Dark Sky Tracking

As the Valley of the Sun has grown to a sprawling, sun-drenched metropolis, we are quietly losing our magnificent and unique dark skies.  The Grand Canyon state has been a magnet for professional and amateur astronomers for over a century, yet places in which to view the wonders of the universe with the naked eye are dwindling. City lights that shine 24/7 create what scientists call "light pollution" and can begin to obscure what lies above us. Light pollution also impacts wildlife, like migrating birds, as well as human health. The impact of artificial light is a very interesting study in itself.

There are still many places in Arizona where you can experience a truly black night sky.  The International Dark Sky Association based in Tucson provides a wealth of information about the benefits of our night skies, as well as lists of locations throughout the world where dark skies prevail. 

Oracle State Park, Grand Canyon National Park, Wupatki National Monument and Grand Canyon-Parashant National Monument are four designated "dark sky" parks in Arizona, and many towns strive to minimize unnecessary light. The area to the east of Phoenix and Scottsdale still offers some amazing sky gazing opportunities, especially during the new moon.

January 17, 2018 is the next new moon, meaning that it is on the same side of the earth as the sun so it won't be visible. New moon nights are the best nights to get out and search for constellations, planets and even galaxies. A good pair of binoculars help, but to start, just scan the sky for patterns and objects. Phone apps like Skyview, Night Sky, or Night Sky Tools can help you identify the constellations and names of the heavenly bodies. 

Enjoy tracking the moon and its phases throughout the month and be sure to calendar upcoming sky events. 

References and Resources
International Dark Sky Association
Arizona Republic - Where are the Darkest Places in Arizona?
timeanddate.com - Where is the Moon? (in real time)

Image - Public Domain Pictures

Geminid Meteor Shower

December 13 - I love any excuse to be in natural places in the dark of night.  It makes me feel so adventurous.  In north Scottsdale, we are blessed with a velvety black sky that is usually studded with thousands of stars.  A few weeks ago, we enjoyed a night walk under a super moon, but tonight the moon is hiding and it's a good thing too for tonight is the best bet for seeing the annual Geminid Meteor Shower. We decided to drive to the edge of the desert wilderness and search the sky for any flashes of light. We were not disappointed.  We saw about two dozen meteors during the 40 minutes we stood marveling at the sky.

Every December, earth cross the orbital path of a "rock comet" or asteroid known as 3200 Phaethon, which is the parent body for the Geminid meteors flashing past our planet. The term "Geminid" refers to the fact that these meteors appear to originate from the constellation Gemini (the twins), even though one has nothing to do with the other.  As a general rule, the higher the constellation Gemini climbs in the sky, the more the number and intensity of meteor sightings increases. 

If you missed the Geminid shower this year, it is an annual event and will occur next December once again on the 13th and 14th.  At the beginning of the new year, mark your calendar with major sky happenings found on sites like Sea Sky's Astronomy Calendar. There are also phone apps that send alerts or help you navigate the night sky. Viewing celestial events with your family or others can be a fun after dark activity.   Children love the excitement of being outside in the dark.  Sit under the stars with snacks and hot chocolate, as well as lots of cozy blankets. 

References and Resources

earthsky.org - Don't miss the Geminids in 2017!

space.com - Geminid Meteor Shower 2107

seasky.org - Astronomy Calendar 2018

Image: zyzixun.net

Night Sky Travelers

Another crisp December evening.  We joined our neighbors to attend an astronomy presentation under a classic Arizona star-studded sky.  We were treated to many fantastic views of the heavens through a celestron telescope.  Without visual assistance, we were also able to witness various satellites that appeared like fast moving stars, here and gone as they continued in their orbit.  According to our presenter, satellites and other space craft can be seen with the naked eye many times a night, depending on the situation.  

The perfect balance of gravity and inertia (forward momentum) is required for natural or man-made satellites to complete their orbits flawlessly.  Craft designers must adjust the speed of a satellite to "match" the curve of the earth. Imagine throwing a ball through the air. It gradually curves downward until it meets the ground.  Satellites also curve downward, but due to the curve of the earth, they don't crash.  The perfect amount of gravitational pull coupled with the speed of the object keeps it moving in a circular or elliptical path.

The same is true for planets and moons. The earth orbits the sun and the moon orbits the earth as each body moves due to a precise interplay of forces acting on one another. Amazingly, the design of the earth's orbit positions our beautiful planet not too close or too far to the sun, which would cause it to be too hot or cold for life.  Instead, all life on earth exists because of our perfect place in space. Seasons are caused by the tilt design of our earth and is another incredible concept to explore.

