Week of April 21, 2014

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, April 21.  All times are given as local St. Louis time (Central Daylight Time).  For definitions of terminology used in the night sky update, click the highlighted text.

Information updated weekly or as needed.

Join us for our next star party, Friday, May 2, 2014 held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page.

The Sun and the Moon

Sunrise is at 6:16 a.m. on Monday, April 21 and sunset is at 7:44 p.m. providing us with over 13 hours of daylight.  Even after sunset, the light from the Sun will still illuminate our sky for about one hour and 30 minutes.  This period of time is called twilight, which ends around 9:20 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 1:01 p.m. this week.     

Moonrise for Monday, April 21 occurs at 1:13 a.m.  Moonset will occur at 11:44 a.m.  On Monday the 21st the Moon will be exhibiting a waning gibbous phase with 57% of the lunar disk illuminated.  Last quarter moon occurs on April 22.

International Space Station (ISS) Observing

The next visible passes of ISS over St. Louis are evening passes.  The best passes are on the evenings of April 21, 23 and 24.  Learn more about these passes and others this week in the table below.

Catch ISS flying over St. Louis in the evening hours starting Monday, April 21. 




Max. altitude











21 Apr











22 Apr











22 Apr











23 Apr











24 Apr











25 Apr











26 Apr











Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be.

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon.

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°.

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:


The Planets Visible Without A Telescope


Venus is now well within its current morning apparition. It rises around 4:34 a.m. becoming easily visible by 5:15 a.m.  For those awake at this time you will see Venus in the southeast and Saturn southwest.  This planetary display nicely represents the path that the planets, Sun and Moon follow.  This path is called the ecliptic.  Take a look at Venus through a telescope and you will see it is phased much like the Moon.  Venus is currently exhibiting a gibbous phase with roughly 63% of the Venusian disk illuminated.


Mars is now in the constellation Virgo and will rise around 6:07 p.m. this week becoming visible shortly after the Sun sets.  For those awake around 9:00 p.m. look to the east and you will see a reddish-orange object high in the southeastern skies. 

We have now passed by Mars in our orbit and will continue to move further away each day.  We probably have another month or so to view the surface of Mars through a backyard telescope.  Take a look at the red planet now for it will be another 26 months before we get this opportunity again.   


Jupiter will be visible high in the western skies roughly 30 minutes after sunset.  As twilight fades you will see the bright stars Castor and Pollux just east of Jupiter.  Looking at these stars and then comparing them to Jupiter you will see that the stars are twinkling and Jupiter is not.  The twinkling you see is called scintillation which is a distortion of the stars light by Earth’s atmosphere.  Testing for scintillation is how you can distinguish stars from planets.  Jupiter is currently in the constellation Gemini the Twins. 


Saturn rises by 9:10 p.m. and will be an easy target by 10:00 p.m.  Saturn is currently in the constellation Libra.  It forms a nice triangle in the sky with Libra’s two brightest stars Zubenelgenubi and Zubeneschamali.  If you watch Saturn in relation to these two stars you will notice it is exhibiting retrograde motion.  This is caused as the Earth catches up with a planet and then passes it by.  During this we see the planet from changing angles making it appear to move westward and then eastward again.  This motion is more prevalent with planets closer to us such as Mars.  If you go outside once a week for the rest of the year and sketch where Saturn is in relation to Zubenelgenubi and Zubeneschamli you will see this retrograde motion.  As retrograde motion is occurring that also means we are approaching another opposition with Saturn.  This occurs on May 10th 2014.  As we approach this date Saturn will continue to get brighter in the sky. 

Constellation of the Month

Each month we will highlight one constellation and some of the objects that can be found within the boundaries of that constellation.  At the start of the month we will list only a few of these objects and each week we will add another to the list.  Some objects will be visible to the unaided eye and some may require a telescope.  Many of the objects listed will require a map of the sky to find or may require repeat observations to notice various properties.  Links to star charts and other information that will be useful in identifying the objects listed will be given at the end of each week’s section. 

The constellation for the month of April is Camelopardalis.  This little known constellation is found in our circumpolar sky so it can be viewed throughout the entire year.  With such visibility it might seem odd that most have never heard of let alone seen this large northern constellation.  The brightest stars in Camelopardalis only reach 4th magnitude meaning that for city observers these stars may need a pair of binoculars to be seen.

Camelopardalis is considered a modern constellation having only been recognized for about 400 years.  It is usually referred to as the giraffe as its name means spotted camel.  It was introduced as a constellation in 1612 by Dutch astronomer and cartographer Petrus Plancius.  Along with this constellation he is responsible for helping map out constellations of the southern hemisphere and introducing a few other constellations still recognized today.

