Winter 2014
Transcription
Winter 2014
Public Is Invited Marietta Natural History Society Winter 2014 Newsletter . What’s in the Thursday, January 9, 6:00 PM, MNHS Annual Potluck Dinner, St. Luke’s Lutheran Church 4th & Scammel Sts. Presenter: Dr. Almuth Tschunko Botany Professor, Marietta College Have you ever wondered which plants and parts of plants are in a delicious spice cake? Come and find out! Bring a covered dish to share and table service. Seed Production in the American Chestnut Thursday, February 6, 7:00 PM, Anderson-Hancock Planetarium , Marietta College Presenter: Dr. Ann Bragg Astronomy Professor, Marietta College Ann has written an article (page 4) and will make a presentation on The Winter Sky: Bright Stars, Young and Old. She will also be showing a video called The Astronomer Cowboy. Read the article, see the show, and the winter sky you will better know. Thursday, March 13, 7:00 PM Selby Hall, Rm 150, Marietta College Presenter: Dr. Brian McCarthy Assoc. Dean and Professor of Forest Ecology, Ohio University Brian has been very active in the American Chestnut Foundation, doing basic research and helping to re-establish disease-resistant hybrids. He will talk about research on chestnut seed production and nutritional qualities compared to other hardwood species (e.g., oaks) and the potential impacts of chestnut decline on wildlife communities. Page 2 Marietta Natural History Society It’s Time for MNHS Membership Renewal Use the enclosed membership form to renew today! Please send to: Marietta Natural History Society P.O. Box 983 Marietta, OH 45750 Dinner with the speakers Meets at 5:30 at the Levee House Restaurant Check with Marilyn (373-3372) or Elsa (373-5285) first. Members should make their own reservations. Events Sponsored by the Friends of Ohio River Islands National Wildlife Refuge All activities are free and open to the public. Meet inside the refuge visitor center (3982 Waverly Rd., Williamstown, WV), unless otherwise indicated. To learn more about any of the activities, please call or email: Matthew Magruder, (304) 375-2923, Ext. 117 matthew_magruder@fws.gov. January 28 - Owls of the Ohio Valley Presented by Mike Williams – 7:00 PM February 25 -Insects of the kroger Wetlands Presented by Brad Bond - 7:00 PM. March 25 - Amphibians: Voices of Spring Presented by Lynn Barnhart – 7:00 PM. Winter 2014 Ohio Wildlife Legacy Stamp The fifth annual Ohio Wildlife Legacy Stamp will feature a reflective image of a midland painted turtle photographed by Sharon Cummings, Graytown, Ohio. The photo will appear on the 2014 Ohio Wildlife Legacy Stamp, which goes on sale March 1, 2014. Her image was selected as the top photo out of 143 entries from 83 photographers. Those interested in purchasing a Legacy Stamp can visit wildohiostamp.com for details. Additional information about the Ohio Wildlife Legacy Stamp and other wildlife-related topics can be found at wildohio.com. Buying an Ohio Wildlife Legacy Stamp is a way that you can help Ohio's wildlife and the habitat they call home. Fourteen dollars of every $15 Ohio Wildlife Legacy Stamp sold is invested in the state’s Wildlife Diversity Fund. Proceeds from the sale of the Wildlife Legacy Stamp help support a range of wildlife diversity projects including management of endangered and threatened wildlife species and their habitats; habitat restoration, land purchases and conservation easements; and development of educational products for students and wildlife enthusiasts. With a stamp purchase you'll receive an attractive collectible stamp, window cling, and commemorative card. Proceeds from the stamp go into the Endangered Species and Wildlife Diversity Fund. With your Legacy Stamp, you also receive a lapel pin (wear it and let others see that Ohio’s wildlife matters to you), distinctive commemorative card suitable for framing, and a certificate of appreciation. The Ohio legacy stamp is chosen each year from submissions to the Ohio Wildlife Legacy Stamp Contest which runs annually. The contest is open to Ohioans age 18 years and older, and the photographer with the winning image will win $500. Photographers, age 17 and younger, will be able to compete in the youth division. For contest rules, visit www. wildohiostamp.com. Suggestions, Comments or Contributions for the MNHS Newsletter? Send them to the Editor: 374-8778 Page 3 Marietta Natural History Society Winter 2014 Still Time to Watch the Bird Feeder We are in the middle of the Winter Bird Feeder Watch. Participants record species and number of birds at their bird feeders every other weekend from November through March (on days marked with the bird icon). You don’t have to watch every weekend; all data collected can be used. If you want to participate, contact Marilyn Ortt (3733372 or Bird Watcher's Digest (373-5285). Learn more about calendar events marked with a “*” on page 5. Some definitions Recycled Paper 30% Post-Consumer AU (Astronomical Unit): 1 AU equal average distance between the earth and Sun. Elongation: the angle between the Sun and the planet with Earth as the reference point. Perihelion: