[astronews] IAAS Monthly Astronomy Newsletter

  • From: Burness Ansell <ki0ar@xxxxxxxxx>
  • To: Astronomy Newsletter <astronews@xxxxxxxxxxxxx>
  • Date: Sat, 30 Apr 2011 14:13:06 -0700 (PDT)

IAAS Monthly Astronomy Newsletter
May 2011

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 
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 

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

* New Moon occurs on the 3rd.
* First Quarter Moon occurs on the 10th.
* Full Moon occurs on the 17th.
* Last Quarter Moon occurs on the 24th.

* The Moon is at Perigee on the 15th, 225,020 miles from Earth.
* The Moon is at Apogee on the 27th, 251,657 miles from Earth.

Moon/Planet Pairs:
* The Moon passes 8° north of Mercury on the 1st.
* Mars passes 0.4° north of Jupiter on the 1st.
* The Moon passes 6° north of Jupiter on the 1st.
* The Moon passes 6° north of Mars on the 1st.
* Mercury passes 2° south of Jupiter on the 10th.
* Venus passes 0.6° south of Jupiter on the 11th.
* The Moon passes 8° south of Saturn on the 14th.
* Mercury passes 2° south of Mars on the 19th.
* Venus passes 1.1° south of Mars on the 22nd.
* The Moon passes 6° north of Neptune on the 24th.
* The Moon passes 6° north of Uranus on the 27th.
* The Moon passes 6° north of Jupiter on the 29th.
* The Moon passes 4° north of Mars on the 30th.
* The Moon passes 4° north of Venus on the 30th.

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 May - "The stage is set for the finest planetary 
conjunction of the year. Mercury, Venus, Mars and Jupiter cluster near one 
another before dawn during May's first three weeks. But the highlight comes on 
the 11th when the two brightest - Venus and Jupiter - lie 1 Moon-width apart. 
Uranus and Neptune lurk in the east before sunrise, although you'll need 
binoculars or a telescope to spot them.
   Among the solar system's major planets, only Saturn plays on the evening 
stage. This magnificent actor will command the attention of the observing 
audience from dusk until well past midnight. To spot the minor character Pluto, 
you'll have to look carefully and use an 8-inch or larger scope. It rises in 
late evening and appears best by dawn." Astronomy Magazine, May 2011, P.36. 

* Mercury - Is at greatest western elongation on the 7th. Mercury is visible in 
the morning sky this month. Mercury rises at 5:09 a.m. on the 1st and about 
4:57 a.m. by the end of the month. Mercury moves from the constellation of 
Pisces into Taurus this month shining at magnitude 0.1.

* Venus - Rises at 4:57 a.m. on the 1st and about 4:33 a.m. by month's end. 
Venus shines brightly in the morning sky before sunrise. Venus moves from the 
constellation of Pisces into Aries this month shining at magnitude -3.8.

* Earth - N/A.

* Mars - Rises at 5:18 a.m. on the 1st and about 4:16 a.m. by the end of the 
month. Mars moves from the constellation of Pisces into Aries this month 
shining at magnitude 1.3.

* Jupiter - Rises at 5:19 a.m. on the 1st and about 3:35 a.m. by month's end. 
Jupiter is in the constellation of Pisces this month shining at magnitude -2.1.

* Saturn - Rises at 5:15 p.m. on the 1st and about 3:05 p.m. by month's end. 
Saturn is still the dominant evening planet this month and will remain so for 
several more months. Saturn is in the constellation of Virgo shining at 
magnitude 0.6.

* Uranus - Rises at 4:30 a.m. on the 1st and about 2:31 a.m. by month's end. 
Uranus is in the constellation of Pisces shining at magnitude 5.9.

* Neptune - Rises at 3:12 a.m. on the 1st and about 1:11 a.m. by month's end. 
Neptune is in the constellation of Aquarius shining at magnitude 7.9.

Dwarf Planets  
* Ceres - Rises at 4:24 a.m. on the 1st and about 2:50 a.m. by month's end. 
Ceres is in the constellation of Aquarius this month shining at magnitude 9.2.

