[astronews] IAAS Monthly Astronomy Newsletter

  • From: Burness Ansell <ki0ar@xxxxxxxxx>
  • To: Astronomy Newsletter <astronews@xxxxxxxxxxxxx>
  • Date: Sat, 31 Jul 2010 22:03:43 -0700 (PDT)

IAAS Monthly Astronomy Newsletter
August 2010


The International Association for Astronomical Studies provides this newsletter 
as a service for interested persons worldwide.


This newsletter is published on the World Wide Web at 
http://www.ki0ar.com/astro.html - The Home of KI0AR - and is received 
nationally and internationally. A PDF formatted downloadable version of the 
newsletter is at http://www.ki0ar.com/current_nl.pdf.

This newsletter is now available as an iTunes podcast. Visit 
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Search for "IAAS" and subscribe to the podcast. You may also go to 
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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 


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


The Month At-A-Glance at http://www.ki0ar.com/ataglance.html
A calendar displaying the daily astronomical events.


The Moon

* Last Quarter Moon occurs on the 3rd.
* New Moon occurs on the 9th.
* First Quarter Moon occurs on the 16th.
* Full Moon occurs on the 24th.

* The Moon is at Perigee on the 10th, 222,362 miles from Earth.
* The Moon is at Apogee on the 25th, 252,518 miles from Earth.

Moon/Planet Pairs:
* Mars passes 1.9° south of Saturn on the 1st.
* Venus passes 3° south of Saturn on the 9th.
* The Moon passes 2° south of Mercury on the 12th.
* The Moon passes 8° south of Saturn on the 13th.
* The Moon passes 5° south of Venus on the 13th.
* The Moon passes 6° south or Mars on the 13th.
* Venus passes 2° south of Mars on the 23rd.
* The Moon passes 5° north of Neptune on the 24th.
* The Moon passes 6° north of Uranus on the 27th.
* The Moon passes 7° north of Jupiter on the 27th.

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 August - "Four planets come into view shortly after 
sunset. Mercury, Venus, Mars, and Saturn gather low in the west at dusk and set 
within 2 hours of the Sun. Brilliant Venus stands out far more than the others.

Three more planets rise after the sky grows dark. Jupiter becomes the major 
attraction from late evening until dawn, but both Uranus and Neptune make 
worthy targets for binocular users. All seven planets provide a thrill when 
viewed through a telescope, although some appear more spectacular than others." 
(Astronomy Magazine, August 2010, p. 38)

* Mercury - Is at greatest eastern elongation (27° above the western horizon) 
on the 6th. Mercury is stationary on the 19th. Mercury sets at 9:21 p.m. on the 
1st and about 7:17 p.m. by month's end. Look for Mercury about 6° above the 
western horizon during the first two weeks of July. Mercury moves from the 
constellation of Leo into Sextans this month shining at magnitude 0.1 on the 
1st and dimming considerably by the end of the month..

* Venus - Is at greatest eastern elongation (46° above the western horizon) on 
the 19th. As the month progresses, Venus passes by Saturn on the 9th and then 
Mars on the 23rd. Venus brightens from magnitude -4.3 to -4.6 by month's end. 
Venus is visible in the west soon after sunset. Venus sets at 10:08 p.m. on the 
1st and about 7:17 p.m. by month's end. Venus is in the constellation of Virgo 
this month.

View the "Venus in August" movie: http://www.ki0ar.com/Venus_in_August.mov
Looking towards the West about 7:30 p.m local time.

* Earth - N/A.

* Mars - Sets at 10:26 p.m. on the 1st and about 9:09 p.m. by month's end. Mars 
is in the constellation of Virgo this month shining at magnitude 1.5.

* Jupiter - Rises is 10:28 a.m. on the 1st and about 8:21 p.m. by month's end. 
Jupiter rises about the same time as Saturn sets this month. Look for Jupiter 
in the east and south in the late evening and early morning after midnight. On 
the evening of the 11th/12th, watch Europa disappear into Jupiter's shadow. On 
the evening of the 14th/15th, beginning at 12:40 a.m. EDT, watch the transit of 
Io across the face of Jupiter. Jupiter is in the constellation of Pisces this 
month shining at magnitude -2.8.

