Astronomy News for the Month of April 2018

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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 W0WYX 146.94 MHz and 449.825 MHz repeaters. The RMRL 146.94 repeater is also linked with the WB0WDF Cripple Creek 447.400 MHz repeater and Allstar nodes 28298, 28299 and 29436. We are also linked via Echolink, links are k0jsc-r and canoncty courtesy of K0JSC and K0GUR. More information on the WB0WDF repeater links and Allstar nodes and Echolinks can be found at We are also linked with Allstar nodes in Florida as well, courtesy of KA4EPS. The net meets on Tuesday nights at 7 P.M. Mountain Time (US).

Obtain your Amateur Radio (Ham) License or your General Radio Operator's License (GROL)! Visit the South Metro VE Team website for more information. The South Metro VE Team provides test sessions on the 1st Saturday of each month at our new Eagle Street Facility, The City of Centennial, 7272 South Eagle Street, Centennial, Colorado 80112-4244 at 9am.

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In this Newsletter...

Background screen credits: NGC5775
Imaged March 21/22, 2001
using the 16" Kitt Peak Visitors Center telescope
as part of the Kitt Peak Advanced Observing Program.

"Mars and Saturn appeared a few degrees apart against the backdrop of Virgo (with blue-white Spica just to their left) in August 2012. The two planets make a return engagement in Sagittarius in early April." Astronomy Magazine, April 2018, p.36.

The Month At-A-Glance
A calendar displaying the daily astronomical events.

17 day moon

The Moon



Moon/Planet Pairs

For reference: The Full Moon subtends an angle of ~0.5°.

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The Planets & Dwarf Planets

Planetary Reports generated by "TheSky" software. 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 as well as meteor shower radiants 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 March

"The evening sky hosts the two brightest planets -- Venus and Jupiter -- with the former on view shortly after sunset and the latter rising later in the evening. April mornings belong to the equally riveting duo of Mars and Saturn. The Red Planet grows steadily bigger and brighter this month as it approaches a spectacular opposition in late July. Although the ringed planet appears a bit dimmer, it’s always a treat to view through a telescope. These two worlds enjoy a memorable conjunction when they pass within a couple of degrees of each other in early April." Astronomy Magazine, April 2018, p. 36.


Is in inferior conjunction on the 1st. Mercury is stationary on the 13th. Mercury is at greatest western elongation (27°) on the 29th. Mercury rises at 6:33 a.m. on the 1st and about 5:07 a.m. by month's end. Mercury is visible in the morning sky this month low in the east. Start looking for Mercury after the first week of the month when it will have moved out of the Sun's morning twilight glow, though the best time to view Mercury will be at the end of the month then it will be highest in the morning sky. Mercury is in the constellation of Pisces this month shining at magnitude 0.3 on the 30th.


Venus sets at 9:03 p.m. on the 1st and about 10:13 p.m. by month's end. Venus continues to set later in the evening and is easily spotted low to the west as evening descends. Venus moves from the constellation of Aries into Taurus this month shining at magnitude -3.9.




Rises at 2:18 a.m. on the 1st and about 1:23 a.m. by month's end. Mars continues to brighten, reaching its best appearance in 15 years sometime in July. On the morning of the 2nd, look for Mars and Saturn in conjunction. These two planets appear within 1.3° of each other to the southeast before sunrise. On the morning of the 25th, Mars passes within 1.6° of Pluto. Mars is in the constellation of Sagittarius shining at magnitude 0.0.


Rises at 10:35 p.m. on the 1st and about 8:22 p.m. by month's end. Look for Jupiter now rising in the late evening. About the same time Venus is setting, Jupiter will be rising. Jupiter is in the constellation of Libra shining at magnitude -2.4.


Rises at 2:16 a.m. on the 1st and about 12:18 a.m. by month's end. Saturn has caught up with Mars. These two planets are in conjunction the 2nd. As the month progresses, these two planets will separate with Saturn rising earlier each night. Saturn is at aphelion (936 million miles from the Sun) and is stationary on the 17th. Look for Saturn to the southeast in the early morning sky in the constellation of Sagittarius, shining at magnitude 0.4.


Is in conjunction with the Sun on the 18th and is lost in the Sun's twilight glow all month. Uranus is in the constellation of Pisces shining at magnitude 5.9.


Rises 5:46 a.m. on the 1st and about 3:51 a.m. by month's end. Neptune can be spotted to the south-east before dawn. Neptune is in the constellation of Aquarius shining at magnitude 7.9.