* Pluto - Rises at 11:53 p.m. on the 1st and about 9:49 p.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 Eta Aquarid Meteor Shower - This shower is visible during the period of 
April 21 to May 12. It reaches maximum on May 5. During the period of greatest 
activity hourly rates usually reach 20 for observers in the northern hemisphere 
and 50 for observers in the southern hemisphere.

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

* Comet C/2009 P1 Garradd is beginning its visit to the inner solar system this 
month, although it shines at around 10th magnitude in the area of Aquarius, 
comet Garradd will hopefully brighten to 6th magnitude sometime in autumn.

* 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/.

* There is no eclipse activity this month.

Observational Opportunities
* On the morning of the 11th, Venus passes within 0.6° of Jupiter at 5 a.m. 
EDT. This is the closest these two planets will be until August of 2014. Also 
look for Mercury and Mars joining the pair.

Asteroids (From west to east)
* Hygiea is at opposition on the 13th in the constellation of Libra.
* Vesta is in the constellation of Capricornus.

* 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 - April 20, 2011
Cassini Sees Saturn Electric Link with Enceladus

"PASADENA, Calif. -- NASA is releasing the first images and sounds of an 
electrical connection between Saturn and one of its moons, Enceladus. The data 
collected by the agency's Cassini spacecraft enable scientists to improve their 
understanding of the complex web of interaction between the planet and its 
numerous moons. The results of the data analysis are published in the journals 
Nature and Geophysical Research Letters.

Scientists previously theorized an electrical circuit should exist at Saturn. 
After analyzing data that Cassini collected in 2008, scientists saw a glowing 
patch of ultraviolet light emissions near Saturn's north pole that marked the 
presence of a circuit, even though the moon is 240,000 kilometers (150,000 
miles) away from the planet.

The patch occurs at the end of a magnetic field line connecting Saturn and its 
moon Enceladus. The area, known as an auroral footprint, is the spot where 
energetic electrons dive into the planet's atmosphere, following magnetic field 
lines that arc between the planet's north and south polar regions."

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 - April 20, 2011
Wanted: Kuiper Belt Targets
New Horizons team launches search for post-Pluto flyby prospects

"The New Horizons team, working with astronomers using some of the largest 
telescopes on Earth, will begin searching this month for distant Kuiper Belt 
objects that the New Horizons spacecraft hopes to reconnoiter after completing 
its observations of the Pluto system in mid-2015. 

No spacecraft has ever visited the Kuiper Belt, a distant, donut-shaped region 
of the solar system filled with small planets and comets that formed early in 
the solar system's history.

Diagram of the Kuiper Belt, beyond the orbit of Neptune, more than 3 billion 
miles from the Sun. Pluto's orbit in the Kuiper Belt is shown in yellow; the 
trajectory of the New Horizons spacecraft is shown in red.

While the main target for NASA's New Horizons mission is Pluto and its three 
moons, New Horizons was built with post-Pluto Kuiper Belt object (KBO) flybys 
in mind."

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 March 29, 2011
When is an Asteroid Not an Asteroid?

"On March 29, 1807, German astronomer Heinrich Wilhelm Olbers spotted Vesta as 
a pinprick of light in the sky. Two hundred and four years later, as NASA's 
Dawn spacecraft prepares to begin orbiting this intriguing world, scientists 
now know how special this world is, even if there has been some debate on how 
to classify it.

Vesta is most commonly called an asteroid because it lies in the orbiting 
rubble patch known as the main asteroid belt between Mars and Jupiter. But the 
vast majority of objects in the main belt are lightweights, 100-kilometers-wide 
(about 60-miles wide) or smaller, compared with Vesta, which is about 530 
kilometers (330 miles) across on average. In fact, numerous bits of Vesta 
ejected by collisions with other objects have been identified in the main belt.

