IAAS Monthly Astronomy Newsletter
The International Association for Astronomical Studies provides this newsletter as a service for interested persons worldwide.
This newsletter is now available as an iTunes podcast. Visit http://www.apple.com, download and install iTunes (for either Mac or Windows). Search for "IAAS" and subscribe to the podcast. You may also go to http://www.ki0ar.com/astro.html and click on the Subscribe/RSS link. Update your iPod or mp3 player and listen to the newsletter at your leisure. Since this is a new feature, comments and constructive criticisms are greatly appreciated. An Open Invitation - For amateur radio operators and scanner enthusiasts, when in the Denver metro area, please join the Colorado Astronomy Net on the Rocky Mountain Radio League's (http://rmrl.hamradios.com/) 146.94 MHz repeater on Tuesday nights at 7 P.M. local time. Special Notice to Denver, CO area residents and visitors to the area: The Plains Conservation Center in Aurora hosts Full Moon Walks every month, weather permitting, on or near the night of the full Moon. Visit http://www.plainsconservationcenter.org for more information and directions.
Excerpts from JPL mission updates are provided as a public service as part of the JPL Solar System Ambassador / NASA Outreach program.
In This Newsletter...
* The Moon
* The Planets
* Astronomical Events
* Planetary/Lunar Exploration Missions
* Web Sites of Interest
* Acknowledgments and References
* Subscription Information
A calendar displaying the daily astronomical events.
* First Quarter Moon occurs on the 4th.
* Full Moon occurs on the 12th.
* Last Quarter Moon occurs on the 20th.
* New Moon occurs on the 27th.
* The Moon is at Apogee on the 15th, 252,317 miles from Earth.
* The Moon is at Perigee on the 27th, 222,176 miles from Earth.
* Mercury passes 0.7° north of Regulus on the 8th.
* Mars passes 6° north of Pollux on the
* The Moon passes 6° north of Neptune on the 10th.
* The Moon passes 6° north of Uranus on the 13th.
* The Moon passes 5° north of Jupiter on the 16th.
* The Moon passes 5° south of Mars on the 23rd.
For reference: The Full Moon subtends an angle of 0.5°.
The Planets & Dwarf Planets
Planetary Reports are generated by "TheSky" software. (http://www.ki0ar.com/planrpts.html) These reports provide predicted data for the planets on the first of each month for the current year. The rise and set times for the Sun and the Moon for each day of the month are also included in the reports. These reports have been optimized for the Denver, Colorado location, however, the times will be approximate for other locations on Earth.
(All times are local unless otherwise noted.)
* Planetary Highlights for September - Look for Saturn in the early evening skies. Venus returns to the evening sky as Saturn departs. Pluto, Neptune, Ceres, Uranus and Jupiter follow in the early and late evening. Mars and Mercury are visible before sunrise. The Earth reaches the Autumnal Equinox, starting the fall season in the northern hemisphere and the spring season in the southern hemisphere.
* Mercury - Is at greatest western elongation (18° above the eastern horizon) on the 3rd. Mercury is in superior conjunction on the 28th. Mercury rises about 4:59 a.m. on the 1st and rises about 7:06 a.m. by month's end. Look for Mercury in the morning sky during the first two weeks of September. Mercury moves from the constellation of Leo into Virgo this month shining at magnitude 0.1.
* Venus - Will return to the evening sky by the end of the month. Look for Venus setting about 25 minutes after the Sun during the last week of September. Venus sets about 7:15 p.m. by month's end. Venus is in the constellation of Virgo shining at magnitude -3.9 on the 30th.
* Earth - The Autumnal Equinox occurs on the
23rd at 5:05 a.m. EDT.
* Mars - Rises at 2:16 a.m. on the 1st and about 1:49 a.m. by month's end. Mars moves from the constellation of Gemini into Cancer this month shining at magnitude 1.4.
* Jupiter - Rises at 10:00 p.m. on the 1st and about 7:57 p.m. by month's end. Jupiter dominates the mid to late evening sky as it is the brightest object in the sky during these cool autumn evenings. Jupiter is in the constellation of Aries this month shining at magnitude -2.7.