Dwarf Planets


Sets at 5:09 a.m. on the 1st and about 3:17 a.m. by month's end. Once the skies darken, Ceres may be spotted to the southwest maybe an hour or two after sunset. Ceres can be spotted just above the apex of the constellation Cancer shining at magnitude 8.2.


Rises at 3:04 a.m. on the 1st and about 1:07 a.m. by months end. Pluto is stationary on the 22nd. Pluto is better placed for early morning viewing this month. Mars is in conjunction with Pluto on the morning of the 25th. Pluto is in the constellation of Sagittarius shining at magnitude 14.3.

As always, good luck at spotting Neptune, Ceres and Pluto, a large telescope and dark skies will be needed.

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Astronomical Events

Meteor Showers

  • The Lyrids [meteor showers] 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.

    Meteor Shower Radiant Report

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

    Meteor Scatter (or Meteor burst communications) - "is a radio propagation mode that exploits the ionized trails of meteors during atmospheric entry to establish brief communications paths between radio stations up to 2,250 kilometres (1,400 mi) apart." Tune your shortwave or your HF amateur radio to 54.310 MHz SSB and see if you can hear any pings.

  • Comets

    Comet PANSTARRS (C/2016 R2) is still passing through the constellations of Perseus and Auriga this month. Comet PANSTARRS has dimmed to 11th or 12th magnitude this month, requiring a 10-12 inch telescope to spot this one. Look high in the west during the early evening to spot Comet PANSTARRS.

  • 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 webpage.

  • Eclipses

    Solar Eclipses

  • No solar eclipse activity this month.

    Lunar Eclipses

  • No lunar eclipse activity this month.
  • Observational Opportunities

  • Enjoy Venus and Jupiter in the evening skies after sunset.
  • Look for Mars and Saturn in the morning skies before sunrise.
  • Try to spot Comet PANSTARRS passing through Perseus and Auriga.

  • Asteroids

    (From west to east)

    IOTA Logo

  • Information on various occultations can be found by clicking the IOTA logo.
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    Subscriber Gallery

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    Member Meteor Sightings

    This is a new section where I will post meteor, fireball, etc sightings that have been published on the American Meteor Society's web site. I want to make this an active section of the web pages and newsletter and would like to publish the links to member sightings. If you have any published sightings, please provide me with the links and I will post them here for all to enjoy.

    Event ID Date/Time Location Observer Link
    3587-2015 2015-11-22 17:38 MST CO Kevin S 3587aw
    3829-2015 2015-12-05 18:06 MST Highlands Ranch, CO Burness A 3829a
    3871-2015 2015-11-13 01:55 MST CO Charles N 3871a

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    Planetary/Lunar Exploration Missions

    (Excerpts from recent JPL mission updates)
    JPL Latest News
    The Latest from Space

    JPL Latest News

    March 30, 2018
    NASA Invests in Shapeshifters, Biobots, Other Visionary Technology

    Full Article & Images

    "NASA is investing in technology concepts that include meteoroid impact detection, space telescope swarms and small orbital debris mapping technologies that may one day be used for future space exploration missions. Five of the concepts are from NASA's Jet Propulsion Laboratory, Pasadena, California.

    The agency is investing in 25 early-stage technology proposals that have the potential to transform future human and robotic exploration missions, introduce new exploration capabilities, and significantly improve current approaches to building and operating aerospace systems."

    "Read the latest news and discoveries from JPL's dozens of active space missions exploring Earth, the solar system and worlds beyond."

    Past, Present, Future and Proposed JPL Missions.

    For special JPL programs and presentations in your area visit the JPL Solar System Ambassador web site.

    Juno - March 07, 2018
    NASA Juno Findings - Jupiter's Jet-Streams Are Unearthly

    Full Article & Images

    "Data collected by NASA's Juno mission to Jupiter indicate that the atmospheric winds of the gas-giant planet run deep into its atmosphere and last longer than similar atmospheric processes found here on Earth. The findings will improve understanding of Jupiter's interior structure, core mass and, eventually, its origin.

    Other Juno science results released today include that the massive cyclones that surround Jupiter's north and south poles are enduring atmospheric features and unlike anything else encountered in our solar system. The findings are part of a four-article collection on Juno science results being published in the March 8 edition of the journal Nature."

    NASA's JunoCam website can be visited at:

    More information on the Juno mission is available at:

    The public can follow the Juno mission on Facebook and Twitter.

    Cassini Legacy - March 29, 2018
    Linda Spilker: Cassini's Amazing Discoveries

    Full Article & Images

    "In this recording, Spilker's remarks begin at the 11:45 mark."

    Raw images are available at

    More information about Cassini is available at the following sites:

    Cassini Imaging Team - Archives from Dec. 2015 and earlier.

