SKY HIGHLIGHTS provides information about things happening in the sky for the upcoming month.
The information here is a rough transcript of information covered on the popular CBC Radio
One Calgary Eyeopener "Eye on the Night Sky"
segment presented by Calgary Centre member Don Hladiuk and heard on the CBC radio morning show
the first Tuesday of each month at 6:22 AM. Don is a life member of the Royal Astronomical Society
of Canada and was twice President of the Calgary Centre. Since June 1984, Don has had a regular radio spot on
the Eyeopener describing monthly Sky Highlights to southern Albertans.
For additional sources of sky information see the list of links below this month's article.
For information about the Calgary Centre of the RASC, please
visit our web site at http://calgary.rasc.ca/ or contact one of
the Calgary Centre Executives.
ASTRONOMICAL HIGHLIGHTS
March 2010
Canada's first study of how trees grow in space (CSA Press Release)
http://www.asc-csa.gc.ca/eng/missions/sts-129/apex.asp
 Bob Thirsk (CSA) with willow tree stems
While in Florida to witness one of the last night launches of a space shuttle, I learned the STS 130 crew was bringing back an experiment started by Dr. Bob Thirsk. During his long-term expedition to the International Space Station (ISS), Bob Thirsk found himself engaging in the unusual task of bending willow tree stems into loops. No, he was not taking up basket-weaving as a hobby; rather, he was conducting a study known as APEX-Cambium (Advanced Plant EXperiments on Orbit). Funded by the Canadian Space Agency (CSA), APEX-Cambium will help determine the role gravity plays in trees forming different kinds of wood.
Parts of a tree that are not vertical typically grow one kind of wood on one side and another kind on the other, according to Rodney Savidge, a University of New Brunswick tree physiologist who is principal investigator of the experiment. This is known as "reaction wood" and the mix of different kinds of this wood in trees influences their suitability for different uses, such as construction or paper. Scientists believe reaction wood is a response to gravity, but they have not been able to prove it.
Savidge's experiment will reveal whether this reaction wood will grow on the upper sides of the tops and bottoms of willow stem loops in the weightless environment of space, as they do on Earth. He explains, "If we do not get reaction wood in the loops in the expected places in space, it will be an indication that weight on Earth, caused by gravity, is involved." Cambium is the plant tissue that actually grows to form wood in trees; this remarkable tissue allows tree trunks and branches to increase in girth as the tree grows, so that the tree has the strength to remain standing as it becomes more massive.
The looped tree stems, along with unlooped plants that will serve as controls, will be placed in the Advanced Biological Research System (or ABRS), an incubator in which they'll grow for about a month before being returned to Earth. Plant growth will occur in the cambium, a layer of tissue that produces the cells that ultimately become wood and bark (hence the experiment's name, APEX-Cambium).
The space samples will be compared with samples grown in the ground version of the ABRS incubator on Earth. "The idea is for the only variable to be weight," Savidge says.
The goal of this research is to improve knowledge of fundamental biological processes in trees. Despite all the money spent on forestry research, relatively little focuses on basic physiology, relates Savidge. "We don't understand how trees make wood."
He added that efforts to accelerate tree growth for commercial uses have increased the amount of reaction wood found in plantation trees. "This is a big concern. Our research will complement the effort to understand whether we're pushing trees too far, too fast."
Dr. Thirsk was responsible for marking, measuring, growing, and modifying-with the looping tool developed by the CSA in collaboration with Savidge-eighteen willow trees, twelve of which he looped and another six that were left to grow naturally, as controls. After thirty days, the trees were harvested (the looped and control plants) and frozen for their journey back to Earth, where Savidge will analyze the results.
3D Sun for the iPhone
http://www.nasa.gov/topics/solarsystem/features/iphone-sun.html
iPhone with 3D Sun application. Photo Credit: NASA
Imagine holding the entire sun in the palm of your hand. Now you can. A new iPhone app developed by NASA-supported programmers delivers a live global view of the sun directly to your cell phone. Users can fly around the star, zoom in on active regions, and monitor solar activity.
