Here in Boulder, Colorado, the changing color of the leaves is a sure sign that fall is here. While the leaves are beautiful - especially up in the Rockies - I have to say that I'm not looking forward to the cold of winter. On the other hand, I'm really happy that our friends in the southern hemisphere are undoubtedly looking forward to a beautiful spring and summer!
Windows to the Universe has content that helps you help your students to understand the seasons. The tilt of Earth's rotational axis and the Earth's orbit work together to create the seasons. As the Earth travels around the Sun, it remains tipped in the same direction, towards the star Polaris.
At the equinox times in the Earth's revolution, the Earth is neither tilted directly towards nor directly away from the Sun. In other words, both hemispheres receive roughly equal amounts of sunlight. Equinoxes mark the seasons of autumn and spring and are a transition between the two more extreme seasons, summer and winter.
In this month's newsletter, we have information about the Orionid meteor shower, new extremes of sea ice melt in the Arctic, a heads-up about new Postcards from the Field coming your way, the anniversary of Sputnik, Earth Science Week, volcanoes, the many names of the full moon, and the Great World Wide Star Count starting October 1. In addition, we highlight opportunities to present at NESTA Share-a-Thons at NSTA Regional Conferences this fall, and Polar Palooza events at venues across the US this fall which will highlight International Polar Year.
Finally, if you get a chance, please join us at one or more of our events at NSTA this fall - and please let us know if you heard about them in our newsletter!
Each year, October brings us an entertaining celestial light show in the form of the Orionid meteor shower. The Orionids are named, as is customary with meteor showers, after the point in the sky (called the shower's "radiant") from which the meteors appear to fan out, which in this case lies within the constellation Orion. Several well-known meteor showers occur around the same dates each year, for these showers mark the points in Earth's orbit where our planet passes through the dusty debris from some comet. The Orionids are one of two showers that mark our planet's passage through the dust trail left behind by Halley's Comet! The Orionid "shooting stars" will be visible for several days around October 21st. 2007 should be an average year for viewing the Orionids. The moon will be in its waxing gibbous phase (almost full) when the Orionids peak on October 21st, so the Moon's light will make it harder to see meteors. However, the Moon will set in time for the best meteor observing period each night, which is between midnight and dawn.
Did you know that trees in temperate forest ecosystems sense the onset of shorter days and longer nights in the fall? This change of seasons triggers the development of a weak zone of tissue at the base of each leaf in deciduous trees. Stems will eventually snap in the breeze, releasing leaves to the ground.
The bright side of this story is that some leaves may become brilliantly colored before they fall, thanks to their pigments—green chlorophyll, orange carotenoid, and yellow xanthophyll. Leaf pigments sustain plants by means of photosynthesis throughout spring and summer by capturing visible light energy in the blue, violet, and red wavelengths of the Sun’s electromagnetic spectrum. This chemical reaction enables plants to grow, flower, and produce seeds by harnessing light energy to transform carbon dioxide and water into sugar, releasing the byproduct, molecular oxygen.
As transport of water and nutrients to the leaves decreases in autumn, chlorophyll production ceases. The green color fades, and the more stable carotenoid and xanthophyll pigments become visible, delighting our eyes with shows of gold and orange foliage. In plant species such as maple and sumac, sugars trapped in autumn leaves are turned into anthocyanin pigments. They appear to set forests ablaze with breath taking hues of red and purple. The best autumn colors can be expected when a moist growing season is followed by dry, cool, and sunny fall days with no night time frost.
You don’t have to live in the Arctic to know that sea ice is very important. Polar bears roam on top of it. Arctic marine life lives under it. And its light color reflects solar energy out to space, helping to keep the Earth’s climate from warming too fast.
Each year sea Arctic sea ice freezes during the cold winter months and then melts during the warm summer months. September is the time of year when there is the least sea ice in the Arctic. However, in August of this year, scientists discovered that there was less sea ice in the Arctic than ever before in observed history. The ice had reached a new low and there was still a month of warmer temperatures during which even more sea ice would melt.
And it has.
In September, Arctic sea ice dropped to a new record low. (The previous record low happened in 2005.) Because of global warming, the sea ice starts melting a little earlier each spring and starts freezing a little later each autumn. So there is more time during the year when melting occurs. As more ice melts, the albedo of the Arctic is decreased, meaning that less solar energy is reflected and more is absorbed by the Earth. More energy means more warmth in the Arctic which causes more ice to melt. This compounding process is called the ice-albedo feedback. For up to date information on this year's Arctic sea ice minimum, take a look at this web page from the National Snow and Ice Data Center.
Fifty years ago, on October 4th, 1957, the Soviet Union launched the first artificial satellite, called Sputnik 1, into space, starting the space age. It stayed in orbit for 6 months before falling back to Earth. The name "Sputnik" means "satellite" or "traveling companion" in Russian. This event signified the beginning of the space race between the USA and the Soviet Union, leading to the creation of NASA and major increases in U.S. government spending on scientific research and education.
The second Sputnik satellite was launched on Nov 3, 1957, and carried a dog named Laika into space. Biological data was returned for a week before the animal had to be put to sleep.
Read more about satellites and other robotic spacecraft on Windows to the Universe!
You may have seen our postcards from Antarctica last year. They were submitted by educator Jean Pennycook and were first-hand reports of what it was like to be with the Adelie Penguins in Antarctica during the season when the chicks hatch and grow.