    New Horizons - March 13, 2018
    New Horizons Chooses Nickname for 'Ultimate' Flyby Target

    Full Article & Images

    "As NASA's New Horizons mission continues exploring the unknown, the mission team has selected a highly appropriate nickname for its next flyby target in the outer reaches of the solar system.

    With substantial public input, the team has chosen "Ultima Thule" (pronounced ultima thoo-lee") for the Kuiper Belt object the New Horizons spacecraft will explore on Jan. 1, 2019. Officially known as 2014 MU69, the object, which orbits a billion miles beyond Pluto, will be the most primitive world ever observed by spacecraft -- in the farthest planetary encounter in history."

    New Horizons gallery

    Find New Horizons in the iTunes App Store here.

    For more information on the New Horizons mission - the first mission to the ninth planet - visit the New Horizons home page.

    Dawn - March 14, 2018
    NASA Dawn Reveals Recent Changes in Ceres' Surface

    Full Article & Images

    "Observations of Ceres have detected recent variations in its surface, revealing that the only dwarf planet in the inner solar system is a dynamic body that continues to evolve and change.

    NASA's Dawn mission has found recently exposed deposits that give us new information on the materials in the crust and how they are changing, according to two papers published March 14 in Science Advances that document the new findings.

    Observations obtained by the visible and infrared mapping spectrometer (VIR) on the Dawn spacecraft previously found water ice in a dozen sites on Ceres. The new study revealed the abundance of ice on the northern wall of Juling Crater, a crater 12 miles (20 kilometers) in diameter. The new observations, conducted from April through October 2016, show an increase in the amount of ice on the crater wall."

    A gallery of images can be found online.

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


    The MESSENGER mission is officially ended but there is a lot to learn about the planet closest to our Sun. Visit the new, updated MESSENGER website:

    for resources, to learn, and to explore.

    (Click Link above for Full Article & Images)


    "After more than 10 years in operation, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury on April 30, 2015, at a speed of more than 3.91 kilometers per second (8,750 miles per hour), marking the end of operations for the hugely successful Mercury orbiter. At the MESSENGER Nears End of Operations media and public event, scientists and engineers discussed the mission's accomplishments, providing the top 10 scientific discoveries, as well as the technological innovations that grew out of the mission."

    The MESSENGER app is available for download from iTunes.

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

    Past, Present, Future and Proposed JPL Missions

    Visit JPL's mission pages for current status.

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    Mars Missions

    Be A Martian

    Mars website mobile version is here!

    Mars on the Go! NASA Be A Martian Mobile App
    If you want the latest news as it happens, try our Be A Martian app.
    Download on Mobile Devices
    Android | iPhone | Windows Phone

    JMARS is an acronym that stands for Java Mission-planning and Analysis for Remote Sensing. It is a geospatial information system (GIS) developed by ASU's Mars Space Flight Facility to provide mission planning and data-analysis tools to NASA's orbiters, instrument team members, students of all ages, and the general public.

    Laboratory for Atmospheric and Space Physics

    "The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder (CU) began in 1948, a decade before NASA. We are the world's only research institute to have sent instruments to all eight planets and Pluto. LASP is an affiliate of CU-Boulder AeroSpace Ventures, a collaboration among aerospace-related departments, institutes, centers, government labs, and industry partners."

    MAVEN - December 13, 2017
    MAVEN Sheds Light on Habitability of Distant Planets

    Full Article & Images

    "How long might a rocky, Mars-like planet be habitable if it were orbiting a red dwarf star? It's a complex question but one that MAVEN can help answer.

    "The MAVEN mission tells us that Mars lost substantial amounts of its atmosphere over time, changing the planet's habitability," said David Brain, a MAVEN co-investigator and a professor at the Laboratory for Atmospheric and Space Physics, or LASP, at the University of Colorado Boulder. "We can use Mars, a planet that we know a lot about, as a laboratory for studying rocky planets outside our solar system, which we don't know much about yet.""

    Visit LASP and MAVEN for more information.

    Mars Science Laboratory - Curiosity - March 30, 2018
    Sols 2008-2010: Exploring variations in composition, texture, and color

    Full Article & Images

    "Yesterday Curiosity drove 35 m to the southeast, which set us up for some great contact science on the rim of a small impact crater. We're working our way toward Region 13 on Vera Rubin Ridge and exploring changes in bedrock composition, texture, and color, as shown in the Navcam and MAHLI images."

    To follow the Mars Curiosity rover and NASA on Foursquare, visit: and

    For information about NASA's partnership with Foursquare, visit:

      Mars Rover Landing - Free for the Xbox 360 (requires Kinect)

      Visit the Mars Science Laboratory page.