Owing to its dim nature Camelopardalis can be difficult to find particularly in light polluted skies.  The first thing to do is find the constellation Perseus and Auriga.  Camelopardalis is north of these two constellations.  Next find the bright star Capella in Auriga.  About 8 degrees north of Capella you will find the two brightest stars of Camelopardalis called Beta and Alpha Cam.  Unfortunately there is no distinct pattern that stands out in Camelopardalis so you will have to use the star chart below to find the rest of the constellation.  Camelopardalis is north of the constellations Draco, Ursa Major, Lynx, Auriga and Perseus.  Its western boundary is at Cassiopeia and its northern boundary is at Ursa Minor and Cepheus.  This will be a difficult constellation to find but it is worth the effort as it will be the source location for a new meteor shower that will peak this year on May 24.  As we approach this new and potentially amazing meteor shower I wanted to help prepare readers for this event by introducing them to the constellation that houses its radiant.  Before we cover the meteor shower I want to first take a tour of this often over looked constellation.


The first object we will explore in Camelopardalis is its brightest star Beta Camelopardalis.  Beta cam is a G-class yellow supergiant star that is in the process of evolving off of its main sequence into the red giant phase.  It has started to fuse the helium at its core which has allowed for its outer atmosphere to cool and begin expanding.  Beta Cam is at a point where it should begin to pulsate as a Cepheid variable but has yet to start the clockwork like pulsations.  At a distance of 1000 light years this giant star with a luminosity that is 3300 times that of the Sun only shines as a 4th magnitude star.  This is because of Beta Cam’s distance and the dimming caused by interstellar dust.  

Another strange feature of this star is it was observed to suddenly display a bright flash of light in 1967  This and the fact that Beta cam is an x-ray source indicates the star likely experiences magnetic upheaval much like our Sun.  It is possible that the bright flash seen by pilots in 1967 was caused by a magnetic reconnection event similar to a solar flare on the Sun.   

Beta Cam is also a multiple star system.  A small telescope and large binoculars will be able to resolve a fainter companion (B-component) that is separated by 83 arc seconds.  The primary yellow supergiant star shines at 4th magnitude and the fainter companion shines at 7.4 magnitude.  The fainter B-component is itself a double star.  Very little is known about the second star in the B-component system.

To find Beta Cam first locate the star Capella in the constellation Auriga.  From here scan about 8 degrees north until you find the next brightest star.  This will be Beta Cam.  This triple star system will be the easiest thing to find that we cover for this month’s constellation.  Due to dim nature of the Camelopardalis our ability to star hop will be tested.  Use the map below to find Beta Cam and start familiarizing yourself with the other stars of Camelopardalis.


The next object for the week of April 7 is the asterism known as Kemble’s Cascade.  Most of the objects we include in this section are cataloged objects that are normally some kind of star cluster, nebula or galaxy.  However there are some objects that are no more than a chance grouping or alignment of stars that stand out to observers and can be quite nice to look at.  One such asterism is known as Kemble’s Cascade.  This grouping of stars was discovered by an amateur astronomer named Lucian Kemble.  He was scanning Camelopardalis and noticed a string of stars that spanned about 2.5 degrees of sky.  It was later named in his honor and remains a popular target in the sparse constellation of Camelopardalis.

Kemble’s Cascade is a string of 20 stars, mostly 7th to 10th magnitude, which spans about 2.5 degrees.  The center of the string is accented with a 5th magnitude star.  The stars that make up Kemble’s Cascade are not related to each so what we see is just a chance alignment.  Following this cascade of stars to the southeast will bring us to an open star cluster called NGC 1502.  This cluster contains about 45 stars that will appear as a faint glow at the end of Kemble’s Cascade. 

To find Kemble’s Cascade start by locating Beta and Alpha Cam again.  From these two stars sweep about one binocular field to the west and you will see a line of stars that appear to cascade down from northwest to southeast.  This is Kemble’s Cascade.  Using the map linked below you will see a small curved grouping of four stars.  The eastern most of the four is set a little further off from the other three.  This fourth star is the bright 5th magnitude star in the middle of Kemble’s Cascade.    


There are loads of interesting objects like Kemble’s Cascade scattered throughout the sky.  Backyard astronomy is not always just about finding distant galaxies or scanning the skies trying to complete deep sky catalogs.  Sometimes a keen eye and an imagination will allow an observer to see other chance alignments of stars like Kemble’s Cascade.  Reading monthly astronomy magazines and searching out observing forums is a great way to learn about many things that will not be included in the official deep sky catalogs. 

The Object for the week of April 14 is the spiral galaxy NGC 2403.  This galaxy lies about 12 million light years away and shines with an apparent magnitude of 8.4.  At this magnitude NGC 2403 is visible in binoculars but it will be considerately more difficult to see than a star with the same magnitude.  Stars have all their light concentrated into a singular point in the sky.  Whereas galaxies and other deep sky objects have more surface area so their surface brightness appears dimmer.  This is why when we see them they are frequently described as faint and fuzzy objects. 