an object’s closest approach to the sun. Occult: to pass in front of. Page 4 Marietta Natural History Society Winter 2014 The Winter Sky: Bright Stars, Young and Old by Ann Bragg, Associate Professor of Physics, Marietta College Early sunsets, long nights and dry air make winter a wonderful season for viewing the night sky. And although cold air temperatures may be an impediment to spending too much time standing still outdoors, winter’s stunning constellations make stargazing at this time of year worth the discomfort. Any exploration of the winter sky inevitably begins with the most striking constellation in our sky, Orion the Hunter. The most prominent part of the Hunter is Orion’s Belt. The three stars comprising the Belt are similar in brightness and evenly spaced along a line, making the structure easy to spot. At midnight on New Year’s Day, Orion is high in the southern sky, with the Belt more or less parallel to the horizon. By February 1, Orion reaches this position around 10pm and by March 1, around 8pm. Roughly 10° above Orion’s Belt (or about the width of a human palm at arm’s length) we see two bright stars where Orion’s shoulders ought to be. The leftmost and brightest, Betelgeuse, has a reddish cast. Betelgeuse is a red supergiant and glows orange-red because its surface is actually cooler than the surfaces of most other stars we see in the night sky. Having exhausted the hydrogen fuel in its core, someday Betelgeuse will explode in a brilliant supernova. Because Betelgeuse is relatively nearby, the glow from this explosion will be visible even in the daytime sky. The star to the right is Bellatrix. While it is only the third brightest star in Orion, it is one of the 30 brightest stars in our entire sky and it appears somewhat blue-white due to its higher-than-average surface temperatures. Roughly the same distance below Orion’s Belt as Betelgeuse and Bellatrix are above it, we see two more bright stars. The brighter star, on the right, is Rigel, the foot of Orion. This star has a bluish appearance due its very high surface temperature. Like Betelgeuse, Rigel will someday explode in a supernova, but Rigel is farther from this stage than Betelgeuse. Between Orion’s Belt and his feet, we can see a famous region of star formation known as the Orion Nebula. To the casual observer, this nebula looks like a star due to its great distance, but a telescope will reveal the gas as well as many of the stars forming within. To find the Nebula, look for a line of three dimmer stars below Orion’s Belt, sometimes known as Orion’s Sword. The topmost of the three stars will look fainter than the other two. The middle “star” is actually the Orion Nebula. In addition to helping us find Orion, the three stars of Orion’s Belt can help us find other nearby stars and constellations as well. If we follow the line created by the Belt upwards and towards the right, we will find ourselves looking at a second reddish star. You may notice that this star, Aldebaran, in a group of stars that looks like the uppercase letter “V”, which forms the head in the constellation Taurus the Bull – Aldebaran is the bull’s eye. Although Aldebaran and Betelgeuse look very similar in brightness, Aldebaran is actually 10x closer to Earth. Aldebaran has less than twice the Sun’s mass and is considered a low-mass star. Aldebaran is also near the end of its life; however, it will meet a less violent end, leaving behind a white dwarf “star.” Astronomers have estimated that roughly half the non-dark-matter mass of our Galaxy may be made up of white dwarfs left behind after lower-mass stars reach their ends. If we follow the arms of the “V” forming Taurus’ head, we will come to the two stars marking the ends of the bull’s horns. In between these two horns is an interesting object that is not visible without a telescope, the Crab Nebula. This nebula was left behind by a supernova explosion that occurred in 1054. We know the date because the explosion was noted by Chinese astronomers. Although telescopes did not exist at that time, the explosion was bright enough see by eye. We can find another interesting object in Taurus if we once again follow Orion’s Belt to Aldebaran, but this time continue on about the same distance across the sky, until we reach a star cluster best known as the Pleiades. As we saw in the Orion Nebula, stars often form in big batches. Continued on next page Page 5 Marietta Natural History Society After this process ends, a star cluster is left behind. The Pleiades star cluster is close enough that we can see the brightest several stars by eye. Returning to Orion, we can follow the Belt down and to the left and find ourselves at the brightest star in Earth’s night sky, Sirius. Sirius is one of the closest stars to the Earth, which is why it appears so bright. Sometimes called the “Dog Star,” Sirius is a part of the constellation Canis Major, the Big Dog. While many stars in our night sky appear white primarily because our eyes are poor at detecting color in low-light conditions, Sirius is actually white in color. To the upper left of