* Saturn - Sets at 9:05 p.m. on the 1st and about 9:05 p.m. by month's end. By the time the Sun sets, Saturn is sitting just a few degrees above the western horizon. On the 1st, look about 20° to the right of the crescent Moon to
find Saturn. Saturn is in the constellation of Virgo shining at magnitude 0.8.
* Uranus - Reaches opposition on the 25th, rising as the Sun sets. Uranus rises at 8:25 p.m. on the 1st and about 6:24 p.m. by month's end. Uranus is also at its best and brightest at this time. Uranus is in the constellation of Pisces shining at magnitude 5.7.
* Neptune - Rises at 7:01 p.m. on the 1st and about 5:01 p.m. by month's end. Neptune still appears near its best for the year. Look for Neptune about 30° to the southeast around 9 p.m. local and then around midnight when Neptune reaches its peak altitude. Neptune is in the constellation of Aquarius shining at magnitude 7.8.
* Ceres - Is at opposition on the 16th, rising as the Sun sets. Ceres rises at 9:21 p.m. on the 1st and about 7:08 p.m. by month's end. Ceres moves from the constellation of Cetus into Aquarius this month shining at magnitude 7.7.
* Pluto - Sets at 1:36 a.m. on the 1st and about 11:33 p.m. by month's end. Pluto is in the constellation of Sagittarius shining at magnitude
As always, good luck at spotting these two, a large telescope and dark skies will be needed.
* No significant meteor shower activity this month, but you can expect to see from 1 to 6 meteors per hour early in the month.
* Comet C/2009 P1 Garradd should provide excellent viewing for the fall months. Comet Garradd is expected to reach 7th magnitude and be visible through backyard telescopes under dark skies passing through the constellation of Sagitta into Hercules this month.
* No eclipse activity this
* Comet Garradd passes near the Coathangar asterism (Cr 399) on the 2nd and 3rd.
* Uranus is at its best on the 25th.
Asteroids (From west to east)
* Vesta is in the constellation of Capricornus.
* Nausikaa is at opposition on the 1st in the constellation of Aquarius.
* Euterpe is in the constellation of Pisces.
* Amphitrite is in the constellation of Aries.
* Eunomia is in the constellation of Perseus.
(Excerpts from recent mission updates)
* Cassini - August 26, 2011
Cassini Closes in on Saturn's Tumbling Moon Hyperion
"NASA's Cassini spacecraft captured new views of Saturn's oddly shaped moon Hyperion during its encounter with this cratered body on Thursday, Aug. 25. Raw images were acquired as the spacecraft flew past the moon at a distance of about 15,500 miles (25,000 kilometers), making this the second closest encounter.
Hyperion is a small moon -- just 168 miles (270 kilometers) across. It has an irregular shape and surface appearance, and it rotates chaotically as it tumbles along in orbit. This odd rotation prevented scientists from predicting exactly what terrain the spacecraft's cameras would image during this flyby.
However, this flyby's closeness has likely allowed Cassini's cameras to map new territory. At the very least, it will help scientists improve color measurements of the moon. It
will also help them determine how the moon's brightness changes as lighting and viewing conditions change, which can provide insight into the texture of the surface. The color measurements provide additional information about different materials on the moon's deeply pitted surface.
The latest raw images of Hyperion are online at:
* New Horizons - August 16, 2011
The PI’s Perspective: Visiting Four Moons, in Just Four Years, for All Mankind
"In June and July, members of the New Horizons science team, using the Hubble Space Telescope, discovered and confirmed that Pluto has a fourth moon! The new satellite, provisionally called P4,
is fainter and therefore likely much smaller, than either Nix or Hydra or Charon – Pluto’s other three known moons. For comparison, while Charon is about as wide as the U.S. state of Colorado, Nix and Hydra are closer to the width of Vermont, and P4 is likely to be no wider across than Boulder County, Colorado.
New Horizons remains healthy and on course, now approximately 21 times as far from the Sun as the Earth is – well on its way, between the orbits of Uranus and Neptune."
For more information on the New Horizons mission - the first mission to
the ninth planet - visit the New Horizons home page: http://pluto.jhuapl.edu/.
