on Earth. Astronomers discovered that the blade of the knife contained much more nickel than is found in terrestrial iron, an amount consistent with iron meteorites, especially with one found in the year 2000 in the Kharga region in northern Egypt. For more information about the dagger, go to http://goo.gl/BHBivd.

Sunday: Celebrate Asteroid Day with Vesta, the brightest asteroid as seen from Earth. First, find Saturn, about two fists above the south-southeast horizon. Get Saturn on the left hand side of your binocular field of view. There should be a large, fuzzy object on the right half of your field of view. That’s the Lagoon Nebula. (More about that next week.) Move the Lagoon Nebula to the lower left part of your field of view. Then, move your binoculars up and to the right. You will come to a triangle with three stars at its base and one point of light at its peak. This point of light is Vesta. Follow what you think is Vesta over the next few nights. If it moves slightly from night to night, it is Vesta.

Monday: This is a good time of the year to find the Big Dipper. The handle is nearly straight overhead at sunset. The cup is in the northwest sky. You can always use the Big Dipper to find some other bright stars. First, follow the curve, or arc, of the Big Dipper down three fists into the southern sky. This is the bright star, Arcturus, the second brightest nighttime star we can see in Ellensburg. Next, continue on a straight line, or spike, another three fists down toward the south horizon to the star Spica. Spica is the tenth brightest nighttime star we can see in Ellensburg. It is known as the Horn Mansion, one of 28 mansions, or constellations, in the Chinese sky. You now know how to use the Big Dipper handle to “arc” to Arcturus and “spike” to Spica.

Tuesday: At 9:30 p.m., Mercury is nearly one fist above the west-northwest horizon, Venus is one and a half fists above the west horizon, Jupiter is two and a half fists above the south horizon, and Saturn is one fist above the southeast horizon. What about Mars, you say? Wait a couple of hours. Then Mars is a half a fist above the southeast horizon.

Wednesday: When it is sitting low in the western sky, many people mistake the star Capella for a planet. It is bright. It has a slight yellow color. But, Capella is compelling on its own, even though it is “just” a star. It is the fourth brightest star we can see in Ellensburg. It is the most northerly bright star. It is a binary star consisting of two yellow giant stars that orbit each other every 100 days. At 10 p.m., Capella is a half a fist above the north-northwest horizon. You can also use the Big Dipper to find it.  First, find the two “cap” stars on the cup of the Big Dipper, the stars on the top of the cup. Draw line from the “cap” star closest to the handle to the cap star farthest from the handle. Then, continue that line to the next very bright star, which is Capella. Thus, you can “cap” to Capella. If you can’ it tonight, don’t worry. Capella is the brightest circumpolar star meaning it is the brightest star that never goes below the horizon from our point of view in Ellensburg.

Thursday: This Saturday, the CWU Physics Department and the College of the Sciences is hosting its First Saturday planetarium show from noon to 1 pm. CWU physics professor Tony Smith will give a show called Space: The Fun and the Fiction. Hurry up and make the Kessel Run in twelve parsecs so you can come to the presentation. There will be a show at noon on the first Saturday of every month hosted by different CWU astronomers and astronomy educators. These shows are free and open to all ages. The planetarium is room 101 in Science Phase II, just off the corner of 11th and Wildcat Way, H-11 on the campus map found at https://www.cwu.edu/facility/campus-map.

Friday: Hot enough for you? Don’t blame the Earth-Sun distance. Surprisingly, the overall temperature of the Earth is slightly higher in July, when the Earth is farthest from the Sun, than in January, when it is closest. That’s because in July, the Northern Hemisphere is tilted towards the Sun. (This is the real cause of the seasons.) The Northern Hemisphere has more land than the Southern Hemisphere. Thus, in July, the large amount of Northern Hemisphere land heats up the entire Earth about two degrees Celsius warmer than in January. In January, the watery Southern Hemisphere is tilted toward the Sun. But, water does not heat up as fast as land so the Earth is a few degrees cooler. The distance between the Earth and Sun is its greatest today, 152.1 million kilometers. This is called aphelion from the Greek prefix “apo” meaning “apart” and Helios, the Greek god of the Sun.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.

