Author Archives: Kyra Elliott
Happy Chinese New Year!
Happy Chinese New Year, everyone! Lets ring in the Year of the Horse.
Chinese New Year is one of those floating holidays that seems to fall on a different day each year, why is this?
Throughout history, civilizations around the world have used celestial objects to track the passage of time. People used the movements of the Sun, Moon, or stars to define a calendar for their society to live by. Today the majority of the world uses the Gregorian calendar, which is based on the orbit of the Earth around the Sun, or the Solar Year. Lunar calendars use the duration of the Moon’s orbit around the Earth, or the Lunar Month. Lunisolar calendars use a combination of both. Although most countries around the world use the standard Gregorian calendar for official government purposes, citizens of these countries often use a Lunar or Lunisolar calendar to mark important social and religious festivals.
The modern Chinese calendar is known as the Han calendar, it is Lunisolar. Like other Lunisolar calendars, the Han calendar takes into account a Solar Year as well as a Lunar month. The Han calendar uses the tropical solar year, which uses the seasons (the solstices) as the reference for the passage of a year. The Chinese calendar references the Winter Solstice specifically.
The New Year is observed on the day of the second new moon after the Winter Solstice, and occasionally on the third new moon. For the majority of us who use the Gregorian calendar this often translates to the first new moon of the new year.
Following several days of preparation, at midnight last night the festivities for Chinese New Year kicked off. It is a time of renewal, wishes of good fortune, and paying respect to friends and family. The observation of the new year actually lasts for 15 additional days, each having their own symbolic rituals and customs. One of the most well known traditions is the gift of red envelopes to friends and family. These envelopes often contain money, in amounts that correspond to lucky numbers. They are usually presented to younger people, and sometimes they are ornately decorated.
So, why Year of the Horse? The Chinese Zodiac, like the western zodiac, is separated into twelve signs. Unlike the Western Zodiac that associates each sign with a segment of the Solar Year, the Chinese Zodiac associates each sign with a single year in a twelve year cycle. Follow the link above to learn more, it gets even more complex than that! Last year according to the Han calendar was the year of the Snake, before that the year of the Dragon. Once we reach the Gregorian year 2020 the year of the Rat, the cycle will begin again.
So go forth, wish you friends and neighbors peace and happiness, and ask your family members for red envelopes filled with money! The Year of the Horse has begun.
Loki the Volcano
There has been lots of talk in Baton Rouge about ice, snow, and cold. Let’s change focus and talk about something hot: volcanoes! The planetarium is about to debut its latest show “Super Volcanoes” which gives audiences a front row seat to some of Earth’s largest volcanic eruptions. The show features extensive live action footage of geothermal features in Yellowstone National Park, as well as a complex simulation of an eruption of the Solar System’s largest active volcano, Loki.
Loki can be found on Jupiter’s moon Io. Named for the Norse God of Mischief (or comic book villain if you prefer), this volcano is considered to be the hottest and most powerful in the Solar System. Loki is officially called Loki Patera which means “Loki Basin”. Loki is not a tall volcano, it has no cone. It is the opposite, a large depression in Io’s surface that is filled with lava. Loki alone puts out more heat than all of Earth’s volcanoes combined!
Volcanism was discovered on Io by Voyager back in the 1970s. Up until this point people thought Earth was the only place with such active geology. Initially it was surprising to discover this much activity on such a tiny world. Scientists thought that since larger bodies (such as the other rocky planets, and larger moons) appeared to have thoroughly cooled and stopped exhibiting signs of active volcanism, tiny bodies such as Io wouldn’t exhibit it either. Voyager snapped photos of Io’s surface, showing large volcanic scars as well as plumes of ash reaching into the skies. Io had even more volcanic activity than Earth!
So why is this? As we rub our hands together to stay warm in this winter weather we’re having here in Baton Rouge, consider the moon Io. Io orbits closest to Jupiter out of the four largest moons. The combination of tidal forces from Jupiter, tidal forces from the other large moons, as well as the shape of Io’s orbit all play a role. The constant tugging on Io is thought to cause friction and internal heat inside the moon. Kind of like when you rub your hands together but a lot more so!
Io has mountains and plains, as well as different types of volcanoes. Loki is thought to be a large lake of lava. Images taken from spacecraft show a large dark depression (almost 130 miles across!) with steep edges. Thermal studies have shown that the surface is extremely hot, likely due to a large pool of lava covered by a thin crust. The crusts of these lava lakes can become disrupted, triggering a wave across the lake. The denser crust sinks below the molten rock beneath causing the lake to resurface itself. Scientists are still unsure about how Loki-type volcanoes form on Io. They could form from a collapsed volcano (this occurs on Earth and they are known as Caldarae), or they could be created from an impact of a large meteor into the surface.
