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Astronomy
Welcome to the Boston Astronomy website ...

This website has been created by and is supported by a group of Boston, MA - area amateur astronomers. It is intended to be a convenient site to access news and information about astronomy and space-related activities of interest to the community and the public.













 



 


 
 

Spring 2014 Astronomy Course

 

Introduction to Astronomy

 

Spring 2014

 

As the brilliant stars of Winter fade and give way to the “Deep Skies” of Spring, our thoughts turn upward and outward. It’s natural to ponder such questions as how the Universe came into existence, how life began, and whether we are alone. Modern astronomy is increasingly in the news, and in this course we’ll come to an understanding of often confusing concepts such as brown dwarfs, red giants, black holes, and dark matter.  We’ll also have a chance to learn some of the constellations of the seasons, see Mars and the moons of Jupiter through a telescope, learn about Orion and the “Seven Sisters”, and construct a model of the Solar System that you can keep in your pocket!

 

One of our meetings will be at a local observatory; there we will be able to use a large telescope to learn about the sky first-hand.

 

No math or science background required!

 

8 Tuesdays 8:00 – 9:30 PM

 

Runs April 1 - May 20.

 

Cambridge Center for Adult Education

 

 

 

April Astronomy-Related Events in the Boston Area   

   

Thursday, April 10th, 2014, at 8:00 PM.

Amateur Telescope Makers of Boston (Boston area’s largest and oldest astronomy club).

(Meets every 2nd Thursday except August).

Phillips Auditorium, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA.

“Solar Probe Plus and SWEAP”, Dr. Justin Kasper (CfA).

Our speaker this month will be Dr Justin Kasper of the Harvard Smithsonian Center for astrophysics. He specializes in the development of instrumentation for measuring extreme environments from the surface of  the sun to the outer solar system and is most interested in exploring the forces driving solar flares and the high energy solar wind continuously streaming away from the sun. He is currently lead investigator for an instrument named SWEAP designed to measure Solar Wind Electrons Alphas and Protons. Tonight Dr. Kasper will talk about this project and the upcoming Solar Probe Plus mission to the sun on which it will be flown. Come and learn about this important and exiting mission that will take a spacecraft into the solar corona.

Please join us for a pre-meeting dinner discussion at Changsho, 1712 Mass Ave, Cambridge, MA at 6:00pm before the meeting.

  

    

Thursday, April 17th, 2014, at 7:30 PM.

Monthly Observatory Night.

(Free lecture and observing every 3rd Thursday except June, July, and August – and sometimes December).

Phillips Auditorium, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA.

Monthly Observatory Night

“Jupiter & Mars Return”

The King of Planets and the God of War dominate the night sky this spring. These two neighboring worlds contrast each other dramatically - one small and rocky, one huge and gaseous. Learn about the differences between gas-giant and terrestrial planets, both in our solar system and beyond, from planetary scientist Ruth Murray-Clay, and then observe both of these worlds through telescopes to highlight this memorable evening.

http://www.cfa.harvard.edu/publicevents

 

 

Friday, April 18, - Sunday, April 27.

Cambridge Science Festival.

The Cambridge Science Festival, the first of its kind in the United States, is a celebration showcasing the leading edge in science, technology, engineering and math. A multifaceted, multicultural event every spring, the Cambridge Science Festival makes science accessible, interactive and fun!

http://www.cambridgesciencefestival.org/Home.aspx

   

     

Friday, April 25th, 2014, 8:00 PM - 11:00 PM.

Sidewalk Astronomy (part of the Cambridge Science Festival).

Deguglielmo Plaza in front of 27 Brattle St., Harvard Square, Cambridge.

You may be in the middle of the city, but that doesn’t mean you can’t see the stars! Join us in Harvard Square to get fantastic view of Jupiter, Mars, Saturn, and distant stars. In case of clouds the event will move to Saturday, April 26. Note: Check for weather cancellations and updates at www.bostonastronomy.net.

http://www.bostonastronomy.net/

 

 

Saturday, April 26th, 1:00 PM - 4:00 PM.

Space Day: MIT at the Final Frontier (part of the Cambridge Science Festival).