Thursday, June 21, 2018

The Ellensburg WA sky for the week of 6/23/18

Saturday:  Jupiter is about a half a fist to the lower right of the Moon at 10 p.m. tonight. More interesting is that "star" you've noticed below Jupiter for the past few weeks. Now it is about a thumb thickness to the lower left of Jupiter. That star is Zubenelgenubi, the second brightest star in the constellation Libra. The name means "southern claw", a holdover from the time when this part of the sky was associated with the neighboring constellation of Scorpius the scorpion. Notice that the word "star" was in quotes earlier. That's because Zubenelgenubi is a binary star system, easily seen with binoculars as a white and yellow pair. To a person living on a planet orbiting the dimmer of the two stars, the brighter star would be nearly as bright as the full Moon appears from Earth. 

Sunday: “Mom, I can’t sleep. It is too light out!” A poor excuse you say? Good astronomy skills, I say. The latest sunset of the year happens this week. Surprisingly, the earliest sunrise and the latest sunset do not both happen on the longest day of the year, the day of the summer solstice. The earliest sunrise occurs just before the longest day and the latest sunset occurs just after the longest day. This phenomenon relates to the angle of the Sun’s path near rising and setting. In Ellensburg, that angle is about 66 degrees near the first day of summer. Because of the Earth’s orbit, which causes the Sun’s apparent motion, the angles are not symmetric. The asymmetries in orbital angles leads to the asymmetry in rise and set times. By the way, picking a specific night to give you the “can’t sleep because it is too light out” line may just be an excuse because the sunset times change by only a few seconds each day in June. This year, the sun sets between 9:01 and 9:02 p.m. between June 22 and June 29. 

Monday: Venus is one and a half fists and Mercury is a half a fist above the west-northwest horizon at 9:45 p.m. 

Tuesday: Saturn is in opposition tonight. That doesn’t mean that Saturn is in the minority party. 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 two fists above due south at 1 a.m. It is about one fist above the southeast horizon at 10 p.m. Careful readers of this column must struggle through bad jokes and sentences that... that... ah... ain't too good. But they also may recall that Saturn was in opposition on nearly the same date last year: June 14. An outer planet is in opposition when the Earth passes it up as both orbit the Sun. The farther out a planet is, the less it has moved along its orbit, and the closer it is to exactly one year from one Earth passing to the next. For comparison, it is about 18 months between successive oppositions for Mars. 

Wednesday: Don’t wait until a week from today to go to those wimpy firecracker shows. Find the hypergiant star Rho Cassiopeiae. Astronomers think that Rho Cassiopeiae will likely go supernova (explode) in the near future. Of course, for stars, near future might mean today. It might mean 20,000 years from now. Rho Cassiopeiae is in the constellation Cassiopeia the queen. At 11:00 tonight, Cassiopeia looks like the letter “W” about three fists held upright and at arm’s length above the northeast horizon. Rho Cassiopeiae is about a finger’s width to the right of the rightmost star in the “W”. Once you find it you’ll be thinking, “Big deal, I can hardly see it.” Although it is barely visible to the naked eye, it is actually very bright. It is the 20th most luminous star in the sky, a whopping 550,000 times more luminous than the Sun. 

Thursday: Mars is a half a fist above the southeast horizon at midnight. 

Friday: Star light. Star bright. The first star you see tonight might be Arcturus, six fists above the south horizon right after sunset. You’ll be able to see Jupiter and Venus earlier. But those won’t help your wish to come true. 

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm 

Thursday, June 14, 2018

The Ellensburg WA sky for the week of 6/16/18

 Saturday: Tomorrow is Father’s Day, the day to celebrate the person who made you a father. No, not her. You celebrated her last month. (You didn’t forget, did you?!) Celebrate your child by getting her/him the book “Woman in Science” by Rachel Ignotofsky (http://www.readwomeninscience.com/). This creatively drawn book highlights the contributions of 50 pioneers of science from Hypatia to Katherine Johnson, the main character in the recent movie “Hidden Figures”. 