To find NGC 2403 start by locating the star Muscida.  This star represents the nose of Ursa Major.  From here start scanning about 12 degrees to the east of this at a slight upward angle.  About two binocular fields to the east you should be able to find the dim patch of light that is NGC 2403.  Use the maps linked below to help you find this neighboring galaxy.



The object for the week of April 21 is another spiral galaxy named IC 342.  This galaxy lies approximately 10 million light years away.  It shines with an apparent magnitude of 8.4 but as we discussed last week it will appear dimmer then a star with the same apparent magnitude.  It is a member of the IC 342/Maffei group of galaxies which is one of the closest groups to the Local Group of galaxies our Milky Way belongs to.   

To find IC 342 start by finding the two brightest stars in Camelopardalis, Beta and Alpha Cam.  Follow them north to the next brightest star Gamma Cam.  About two degrees southeast of this star is where you will find IC 342.  This galaxy is bright enough to be seen in binoculars but it will be difficult to find.  Small telescopes will also have trouble as the galaxy’s core is bright but the rest has a low surface brightness.  Follow the map linked below and you should be able to spot this galaxy.  Remember viewing conditions are important so try when the moon is not up and when humidity is low. 


Lyrid Meteor Shower 

The annual Lyrid meteors shower is once again upon us.  Every year around April 22nd this meteor shower becomes active as the Earth passes through the debris left by comet C/1861 G1 Thatcher.  This is a long period comet that takes approximately 415 years to orbit the Sun.  The last time this comet came close to the Earth was in 1861. 

The sand to baseball sized fragments shed by this comet as it passes by the Sun slam into our atmosphere traveling at 27.8 miles per hour.  When they hit our atmosphere they vaporize and excite the atmospheric gases around them.  This is what causes the bright streak of light we see as meteors. 

The Lyrids do not favor us this year so we can likely only hope for rates around 5 to 10 per hour.  For the best chance to see the Lyrids go outside after midnight on the 22nd and look east.  For more detailed information visit


Our next Star Party will be held on Friday, May 2, 2014, from dusk until 10 p.m.

Weather permitting, the St. Louis Astronomical Society and the ScienceCenter will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 8:00 p.m.  Regardless of the weather on May 2, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m. 

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

President's Sidebar - What Volunteers Mean to Us

Dear Science Center friends,

After a long winter, spring and summer are finally upon us. As we begin to prepare for our crowds this summer, I want to take the time to point out a group of valuable people who help us meet the growing demands of our guests – our volunteers.

Volunteering and nonprofits go hand in hand. Many of us (including myself) who have spent our careers working with and at nonprofits started as volunteers. When I started working in museums, I began as a volunteer at the John G. Shedd Aquarium in Chicago. As my career grew, I remained passionate about giving back to the community, and I still volunteer today. Currently, I serve as a volunteer ski patroller for Hidden Valley Ski Patrol in Wildwood.

The Science Center could not survive without the generous amount of time given by our volunteers. From our teenage interns to our 28-year veterans that help us each and every day, we count on the wealth of knowledge, experience and energy that they bring to the public. Working hand in hand with our staff, our volunteers allow us to help guests, expand our programs and provide a smiling face and helpful attitude for everyone who visits us all year long.

Each year, volunteers provide the Science Center with over 15,000 hours of service. We benefit from the “volunteering spirit” present in the city of St. Louis. According to volunteeringinamerica.gov, from 2010-2012, St. Louis’ volunteer rate ranked in the top 10 amongst major metropolitan areas (ahead of Chicago, Indianapolis, New York and Columbus). 

On your next visit, help us thank those volunteers who make your visit a little more special and who help us ignite passion for science and technology learning in our community.


Bert Vescolani


(Interested in volunteering at the Science Center? Click here for more information and to apply online.)

Invent an Insect Project Winner Visit Harry's Big Adventure

In January, the winners of the Saint Louis Science Center's Invent an Insect Project visited Harry's Big Adventure: My Bug World* - their prize from the contest. 5th Graders from St. Francis of Assisi School took the morning and explored Harry's Big Adventure, the Life Science Lab, the Human Adventure Gallery and more! Check out pictures from their trip below:

Students from St. Francis of Assisi posing in from of the butterfly wall in Harry's Big Adventure.

Getting hands-on with some of Harry's favorite friends.

Students getting a bug's eye view of the world!

Tackling an experiment in the Life Science Lab.

Discovering how their brains help them navigate the world around them in Human Adventure!

Thanks to the wonderful students and teachers from St. Francis of Assisi. We hope you enjoyed your visit!

*Harry's Big Adventure: My Bug World is now closed.