Travel beyond Earth’s realm at the MIT Museum and learn about the wide variety of space research being done at MIT. Learn about the next generation of space suits with Professor Dava Newman and former NASA astronaut Jeffrey Hoffman. Explore new methods of space flight with Professor Paulo Lozano’s ion thrusters, and look to the future of exoplanet research with researchers from the MIT Kavli Institute. See all this and more with hands-on demonstrations and discussions of space research at MIT!
http://web.mit.edu/museum/programs/festival.html

  

 

 

Plus:

Wednesdays:

Boston University

Boston, MA.
Open Night at Coit Observatory most Wednesdays 8:30 PM - 9:30 PM. 
http://www.bu.edu/astronomy/events/public-open-night-at-the-observatory/


And:

Fridays:

Guililland Observatory

Museum of Science

Boston, MA

"Astronomy After Hours" Friday nights 8:30 PM - 10:00 PM.

http://www.mos.org/public-events/astronomy-after-hours

 


 

The Sky Report for the Month of April 2014

 

 

On April 6, the First Quarter Moon passes about 6° to the S of Jupiter. On the 14th – 15th, the nearly Full Moon passes just 3° to the S of Mars. The waning gibbous Moon is 1.2° to the S of Saturn on the 17th. A thin waning crescent is 4° to the N of Venus on the 25th.

  

  

There is an annular solar eclipse on April 29. The annular portion of the eclipse will be visible only from Antarctica; partial phases of the eclipse will be visible in southern Australia.

 

Current Night Sky: At A Glance

 

Phases of the Moon:

 

First Quarter

April 7

4:31 AM EDT

Full Moon

April 15

3:42 AM EDT

Last Quarter Moon

April 22

3:52 AM EDT

New Moon

April 29

2:14 AM EDT

  

 

The Moon & Planets:

  

 

On April 6, the First Quarter Moon passes about 6° to the S of Jupiter. On the 14th – 15th, the nearly Full Moon passes just 3° to the S of Mars. The waning gibbous Moon is 1.2° to the S of Saturn on the 17th. A thin waning crescent is 4° to the N of Venus on the 25th.

 

 

Evening Planets (after sunset):

      • Jupiter, in W
      • Mars, in SE

 

Visible At Midnight:
    • Jupiter, in W
    • Mars, in S
    • Saturn, in SE

 

Morning Planets (before sunrise):

    •  
      • Mars, in W
      • Saturn, in SW
      • Venus, in E
      • Mercury, in E
      • Neptune, in E

   

Comets:

 

  • There are no comets brighter than magnitude 8.0 visible in March.

 

  

Meteors:

  

The Lyrid meteors peak on April 22. Unfortunately, the Last Quarter Moon occurs the same night and its light will swamp all but the brightest meteors.  

  

  


  •   

A Schedule of Events

 

  • Date Day of Week Time   Event
    Apr. 1 Tue. 4:00 AM EDT Jupiter @ east quadrature
    Apr. 2 Wed. 3:00 AM EDT Uranus @ solar conjunction
    Apr. 6 Sat. 7:00 PM EDT Moon 5° S of Jupiter
    Apr. 7 Mon. 4;31 AM EDT First Quarter Moon
    Apr. 8 Tue. 10:52 AM EDT Moon @ apogee (63.42 Earth radii)
    Apr. 8 Tue. 5:00 PM EDT Mars @ opposition
    Apr. 11 Fri. 3:00 AM EDT Asteroid Juno @ solar conjunction
    Apr. 11 Fri. 11:00 PM EDT Venus 40' NW of Neptune
    Apr. 13 Sun. 8:00 AM EDT Asteroid 4 Vesta @ opposition
    Apr. 14 Mon. 9:00 AM EDT Mars closest to Earth (92.4 million km)
    Apr. 14 Mon. 2:00 PM EDT Moon 3° S of Mars
    Apr. 15 Tue. 12:52 AM EDT TOTAL LUNAR ECLIPSE - Moon enters penumbra
    Apr. 15 Tue. 1:58 AM EDT TOTAL LUNAR ECLIPSE - Moon enters umbra
    Apr. 15 Tue. 2:00 AM EDT Asteroid 1 Ceres @ opposition
    Apr. 15 Tue. 3:06 AM EDT TOTAL LUNAR ECLIPSE - Moon enters totality
    Apr. 15 Tue. 3:42 AM EDT Full Moon
    Apr. 15 Tue. 3:45 AM EDT TOTAL LUNAR ECLIPSE - Mid-eclipse
    Apr. 15 Tue. 4:25 AM EDT TOTAL LUNAR ECLIPSE - Moon leaves totality
    Apr. 15 Tue. 5:33 AM EDT TOTAL LUNAR ECLIPSE - Moon leaves umbra
    Apr. 15 Tue. 6:10 AM EDT TOTAL LUNAR ECLIPSE - Moonset
    Apr. 17 Thur. 3:00 AM EDT Moon 0.4° S of Saturn
    Apr. 22 Tue. 3:52 AM EDT Last Quarter Moon
    Apr. 22 Tue. 3:45 PM EDT Lyrid meteor shower peaks
    Apr. 22 Tue. 8:24 PM EDT Moon @ perigee (57.97 Earth radii)
    Apr. 25 Fri. 7:00 PM EDT Moon 4° N of Venus
    Apr. 25 Fri. 11:00 PM EDT Mercury @ superior conjunction
    Apr. 29 Tue.   ANNULAR SOLAR ECLIPSE (not visible from Boston)
    Apr. 29 Tue. 2:14 AM EDT New Moon
       
