The Ellensburg, WA sky for the week of May 29, 2021

Saturday: Stonehenge was created on the island of Great Britain by Neolithic people. “Manhattanhenge” was created on the island of Manhattan by modern day architects and construction workers. Twice a year, the end of May and mid-July, the setting Sun aligns perfectly with the Manhattan grid pattern. That means observers will see the Sun set at the end of the street. The first Manhattanhenge sunset is tonight at 8:13 p.m. Eastern time and then again tomorrow at 8:12 p.m. Eastern time. For more information about Manhattanhenge, go to http://tiny.cc/cd7ytz. 

Sunday: Venus is a little more than a half a fist held upright and at arm's length above the west-northwestern horizon at 9:15 p.m. Because it is the bright point of light in the sky, it should be fairly easy to find. Mercury will be more challenging. It is about two finger-widths to the lower right of Venus, almost exactly a half a fist above the horizon. But it is more than 100 times dimmer than Venus, in the waxing crescent phase. 

Monday:  The questions who, what, where, and when can only be asked with a “W”. At 10:00 p.m., the W-shaped constellation Cassiopeia is two fists above the north-northeastern horizon. The middle star in the W was used as a navigation reference point during the early space missions. The American astronaut Gus Grissom nicknamed the star Navi, his middle name Ivan spelled backwards. After he died in the Apollo 1 fire, the star name was kept as a memorial.

Tuesday: The month of June is named after Juno, the queen of the Roman gods and the mythological protector of the Roman state. In ancient Rome, the month began when the crescent moon was first seen in the evening sky from Capitoline Hill in Rome. If we still started months this way, June would start on a different day each year. This year, the month would start in about a week and a half after the next New Moon. This morning, the Moon is in the waning gibbous phase, two fists above the southeastern horizon at 4:30 a.m. Juno’s husband, Jupiter, is a half a fist above the Moon at this time.

Wednesday: Cygnus the swan flies tonight. Deneb, the brightest star in the constellation, whose name means “tail” in Arabic, is about two and a half fists above the northeastern horizon at 10:00 p.m. Cygnus’ wings make a vertical line one half a fist to the right of Deneb. Its head, marked by the star Albireo, is two fists to the right of Deneb. While Deneb is at the tail of Cygnus, it is at the head of the line of bright stars. It is 160,000 times more luminous than the Sun making it one of the brightest stars in the galaxy. It does not dominate our night sky because it is 2,600 light years away, one of the farthest naked eye stars. If Deneb were 25 light years away, it would shine as bright as a crescent moon. Compare that to Vega, its fellow Summer Triangle star. Vega IS 25 light years away and certainly doesn’t rival the light of the crescent Moon. See for yourself by looking nearly four fists above the east-northeastern horizon at 10:00 p.m.

Thursday: Altair, the lowest star in the Summer Triangle, is one fist above due east at 10:15 p.m.

Friday: As the weather warms up, people start thinking about swimming in a nice cool body of water. Recently, astronomers have discovered evidence of an ocean about 20 miles beneath the surface of Saturn’s moon Enceladus. NASA’s Cassini probes measured variations in how the moon’s gravity pulled on the orbiting spacecraft. These variations can be explained by a large amount of liquid water under one section of the ice because liquid water is denser than an equal volume of ice. While you need a very large telescope to see Enceladus, you can easily see Saturn a half a fist above the southeast horizon at 1:00 a.m. They are both two and a half fists above the southern horizon at 4:30 a.m.

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.

The Ellensburg, WA sky for the week of May 22, 2021

Saturday: In 1979, the group Foreigner recorded the song “Head Games”. They could have been singing about the constellations Hercules and Ophiuchus when they said “head games, it’s just you and me baby, head games, I can’t take it anymore” because the heads of these two constellations have been right next to each other in the nighttime sky for all of human history. And just to make it easy for you, a star that bears an Arabic name that means “the head” represents each head. In Hercules, it's Ras Algethi (head of the kneeler); in Ophiuchus, Ras Alhague (head of the serpent charmer). At 11:00 p.m., Ras Alhague, the brighter of the two, is nearly three and a half fists held  above the east-southeastern horizon. Ras Algethi is about a half a fist to the upper right of Ras Alhague.