Images of spacecraft have also shown plumes of volcanic material being ejected from Loki that have reached nearly 150 Km above the surface (that’s higher than the International Space Station orbits above Earth!). In “Super Volcanoes” audiences will travel to Loki and witness what this eruption might look like from the surface!
If you haven’t already, check out the trailer for “Super Volcanoes”, opening February 1 at the Irene W. Pennington Planetarium.
Go SpaceShip 2!
Trying to decide where to book your next vacation? How about outer space? Virgin Galactic is still in the test phases, but it is getting closer to realizing its goal of sending tourists into space.
Last Friday Virgin Galactic’s SpaceShip 2 took off from the Mojave Air and Space Port in California and made its third successful test flight. SpaceShip 2 is carried to 46,000 feet aboard a carrier aircraft that takes off on a runway similar to an airplane. When it reaches a specific altitude it drops SpaceShip 2 into a short free fall. The rocket motor then takes over and propels SpaceShip 2 upward. Pilots David Mackay and Mark Stucky flew the unique spacecraft 71,000 feet above the Earth’s surface.
Watch the video footage below to see the flight:
Unlike SpaceX, which has been focusing more on commercial transport of supplies, satellites, and eventually people, Virgin Galactic has its sights on the future Space Tourism industry. Richard Branson hopes to launch the first space tourists into space later this year. Tickets are $250,000 a piece, and people are already signed up!
Winter on Pluto
Great job everyone on braving our record cold temperatures this week! In some places it got as cold as -16 degrees Fahrenheit! As we work to stay warm, and in some places dig ourselves out of our driveways, lets be thankful that none of us have to endure a winter on Pluto. Current Plutonian temperatures (it’s not even Winter there right now, Summer is just ending) average around -350 degrees Fahrenheit!
Chicago got lots of snow this year! Temperatures dropped to -16 degrees F.
Pluto is an extremely difficult object to study, it is tiny and its far away. It is roughly 7.5 billion miles from Earth, and takes 248.1 Earth years to orbit the Sun. Pluto was officially discovered in 1930 by Clyde Tombaugh. Interestingly enough Tombaugh was only 23 years old at the time, an intern of sorts. He was tasked with comparing images of the night sky taken at two week intervals using a device called a blink comparator. It would flip the images quickly back and forth, stars (which don’t change position relative to each other in that short of a time) would appear stationary. However a moving object like an asteroid or planet would appear to move past the stars as the images were flipped. Tombaugh discovered Pluto using this method. Since Pluto’s year is 248 Earth years, and it was discovered in 1930, astronomers have yet to observe Pluto through its entire orbital cycle (which won’t happen until the year 2178).
Tombaugh compared these two plates with the blink comparator and saw Pluto moving relative to the background stars. Source: Lowell Observatory Archives.
We still know very little about Pluto today, our best images are fuzzy, but they can tell us how Pluto changes appearance over time. We know what Pluto’s atmosphere is made out of, which by default can tell us what types of chemicals can most likely be found on the surface. Every chemical has its own unique spectrum (pattern of visible light emitted by the electrons in the atoms as they gain then release energy). By studying the spectra of Pluto, astronomers can pin point the chemicals found there.
Highest resolution images of Pluto taken by Hubble Space Telescope. Source: NASA.gov
Most recent studies of Pluto have monitored the thickness of its atmosphere. How do they do this, you ask? They monitor the light from a star that Pluto passes in front of. This is called a stellar occultation. Studying a stellar occultation of a tiny object that is 7 billion miles away is a very complex and delicate process. Basically astronomers observe changes in the star’s light as it is filtered through Pluto’s atmosphere, these changes can tell us about the atmosphere’s composition and thickness.
What is Plutonian winter like? We don’t entirely know. Recent theories suggest that as Pluto continues to get farther from the Sun in its orbit (as it is doing) and enters into winter time, the surface temperature will drop. This would then cause the atmosphere to freeze out and fall to the ground as a fine snow of nitrogen, carbon monoxide, methane, and other chemicals.
In “The Gravity Factor” it’s the next century, people live on Pluto in a large base station. For leisure, they snowmobile and ski around the snow covered surface. Source: LASM.
In fact, LASM is partnering with Houston Museum of Natural Science to produce a planetarium show called “The Gravity Factor”. It takes place in the next century, and explores the possibility of colonizing the planets and moons, and the type of work and life people would have in the different places. LASM is contributing to the show by producing a segment about astronauts living on Pluto during winter time after the annual snow fall. In the show astronauts living at the Pluto base occupy their free time with snowmobiling and rocket-powered skiing over the snow drifts on the surface. A fun prospect!