    May 2 Fri. 7:00 PM EDT Mercury @ perhelion (0.3075 AU)
    May 4 Sun. 9:00 AM EDT Moon 5.4° S of Jupiter
    May 6 Tue.   Eta Aquarid Meteors (good prospects)
    May 6 Tue. 6:00 AM EDT Moon @ apogee (63.39 Earth radii)
    May 6 Tue. 11:15 PM EDT First Quarter Moon
    May 10 Sat.   NATIONAL ASTRONOMY DAY
    May 10 Sat. 2:00 PM EDT Saturn @ opposition
    May 11 Sun. 8:00 AM EDT Moon 2.8° SSW of Mars
    May 14 Wed. 8:00 AM EDT Moon 0.56° S of Saturn
    May 14 Wed. 3:16 PM EDT Full Moon
    May 15 Thur. 7:00 PM EDT Venus 1.2° SSE of Uranus
    May 16 Fri. 5:00 AM EDT Venus @ aphelion (0.7282 AU)
    May 18 Sun. 8:04 AM EDT Moon @ perigee (57.56 Earth radii)
    May 21 Wed. 5:00 AM EDT Mars stationary in R.A.
    May 21 Wed. 8:59 AM EDT Last Quarter Moon
    May 25 Sun. 3:00 AM EDT Mercury @ greatest elongation (22.7° E of Sun)
    May 25 Sun. 11:00 AM EDT Moon 2.2° NNW of Venus
    May 28 Wed. 2:40 PM EDT New Moon
    May 30 Fri. 12:00 PM EDT Moon 5.9° S of Mercury
  •   


  •  

    The Planets

   

The brightest point of light in the early evening sky is Jupiter. It should become visible shortly after sunset, and will appear to be almost overhead once darkness falls. Even from deeply light-polluted urban skies and under marginal clear sky conditions, Jupiter will be visible when nothing else is. It sets about 2:30 AM as April begins, and about 12:45 AM by month’s end. Jupiter appears in Gemini. If you are more familiar with the unchanging patterns of constellations than with the planets which constantly shift their positions with respect to the background stars, then you should find it easy to recognize the distinctive stars of Orion; if you draw a line from Rigel to Betelgeuse and extend it by one additional length, you will come to Jupiter. At midmonth, the planet is about 499 million miles away, and is slowly increasing its distance from us. Light from the sunshine illuminating its cloudtops takes about 45 minutes to reach us; we can thus say that Jupiter is now 45 light-minutes away. Even a small telescope reveals the two main dark belts – the North and South Equatorial Belts – on either side of the planet’s equator. Larger scopes reveal numerous others. Jupiter is at eastern quadrature - 90° E of the Sun – on April 1st, so any shadows Jupiter’s four large Galilean moons cast appear far from the moons themselves. And you might see an unusual sight on April 21st: though the moons are usually strung out in a line parallel to the planet’s equator; for a short time around 11:15 PM EDT, Callisto, Io, and Europa form a line inclined about 45° to the planet’s axis.