Starting in mid-November, the Penguin Science team will again be in Antarctica studying the Adelie penguins of Ross Island. Don't miss out on seeing new postcards having to do with how climate change is affecting these wonderful birds! And don't miss some awfully cute pictures!
Starting even sooner in October 2007, the ANDRILL team of educators will also be submitting postcards from their site in Antarctica. The project team is drilling into sedimentary rocks below the ice of the Ross ice shelf to help us learn more about the environmental changes that have affected the continent in the past.
The theme for this year's Earth Science Week 2007 is "The Pulse of Earth Science." This is a great time to explore the Earth section of Windows to the Universe! This section includes content on the different components of the Earth system, including: the atmosphere, the hydrosphere (water), the biosphere (living things), and the geosphere (geology). This is also a great opportunity to delve into the content available on the polar section of Windows to the Universe, since the cryosphere (ice) is an important part of the Earth system. International Polar Year is underway and you can use this content to help your students learn more about Earth's polar regions.
The word volcano comes from the little island of Vulcano in the Mediterranean Sea off Sicily. Centuries ago, people living in that area believed that Vulcano was the chimney of the forge of Vulcan--the blacksmith of the Roman gods. They thought that the hot lava fragments and clouds of dust erupting from a volcano came from Vulcan's forge as he beat out thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war. In Polynesia, the people attributed eruptive activity to the beautiful but wrathful Pele Goddess of Volcanoes, whenever she was angry or bad tempered.
Volcanoes destroy and create; they have played a key role in forming and modifying our planet. There are more than 500 active volcanoes in the world. Volcanic eruptions have produced mountains, plateaus, and plains, which subsequent erosion and weathering have sculpted into majestic landscapes, some with fertile soils. These volcanic soils attract people to live on the flanks of volcanoes. So for this reason population density increases in regions of active or potentially active volcanoes. People living in volcanoes foothills must live in harmony with them and expect periodic violent unleashing of their pent-up energy and should plan to avoid being victims of their catastrophic and overwhelming power! In the past, cities and communities have disappeared such as during renowned eruptions of Mt. Vesuvius and Mount Pelee.
You've probably heard a Full Moon in the autumn called a "Harvest Moon" or a "Hunter's Moon". You may even realize that farmers can work late, after sunset, by the light of the Full Harvest Moon; hence the name. But did you know the Moon has ten other aliases, one for each month of the year? That the names of the Full Moon come from Native Americans, the Algonquian tribes of eastern and northern North America? Learn more at "Full Moon Names".
Join us in October for the first Windows to the Universe After Dark citizen science campaign – the Great World Wide Star Count. This international event encourages everyone to go outside, look skywards after dark, count the stars they see in certain constellations, and report what they see online. This inaugural Windows After Dark event is designed to raise awareness about the night sky and encourage learning of astronomy. All the information needed to participate is available on the Star Count Web site. The Star Count uses a simple protocol and an easy data entry form. At the conclusion of the event, the submitted data will be analyzed and a map will be generated highlighting the results of this exciting citizen science campaign. Mark your calendars and plan on joining thousands of other students, families, and citizen scientists counting stars this fall. The Great World Wide Star Count will be held from October 1st through October 15, 2007. For more information visit www.starcount.org or email firstname.lastname@example.org.
Will you be at the NSTA Regional Conferences in either Detroit (18-20 October) or Denver (8-10 November)? If so, we invite you to participate in one or more of the Windows to the Universe sessions listed below.
Detroit NSTA Regional Conference
Denver NSTA Regional Conference
Table of Contents
Sea Ice Melt
Earth Science Week
W2U at Fall NSTAs
Teacher SubmissionsClick here to submit your ideas to the newsletter
Announcements from PartnersClick here to submit information about your program to the newsletter
Are you planning on attending one of the NSTA regional conventions this fall? If so, please consider sharing your favorite, tested classroom activity with your colleagues at the National Earth Science Teachers Association Share-a-Thons at the fall regionals (see the list of Share-a-Thons below). This is a great opportunity to help your colleagues, and also be listed in the official program as a presenter (if you let us know far enough in advance), which may help you get support from your school administrators for attending the meeting.
What does being presenter at a NESTA Share-a-Thon entail? (1) Let me know that you'd like to present (at email@example.com. (2) Select your favorite activity, make about 100 copies to distribute to your colleagues. (3) If appropriate - bring along a demo or samples to illustrate the activity. (4) Appear 30 min before the Share-a-Thon is scheduled to start and select a table to sit at. Set out your materials and then get ready! The fun is about to start! (5) When the Share-a-Thon starts, teachers stream in and browse for resources they think might be useful to them. This is your chance to share and also meet new colleagues as well as old friends! (6) When the Share-a-Thon is over, pack up your materials and you're all done! Be sure to take along the set of copies that NESTA provides to presenters of all the other activities that have been shared at the Share-a-Thon (it will be delivered to you during the session).NESTA Share-a-Thon and Rock Raffles at Fall NSTA Regional Conferences
Polar Palooza is a public outreach project sponsored by the National Science Foundation and NASA to bring the poles to you through a national science center and museum tour, vodcasts, and more. Events are scheduled across the country this fall. Check out the list of events and locations to find out about opportunities to attend for yourself, your family, and your students!
The source of this material is Windows to the Universe, at http://www.windows.ucar.edu/ at the University Corporation for Atmospheric Research (UCAR). © 1995-1999, 2000 The Regents of the University of Michigan; © 2000-07 University Corporation for Atmospheric Research. All Rights Reserved.