    Mars Exploration Rover Mission (Spirit and Opportunity) - March 27, 2018

    SPIRIT UPDATE: Spirit Remains Silent at Troy - sols 2621-2627, May 18-24, 2011:

    "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 Completes In-Situ Work on 'Aguas Calientes' - sols 5033 to 5038, March 19, 2018 - March 27, 2018:

    "Opportunity is continuing the exploration of "Perseverance Valley" on the west rim of Endeavour Crater.

    The rover is positioned about halfway down the approximately 656 feet (200-meter) valley. Opportunity is investigating the surface target called, "Aguas Calientes," an exposed rock outcrop. Although the target had been ground already, the science team wanted to grind "Aguas Calientes" another 2 millimeters deeper.

    On Sol 5032 (March 20, 2018), the Rock Abrasion Tool (RAT) was placed back into the ground hole and ground further. During the grind the Inertial Measurement Unit (IMU) reported a questionable flag. However, the IMU was tested again on Sol 5035 (March 24, 2018) and was found to be healthy. After the deeper grind, the Microscopic Imager (MI) collected a mosaic of the grind and then the Alpha Particle X-ray Spectrometer (APXS) was placed for a multi-sol integration.

    The rover also collected a set of 13-filter Panoramic Camera (Pancam) images of selected targets. On Sol 5035 (March 24, 2018), the robotic arm offset the APXS for further integrations, along with the IMU test, and imaged the RAT bit for wear. No additional bit wear was seen after the grind. By Sol 5038 (March 27, 2018), the in-situ (contact) work on "Aguas Calientes" was finished and the rover bumped away about 7.5 feet (2.3 meters).

    As of Sol 5038 (March 27, 2018), the solar array energy production was 670 watt-hours with an atmospheric opacity (Tau) of 0.524 and an improved solar array dust factor of 0.830.

    Total odometry is 28.04 miles (45.12 kilometers)."

    Landing sites

    Visit the Mars Exploration Rover page.

    Mars Reconnaissance Orbiter Mission - February 20, 2018
    Nearly a Decade After Mars Phoenix Landed, Another Look

    Full Article & Image

    "A recent view from Mars orbit of the site where NASA's Phoenix Mars mission landed on far-northern Mars nearly a decade ago shows that dust has covered some marks of the landing.

    The Phoenix lander itself, plus its back shell and parachute, are still visible in the image taken Dec. 21, 2017, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. But an animated-blink comparison with an image from about two months after the May 25, 2008, landing shows that patches of ground that had been darkened by removal of dust during landing events have become coated with dust again."

    All of the HiRISE images are archived here.

    More information about the MRO mission is available online.

    Mars Odyssey Orbiter - October 4, 2017
    Examining Mars' Moon Phobos in a Different Light

    Full Article and Images

    "NASA's longest-lived mission to Mars has gained its first look at the Martian moon Phobos, pursuing a deeper understanding by examining it in infrared wavelengths.

    The Thermal Emission Imaging System (THEMIS) camera on NASA's Mars Odyssey orbiter observed Phobos on Sept. 29, 2017. Researchers have combined visible-wavelength and infrared data to produce an image color-coded for surface temperatures of this moon, which has been considered for a potential future human-mission outpost."

    Daily Mars Odyssey THEMIS Images
    Can be found at the Thermal Emission Imaging System (THEMIS) website.

    The Odyssey data are available through a new online access system established by the Planetary Data System.

    Visit the Mars Odyssey Mission page.

    Journey to Mars - InSight - Revealing the Heart of Mars - March 29, 2018
    NASA is Ready to Study the Heart of Mars

    Full Article and Images

    "NASA is about to go on a journey to study the center of Mars.

    The space agency held a news conference today at its Jet Propulsion Laboratory in Pasadena, California, detailing the next mission to the Red Planet.

    InSight -- short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport -- is a stationary lander scheduled to launch as early as May 5. It will be the first mission ever dedicated to Mars' deep interior, and the first NASA mission since the Apollo moon landings to place a seismometer on the soil of another planet."

    Learn more about the InSight Mission.

    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 and the Mars Exploration page.

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    Astronomy Links and Other Space News

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

    Green Laser

    Colorado Astronomy Links

    Radio Astronomy Links

    Other Astronomy Links

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    Astronomical Lexicon

    Definitions of astronomical terms. Many of the astronomical terms used in this newsletter are defined here.

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    UT Logo

    Read the Universe Today Newsletter by clicking on the logo.

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    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, and other astronomical sources that I have stashed on my bookshelves.

    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!

    More Acknowledgements and References

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