 

 

At every opposition – roughly every 26 months - Mars gets to be a star. This April is such a time. This is when Mars is at its closest and brightest, and draws the most attention. On April 8th, the planet is directly opposite to the Sun in our sky, so – naturally – it rises as the Sun is setting, is highest around midnight, and sets as the Sun is rising. If Mars’ orbit around the Sun was more circular – say, like that of Earth – opposition would also be the time the planet is closest to Earth. However, the Red Planet’s orbit around the Sun is rather elliptical, so the two events do not necessarily coincide. This year, for instance, opposition occurs on April 8th, but Mars’ closest approach to Earth is on April 14th. And just how far apart are the two planets? Their separation is about 57.4 million miles; even though they are relatively close as Solar System objects go, it still takes 5 minutes for its light to reach us. At its closest distance, Mars shines at magnitude -1.5, brighter than Sirius. In a telescope, it subtends an angle of 15.2” – large enough to show considerable detail to skilled observers under good conditions. It is important to note that not all oppositions of Mars are created equal. During the next several oppositions, Mars will be closer and larger; during the opposition in 2016, we’ll get to see it as large as 18.4” across. Better yet, during the 2018 opposition the planet will swell to 24.1” across. This year, Mars’ Northern Hemisphere is tilted toward us, so features such as the North Polar Cap will be well displayed. In spite of the fact that it is now early summer in the Martian north, and the carbon dioxide frost covering it is sublimating away, the water ice the water ice cap underneath never completely disappears. Some of the larger dark albedo features, particularly the more northerly ones such as Syrtis Major and Mare Acidalium, will be the ones most easily visible. And keep an eye out for clouds and possible dust storms.

 

 

After Mars, the next planet to come up is majestic Saturn. The Ringed Planet rises at about 10:30 PM local time as April begins, and about 8:25 PM by month’s end. It is approaching opposition in May, so is not quite at its best, but next month it will only get marginally closer, larger and brighter than it is now. During April, it brightens slightly from magnitude +0.3 to +0.1; the angular diameter of the planet’s disk grows from 18.2” to 18.6”, while its visible rings swell from 41.3” to 42.2” across. Through a telescope, the rings are quite a sight; their tilt toward us of 22° to our line of sight shows off the detailed structure, beauty, and complexity of the ring system. In a moderately sized telescope, one can distinguish the bright B ring from the outer, dimmer A ring. Under good conditions, the dark hairline of the Cassini Division between these two rings may be visible. This in itself is an amazing fact; at midmonth, Saturn is 836 million miles away; yet the Cassini Division is only about 3,000 miles wide. Larger telescopes under ideal conditions reveal several more gaps in the ring system; flyby and orbiter space missions have revealed thousands. Also not to be missed are Saturn’s wonderful moons. Titan, the largest, is larger than the planet Mercury, and has an atmosphere denser than Earth’s! At magnitude 8, the moon is visible in almost any small telescope. The next set of smaller moons – Rhea, Dione, Tethys, and Iapetus – are in the range of 10th – 11th magnitude, and require larger scopes.

 

 

The next planet to rise in April skies is Venus. It doesn’t come up until after 4 AM local time, so it is now most definitely a morning “star”. At magnitude -4.3, it is by far the brightest point of light in the night sky. As seen through a telescope, however, it can be a bit of a disappointment. When we look at Venus, we never see its surface. The planet is completely blanketed by a thick layer of bright clouds. While the features of the planet have been thoroughly mapped by spacecraft in orbit around it using radar, no one has ever seen its surface. What we can see, in even the smallest telescopes, are the phases of Venus. There can be a crescent Venus, a gibbous Venus, a full Venus, etc. At the beginning of this month, the planet’s disk is 22” across and 54% illuminated; by April’s end, it will have shrunk to a ball 17” across and 66% illuminated.

 

 

As viewed from our vantage point in the Solar System, the brightest planet in the sky, Venus, makes a close passage to the dimmest one: Neptune. In the early morning hours of April 12th, Venus passes just 0.7° - a little over a Moon-width – N of Neptune. The latter will be difficult to see in the twilit sky; at magnitude 7.9, it will be dimmer than Venus by a factor of almost 70,000 times!