* Saturn - Another one of the early evening quartet, precedes Mars. Saturn sets 
at 10:32 a.m. on the 1st and about 8:38 p.m. by month's end. Look for Saturn in 
the evening in the west after sunset. Saturn is in the constellation of Virgo 
shining at magnitude 1.1.

* Uranus - Should once again be relatively easy to spot this month lying just 
3° west of Jupiter. Uranus rises at 10:18 p.m. on the 1st and about 8:14 p.m. 
by month's end, preceding Jupiter by just a few minutes all month. Uranus is in 
the constellation of Pisces shining at magnitude 5.8.

* Neptune - Is at opposition on the 20, rising as the Sun sets. Rises at 8:58 
p.m. on the 1st and about 6:54 p.m. by month's end. Even though Neptune will be 
at opposition and at its best for this year, observers will still need good 
binoculars or a small telescope to spot Neptune. Neptune is in the 
constellation of Aquarius this month shining at magnitude 7.8.

Dwarf Planets  
* Ceres - Sets at 1:03 a.m. on the 1st and about 11:01 p.m. by month's end. 
Ceres is in the constellation of Ophiuchus this month shining at magnitude 8.4. 

* Pluto - Sets at 3:32 a.m. on the 1st and about 1:28 a.m. by month's end. 
Pluto is in the constellation of Sagittarius shining at magnitude 14.0.

As always, good luck at spotting these two, a large telescope and dark skies 
will be needed.


Astronomical Events

Meteor Showers
* The Northern Delta Aquarids extends from July 16 to September 10. Maximum 
occurs on August 13. The hourly rates reach a high of 10.

* The Perseids meteor shower is generally visible between July 23 and August 
22. Maximum occurs during August 12/13. The hourly rate typically reaches 80, 
although some years have been as low as 4 and as high as 200. The meteors tend 
to be very fast, possess an average magnitude of 2.3 and leave persistent 

This year, the Perseids will not be hindered by Moon light, so even may faint 
ones should be quite visible. Also evenings should be good for spotting Earth 
grazers. This meteor shower is usually one of year's the best and observers can 
expect to see many meteors during the week before and after the meteor shower 
as well as during the peak. The best time to view most any meteor showers is 
between midnight and dawn.

* For more information about Meteor Showers, visit Gary Kronk's Meteor Showers 
Online web page at http://meteorshowersonline.com/.

* Comet 10P/Temple may peak around 8th magnitude this month. Look for Comet 
Temple around mid-month after 1:00 a.m. local time traveling through Cetus this 
month. A small to medium sized telescope (4 to 8 inches) should allow observers 
to see a well defined nucleus and a short tail.

* For information, orbital elements and ephemerides on observable comets visit 
the Observable Comets page from the Harvard-Smithsonian Center for Astrophysics 

* For more information about Comets, visit Gary Kronk's Cometography.com web 
page at http://cometography.com/.

* No eclipse activity this month.

Observational Opportunities
* On July 15th, look for the crescent Moon passing near Venus, Mars and Saturn.

* On the evening of the 31st, Mercury joins Venus, Mars and Saturn in the 
evening sky. 

Asteroids (From west to east)
* Pallas is in the constellation of Boötes.
* Eunomia is in the constellation of Sagittarius.
* Flora is in the constellation of Aquarius.
* Laetitia is in the constellation of Pisces.
* Hebe is in the constellation of Cetus.
* Iris is in the constellation of Taurus.

* Information about the Minor Planets can be found at 
http://www.minorplanetobserver.com the Minor Planet Observer web site.

* Information on various occultations can be found at 
http://lunar-occultations.com/iota/iotandx.htm , the International Occultation 
Timing Association's (IOTA) web site.


