Friday, July 10, 2020

The Ellensburg, WA sky for the week of July 11, 2020


Saturday:  Over the past few months, we have been teased with stories of possible naked eye comets. Or, at least binocular comets. But none have panned out until now. Comet NEOWISE (C/2020 F3) survived its closest approach to the Sun and is moving towards its closest approach to Earth on July 23. This week, the best time to see the comet is about an hour before sunrise. Tomorrow morning, it will be one fist held upright and at arm’s length above the north-northeastern horizon at 4:00 a.m. First find Capella, the bright star about two and a half fists above due northeast. Then, move your gaze about one fist to the lower left to the next bright star, about one fifth as bright as Capella. Finally move your gaze about one fist to the lower left again. That is where Comet NEOWISE is located. You’ll likely need binoculars to find it. By the end of the week and through the rest of the summer, the better viewing will be in the evening. For an added challenge this week, try to spot the comet at both dawn and dusk. For more information about the comet and maps on how to find it, go to https://skyandtelescope.org/astronomy-news/comet-neowise-delights-at-dawn/

Sunday: Star light. Star bright. The first star you see tonight might be Arcturus, six fists above the southwestern horizon right after sunset.

Monday: Mars rises just after midnight. By 4:00 a.m., it is three and a half fists above due southeast.

Tuesday: Five years ago today, NASA’s New Horizons probe passed 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/. Pluto, itself, is about one fist above the southeastern horizon, and just to the lower left of the much brighter Jupiter, at 10:30 p.m. Saturn is farther to the lower left of Jupiter.
Hey, wait, I’ve got a new complaint. People should be more interested in astronomy. The best group to start with is children. If you are stuck at home, wondering what to do (Hmm, who could that be?), go to the NASA Kids Club website at https://www.nasa.gov/kidsclub/. There are fun and educational activities for younger children. Older children may like my favorite NASA website about planets outside our Solar System. I suggest first exploring the “Galaxy of Horrors!” at https://exoplanets.nasa.gov/alien-worlds/galaxy-of-horrors/

Wednesday: Earlier in the week, you used Capella to find Comet NEOWISE. 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 10:00 p.m., Capella is a half a fist above the northern 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 a 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’t “cap” 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: For the next two mornings, the Moon, Venus, and the bright star Aldebaran will make a skinny triangle about a fist above the eastern horizon at 4:00 a.m. Aldebaran is about two finger widths to the right of Venus, the brightest point of light in the sky. This morning, the waning crescent Moon is to the upper right of the two. By tomorrow morning, the Moon will have moved to the left of Venus.

Friday: Say "Cheese". 170 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 night time star we can see in Ellensburg, behind Sirius and Arcturus. Vega is nearly straight overhead at 11:00 tonight. 

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 3, 2020

The Ellensburg, WA sky for the week of July 4, 2020

Saturday: Tonight’s Full Moon is in the constellation Sagittarius. The good news: there

is a penumbral lunar eclipse. The bad news: a penumbral lunar eclipse is where the Moon is in the Earth’s partial shadow and is barely noticeable. But if you want to check “penumbral lunar eclipse” off of your astronomy bingo card, look at the Moon for the 90 minutes after sunset. By 4:00 a.m. tomorrow, the Moon, Jupiter, and Saturn make a two-fist long line going diagonally up from due southwest.


Sunday: Did you see the Moon-Jupiter-Saturn neighborly meeting at 4:00 am this morning? What!? You weren’t up then. That’s okay. They form a small triangle throughout the entire night. They are just above the southeastern horizon at 10:00 p.m., with Saturn to the upper left of the Moon and bright Jupiter to the upper right of the Moon. Follow them throughout the night until they set right after sunrise tomorrow morning.


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 wait for a VERY long time, Eltanin will be the brightest star in the entire 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 the brightest star.


Tuesday: Mars rises a little after midnight. By 1:00 a.m., Mars is a half a fist held upright and at arm’s length above the eastern horizon.


Wednesday: This morning, Venus is at its brightest for this orbital cycle, magnitude -4.5. The magnitude scale is somewhat counterintuitive: the brighter the object appears in the sky, the smaller the magnitude number. Magnitude values are defined so that a magnitude difference of 5 corresponds to a brightness ratio of 100. This morning, Venus is about a thumb width above Aldebaran, a star of magnitude 1.0. Venus appears more than 100 times brighter than Aldebaran because it has a magnitude 5.5 more than Aldebaran. Venus and Aldebaran are a little more than a fist above the eastern horizon at 4:30 a.m.


Thursday: 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 three fists above the western horizon at 11:00 p.m.


Friday: 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 outsmarted. Mizar doesn’t play as big a role in its episode. It is the star of the homeworld of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and five and a half fists above the west-southwestern horizon at 11:00 p.m. Mizar is five and a half fists above the northwest horizon at this time.


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
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Thursday, June 25, 2020

The Ellesnbrug, WA sky for the week of June 27, 2020


Saturday:  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 Pleiades 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 and a half fists held upright and at arm’s length above the eastern horizon at 11:00 p.m. Two fists above Vega, and close to straight overhead, is a keystone shape. Aim your binoculars at the upper left hand star of the keystone, the star closest to straight overhead. 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”.

Sunday: Six 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: Jupiter and Saturn are less than a fist above the southeastern horizon at 11:00 p.m. They are a little more than a half a fist apart. Jupiter is the brighter of the two.

Tuesday: 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.

Wednesday: Speaking of bright planets, Venus, the brightest of the planets as seen from Earth, is one fist above the east-northeastern horizon at 4:30 a.m. The bright star Aldebaran is about a half a fist below it. By this time, Mars is more than three fists above the southeastern horizon.

Thursday: You’ve seen all of the top 100 lists: top 100 ways to use Duct Tape, top 100 Somali restaurants in Washington, etc. Now get excited for this weekend’s full Moon by reading about and finding some of the lunar 100 at http://goo.gl/ldGvH6 This list describes 100 interesting landmarks on the Moon that are visible from Earth. They are listed from easiest to see, starting with the entire moon itself at number 1, to most difficult (Mare Marginis swirls, anyone?). Stay up all night to binge watch the moon or just make a few observations a month. It’s your decision. It’s our moon. Start your viewing tonight at 10:00 p.m. when the Moon is two fists held upright and at arm’s length above the southern horizon and one fist above the bright reddish star Antares. I suggest starting with Mare Crisium, the circular, dark, basaltic plain in the upper right-hand portion of the moon. Items such as Crisium were named "Mare" by early astronomers who mistook them for seas, instead of the hardened lava beds that they really are. 

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 the Sun is its greatest tomorrow, 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