 

 

Like, Venus, Mercury is very low in the morning sky as April begins. It reaches inferior conjunction – passing “behind” the Sun – on the 25th.

 

 

Uranus reaches solar conjunction on April 2nd, and is too close to the Sun to be visible this month.

 

   

Dwarf Planets/Asteroids:

 

The dwarf planet/asteroid 1 Ceres, in Virgo, reaches opposition on April 14th. Now at its closest distance to us, it lies 152 million miles away, and shines at magnitude 7.0. On opposition night, it lies about 15° from both Mars and the Full Moon.    

 

The asteroid 4 Vesta, also in the constellation Virgo, remains just 2½° W of Ceres. Like Ceres, Vesta reaches opposition this month – in Vesta’s case, on the 13th. The asteroid is about 115 million miles away, and shines at magnitude 5.8; this implies that, under dark skies, it should be well within the range of naked-eye visibility.  

  


  •  

    What's New

  •  

  • The Total Lunar Eclipse of April 15th, 2014.

  •                                 

  • In the early morning hours of April 15, a total lunar eclipse will be visible from most of the Western Hemisphere. During such an eclipse, the Moon enters the shadow cone Earth casts into space, and thus is no longer illuminated by the direct light of the Sun. Such  a transition does not happen instantaneously; a lunar eclipse can be divided into a number  of phases, each with implications for how the phenomenon appears to observers on Earth. The eclipse begins very subtly, with the western (in the geographic sense) limb of the Moon beginning its entry into Earth’s outermost shadow. This is the beginning of the so-called penumbral phase, during which the Moon is still illuminated – not by light coming from the entire Sun – but by the portion of direct sunlight not yet blocked by the Earth. This phase of the eclipse is almost undetectable to observers at its beginning. As the Moon continues to move into earth’s shadow, however, less and less sunlight is available to illuminate the Moon, and the western limb of the Moon becomes visibly darker. The end of the penumbral phase, and the beginning of the umbral phase, occurs once portions of the Moon begin to enter the Earth’s shadow, and no direct sunlight from any portion of the Sun reaches some areas of the Moon. At this point, the fact that there is an eclipse underway is obvious to observers on Earth. The next phase – totality – begins when the entire Moon is in Earth’s deep shadow. The total phase may continue for an hour or more, during which the Moon may appear dark grey or blood red. Its disk rarely disappears completely, as a certain amount of sunlight will be refracted around Earth’s edge by our planet’s atmosphere. In fact, the blood-red color of the Moon is caused by the light from the simultaneous sunrises and sunsets occurring everywhere on Earth at the time! Alternatively, when the Earth’s atmosphere at locations around its limb are dark, due, perhaps, to volcanic eruptions or smoke from forest fires, the Moon may appear faint and grey. Once totality is over, the eclipse continues with the sequence of events in reverse.

     

     

    In the case of the particular eclipse occurring on Aril 15, the sequence of events occurs as follows:

     

     

    Penumbral phase begins

     

    12:52 AM EDT

    Partial (Umbral) phase begins

    1:58 AM EDT

    Total Eclipse begins

    3:06 AM EDT

    Greatest Eclipse

    3:45 AM EDT

    Total Eclipse ends

    4:25 AM EDT

    Partial (Umbral) phase ends

    5:33 AM EDT

    Penumbral phase ends

    6:37 AM EDT

     

    See the illustration below for the sequence of events:

          

  •     

  •  The circumstances of the Total Lunar Eclipse of April 15, 2014

  •     


      

March 2014 Star Chart

      

   

9:00 PM EST on  April 15th, 2014.

Looking at Zenith, South at Bottom.

 (Click to enlarge)*

   

Saturn is just rising on mid-April evenings. In 1610, when Galileo first turned his crude telescope at the planet, he could make out the rings only as two smaller spheres surrounding Saturn’s main disk. It wasn’t until 1655 that Christiaan Huygens made out the rings as a disk shape surrounding the planet. Huygens went on to discover Titan, Saturn’s largest moon; in his honor, the Huygens probe, the first object to land on Titan, carried his name.