Planetary/Lunar Exploration Missions
(Excerpts from recent mission updates)

* Cassini - July 29, 2010
Blowing in the Wind: Cassini Helps with Dune Whodunit

"The answer to the mystery of dune patterns on Saturn's moon Titan did turn out 
to be blowing in the wind. It just wasn't from the direction many scientists 

Basic principles describing the rotation of planetary atmospheres and data from 
the European Space Agency's Huygens probe led to circulation models that showed 
surface winds streaming generally east-to-west around Titan's equatorial belt. 
But when NASA's Cassini spacecraft obtained the first images of dunes on Titan 
in 2005, the dunes' orientation suggested the sands - and therefore the winds - 
were moving from the opposite direction, or west to east.

A new paper by Tetsuya Tokano in press with the journal Aeolian Research seeks 
to explain the paradox. It explains that seasonal changes appear to reverse 
wind patterns on Titan for a short period. These gusts, which occur 
intermittently for perhaps two years, sweep west to east and are so strong they 
do a better job of transporting sand than the usual east-to-west surface winds. 
Those east-to-west winds do not appear to gather enough strength to move 
significant amounts of sand."

Cassini Imaging Team's website - http://ciclops.org.

For the latest mission status reports, visit 
http://saturn.jpl.nasa.gov/home/index.cfm. The speed and location of the 
spacecraft can be viewed on the "Present Position" web page.

* New Horizons - July 27, 2010
LORRI Looks Back at "Old Friend" Jupiter

"In early 2007 New Horizons flew through the Jupiter system, getting a 
speed-boost from the giant planet's gravity while snapping stunning, close-up 
images of Jupiter and its largest moons.

Fast forward to 2010 and New Horizons has given us another glimpse of old 
friend Jupiter, this time from a vantage point more than 16 times the distance 
between Earth and the Sun, and almost 1000 times as far away as when New 
Horizons reconnoitered Jupiter. While the planet is too far for the camera to 
pick up the swirling clouds and brewing, Earth-sized storms it saw just three 
years ago, "the picture is a dramatic reminder of just how far New Horizons, 
moving about a million miles a day, has traveled," says mission Principal 
Investigator Alan Stern, of the Southwest Research Institute.


New Horizons gallery http://pluto.jhuapl.edu/gallery/sciencePhotos/.

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 - No new news since June 29, 2010
Engineers Assess Dawn's Reaction Wheel

"Engineers are studying the reaction wheels on NASA's Dawn spacecraft after 
automatic sensors detected excess friction building up in one of them and 
powered it off early on the morning of June 17, 2010. Reaction wheels spin to 
help a spacecraft maintain attitude control, and Dawn, which is exploring the 
asteroid belt, uses three wheels in normal operations.

The three other reaction wheels are functioning normally. Mission managers said 
plans for Dawn to visit the asteroid Vesta in 2011 and 2012 and dwarf planet 
Ceres in 2015 will not be not affected."

For more information on the Dawn mission, visit the Dawn home page: 

* MESSENGER - July 20, 2010
AGU Selects MESSENGER Paper as Eos Research Spotlight

"The American Geophysical Union has selected a research paper detailing 
observations of Mercury's magnetosphere during the probe's third flyby as a 
"Research Highlight" in today's issue of Eos, the AGU's weekly online and print 

"Observations of Kelvin-Helmholtz waves along the dusk-side boundary of 
Mercury's magnetosphere during MESSENGER's third flyby," by Scott Boardsen and 
coauthors, originally published in Geophysical Research Letters, is available 
online at http://www.agu.org/pubs/crossref/2010/2010GL043606.shtml.";

For more information on the MESSENGER mission, visit the MESSENGER home page: 

* 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.
+ http://virtualfieldtrip.jpl.nasa.gov/ ;
* Past, Present, Future and Proposed JPL Missions - 

* For special JPL programs and presentations in your area visit the JPL Solar 
System Ambassador web site at http://www2.jpl.nasa.gov/ambassador/index.html.