Most recent research has suggested an alternative to this theory. Astronomers have been observing Pluto’s atmosphere expecting to see evidence of it thinning as the “snow storm” begins, however they have observed the opposite. Pluto’s atmosphere is staying the same, in fact it appears to be getting thicker. Some scientists believe that this indicates that the snow storm isn’t going to happen (as it should have started by now). They conclude that this is an indication of thermal inertia, the ability for Pluto to retain energy absorbed from the Sun during the Summer. Pluto has higher thermal inertia than previously thought, so its atmosphere is not cooling as quickly as scientists would have expected, despite the planet approaching its Winter season.
Artist’s conception of the New Horizons Spacecraft.
So what does all of this mean? Our knowledge of Pluto is constantly changing as we learn more about this distant world. The New Horizons spacecraft is hurtling towards Pluto at a whopping 31,000 miles per hour, making it one of the fastest spacecraft ever. It will reach Pluto in 2015 and get an up close view of the dwarf planet. Astronomers eagerly anticipating data and imagery from New Horizons will help them gain a better understanding of Pluto. The general public is excited too, for the first time we’ll be able to see what Pluto looks like up close!
How many arms does the Milky Way have?
During the last century telescope and image capturing technology grew by leaps and bounds. Astronomers for the first time could peer into the far reaches of space to study the hundreds of billions of galaxies that lie beyond our own. Over the years, astronomers developed a systems of galactic classification that categorized galaxies based on their shape and composition. Edwin Hubble created the original system of classification in the early 1900s, which was later expanded to include various other sub-categories as galactic observations improved. A majority of galaxies fall into the following categories…
Elliptical
These galaxies are spherical or ellipsoid in shape, with very few visible features. They contain up to one trillion stars, and very little interstellar dust and gas. Research has indicated that stars in elliptical galaxies are often very old, which is why the galaxies themselves glow with a yellowish-white hue. Also there is less star formation occurring in this type of galaxy.
Lenticular
Lenticular galaxies can be imagined as a mid category between that of the featureless elliptical galaxies and the dramatic spiral galaxies. These galaxies have a defined disk of gas and dust, as well as a glowing bulge at their middle. They do not exhibit spiral arms, but do have large amounts of gas and dust within their disks. This leads to high amounts of star formation within.
Spiral
Spiral galaxies have very distinct shape and structure consisting of a central bulge of bright stars, and bright arms. Spiral galaxies contain large amounts of gas and dust, and stars of varying ages. Recent theories have explained that the arms are shaped by slowly rotating matter density waves that compress the interstellar gas and dust triggering star formation.
So what type of galaxy is our own Milky Way? That has proven to be a tricky question to answer, since we live inside of it, we can’t simply take a picture of it as we do with the countless other galaxies in our universe. You can take pictures of your neighbors’ houses from out your window, but you can’t take a picture of your whole house unless you go outside and walk away to get a view. The Voyager Spacecraft launched in the 1970s are the furthest man-made probes, and they have only recently exited the Solar System; we are not anywhere close to taking a picture like this of our home galaxy any time soon.
There are some simple observations anyone can make to help them classify our Milky Way.
1. The Milky Way appears as a thin strip across our sky, which implies that it is a thin disc, rather than a sphere of stars.
2. The center of the Milky Way is visible in the southern sky each Summer. This shows that our galaxy has a definite bulge at its middle.
These facts, paired with other astronomical observations have indicated that our Milky Way is a spiral galaxy. However, the question still remains… How many arms does it have?
The interstellar dust in our galaxy blocks our view of faraway stars in the visual wavelengths. Radio telescopes allow astronomers to see through the dust to identify the locations and motions of these stars. Using this information, astronomers extrapolate the shape of our galaxy. Up until recently, data from the Spitzer Space Telescope indicated that there were two distinct spiral arms (where previous theories had suggested four arms). Spitzer was targeting middle-aged cooler stars like our Sun.
A very recent study that targeted supermassive hot young stars painted a different picture: four arms. Due to the large amount of star formation that occurs in the arms of spiral galaxies, these types of stars are found nearly exclusively in the arms. Though these stars live short lives, the high rate of star formation in the arm regions replenishes the populations of them.
Some astronomers theorize that gravitational forces within the Milky Way may have lead to an uneven distribution of the middle-aged and older cooler stars into two of the arms more than the other two, leading the Spitzer data to indicate two arms. Meanwhile the populations of supermassive hot young stars flourish in all four arms.
Truly understanding our home galaxy is a unique challenge that motivates astronomers world wide. Our picture of our galaxy and the universe beyond continues to evolve as we continue to look outward.
The Geminid Meteor Shower
The Geminid Meteor shower occurs each December, and this year we can expect to see up to 50 meteors each hour. Check out this awesome timelapse that I wish I could say I did, but someone else made it…. This timelapse was taken of the Geminids last year over the Pacific Coast.
