Spring 2013 astronomy videos

Check out past "Eyes on the Sky" videos from Spring 2013, here!

Click here to go ahead to Summer 2013, or click here to go back to Winter 2013 "Eyes on the Sky" astronomy videos.

A hidden mare, and short-lived letters

The moon has several maria that are visible easily from Earth, as they always show their face to us, as the Moon's locked rotation ensures.  However, due to the tilted axis of the Moon, and a slight wobble, we can actually see about 59% of the Moon's surface from Earth - though not all at the same time.  On June 13th of this week, the Moon tilts such that we can 'see around the corner' and spot Mare Humboltianum, a rarely seen mare on the Moon's northern side.

Later in the week on the 15th, the Lunar "X" and "V" phenomena are visible on the terminator around 2 hours either side of 2130 UT (the "V" is visible for a bit longer, and appears slightly later, but not by much).  Learn where you can find and see these two interesting short-lived letters that appear on the Moon, then disappear due to the Moon's rotation and revolution as the Sun bathes the area in more sunlight.   

Minding Mercury

Often Mercury can be difficult to both find and see.  This week, Mercury is not only well placed because it is slightly further from the Sun than it often is (making it easier to see), but it is within a few degrees of the brighter Venus (making it easier to find).  But that's not all; the innermost planet offers an interesting view through a telescope over the next couple of weeks too - find out how and where to observe this most-challenging of naked eye planets over the coming days.

Hercules' great globular

The "Realm of Galaxies" is an early spring phenomenon for northern hemisphere observers.  Later in the spring, those galaxies have moved westward, and our own galaxy's globular clusters that orbit the central portion of our Milky Way rise in the east.  One of those clusters is Messier 13, nearly on par with the wonderful sight we saw a few weeks ago in Messier 5.  Learn about Hercules the mythological character, where and how to see Messier 13, and some interesting details about this splendid spring sight.  For a star chart you can print to help you find this object, download star chart #6.

Three to tango

Triple conjunctions don't happen all that often in the night sky, but when they do, they are a sight worth seeking out.  This week, as the Earth hurtles around the Sun more quickly than Jupiter, the giant planet will sink rapidly towards the horizon.  But as it does, two other planets, Mercury and Venus - both orbiting faster than Earth - rise up to meet it by the weekend.  All three can be seen naked eye, though binoculars will make it easier to find and see Mercury early in the week, especially as twilight fades and Venus becomes visible before the innermost planet does.  Friday, Saturday and Sunday offer the best, and closest views of the three planets together, but this trio is worth observing all of this week and into next week.

Going for a globular

Messier 5 is often overlooked in the northern hemisphere, because M13 and M22 will often get top-billing for globular clusters.  But this one should not be missed - the large size, plentiful stars and bright core make for a great view in most any small telescope.  And it is not all that hard to find; a hop, skip and a jump from Unukalhai (say what?) - a 2.6 magnitude star in Serpens - and you are there!  Learn all about this fantastic sight in this week's Eyes on the Sky, which will be visible for several months to come too.  For a printable star chart of this area, use Star Chart #11 here at Eyes on the Sky, and look for M5 in the upper left hand corner near Serpens Caput - the greek alpha symbol is the star Unukalhai.  (NOTE: Saturn will not be on this star chart.)

Sighting the Sombrero

The Sombrero Galaxy is one of the better-known photographs of night sky phenomenon.  But where to find it in the night sky?  It's not as difficult as it might seem, and Saturn helps point the way for the next few weeks as well.  With a fairly high surface brightness, along with several nearby double stars that are worth observing (even if you can't find or see the galaxy), get to know this area of sky this week while the Moon stay mostly out of the way and provides darker skies.  For a printable star chart of this area, use Star Chart #11 here at Eyes on the Sky, and look for M104 in the lower right hand corner near Corvus.  (Saturn will not be on this star chart.)

Combing Coma Berenices

What better way to talk about a constellation representing stolen locks of long blonde hair in the sky than to tell the story of Ptolemy Soter and Berenice in Astronomy Theater?  Despite being somewhat dim for us to see naked eye, the Coma Star Cluster - which represents a portion of the constellation Coma Berenices (literally meaning Berenice's Hair) - is best seen with binoculars anyway.  Learn how this cluster was originally seen by the astronomy Ptolemy (different from Ptolemy Soter) as a nebula, but not listed as a star cluster until Jacques Melotte in his open cluster catalog in 1915, yet still not confirmed as one until Robert Trumpler did so years later.  This cluster is to the east of Leo the Lion, but be sure to look west of Leo in Cancer the Crab for The Beehive / Praesepe / Messier 44 - another hazy patch in the sky known since antiquity.

Suave Saturn

There are few sights in the night sky that cause people to audibly gasp at the eyepiece of a telescope; craters on the Moon, Albireo, and a few others are up there on the list.  But almost without fail, the one object that tops that list?


With its majestic rings floating silently against a velvety black (or even slightly orange from light pollution) background, this planet evokes the wonder and awe inside many observers minds unlike other planets can.  At opposition this coming weekend, the planet will become a mainstay of evening observing from now through the end of summer.  Look for Titan, the Cassini division, and the subtle shading of the cloud tops - all covered in this video, along with observing tips on how to see this best-of-the-planets solar system object.