Mars Missions

* Mars Odyssey Orbiter - July 23, 2010
NASA Spacecraft Camera Yields Most Accurate Mars Map Ever

"PASADENA, Calif. - A camera aboard NASA's Mars Odyssey spacecraft has helped 
develop the most accurate global Martian map ever. Researchers and the public 
can access the map via several websites and explore and survey the entire 
surface of the Red Planet.
The map was constructed using nearly 21,000 images from the Thermal Emission 
Imaging System, or THEMIS, a multi-band infrared camera on Odyssey. Researchers 
at Arizona State University's Mars Space Flight Facility in Tempe, in 
collaboration with NASA's Jet Propulsion Laboratory in Pasadena, Calif., have 
been compiling the map since THEMIS observations began eight years ago.

The pictures have been smoothed, matched, blended and cartographically 
controlled to make a giant mosaic. Users can pan around images and zoom into 
them. At full zoom, the smallest surface details are 100 meters (330 feet) 
wide. While portions of Mars have been mapped at higher resolution, this map 
provides the most accurate view so far of the entire planet.

The new map is available at: 

"A simulated fly-through using the newly assembled imagery is available online 
at http://www.nasa.gov/mission_pages/mars/missions/odyssey/20060313.html.

The fly-through plus tools for wandering across and zooming into the large 
image are at http://themis.asu.edu/.";

Thermal Emission Imaging System (THEMIS) web site: 

The Odyssey data are available through a new online access system established 
by the Planetary Data System at: http://starbrite.jpl.nasa.gov/pds/ ;

Visit the Mars Odyssey Mission page at 

* Mars Exploration Rover Mission (Spirit and Opportunity) - July 22, 2010

SPIRIT UPDATE: Spirit Remains Silent at Troy - sols 2321-2329, July 14-22, 2010:

"Spirit remains silent at her location called "Troy" on the west side of Home 
Plate. No communication has been received from the rover since Sol 2210 (March 
22, 2010).

It is likely that Spirit has experienced a low-power fault and has turned off 
all sub-systems, including communication and gone into a deep sleep. While 
sleeping, the rover will use the available solar array energy to recharge her 
batteries. When the batteries recover to a sufficient state of charge, Spirit 
will wake-up and begin to communicate.

There is the additional risk that the rover may trip a mission clock fault. If 
that happens, the rover would remain asleep until the batteries have recharged 
sufficiently, and there is enough sunlight on the solar arrays to wake the 
rover. With the southern winter solstice back on May 13, 2010, solar energy 
levels and temperatures are expected to be improving.

Total odometry is unchanged at 7,730.50 meters (4.80 miles)."

OPPORTUNITY UPDATE: Opportunity in Good Health and Continues to Drive, Despite 
Lack of Downlink - sols 2301-2307, July 15-21, 2010:

"Due to Odyssey's safing event none of the planned Ultra-High Frequency (UHF) 
downlink passes for this period occurred.

All available X-band passes (which are normally uplink only) were changed to 
two-way, but supportable downlink data rates for these passes are low, and only 
basic engineering telemetry was received. However, this was enough data to 
determine that the rover continued to be in good health.

As a result of the lack of downlink data, very little in the way of activity 
was performed on the rover. A drive that had been designed based on Sol 2300 
(July 14, 2010) data was uplinked and executed on Sol 2301 (July 15, 2010), and 
the telemetry available indicates that this drive ran nominally.

Insufficient data is available to update power numbers, but as of Sol 2300 
(July 14, 2010), solar array energy production had improved to 492 watt-hours, 
atmospheric opacity (Tau) was 0.223 and the solar array dust factor was 0.700.

Total odometry as of Sol 2307 (July 21, 2010), is estimated at approximately 
21,830 meters (21.83 kilometers, or 13.56 miles)."

Landing sites link - http://marsoweb.nas.nasa.gov/landingsites/ ;

Visit the Mars Exploration Rover page at

* Mars Reconnaissance Orbiter Mission - No new news since June 24, 2010
New Clues Suggest Wet Era on Early Mars Was Global

"PASADENA, Calif. -- Minerals in northern Mars craters seen by two orbiters 
suggest that a phase in Mars' early history with conditions favorable to life 
occurred globally, not just in the south.

Southern and northern Mars differ in many ways, so the extent to which they 
shared ancient environments has been open to question.