Meteor showers are caused when Earth passes through the orbital path of a comet, the debris left behind by the comet falls into Earth’s atmosphere creating many shooting stars. The Geminid shower is different. Scientists have determined that this shower occurs when Earth passes through a debris field of an asteroid. This asteroid is called 3200 Phaethon. Observations show that this object is strange indeed, and sometimes behaves similar to a comet. Its orbit brings it in close to the Sun, and then back out again. Jets of dust and gas have been seen spewing from the asteroid at times. Tiny pieces of dust and rock are left behind by 3200 Phaethon as it travels through space, and these cause the Geminid Meteor Shower. The tiny arrows in the image below point to 3200 Phaethon, this image was created by combining multiple images over the span of 20 minutes to show the asteroid’s movement relative to the background stars.
Meteor showers are named for constellation that their radiant lies in. The radiant is the point from which the meteors appear to radiate from in the sky. The constellation Gemini will rise above the horizon around 9 PM Central Time tonight (December 13th). It will be nearly overhead around 2 AM. This year the moon will also be visible in the sky, which will make it more difficult to see the fainter meteors.
While Baton Rouge forecasts are saying rain throughout this evening, some reports indicate that the sky will clear a bit after midnight. Incidentally this is the best time to go out and find meteors! Meteor watching requires patience and sharp eyes, each year the number of meteors changes. Happy viewing!
Cancel the Eulogy! ISON lives!
“Reports of my demise have been greatly exaggerated!” says comet ISON. Data gathered yesterday led astronomers to the unfortunate conclusion that ISON was broken up and vaporized as it grazed the Sun. However a new look at the images show a tiny piece of the comet has survived and is continuing on its journey back into the far reaches of space. Look for ISON in the upper left corner of this picture.
What does this mean? Will it still prove to be the comet of the century? We don’t know yet. Observing comets is exciting because we never truly know what they will do. ISON may still flare up in brightness to put on one final show before exiting the Solar System or it may fizzle out and be gone forever. Stay tuned!
Remembering JFK
Today we remember President John F Kennedy, on the 50th anniversary of his assassination. He challenged our nation to achieve one of its greatest accomplishments: landing people on the Moon safely. President Kennedy’s vision for innovation, paired with the bravery of the astronauts who made the journey and the ingenuity of the engineers who built the spacecraft, paved the way for decades of space exploration. He continues to inspire us today to strive for excellence, to lead, and to never stop reaching for the stars…
Related articles
- Friday throwdown: Remembering JFK (bostonherald.com)
- JFK 50th: Nation pauses to remember lost president (miamiherald.com)
Why is Comet ISON Green?…. and other updates
Great news, everyone! Astronomers world wide have confirmed that in the last day or so, ISON has increased in brightness to the point where it is visible to the naked eye. You still have to look closely, as it is still on the border of visibility. Astronomers expect the comet to brighten as it continues to approach the Sun, but no one can know for sure. Through telescopes the green color of the comet is visible.
So why is the comet green? It isn’t uncommon for comets to glow green. This is due to the presence of certain chemicals inside the comet that are released as the nucleus sublimates away into space. Most often these chemicals are cyanogen (CN) and diatomic carbon (C2). Both of these chemicals emit greenish-blue light when in a vacuum (like outer space) and exposed to large amounts of energy (which they are getting from the Sun).
Today I came across this awesome interactive website that allows you to track ISON (as well as other Solar System objects) through the sky from different points of view. I’ll be using it to see where ISON will be over the next view weeks, it also gives you key dates and info. Click the picture below to visit the site:
Unfortunately for us here in Baton Rouge, the next few days have a lot of clouds in the forecast! There will still be time to view the comet early next week once the sky clears… Between now and November 28 the comet is approaching the Sun. From Earth it will be getting closer and closer to the horizon in the early morning sky. If you can, try and view it before Thanksgiving. All you have to do is:
1. Wake up very early, around 5:00 AM!
2. Find a place with a clear view of the eastern horizon.
3. Find the constellation Virgo (outlined in the image above), it will be nearly due east.
4. Look for a faint fuzzy object
5. If you’re feeling up to it, bring the camera out and snap a picture. Click here for a past article about astrophotography tips, it is for a meteor shower, but similar rules apply.
6. While you’re out, don’t miss Saturn, Mercury, and Mars.
Astronomers are unsure of ISON’s fate after it’s close approach to the Sun (which will occur on Thanksgiving Day), it is possible that the Sun’s gravity will cause ISON’s nucleus to break apart. If ISON survives its close encounter with the Sun, it will be visible once again in the morning sky around December 6th. Cross your fingers for ISON’s safe passage around the Sun, and happy viewing!
Irene W. Pennington Planetarium 