Sunday: Antares is a half a fist above the southeastern horizon at 10:00 p.m.

Monday: In 1982, the British group Bow Wow Wow first sang, “I Want Candy”. In May 2019, NASA finally granted that wish by releasing images of Mars’ moon Phobos looking like candy.  The thermal imaging camera on NASA’s long lived Odyssey orbiter took a series of images of the full phase of Phobos. The resulting composite, looking like a many layered jaw-breaker, shows how the temperature varies throughout the small moon. This temperature distribution, in turn, can help astronomers determine what the moon is made of. For more about this yummy treat, go to https://www.jpl.nasa.gov/news/news.php?feature=7398. Mars is two fists above the western horizon at 10:00 p.m. 

Tuesday: Venus and Mercury are close together in the early evening sky for the next few nights. At 9:00 p.m., Mercury is less than a fist to the upper left of Venus, about one fist above the west-northwestern horizon.

Wednesday: There is a total lunar eclipse tonight. What could be better than that? A supermoon total lunar eclipse. The Moon is near perigee meaning it is near its closest to Earth. Total lunar eclipses are not as noticeable as total solar eclipses because light still reaches the Moon even when it is completely blocked by the Earth. That is because the Earth’s atmosphere acts like a lens and bends rays of light toward the Moon that would normally miss the Moon. However, that doesn’t mean the Moon looks the same during a total lunar eclipse as it does during a normal full moon.

Sunlight is white. White light is the sum of all of the colors in the visible spectrum (red, orange, yellow, green, blue, indigo and violet). Our atmosphere scatters the blue component of the Sun’s white light. That is why our sky is blue. (If our atmosphere consisted of different gasses, we would likely have a different colored sky.) When the Sun or Moon is near the horizon, the light passes through a lot of the atmosphere meaning a lot of the blue light is scattered and the Sun or Moon looks redder than when it is high in the sky. During a total lunar eclipse, sunlight passes through a large slice of the Earth’s atmosphere. The remaining light that reaches the Moon is reddish. Some people say the fully eclipsed Moon looks Blood Red! These people exaggerate. It arrears a dull reddish color.

From our perspective in Ellensburg, Washington, Pacific Time Zone, the partial eclipse stage will start at 2:45 a.m. The Moon will slowly move into the Earth’s shadow and get dark from left to right. At 4:11 a.m., the Moon will be fully eclipsed. The total eclipse lasts until 4:26 a.m. Soon after this, the Moon will set. Thus, during the entire eclipse, the moon looks white, then black, then red all over. For more information about the eclipse, including information about the specific times for your location, go to https://www.timeanddate.com/eclipse/lunar/2021-may-26.

Thursday: Since you got up early yesterday to watch the lunar eclipse, why not get up early to see Jupiter and Saturn. At 4:30 a.m., Jupiter is more than two fists above the southeastern horizon while Saturn is nearly two fists to the  right of Jupiter. Unless you are a robot or an alien, you are looking at the visible wavelengths coming from Jupiter. In addition to visible wavelengths, there are telescopes that observe Jupiter in ultraviolet and infrared wavelengths. Studying multiple wavelengths will teach you a lot more about an object just like studying multiple languages will teach you more about a culture. For example, Jupiter's Great Red spot looks larger in the infrared image. NSF’s NOIR Lab has published an article that allows you to easily compare the three wavelength views of Jupiter. Go to https://noirlab.edu/public/news/noirlab2116/. Es muy bueno.