Join us for the Minority Scientists Showcase for the chance to interact one on one with scientists, engineers and other science related professionals. Enjoy this unique career awareness opportunity as scientists share their insights with visitors as well as demonstrate their work.

This is a FREE event.

Location: Main Building

NASA Grant Will Create New Robotic Mars Rover Exhibit

A grant of $815,000 from NASA to the Saint Louis Science Center will support the creation of a new exhibit allowing visitors to experience the thrills and challenges of Mars exploration. The exhibit, “Bridging Earth and Mars (BEAM): Engineering Robots to Explore the Red Planet” is scheduled to open in the summer of 2015.  

The Saint Louis Science Center is one of only ten organizations or science centers across the country to share $7.7 million in grants from NASA’s Competitive Program for Science Museums, Planetariums and NASA Visitor Centers Plus Other Opportunities, a program that funds informal STEM (science, technology, engineering and math) learning experiences.

“St. Louis has a long, rich history in aviation and space and, for over 50 years now, the James S. McDonnell Planetarium has played a vital role in conveying these discoveries and achievements to our visitors,” said Bert Vescolani, President and CEO of the Saint Louis Science Center. “We are enthusiastic about NASA’s support in this new opportunity and we hope to inspire the next generation of space scientists and engineers.”

BEAM will let visitors simulate what NASA engineers experience when they send instructions to a robotic rover over 35,000,000 miles away on Mars. Utilizing the unique campus of the Saint Louis Science Center to represent the distance between Earth and Mars, visitors will program a robotic rover in the Science Center’s main building then cross the Skybridge (that spans I-64/Highway 40) to view the rovers at work in the James S. McDonnell Planetarium in Forest Park.

“Informal education providers play a key role in NASA Education’s effort to make interactive STEM experiences available to students and the general public,” said Leland Melvin, NASA’s associate administrator for education. “Using compelling NASA content, they create fun, hands-on learning activities that help us stimulate greater interest in STEM. Increasing STEM literacy in students today is crucial to having the talent NASA will require for future missions of science and discovery.”

In being awarded the NASA grant, Vescolani also credits the project’s St. Louis collaborators including Raymond Arvidson, the James S. McDonnell Distinguished Professor in earth and planetary sciences at Washington University in St. Louis, a key member of NASA’s Mars exploration team. “Ray is a rock star in Mars exploration,” said Vescolani.

“The Saint Louis Science Center is a great place for hands-on experiences and the addition of commanding a Mars-like rover will allow visitors to experience first-hand the thrill of exploration and discovery. It also reinforces the importance of the Saint Louis area for aerospace engineering and space exploration,” said Arvidson.

Paul Freiling, director of engineering and robotics education at the Saint Louis Science Center, will use his expertise in Lego MINDSTORMS and FIRST Robotics to help young students understand how learning about Mars missions can link them to careers in space exploration, science, technology, engineering and mathematics.

“So much of the fun of engineering is getting to build things and try things out,” said Freiling.  “This funding from NASA will allow us to offer a series of hands-on workshops for K-8 students that will allow them to use their hands and minds to solve a design challenge.”

Additional components of the project include public lectures by local scientists involved in space technology, and outreach to St. Louis Public Schools and other Science Center community partners to attract a diverse audience for the K-8 workshops. Website resources will include design challenges that kids can do at home, and links to out-of-school opportunities for K-12 students to experience engineering design and robotics.

The Science Center’s other project collaborators include Theodosios Alexander, dean, Parks College of Engineering, Aviation and Technology at Saint Louis University; Tasmyn Front, director of the Challenger Learning Center St. Louis; Kent Schien, Chief Executive Officer of Innoventor and Saint Louis Science Center commissioner; and Donald Peacock, district sales manager for National Instruments.

Paleo Preschool is the perfect program for your young learners interested in paleontology! You can choose any or all of these unique and private sessions featuring the Science Center’s dinosaurs. Programs are designed for children ages three to five years old.

Tickets are required: $5 per Member adult-child pair and $10 per non-Member adult-child pair.

Call 314.289.4424 to make your reservations today!

Location: Lower Level, Dana Brown Fossil Prep Lab & Dig Site

On selected school holidays and breaks, the Science Center gives your kids something fun (and educational) to do. Holidazed Camps are for kids in grades 1-5. With lots of different topics and activities, the campers will stay excited about learning all year long. Half-day or full-day sessions are available as are flexible extended care options.

Reservations are required.

For more information, please visit our Holiday Camps page, email daycamps@slsc.org or call 314.289.4439.

What makes a dinosaur a dinosaur? Did the Brontosaurus ever really exist? Do the books and movies from your childhood provide an accurate representation of dinosaurs according to current scientific research? Join Ecology & Environment staff in our Fossil Prep Lab to examine real fossils, explore these questions and more!

Call 314.289.4424 for reservations.

Cost: $5 a person