* Dawn - August 11, 2011
NASA's Asteroid Photographer Beams Back Science Data
"The Dawn spacecraft has completed a graceful spiral into the first of four planned science orbits during the spacecraft's yearlong visit to Vesta. The spacecraft started taking detailed observations on Aug. 11 at 9:13 a.m. PDT (12:13 a.m. EDT), which marks the official start of the first science-collecting orbit phase at Vesta, also known as the survey orbit.
Survey orbit is the initial and highest orbit, at roughly 1700 miles (2700 kilometers) above the surface, which will provide an overview or "big picture" perspective of the giant asteroid."
* MESSENGER - August 15, 2011
MESSENGER Co-Investigator Elected Fellow of the Geological Society of America
"MESSENGER Co-Investigator Louise Prockter has been elected a fellow of the Geological Society of America (GSA). Established in 1888, the GSA — comprised of about 25,000 members — seeks to foster the quest for understanding the Earth, planets, and life; catalyze new scientific ways of thinking about natural systems; and support the application of geoscience knowledge and insight to human needs, aspirations, and Earth
To become a fellow, an honor reserved for less than 3 percent of the national society’s members, honorees must be nominated by an existing GSA fellow in recognition of distinguished contributions to the geosciences and approved by the entire GSA senate.
Prockter "is deserving of this recognition because of her high standing in the scientific community, contributions to major spacecraft missions, the significance of her planetary geology research, her leadership of scientific teams, and her service through editorships, peer review panels, and as a GSA officer in the Planetary Geology Division," wrote NASA Geophysicist Herbert V. Frey, in the nomination letter he submitted."
* Pack Your Backpack
Calling all explorers! Tour JPL with our new Virtual Field Trip site. Stops include Mission Control and the Rover Lab. Your guided tour starts when you select a "face" that will be yours throughout the visit. Cool space images and souvenirs are all included in your visit.
* Mars Odyssey Orbiter - No new news since December 15, 2010
NASA's Odyssey Spacecraft Sets Exploration Record on Mars
"PASADENA, Calif., -- NASA's Mars Odyssey, which launched in 2001, will break the record Wednesday for longest-serving spacecraft at the Red Planet. The probe begins its 3,340th day in Martian orbit at 5:55 p.m. PST (8:55 p.m. EST) on Wednesday to break the record set by NASA's Mars Global Surveyor, which orbited Mars from 1997 to 2006.
Odyssey's longevity enables continued science, including the monitoring of seasonal changes on Mars from year to year and the most detailed maps ever made of most of the planet. In 2002, the spacecraft detected hydrogen just below
the surface throughout Mars' high-latitude regions. The deduction that the hydrogen is in frozen water prompted NASA's Phoenix Mars Lander mission, which confirmed the theory in 2008. Odyssey also carried the first experiment sent to Mars specifically to prepare for human missions, and found radiation levels around the planet from solar flares and cosmic rays are two to three times higher than around Earth."
The fly-through plus tools for wandering across and zooming into the large image are athttp://themis.asu.edu/."
DAILY MARS ODYSSEY THEMIS IMAGES
* Mars Exploration Rover Mission (Spirit and Opportunity) - August 24, 2011
SPIRIT UPDATE: Spirit Remains Silent at Troy - sols 2621-2627, May 18-24, 2011:
"No communication has been received from Spirit since Sol 2210 (March 22, 2010).
More than 1,300 commands were radiated to Spirit as part of the recovery effort in an attempt to elicit a response from the rover. No communication has been received from Spirit since Sol 2210 (March 22,
2010). The project concluded the Spirit recovery efforts on May 25, 2011. The remaining, pre-sequenced ultra-high frequency (UHF) relay passes scheduled for Spirit on board the Odyssey orbiter will complete on June 8, 2011.
Total odometry is unchanged at 7,730.50 meters (4.80 miles)."
OPPORTUNITY UPDATE: Opportunity Studies Rocks on Crater Rim - sols 2690-2696, August 18-24, 2011:
"Opportunity is less than 500 meters (0.31 miles) from "Spirit Point," the first landfall on the rim of Endeavour crater.
