[astronews] IAAS Monthly Astronomy Newsletter

  • From: Burness Ansell <ki0ar@xxxxxxxxx>
  • To: Astronomy Newsletter <astronews@xxxxxxxxxxxxx>
  • Date: Mon, 31 Mar 2008 21:41:30 -0700 (PDT)

                IAAS Monthly Astronomy Newsletter
                           April 2008


The International Association for Astronomical Studies provides this newsletter 
as a service for
interested persons in the Denver Metro area. The astronomical data presented 
here is not only
useful in Colorado but in other parts of the world as well.


This newsletter is published on the World Wide Web at 
http://bfa3.home.att.net/astro.html - The
Home of KI0AR - and is received nationally and internationally.


An Open Invitation - For amateur radio and scanner enthusiasts, when in the 
Denver metro area,
please join the Colorado Astronomy Net on the Rocky Mountain Radio League 
repeater on a frequency
of 146.94 MHz on Tuesday nights at 7 PM 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 Moon

* New Moon on the 5th.
* 1st Quarter Moon on the 12th.
* Full Moon on the 20th.
* Last Quarter Moon on the 28th.

* Perigee on the 7th, 224,365 mi. from Earth.
* Apogee on the 23rd, 252,241 mi. from Earth.

Moon/Planet Pairs:
* The Moon passes 0.002 deg. north of Neptune on the 2nd.
* The Moon passes 3 deg. North of Uranus on the 4th.
* The Moon passes 4 deg. south of Jupiter on the 2nd.
* The Moon passes 5 deg. north of Venus on the 5th.
* The Moon passes 1.2 deg. north of Mars on the 12th.
* The Moon passes 0.9 deg. south of Regulus on the 15th.
* The Moon passes 3 deg. south of Saturn on the 15th.
* The Moon passes 0.3 deg. south of Antares on the 23rd.
* The Moon passes 3 deg. south of Jupiter on the 27th.
* Mars passes 5 deg. South of Pollux on the 28th.


The Planets & Dwarf Planets
Planetary Reports generated by "TheSky" software. 
(http://bfa3.home.att.net/planrpts.html) These
reports provide predicted data for the planets for 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
(All times are local unless otherwise noted.)

* Planetary Highlights for April - On the 8th, the Moon occults the Pleiades 
star cluster. This
thin crescent will pass in front of several of the stars in the northern part 
of the cluster. Mars
and Saturn continue to present fine views in the evening sky. Jupiter can be 
found in the morning
sky before sunrise and the Lyrid meteor show peaks on the 22nd.

* Mercury - Is in superior conjunction on the 16th. Look for Mercury in the 
evening sky late in
the month. Mercury sets about 9:23 pm by month's end in the constellation of 
Taurus shining at
magnitude -1.0.

* Venus - Rises about 5:09 am on the 1st and about 5:39 am by month's end. For 
northern hemisphere
observers, Venus rises about 30 minutes before sunrise and is lost in the 
twilight glow, but for
those in the southern hemisphere, Venus rises conspicuously about 90 minutes 
before the Sun
shining at magnitude -3.8.

* Earth - N/A.

* Mars - Sets at 1:43 am on the 1st and about 1:38 am by month's end. Mars is 
in the constellation
of Gemini. Mars shines at magnitude 1.0.

* Jupiter - Rises at 2:01 am on the 1st and about 1:11 am by month's end. 
Jupiter continues to
climb higher in the southeast in the morning sky. Jupiter is in the 
constellation of Sagittarius
shining at magnitude -2.2.

* Saturn - Rises around 2:53 pm on the 1st and about 1:51 pm by month's end. 
Saturn is high in the
evening sky after the Sun sets and is visible for most of the night. Saturn 
shines at magnitude
0.4 in the constellation of Leo.

* Uranus - Has returned to the morning sky this month. Uranus rises at 4:56 am 
on the 1st and
about 4:01 am by month's end. Uranus is in the constellation of Aquarius 
shining at magnitude 5.9.

* Neptune - Rises at 3:47 am on the 1st and about 2:51 am by month's end. 
Neptune is in the
constellation of Capricornus shining at magnitude 7.9.

Dwarf Planets

* Ceres - Sets about 10:29 pm on the 1st and about 9:31 pm by month's end. 
Ceres is in the
constellation of Taurus and shines at magnitude 9.0.

* Pluto - Rises about 12:20 am on the 1st and about 11:17 pm by month's end. 
Pluto shines at
magnitude 13.9 in the constellation of Sagittarius. As always, good luck at 
spotting this one, a
large telescope and very dark skies will be needed.