The name of the app is "3D Sun" and it may be downloaded free of charge at Apple's app store. Just enter "3D Sun" in the Store's search box or visit
http://3dsun.org
for a direct link. Realtime images used to construct the 3-dimensional sphere are beamed to Earth by the Solar-Terrestrial Relations Observatory (STEREO), a pair of spacecraft with a combined view of 87% of the solar surface. STEREO-A is stationed over the western side of the sun, while STEREO-B is stationed over the east. Together, they rarely miss a thing.
Telescopes onboard the two spacecraft monitor the sun in the extreme ultraviolet (EUV) portion of the electromagnetic spectrum. That's why the 3D sun looks false-color green as the images are not looking at the white light part of the spectrum. That's okay because EUV is where the action is. Solar flares and new sunspots shine brightly at these wavelengths. EUV images also reveal "coronal holes," vast dark openings in the sun's atmosphere that spew streams of solar wind into the solar system. Solar wind streams that hit Earth can spark intense displays of Northern Lights. One of the most popular features is when a solar flare erupts, you phone will play a little jingle to alert you. The app comes alive on its own when the sun grows active or when interesting events are afoot. For example, a recent alert notified users that a comet just discovered by STEREO-A was approaching the sun. When the comet was destroyed by solar heating, the app played a movie of Comet STEREO's last hours. Another remarkable aspect of the app is that it shows the far side of the sun -- the side invisible from Earth. Recently, STEREO-B was monitoring a far side sunspot (AR1041) when the sunspot's magnetic field erupted. For the first time in almost two years, an active region on the sun produced a strong "M-class" solar flare. The unexpected interruption of the sun's deep solar minimum was invisible from Earth, but anyone with the 3D Sun application had a ringside seat for the blast.
3D Sun was created by a team of programmers led by Dr. Tony Phillips, editor of Science@NASA. He says that version 1 of the app is just the beginning. Soon-to-be released 3D Sun 2.0 will offer higher-resolution images and multiple extreme ultraviolet wavelengths. These additions will reveal even more solar activity than before.
Can You See the Stars? http://www.globeatnight.org/
Southern Sky as seen from Alberta around 8:00 pm local time.
GLOBE at Night is an annual 2-week campaign in March. People all over the world record the brightness of their night sky by matching its appearance toward the constellation Orion with star maps of progressively fainter stars. They submit their measurements on-line and a few weeks later, organizers release a map of light-pollution levels worldwide. Over the last four GLOBE at Night campaigns, volunteers from over 100 nations have contributed 35,000 measurements.
GLOBE at Night, (students and their teachers, parents and community members) amassed a data set from which they can begin to explore the concept of light pollution and to research the patterns of light pollution across the globe.
A record number of over 15,000 measurements were received in the 2009 campaign! See this data at the website address listed above on the Map page.
The Calgary Centre of the Royal Astronomical Society of Canada has posted a second set of star charts for checking out the degree of light pollution from your backyard. See:
http://calgary.rasc.ca/skybrightness2010.htm
NASA's Chandra Reveals Origin of Key Cosmic Explosions - NASA News Release
http://www.nasa.gov/mission_pages/chandra/news/H-10-042.html
Composite X-Ray/Optical Infrared image of M31 Photo Credit: NASA
New findings from NASA's Chandra X-ray Observatory have provided a major advance in understanding a type of supernova critical for studying the dark energy that astronomers think pervades the universe. The results show mergers of two dense stellar remnants are the likely cause of many of the supernovae that have been used to measure the accelerated expansion of the universe.
These supernovae, called Type 1a, serve as cosmic mile markers to measure expansion of the universe because they can be seen at large distances, and they follow a reliable pattern of brightness. However, until now, scientists have been unsure what actually causes the explosions.
Most scientists agree a Type 1a supernova occurs when a white dwarf star -- a collapsed remnant of an elderly star -- exceeds its weight limit, becomes unstable and explodes. Scientists have identified two main possibilities for pushing the white dwarf over the edge: two white dwarfs merging or accretion, a process in which the white dwarf pulls material from a sun-like companion star until it exceeds its weight limit.