In recent years, the European Space Agency's Mars Express orbiter and NASA's 
Mars Reconnaissance Orbiter have found clay minerals that are signatures of a 
wet environment at thousands of sites in the southern highlands of Mars, where 
rocks on or near the surface are about four billion years old. Until this week, 
no sites with those minerals had been reported in the northern lowlands, where 
younger volcanic activity has buried the older surface more deeply."


All of the HiRISE images are archived here:

More information about the MRO mission is available online at 

* Mars Missions Status - New Mars missions are being planned to include several 
new rover and sample collection missions. Check out the Mars Missions web page: 
http://mars.jpl.nasa.gov/missions/ and the Mars Exploration page: 


Links and Other Space News
(If you have a link you would like to recommend to our readers, please feel 
free to submit it.)

*** NEW *** Astronomy A-Go-Go - http://astronomy.libsyn.com/
In the car, at work or under the night time sky astronomy goes where you go!

* "TheSky" Software - http://www.bisque.com ;

* A Short Guide to Celestial Navigation - http://www.celnav.de/ ;

* Astrogirl Homepage - http://www.astrogirl.org ;

* Astronomical Lexicon - http://www.ki0ar.com/astrolex.html ;
Many of the astronomical terms used in this newsletter are defined here.

* Astronomy Picture of the Day - http://antwrp.gsfc.nasa.gov/apod/astropix.html ;

* Black Hole Encyclopedia - http://blackholes.stardate.org/ Excellent site from 
StarDate - University of Texas McDonald Observatory 

* Celestron Telescopes - http://www.celestron.com/c2/index.php - New beta 

* Cloudbait Observatory, Guffey Colorado - http://www.cloudbait.com - Submit 
your fireball reports here. Interesting, knowledgeable site.

* The Constellations and Their Stars - 
http://www.astro.wisc.edu/~dolan/constellations/constellations.html ;
Good site for finding out more about the 88 constellations and their associated 

* Denver Astronomical Society - http://www.denverastrosociety.org ;

* Distant Suns - http://www.distantsuns.com/ ;
Desktop Astronomy package for PCs.

* Eric's Black Sun Eclipse website -
http://www.ericsblacksuneclipse.com ;

* Groovy Adventures - http://www.groovyadventures.com ;
Unique adventures and vacations including astronomy related vacations.

* The International Dark-Sky Association - http://www.darksky.org
To preserve and protect the nighttime environment and our heritage of dark 

* JPL Solar System Ambassador Program -

* JPL Solar System - http://www.jpl.nasa.gov/solar_system/ ;

* 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.

* My Stars Live - http://www.mystarslive.com/ ;
Interactive Star Chart

* NASA Science News - http://science.nasa.gov/ ;

* Northern Colorado Astronomical Society - http://ncastro.org/ ;

* Sangre Stargazers - http://sangrestargazers.skymtn.com/ - New astronomy club 
in the Wet Mountain Valley of Custer County (about 45 miles due west of Pueblo, 

* Sky and Space - http://www.skyandspace.com.au/public/home.ehtml ;
Astronomy from Down Under - The Southern Hemisphere's first astronomy and space 

* Skymaps.com - http://www.skymaps.com/

* Skywatch Sightings from NASA - 
http://spaceflight.nasa.gov/realdata/sightings/ ;
This site gives you the best times to watch the ISS pass over or near your 

* Southern Colorado Astronomical Society - http://www.scasastronomy.info/

* Space.com - http://space.com ;
Interesting space and astronomy articles.

* Space.com - Sky Watch Calendar -
http://www.space.com/spacewatch/sky_calendar.html ;

* Spaceflight Now - http://spaceflightnow.com/ ;

* "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.

* Stellarium - http://www.stellarium.org
Free, downloadable planetarium/astronomy software.

* Universe Today - http://www.universetoday.com

* Wikisky - http://www.wikisky.org
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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Keep looking UP!
73 from KI0AR

Created by Burness F. Ansell, III

COO, Director of Aerospace Technologies, IAAS
JPL Solar System Ambassador, Colorado
Last modified: July 31, 2010


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