Friday: Mercury and Venus are in “conjunction” tonight, one fist above the west-northwestern horizon at 9:00 p.m. I put “conjunction” in quotes because it makes me appear too important to take the time to look up a better word. Strictly speaking, two objects are in conjunction when they are at the same sky longitude, called Right Ascension. From the point of view of Ellensburg, that will happen when the two planets are below the horizon. But they are closest together in the sky tonight, right after sunset. Mercury is just to the lower left of Venus, so close that you may not be able to fit your pinky between them. Before going outside, type the following url with your pinky and read about the conjunction: https://earthsky.org/?p=356424. 

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.

The Ellensburg, WA sky for the week of May 15, 2021

Saturday: You know Metis and Thebe and Adrastea and Amalthea. Io and Ganymede and Callisto and Europa. But do you recall? There are 79 Jovian moons in all.  Just 60 years ago, Jupiter was thought to have only 12 moons. But, astronomers are red-nosed with delight that the advent of supersensitive electronic cameras has caused the number of discovered moons to rapidly increase. Jupiter’s 79 moons range in size from Ganymede, the largest in the Solar System with a diameter of 5,262 kilometers, to numerous moons with diameters of only one kilometer. Recently, Saturn moved into first in the moon race with 82. Uranus is next with 27. Then comes Neptune with 14, Mars with 2, and Earth with 1. Our moon is the fifth largest in the Solar System, with a diameter of 3,475 kilometers. (One kilometer is 0.62 miles.) Even dwarf planets have moons. Pluto has 5, Eris has 1, Haumea has 2, and Makemake has 1. Eris is an outer solar system object that was discovered in 2005 and named in September of 2006. Because astronomers thought it was larger than Pluto, people called it the tenth planet for a while. (More recent measurements show Eris to be a little smaller in diameter than Pluto.) Haumea, the newest dwarf planet with a moon, was discovered in 2004 and officially named a dwarf planet on September 17, 2008. Go to https://solarsystem.nasa.gov/moons/ for more information about Solar System moons.

Tonight, Mars is about a finger-width to the left of our own Moon, three fists held upright and at arm’s length above due west at 9:00 p.m.

Sunday: Mercury will be as far away from the Sun in the sky as it will get this orbital cycle. This "farthest away" point is known as the planet's greatest elongation. Since Mercury is in the evening sky, it is east of the Sun so this occurrence is called the greatest eastern elongation. This evening will be the best evening to observe Mercury for the next few weeks. Mercury is nearly a fist and a half above the west-northwestern horizon at 9:00 p.m. Over the next few weeks, Mercury will move toward the Sun in the sky. By July, it will be barely visible in the morning sky. Venus is to the lower right of Mercury… and much brighter.

Monday: Are you thirsty? I'll wait while you get some water. I will NOT wait while Corvus the crow gets you some water. The Greco-Roman god Apollo made this mistake. He sent Corvus the crow to get some water in the cup known as Crater. Some figs distracted Corvus and he waited for them to ripen so he could eat them. When Corvus got back late, Apollo put Corvus and Crater in the sky with the gently tipping cup just out of the reach of the perpetually thirsty crow. Corvus is a trapezoid-shaped constellation about two fists above due south at 10:00 p.m. Crater is just to the right of Corvus.

Tuesday: You can set your watch tonight by carefully observing Navi, the center star in the W-shaped Cassiopeia. It will be due north at exactly 10:12 p.m. However, another star in Cassiopeia is causing astronomers to doubt whether or not they can use neutron stars as the most precise known clocks in the universe. Neutron stars have such a precise spin rate that they are used to set super accurate clocks on Earth. In 2013, astronomers using NASA’s Swift x-ray telescope noticed that the neutron star called 1E 2259+586 exhibited a spin glitch that had never been seen before. The spin rate of about eight times a minute decreased by 2.2 millionths of a second. Read more about this at http://goo.gl/C4V8R1. In 2016, astronomers using NASA’s Swift x-ray telescope observed the slowest rotating neutron star, once every 6.5 hours. What is it with using a telescope named Swift to make discoveries about something slowing? Maybe that slow developing question will be answered at https://tinyurl.com/y6ag6g7c.  