Orion, we find the brightest object (besides the Moon) in our 2014 winter sky, the planet Jupiter. While the various stars and constellations discussed above remain in the same relative positions year after year, the planets move around in our sky because of their orbits around the Sun. Due to its twelve-year orbit, Jupiter moves through about one constellation each year and is currently found in Gemini the Twins. To identify Jupiter in the current winter sky, follow a line from Rigel through Betelgeuse and then continue away from Orion until you reach Jupiter. Jupiter is about as far on the sky from Betelgeuse as Betelgeuse is from Rigel. Our closest approach to Jupiter for the year will occur on Sunday, January 5, 2014 when Earth overtakes and passes the slower-moving Jupiter. We call this event “opposition”because Jupiter is opposite the Sun in Earth’s sky. At this time, Jupiter will be about 392,000,000 miles away. Continuing beyond Jupiter, we find the two brightest stars in Gemini, Castor and Pollux, which form the heads of the twins, whose stick-figure-like bodies extend back towards Betelgeuse and Orion. The most variable astronomical feature of the sky at any time of year is, of course, the Moon. Full moons are beautiful to look at, and reach their highest altitudes in the sky during winter months, although they do make star-gazing more challenging by introducing a great deal of background light. The best observing is done at times at least one week away from full moon dates. During the week leading up to the full moon, the evening sky tends to be quite bright, growing more so night-by-night. A special event will be on April 15 when there will be a full moon lunar eclipse visible throughout much of the continental United States. This eclipse will begin around 12:58am and end around 4:33am, with totality occurring from 2:06am until 3:24am (http://eclipse.gsfc.nasa.gov/OH/OH2014.html). Those who are staying up late completing their taxes in time for an April 15 postmark may want to step outside and take an eclipse break! Winter 2014 Calender Notes Rosetta was launched on 2 March 2004, set on a course to comet 67P/Churyumov-Gerasimenko. On its way, it by and imaged asteroids Steins (5/9/08) and Lutetia (10/7/10). In July 2011 the spacecraft was put into deep-space hibernation for the remaining 800 million KM trip. Rosetta's internal alarm clock is set for reawakening on Jan 20. Once Rosetta wakes up, it should signal home that it is still alive. After wake-up, Rosetta will still be about 9 million km from the comet. As Rosetta closes in on its target, it will take thousands of images to reveal the comet's major landmarks, rotation speed and spin axis. Rosetta will also send observations of the comet's gravity, mass, shape, atmosphere, and analyse how it interacts with the Sun's solar wind. Sometime in August or September, after extensive mapping of the comet's surface, Rosetta will dispatch its 100 kg Philae probe for the first attempted landing on a comet. Stay posted. Cassini is a spacecraft that has been orbiting Saturn since 2004. Its elliptical orbit periodically brings Cassini near one of Saturn's moons, encounters called a "Flyby". During a Titan Flyby in 2005, Cassini released the Huygens probe that parachuted through Titan’s murky atmosphere and landed on the surface. The pictures it sent are the only images we have of the surface of a planetary body in the outer solar system. Mars years: While there is no universal (or at least Earthly) agreement on a Martian dating system, many Mars scientists and the Planetary Society have adopted Earth date April 11, 1955 as the beginning of Mars year 1. Since a Martian year, the time required to complete one orbit around the Sun, is about 687 Earth days, by this system, Mars is presently in year 32. Known dwarf planets are smaller than the Earth’s moon. If Earth were the size of a nickel, dwarf planets Pluto and Eris would each be about the size of the head of a pin. Discovered in 2005, Makemake is the second largest dwarf planet in the Kuiper Belt, a region outside the orbit of Neptune, and is 2/3s the size of Pluto. It is named for Makemake, the creator of humanity and the god of fertility in the mythology of the South Pacific island of Rapa Nui, or Easter Island. He was the chief god of the Tangata manu bird-man cult and was worshiped in the form of sea birds, which were his incarnation. Benefits of Membership Invite a Friend to Join the MtÜ|xààt NtàâÜtÄ H|áàÉÜç SÉv|xàç L Monthly programs L Field trips L Quarterly newsletter L Educational Wood Thrush — Individual $15 River Otter — Family $25 Monarch — Friend $50 Why not give a gift membership? Mail check to address given below experiences for kids and adults L Conservation Projects The MNHS Mission i To foster awareness of and sensitivity to our environment and its biodiversity i To provide a place where people with these interests can gather for information and activity i To create a presence in our community representing these ideas Marietta Natural History Society P.O. Box 983 Marietta, Ohio 45750 (740) 373-5285