Astronomical Events

Meteor Showers
* The Lyrid Meteor Shower - The Lyrids are typically visible between April 16 
and 25. Maximum
occurs during April 21-22. Although the maximum rate is about 10, there have 
been instances during
the last 200 years when rates were near or over 100 per hour. The average 
magnitude of the meteors
is near 2.4 and the speed is described as rapid. About 15% of the meteors leave 
persistent trains.

* For more information about Meteor Showers, visit Gary Kronk's Meteor Showers 
Online web page at

* Comet 46P/Wirtanen passes into the constellation of Gemini shining at 11th 
magnitude. The comet
dims to 12th magnitude and will be very difficult to spot with any telescopes 
smaller than about 8
inches in diameter. Good luck.

* 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

* No eclipse activity this month.

* The Moon occults the Pleiades cluster on the 8th. Beginning around 7:45 pm 
MDT, the thin
crescent Moon will pass in front of the northern part of the cluster.

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

Asteroids (From west to east)
* Astraea is at opposition on the 5th in the constellation of Virgo.
* Iris is at opposition on the 5th in the constellation of Corvus.
* Daphne is at opposition on the 5th in the constellation of Virgo.

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


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

* Cassini - March 26, 2008
Cassini Tastes Organic Material at Saturn's Geyser Moon

"NASA's Cassini spacecraft tasted and sampled a surprising organic brew 
erupting in geyser-like
fashion from Saturn's moon Enceladus during a close flyby on March 12. 
Scientists are amazed that
this tiny moon is so active, "hot" and brimming with water vapor and organic 

New heat maps of the surface show higher temperatures than previously known in 
the south polar
region, with hot tracks running the length of giant fissures. Additionally, 
scientists say the
organics "taste and smell" like some of those found in a comet. The jets 
themselves harmlessly
peppered Cassini, exerting measurable torque on the spacecraft, and providing 
an indirect measure
of the plume density."

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 - No new news since February 28 2008
Memories of Jupiter

"A year ago, New Horizons was flying through the heart of the Jupiter system, 
gradually picking up
speed and systematically gathering spectacular data on the solar system?s 
largest planet and its
closest moons. The results of that spectacular flyby have since been featured 
on thousands of
electronic and printed pages, including a special issue of the journal Science 
in October 2007.

New Horizons scientists recently took a new look at one of the more memorable 
images from the
Jupiter collection: that of the erupting volcano Tvashtar on the moon Io. Taken 
through two of the
four filters in the sensitive Multispectral Visible Imaging Camera, the picture 
shows the reddish
colors of the plume deposits surrounding the base of the volcano - a view we 
hadn?t seen in
earlier pictures. Check it out in the 'New Horizons gallery'

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 December 18, 2007
NASA's Dawn Spacecraft Begins Interplanetary Cruise Phase

"NASA's Dawn spacecraft has successfully completed the initial checkout phase 
of the mission and
begun its interplanetary cruise phase, which is highlighted by nearly 
continuous thrusting of its
ion propulsion system. Dawn is on an 8-year, 3-billion mile journey to asteroid 
Vesta and dwarf
planet Ceres."

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

* MESSENGER - March 19, 2008
Critical Deep-Space Maneuver Targets MESSENGER for Its Second Mercury Encounter

"The MESSENGER spacecraft delivered a critical deep-space maneuver today ? 64 
million miles (103
million kilometers) from Earth ? successfully firing its large bi-propellant 
engine to change the
probe?s trajectory and target it for its second flyby of Mercury on October 6, 
2008. This was the
first trajectory-correction maneuver (TCM) to test the continuous slow rotation 
of the spacecraft
throughout the burn, essential for the March 18, 2011, Mercury orbit-insertion 
(MOI) maneuver."

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 

* 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 - March 20, 2008
NASA Mission Finds New Clues to Guide Search for Life on Mars

"PASADENA, Calif. - NASA's Mars Odyssey orbiter has found evidence of salt 
deposits. These
deposits point to places where water once was abundant and where evidence might 
exist of possible
Martian life from the Red Planet's past.

A team led by Mikki Osterloo of the University of Hawaii, Honolulu, found 
approximately 200 places
on southern Mars that show spectral characteristics consistent with chloride 
minerals. Chloride is
part of many types of salt, such as sodium chloride or table salt. The sites 
range from about a
square kilometer (0.4 square mile) to 25 times that size."