Did you see the substantial difference between the regular bulb and the silver-topped one in this week's "Dark Sky Fact"?  Here's where you can try and order some of them:


Light Bulb Emporium

The Lunar X, S and Apollo 16

As humans, we tend to see patterns and shapes in nature - clouds that look like animals or people, or as in this month's video, letters on the Moon due to the angle of sunlight striking it's surface.  Just slightly before 1st quarter phase several times this year, an "X" shape appears where the craters Purbach, LaCaille and Blanchinus are.  This "Lunar X" is only visible for a few hour, as once the Moon's rotation reaches a certain point, the areas surrounding the craters become visible and the "X" is not distinguishable from the background.

Not far away to the east, an "S" shape - laying down on it's side - can be seen, created by the features Mons Penck and the crater Kant.  Not far from here (visually anyway) we can find the location of where the Apollo 16 astronauts landed.  Their mission began on April 16, 1972 and four days later, John Young and Charles Duke stepped on the surface, 41 years ago this week.  You can locate the area where they walked with any small telescope, near the crater Descartes.  The equipment they left behind is too small to see with any Earth or space-based telescope, but the general area where they were is easily found.  Click here to convert UTC time your local time.

Lunar X, S, and Apollo 16 chart, 393 KB - With bonus!  See the Lunar "V" shape as well; download this chart to see where it is

International Dark Sky Week / Dark Sky Month / Leo's Triplet 

April 5 thru 11 is International Dark Sky Week, which is part of Global Astronomy Month.  Here at Eyes on the Sky, light pollution reduction is a top priority.  Please consider some of the steps you can take to actively make a difference in reducing light pollution around you.  And by doing so, that gives all of us a better opportunity to see things like the Leo Triplet of galaxies that are well-placed this week for viewing.  All at approximately 35 million light years distance, Messier 65 & 66 along with NGC 3628, these galaxies make a fine spring-time target for medium to large telescopes in a wide field of view.   

To help you find the Leo Triplet of galaxies, download Star Chart #10.

Bode's "Nebula"

Although Charles Messier is well known for his list of 110 "non comet" objects that are often the best in the northern hemisphere's night sky, he wasn't always the first one to identify all of those objects.  In the case of a galaxy in Ursa Major, he wasn't first: Johann Bode beat him to it, despite the fact that many of us refer to is at M81 today.

Though the Virgo galaxy cluster is perhaps more the realm of seasoned amateur astronomers, the brighter galaxies to be found in spring's sky are more likely to be the pair that includes Bode's Nebula / M81, along with it's companion, M82.  Eyes on the Sky does an overview of the background on Bode, along with information on how to star hop right to these galactic neighbor's of ours, simply by drawing a line in the "bowl" of the Big Dipper.  For a little extra help, download the star chart below, and look for these objects this week or next while the Moon is out of the evening sky.

M81 / M82 star hop chart, PDF 700KB

More on this week's Dark Sky Fact: Dark sky friendly lighting at Lowes

Don't forget!  Comet PANSTARRS is still visible in the western sky (though not naked eye anymore); check the charts below for where to look.  Binoculars and/or a wide field telescope will certainly be required now, but it's bright coma and short tail should still be visible through the atmosphere low in the west.  

Looney Luna

Lunar chart for Schiller-Zucchius Basin, Schiller, Messier and Messier AThe word "looney" is derived from "lunatic / lunacy" which itself is a word borne from "Luna," meaning Moon.  People thought the full Moon made people crazy, a myth that persists to this day, sadly.  But that's not to say there aren't crazy things to see on the Moon.  Without going into transient lunar phenomena, natural processes that created odd shapes or features on the surface abound, and this week is about precisely that - all of which you can see in a small telescope at moderate magnification.  

First up is the Schiller-Zucchius Basin, an area that was overlooked on the Moon until manned missions started mapped the surface several decades ago, and researchers started to overlay those maps on a globe, and noticed the concentric rings.  Due to our perspective, viewing them at somewhat of an oblique angle, these had never been identified previously.  Nearby to that feature is the crater Schiller itself, which clearly had a bit of an odd history given it's shape.  And finally there is the dual-crater system of Messier and Messier A, across Mare Fecunditatis from the large crater Langrenus.  The Messier system stands out in the darker-floored mare, but it has crater rays that formed in some interesting directions given how most crater rays form. 

Lunar chart for Schiller-Zucchius / Schiller / Messier (PDF, 2.3 MB)

More on this week's Dark Sky Fact: Light pollution and safety

Don't forget!  Comet PANSTARRS is still visible in the western sky (though not naked eye anymore); check the chart for where to look.  Binoculars and/or a wide field telescope will certainly be required now, but it's bright coma and short tail should still be visible through the atmosphere low in the west.  

Spring constellations

Nights are getting shorter, and days are getting longer in the northern hemisphere.  As Earth revolves around the Sun, we have turned another 90 degrees, and face a different section of space compared to 90 days previously.  So where are we looking?  And what constellations can we see?  Not only that, where will the planets be going throughout spring, and where can we see them?  Find out the answers to those questions, and more in the March 18 through 24 Eyes on the Sky!

Want to go back in time?  You know, far enough back to view the Winter 2013 Eyes on the Sky videos