Wednesday: Are you thirsty when you get up in the morning? I know you are not waiting for Corvus. That’s okay because the Big Dipper is positioned to hold water in the morning sky. Look three fists above the northwest horizon at 4:30 a.m. You’ll see three stars that make a bent handle and four stars that make a cup.

Thursday: At 4:30 a.m bright Jupiter is two fists above due southeast.  Saturn is about two fists to the upper right of Jupiter.

Friday: Are you up at 2:23 a.m., looking due north and thinking you see a UFO coming to take you away? That's no UFO. It's the bright star Capella, a circumpolar star that never goes below the horizon as viewed from Ellensburg. 

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.

The Ellensburg, WA sky for the week of May 8, 2021

Saturday: Give me an “M”. Give me a “3”. What does that spell? “M3.” “Big deal,” you say. It was a big deal to French comet hunter Charles Messier (pronounced Messy A). M3 was the 3rd comet look-alike that Messier catalogued in the late 1700s. M3 is a globular cluster, a cluster of over 100,000 stars that is 32,000 light years away. It is too dim to be seen with the naked eye but is fairly easy to find with binoculars. First find Arcturus five and a half fists held upright and at arm’s length above due southeast at 10:30 p.m. Move your binoculars up one binocular field of view so two stars of nearly identical brightness are in your field of view. When the top star is in the lower left part of your field of view, there should be a fuzzy patch near the center of your field of view. This is M3. 

Sunday: So you think your mother has issues on Mother’s Day because she has you as a child? Her issues can’t be as bad as Cassiopeia’s issues. First, she was chained to a chair for boasting about her beauty. Second, she has to revolve around the North Star night after night. Third, her daughter Andromeda was nearly killed by a sea monster. Look for poor Cassiopeia about one and a half fists held upright and at arm’s length above the northern horizon at 10:00 p.m. Cassiopeia looks like a stretched out “W”. 

Monday: Mars’ two small moons, Phobos and Deimos, are not visible in typical backyard telescopes. But they are an interesting study. The former view among astronomers was that both moons are captured asteroids. That makes sense given Mars’ proximity to the asteroid belt. But recent findings by European astronomers indicate that Phobos is very porous and made of material similar to the surface of Mars. This implies that Phobos may consist of chunks of Martian debris that was blasted off by numerous impacts and gravitationally bound together. Unfortunately, the Russian Phobos-Grunt probe launched late 2011 to collect material from Phobos crashed to Earth after malfunctioning. For more information about this recent model of Phobos’ formation, go to https://sci.esa.int/web/mars-express/-/31031-phobos. For more information about Mars, look two fists above the western horizon at 10:00 p.m.

Tuesday: You’ve likely heard of Superman. You’ve probably heard of the Super Moon. Last month’s Full Moon was a Full Super Moon and this month’s Full Moon on May 26 will be a Full Super Moon. Between two Full Moons is a New Mini Moon. Thus, tonight’s Moon phase is a New Mini Moon. We can’t see any New Moon because the sunlight is illuminating the back side of the Moon so we won’t see a difference. But the oceans will feel the difference because a Mini Moon is farther from the Earth than average so the tides are lower.

Wednesday: Venus is about a thumb width to the lower right of the one day old waxing crescent moon at 9:00 p.m. They are just above the west-northwestern horizon right after sunset.

Thursday: Tonight the Moon has moved up next to Mercury in the sky. Mercury is less than a fist to the lower right of the two day old waxing crescent moon at 9:00 p.m. They are one fist above the west-northwestern horizon right after sunset.

Friday: The other day in class, we talked about the effort to protect the Earth from risky asteroids. We couldn’t do anything about them. But the European Southern Observatory (ESO) can. They are dedicating their La Silla telescope to detect and track thousands of near-Earth asteroids. Or more information, go to https://www.eso.org/public/news/eso2107/. 

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.