The difference between these two scenarios may have implications for how these supernovae can be used as "standard candles" -- objects of a known brightness -- to track vast cosmic distances. Because white dwarfs can come in a range of masses, the merger of two could result in explosions that vary somewhat in brightness.
Because these two scenarios would generate different amounts of X-ray emission, astronomers used Chandra to observe five nearby elliptical galaxies and the central region of the Andromeda galaxy (M31). A Type 1a supernova caused by accreting material produces significant X-ray emission prior to the explosion. A supernova from a merger of two white dwarfs, on the other hand, would create significantly less X-ray emission than the accretion scenario.
The scientists found the observed X-ray emission was a factor of 30 to 50 times smaller than expected from the accretion scenario, effectively ruling it out. This implies that white dwarf mergers dominate in these galaxies.
An open question remains whether these white dwarf mergers are the primary catalyst for Type 1a supernovae in spiral galaxies. Further studies are required to know if supernovae in spiral galaxies are caused by mergers or a mixture of the two processes. Another intriguing consequence of this result is that a pair of white dwarfs is relatively hard to spot, even with the best telescopes.
In addition to the X-rays observed with Chandra, other data critical for this result came from NASA's Spitzer Space Telescope and the ground-based, infrared Two Micron All Sky Survey. The infrared brightness of the galaxies allowed the team to estimate how many supernovae should occur.
50th Year Anniversary since Launch of First Interplanetary Space Probe
Pioneer 5 was launched on March 11, 1960. Photo Credit: NASA
Pioneer 5 (also known as 1960 Alpha 1, Pioneer P-2, and Thor Able 4) was a spin-stabilized space probe in the NASA Pioneer program used to investigate interplanetary space between the orbits of Earth and Venus. It was launched on March 11, 1960 from Cape Canaveral Air Force Station Launch Complex 17a at 13:00:00 UTC with an on-orbit dry mass of 43 kg. It is a 0.66 m diameter sphere with 1.4 m span across its four solar panels and achieved a solar orbit of 121,000,000 by 149,000,000 km. Among other accomplishments, the probe confirmed the existence of interplanetary magnetic fields. Pioneer 5 was the most successful probe in the Pioneer/Able missions.
What's Up in the March Sky
In the evening sky low in the west, Venus continues to move eastward and Mercury will make a brief appearance in the last week of March. Looking to the southeast after sunset, one will see Mars high in the sky between the head of Leo the Lion and Gemini. About 8:00 pm, Saturn rises in the east in the constellation of Virgo. Saturn's magnificent ring system is one of the best sights viewed in a small telescope. Light from Saturn takes about 71 minutes to reach us here on earth.
In mid March, the ISS will be making several excellent passes right over southern Alberta after sunset tracking west to east across our sky. For dates and times go to:
http://spaceflight.nasa.gov/realdata/sightings/index.html
Just a reminder that there is free telescope viewing at the TELUS World of Science on Friday evenings (weather permitting). There will be additional evening telescope viewing during the school spring break. For more info, go to:
http://www.calgaryscience.ca/schedules/stargazing.php
Dates to Remember:
March 1: 400 years ago Galileo published Sidereus Nuncius, the Starry Messenger, the book that contained the first descriptions of what objects in the sky looked like through a telescope.
March 3: Mars Express spacecraft passes only 50 km above the Martian moon Phobos
March 3-16: Send in your GLOBE at Night observations
March 11: 50th Anniversary of Pioneer 5
March 14: Daylight Savings Time returns
March 17: Crescent moon near Venus
March 18: 45th Anniversary of Leonov's 1st ever space walk
March 18: Free Public Lecture at the TELUS World of Science - "Debunking the 2012 Mayan Doomsday Prophecy"
March 20: Vernal Equinox (first day of spring in the northern hemisphere) arrives at 11:32 am MDT.
March 20: Moon near the Pleiades star cluster in Taurus
March 21: Saturn closest to the earth and the brightest
March 24: Calgary Zoo Presentation - "Chasing Dragons" by Don Hladiuk
March 28: Earth Hour - turn off your lights from 8:00 - 9:00 pm
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Other Sources of Current Sky Information:
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