The rover drove four times in the last week on Sols 2663, 2664, 2667 and 2668 (July 22, 23, 26 & 27, 2011), totaling over 460 meters (0.29 miles) of drive distance. The right-front wheel currents remain behaved. On Sol 2669 (July 28, 2011), Opportunity paused in her driving to collect a microscopic imager (MI) mosaic of the surface and an overnight alpha particle X-ray spectrometer (APXS) spectrum of exposed outcrop. The rover also performed a diagnostic test of the MI poker. The results of that test will be received later today. The plan ahead is more driving.
As of Sol 2668 (July 27, 2011), solar array energy production was 413 watt-hours with an atmospheric opacity (Tau) of 1.01 and a solar array dust factor of 0.587.
Total odometry is 32,973.44 meters (32.97 kilometers, 20.49 miles)."
Visit the Mars Exploration Rover page at
* Mars Reconnaissance Orbiter Mission - August 04, 2011
NASA Spacecraft Data Suggest Water Flowing on Mars
"PASADENA, Calif. -- Observations from NASA's Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.
"NASA's Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form,î NASA Administrator Charles Bolden said, ìand it reaffirms Mars as an important future destination for human exploration."
Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring. Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere.
"The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson. McEwen is the principal investigator for the orbiter's High Resolution Imaging Science
Experiment (HiRISE) and lead author of a report about the recurring flows published in Thursday's edition of the journal Science."
MARS RECONNAISSANCE ORBITER HIRISE IMAGES
of the HiRISE images are archived here:
Links and Other Space News
(If you have a link you would like to recommend to our readers, please feel free to submit it.)
In the car, at work or under the night time sky astronomy goes where you go! (This page has not been updated since September 2010)
Many of the astronomical terms used in this newsletter are defined here.
* Cloudbait Observatory, Guffey Colorado - http://www.cloudbait.com - Submit your fireball reports here. Interesting, knowledgeable site.
Good site for finding out more about the 88 constellations and their associated stars.
Desktop Astronomy package for PCs.
* Eric's Black Sun Eclipse website -
If you're looking for a reasonably priced laser pointer that is great for astronomy work, visit this site.
Unique adventures and vacations including astronomy related vacations.
To preserve and protect the nighttime environment and our heritage of dark skies.
* JPL Solar System
Ambassador Program -
* Meade Advanced Products Users Group - http://www.mapug-astronomy.net/ - Mapug-Astronomy Topical Archive & information resource, containing a massive 335 page archive of discussions about Meade equipment, and much more: observatories, observing lists, permanent piers, equatorial wedges, remote operations, software, eyepieces, etc.
Interactive Star Chart
Astronomy from Down Under - The Southern Hemisphere's first astronomy and space magazine.
This site gives you the best times to watch the ISS pass over or near your location.
Interesting space and astronomy articles.
* "SpaceRef.com" - http://www.spaceref.com/ - SpaceRef's 21 news and reference web sites are designed to allow both the novice and specialist alike to explore outer space and Earth observation.
This site includes links to planetary updates such as Mercury Today, Venus Today, Earth Today, Moon Today, Mars Today, Jupiter Today, Saturn Today, Pluto Today, etc.
Free, downloadable planetarium/astronomy software.
WIKISKY is a non-commercial project. The main purpose of WIKISKY is to consolidate astronomical, astrophysical and other information about different space objects and astrophysical facts.
Acknowledgments and References
Much of the information in this newsletter is from "Astronomy Magazine" (Kalmbach Publishing), JPL mission status reports, "Meteor Showers - A Descriptive Catalog" by Gary W. Kronk and other astronomical sources that I have stashed on my book shelves.
The author will accept any suggestions, constructive criticisms, and corrections. Please feel free to send me any new links or articles to share as well. I will try to accommodate any reasonable requests. Please feel free to send questions,
comments, criticisms, or donations to the email address listed below. Enjoy!
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73 from KI0AR
Created by Burness F. Ansell, III
COO, Director of Aerospace Technologies, IAAS
JPL Solar System Ambassador, Colorado
Last modified: August 31, 2011