"A simulated fly-through using the newly assembled imagery is available online 

The fly-through plus tools for wandering across and zooming into the large 
image are at

Thermal Emission Imaging System (THEMIS) web site: (http://themis.asu.edu/)

March 24-28, 2008

* Hellas Dunes (Released 24 March 2008)

* Lava Channels (Released 25 March 2008)

* Orthogonal Ridges (Released 26 March 2008)

* Dunes (Released 27 March 2008)

* Hellas Basin (Released 28 March 2008)

All of the THEMIS images are archived here:

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) -
March 13, 2008

Spirit Status: Spirit Begins Preparing for "Hibernation" Mode - sol 1484-1490, 
March 6-12, 2008

"Spirit has reached its final position for the coming Martian winter and has no 
plans to move
before the next Martian spring. During the next few months, the rover will 
increasingly go into a
"hibernate" mode as the sun continues to dim.
Spirit is currently wrapping up a campaign of scientific studies of the rock 
target known as
"Wendell Pruitt," interspersed with remote science observations of targets 
nicknamed "Lucius
Theus" and "Theopolis Johnson." These targets were all named in honor of 
distinguished members of
the "Tuskegee Airmen," the popular name for the 332nd Fighter Group, an all 
African-American unit
of the U.S. Army Air Corps that served in the European Theater during World War 

Opportunity Status: Opportunity Finds More Evidence of Ancient Water - sol 
1463-1470, March 5-13,

"Opportunity has completed scientific studies of the undisturbed surface of a 
rock target
informally named "Dorsal" in the "Gilbert" rock layer inside "Victoria Crater." 
Dorsal is a
protruding fin of rock created by minerals deposited in cracks that remained in 
place long after
the original rock eroded away because they were more resistant to weathering.
Data collected with the Mössbauer and alpha-particle X-ray spectrometers show 
that the fins in
Gilbert contain large quantities of the mineral hematite. This iron-bearing 
mineral is also
abundant in the frequently occurring, round concretions known as "blueberries" 
that are believed
to have formed in water. Scientists have been looking for such pristine fins 
ever since
Opportunity first noticed them back in "Eagle Crater," where the rover landed 
more than four years
Next, Opportunity will grind into the rock surface at a point informally named 
"Gilbert_A" to
measure the chemical composition of the rock's interior using the 
alpha-particle X-ray
spectrometer. Along the way, the rover has been getting close-up views of the 
fin with the
microscopic imager."

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

Visit the Mars Exploration Rover page at

* Mars Reconnaissance Orbiter Mission - March 3, 2008
NASA Spacecraft Photographs Avalanches on Mars

"Pasadena, Calif. - A NASA spacecraft in orbit around Mars has taken the first 
ever image of
active avalanches near the Red Planet's north pole. The image shows tan clouds 
billowing away from
the foot of a towering slope, where ice and dust have just cascaded down.

The High Resolution Imaging Experiment (HiRISE) on NASA's Mars Reconnaissance 
Orbiter took the
photograph Feb. 19. It is one of approximately 2,400 HiRISE images being 
released today."

More information about the mission is available online at 

* Phoenix Mars Lander Mission - No new news since February 28, 2008
Spacecraft at Mars Prepare to Welcome New Kid on the Block

"Every landing on Mars is difficult. Having three orbiters track Phoenix as it 
streaks through
Mars' atmosphere will set a new standard for coverage of critical events during 
a robotic landing.
The data stream from Phoenix will be relayed to Earth throughout the 
spacecraft's entry, descent
and landing events. If all goes well, the flow of information will continue for 
one minute after

"We will have diagnostic information from the top of the atmosphere to the 
ground that will give
us insight into the landing sequence," said David Spencer of NASA's Jet 
Propulsion Laboratory,
Pasadena, Calif., deputy project manager for the Phoenix Mars Lander project. 
This information
would be valuable in the event of a problem with the landing and has the 
potential to benefit the
design of future landers."

Visit the Phoenix Mars Lander Mission pages 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 *** "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
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.

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

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

* Astrogirl Homepage -

* Astronomical Lexicon - http://bfa3.home.att.net/astrolex.html
Many of the astronomical terms used in this newsletter are defined here.

* Astronomy Picture of the Day -

* 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 -
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 -

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

* JPL Solar System Ambassador Program -

* JPL 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, CO.)

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

* 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 

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

* Space.com - Sky Watch Calendar -

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

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


Acknowledgments and References

Much of the information in this newsletter is from "Astronomy Magazine" 
(Kalmbach Publishing), JPL
mission status reports, the Internet, "Meteor Showers - A Descriptive Catalog" 
by Gary W. Kronk,
Sky & Telescope web pages (S&T), and other astronomical sources that I have 
stashed on my book

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: March 31, 2008

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