"I don't think Vesta should be called an asteroid," said Tom McCord, a Dawn 
co-investigator based at the Bear Fight Institute, Winthrop, Wash. "Not only is 
Vesta so much larger, but it's an evolved object, unlike most things we call 

The layered structure of Vesta (core, mantle and crust) is the key trait that 
makes Vesta more like planets such as Earth, Venus and Mars than the other 
asteroids, McCord said. Like the planets, Vesta had sufficient radioactive 
material inside when it coalesced, releasing heat that melted rock and enabled 
lighter layers to float to the outside. Scientists call this process 

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

* MESSENGER - April 26, 2011
Profiling Polar Craters with the Mercury Laser Altimeter

"MESSENGER's Mercury Laser Altimeter (MLA) will measure the topography or 
surface relief of the northern hemisphere of Mercury. That data will be used to 
create topographic maps, which will help characterize the geologic history of 
the planet. One of the most important tasks for MLA is to measure the depths of 
craters that are near Mercury's north pole. In the latest "Science Highlights 
from Mercury's Orbit (http://messenger.jhuapl.edu/soc/highlights.html)," 
MESSENGER's Geophysics discipline group explains why."

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 - 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."

Global Martian Map: http://www.mars.asu.edu/maps/?layer=thm_dayir_100m_v11.

"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) - April 19, 2011

SPIRIT UPDATE: Spirit Remains Silent at Troy - sols 2587-2593, April 13-19, 

"No communication has been received from Spirit since Sol 2210 (March 22, 2010).

Deep Space Network X-band listening and commanding covering a range of 
frequencies and local solar times on Mars is continuing. Selected over flights 
by the relay orbiters are exercised to elicit a response from the rover through 
the separate ultra-high frequency (UHF) system.

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

OPPORTUNITY UPDATE: Making Progress to Endeavour Crater - sols 2566-2572, April 
13-19, 2011:

"Opportunity continues the trek towards Endeavour crater with under 6 
kilometers (3.7 miles) to go before reaching the first landfall on the rim of 
Endeavour crater.

The rover drove on Sols 2569 and 2572 (April 16 and 19, 2011), gaining an 
additional 221 meters (725 feet) to the southeast. The rover's right front 
wheel motor currents continue to measure in at reasonable levels. In addition 
to driving, a notable activity included staying up overnight in the Sol 2570 
(April 17, 2011), plan in order to provide the power subsystem with the data 
they need to update the capacity estimate of the battery.

As of Sol 2572 (April 19, 2011), solar array energy production was 400 
watt-hours with an elevated atmospheric opacity (Tau) of 0.922 and a solar 
array dust factor of 0.5414.

Total odometry is 28,040.18 meters (28.04 kilometers, or 17.42 miles)."

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

Visit the Mars Exploration Rover page at

* Mars Reconnaissance Orbiter Mission - April 21, 2011
NASA Orbiter Reveals Big Changes in Mars' Atmosphere

"PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has discovered the 
total amount of atmosphere on Mars changes dramatically as the tilt of the 
planet's axis varies. This process can affect the stability of liquid water, if 
it exists on the Martian surface, and increase the frequency and severity of 
Martian dust storms.

Researchers using the orbiter's ground-penetrating radar identified a large, 
buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south 
pole. The scientists suspect that much of this carbon dioxide enters the 
planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. 
The findings are published in this week's issue of the journal Science.

The newly found deposit has a volume similar to Lake Superior's nearly 3,000 
cubic miles (about 12,000 cubic kilometers). The deposit holds up to 80 percent 
as much carbon dioxide as today's Martian atmosphere. Collapse pits caused by 
dry ice sublimation and other clues suggest the deposit is in a dissipating 
phase, adding gas to the atmosphere each year. Mars' atmosphere is about 95 
percent carbon dioxide, in contrast to Earth's much thicker atmosphere, which 
is less than .04 percent carbon dioxide."


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.)

* Astronomy A-Go-Go - http://astronomy.libsyn.com/
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)

* "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 ;

* Green Laser - http://www.greenlaser.com
If you're looking for a reasonably priced laser pointer that is great for 
astronomy work, visit this site.

* 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: April 30, 2011

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