Objects orbiting in space are not easy for the average person to observe, but there are a few exceptions. One intriguing craft that is fairly easy to spot is the International Space Station (ISS). International Space Station orbits earth (and catches a sunrise) every 90 minutes as it races along at 5 miles per second! You can see where the Space Station is at any given moment and view the tracker to see where it was 90 minutes ago and where it will be in 90 minutes at the ESA site. Enter your location in Spot the Station and learn when and from what direction you can expect to see ISS move over your area.  There are people on board so be sure to wave!

References and Resources
Space Answers - Night Sky: How to catch the International Space Station
International Space Station
How Stuff Works - How do Satellites Orbit the Earth?
Northwestern - What Causes an Orbit?
Spot the Station - Scottsdale, Arizona
Astronomy Nights - Pinnacle Peak Park


Images: NASA - Public Domain

Hummingbird Power Nap

The December desert offers a few winter blooming surprises and two of them are in our back yard. This year, our agave filifera plant sent up an eight foot stalk and is now showing off row after row of magnificent blossoms. Where there are fresh blossoms, there are often hummingbirds slurping up the nectar through their grooved tongues. Our blooms quickly attracted a feisty Anna's Hummingbird, a year round resident of our area.

Hummingbirds are packed with mind blowing design. They are the only birds known to have the ability to fly forward, backward and hover. These tiny birds zip to and fro, finding food to feed their voracious appetites or courageously chasing off territorial intruders. Their little hearts beat 1,260 times per minute and their wings flap an astounding 40-50 times per second! They burn through so much energy that they are literally hours from death at any given moment. They need almost constant access to high energy nectar or insects to survive.

Many species of hummingbirds can live and feed in warm or cold weather, but even they need a well-earned time-out from their feeding frenzies. That's precisely when a tricky design stunt known as torpor comes in handy. Torpor is a short period of very deep sleep or "mini" hibernation. Unlike animals that hibernate for weeks or months, a hummingbird with a limited food supply can enjoy a period of deep sleep every day. The hummingbird can temporarily enter a state of torpor, a time in which the heart slows dramatically, and the bird can appear dead. Body temperature drops and only a fraction of its awake time energy is needed. 

Although it is fairly unusual, if you ever come across a lifeless hummingbird, be careful not to disturb it. It may just be in a state of torpor. You may want to research some of the hummingbird's other design features by setting up a feeder near a window where you can watch these amazing birds zip through the air, hover, perch and feed. Learn how to make Hummingbird food and keep the feeder clean and full. Another way to help the hummingbirds and enjoy watching them is to cultivate plants with nectar-rich blossoms in your yard. Arizona Sonora Museum offers a list of plants, as well as information about how to attract hummingbirds to your yard.

References and Resources

Cornell Lab or Ornithology - Anna's Hummingbirds

World of Hummingbirds - Hummingbird Sleep

Images - Public Domain Pictures and Sharon Pegany

Migrations

The desert is cooling off and with the coming of a mild winter, creatures are stirring and shifting once again.  This is a time of mass movement in the animal world.  All over the planet, animals are on the move, migrating to areas that are more suitable for survival or preparing for the next generation. Each species is designed in such a way that they have the necessary physical and mental "equipment" to embark on such journeys.

For instance, you have probably watched a flock of geese overhead as they line up in a perfect V formation.  Aside from the beautiful symmetry we see from below, how does this design serve the geese? As a bird flaps, rotating air currents swirl off the end of its wing.  That circular movement causes the air directly behind the bird to push down and the air behind and to the sides to lift up. The other birds in a flock are really good at finding the pockets of air that lift up.  It makes flying long distances easier.

The Sonoran Desert is a thoroughfare for many species of animal travelers, particularly birds.  Southeastern Arizona is a unique area because four diverse biomes intersect there.  Birds from all four biomes can be seen in this one little corner of the state.  Around Christmas time, the Audubon Society conducts its annual Christmas Bird Count.  Bird Trackers can participate to help document the bird species moving through a given area.

This year, celebrate bird design by starting a December family tradition.  Take a walk into a natural area and see how many birds you can count.  If you are able, determine how many different kinds of birds and if they are alone or in a flock.

Resources and References
Adventure Birding
The Great Backyard Bird Count - February 16-19, 2018
National Geographic - Birds in a V

Image - Public Domain Pictures