Sunday: Two years ago astronomers using a radio telescope in Australia discovered the source of fleeting radio signal bursts that had been a mystery for 17 years. And they didn’t have to probe the depths of deep space. They only had to probe the depths of… the observatory kitchen. It turns out the signal came from opening the microwave door prematurely. Read more about The Microwave Emission here: http://goo.gl/Ftb04C. Sheldon Cooper used similar methods of science when he discovered a can opener instead of magnetic monopoles in the season three premiere of “The Big Bang Theory” http://goo.gl/kAEoOD. 

Monday: Summer is nearly here. How do I know? Because the days are very long. Because the temperature is rising. Because kids are getting out of school. Also, because the Summer Triangle is fairly high in the eastern sky at 11 p.m. Vega, the third brightest star visible from Ellensburg, is about five fists held upright and at arms length above the east horizon. Deneb, at the tail of Cygnus the swan is about three and a half fists above the northeast horizon. The third star in the triangle, Altair, in Aquila the eagle is two fists above the east horizon. 
If you want to put somebody off, tell her or him to wait until Deneb sets. At Ellensburg’s latitude of 47 degrees, Deneb is a circumpolar star meaning it never goes below the horizon. 

Tuesday: Venus is near the Beehive Cluster for the next two nights. This cluster, one of the closest to Earth, consists of about 350 stars, about 50 of which can be seen with binoculars on a dark night. Venus is about one fist above the west-northwest horizon at 10 p.m. In other sky news, Jupiter is three fists above due south at this time. 

Wednesday: Nearly 400 years ago, Galileo viewed the Pleiades star cluster through his telescope and saw that the seven or so stars in the region visible to the naked eye became many more. There are two main types of star clusters. Open star clusters, like the Pleaides and the Beehive, are groups of a few dozen to a few thousand stars that formed from the same cloud of gas and dust within our galaxy. Stars in open star clusters are young as far as stars go. Globular clusters are groups of up to a few million stars that orbit the core of spiral galaxies such as our own Milky Way. One of the most well known star clusters is the globular cluster in Hercules, an object that is fairly easy to find with binoculars. First find Vega, the bright bluish star five fists above the east horizon at 11 p.m. Two fists above Vega is a keystone shape. Aim your binoculars at the upper left hand star of the keystone. The globular cluster is one third of the way to the rightmost star of the keystone. It looks like a fuzzy patch on the obtuse angle of a small obtuse triangle. If you don’t know what an obtuse angle is, you should not have told your teacher, “I’ll never need to know this stuff”. 

Thursday: Early this morning, the summer solstice occurs. This is when the Sun reaches its highest declination (the official name for sky latitude) of 23.5 degrees above the celestial equator. The celestial equator is the line that divides the northern sky from the southern sky. In Ellensburg, the Sun is about seven fists held upright and at arm’s length above the south horizon at 1:00 p.m. (noon standard time). Contrary to popular belief, the Sun is never straight overhead in Ellensburg or anywhere else in the 48 contiguous states. The northernmost portion of the world where the Sun can be directly overhead is 23.5 degrees north latitude. In ancient times, the Sun was in the constellation Cancer the crab on the first day of summer. Hence, 23.5 degrees north latitude has the nickname "Tropic of Cancer". Because the Earth wobbles like a spinning top, the Sun's apparent path through the sky changes slightly over time. Now, the Sun is in the constellation Taurus the bull on the first day of summer. However, citing the high cost of revising all of the science books, geographers are not changing the name of 23.5 degrees north latitude to "Tropic of Taurus". The first day of summer is often called the summer solstice. However, astronomers refer to the summer solstice as the point in the sky in which the Sun is at its highest point above the celestial equator. Thus, summer starts when the Sun is at the summer solstice point. This year, that happens at 3:07 a.m. Pacific Daylight Time. 

Friday: At midnight, Saturn is two fists above the south-southeast horizon and Mars is a half a fist above the southeast horizon. 

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.