Explore the Universe - Lunar Phases

We have all watched the Moon as it has changed its phase.  By the time we are thirty years old the Moon has gone through nearly 375 cycles.  The Moon is a beautiful sight in the night sky, a bastion of the sky for more than 4 billion years.  What causes the Moon to go through different phases?

The below diagram shows the Sun, Earth and the Moon.  The Moon phases pictured below occur when they are at that angle between the Sun and Earth.  When the Moon is between the Sun and Earth it will be a 'New Moon' and will not seem to appear in the sky.  The Sun is illuminating the far side of the Moon.  As the Moon orbits the Earth it slowly appears as a 'Waxing Crescent'.  Waxing is a term synonymous for 'growing'.  When the Moon is at a 90° angle it becomes a 'First Quarter' Moon.  Some people are confused why it is called a quarter when it seems as though half the Moon is illuminated.  It is referred to as a quarter because it is a quarter of the way through the lunar cycle.

The Moon continues to orbit and becomes a 'Waxing Gibbous' Moon, growing larger towards the next phase of a 'Full Moon'.  The Sun shines directly onto the near side of the Moon and observers on Earth see it as fully illuminated.  The Moon then starts orbiting back towards the Sun to become a 'Waning Gibbous'.  When it reaches 270° it is half illuminated again and called 'Third Quarter' or 'Last Quarter'.  It then continues its trek back to the beginning of the cycle going through its 'Waning Crescent' phase.  Around 29 days since it began the cycle it becomes a 'New Moon' again and restarts the process.

Phases of the Moon

The images above (including the Sun but excluding the Earth) were taken from the backyard.  The below diagram displays the dates and times.  To qualify for the Explore the Universe certificate the 'Last Quarter', 'First Quarter' and 'Full Moon' must be recorded within 18 hours of the actual time the exact phase occurs.  This is recorded below.

Lunar Phases Observation Record

I have a love/hate relationship with Moon phases.  A 'Full Moon' produces a lot of light making it more difficult to fall asleep.  It also brightens the sky with awful light pollution rendering deep-sky observing less fruitful.

The 'First Quarter' phase is one of my favourites.  The Moon is visible in dark skies early in the evening so it is perfect for kids to see before they go to bed.  The terminator goes through some intriguing craters that can be easily viewed from Earth.  Also, by the time adult bedtime arrives, the Moon has set allowing an easier sleep.

Viewing the waning phases in a dark sky is also difficult because it occurs early in the morning accessible by staying up very late or waking up very early.

Keep an eye on the sky and try to figure out what phase the Moon is at.  The weekly posts on my blog will highlight the 0°, 90°, 180°, 270° phases. 

Explore the Universe - M4

As it is approaching late Spring, Scorpius is starting to poke its claws above the southern horizon earlier in the evening.  This is quite exciting as it soon heralds the appearance of the heart of the Milky Way in Sagittarius with all its beauty.  However, this post will focus on Messier 4, a globular cluster sitting right next to Antares.  Antares is the bright heart of Scorpius named after the Greek meaning 'Equal to Ares'.  Ares was the Greek god of war whose Roman equivalent is Mars.  This is noteworthy as Antares and Mars look similar to each other in the sky as bright red objects.  Last year in fact Mars and Antares were less than 5° from each other in April of 2016.  It was an amazing sight.

Lying a little more than 1.25° to the West of Antares is Messier 4.  A typical wider field eyepiece in a moderate sized telescope will be able to locate both within the same field of view.  This is how I found it at 1:30am with a tired mind and sleepy eyes.  I did not have the chance to photograph it as I had already put my imaging scope away for the evening.  It looked like a typical globular cluster as a round, dense formation of stars.  It went across about a third of my 25mm eyepiece with a 62.5' field of view.  Some individual stars were observable around the edge of the blurry object.  It turns out that it was the first globular cluster where individual stars were resolved.  As Scorpius rises higher in the sky I hope to have a better look at it earlier in the evening.  My observation record for M4 is shown below.

Observation Record - M4

After a Winter and Spring of observing open clusters it is quite a gear shift moving onto the Summer globulars.  It is more difficult to see individual stars in a globular as they are further away and orders of magnitude more dense.

Last night was an open house at the Rothney Astrophysical Observatory.  It was very cloudy on the way there but it cleared around 9pm.  One of the members found Jupiter manually nearly an hour before the sun set.  We viewed the 7% waxing crescent Moon, the Hercules Cluster M13 and I was even able to stick the International Space Station into my view and manually tracked it for a few seconds.  The solar panel array can be easily seen.  Jupiter had its Great Red Spot facing directly toward us at 10pm and it provided a great sight for many first-time Jupiter viewers.  There was a hydrogen alpha solar telescope available to use and prominences on the Sun were visible.  Sunspot region 2659 was clearly visible in scopes equipped with a solar filter.

Sunset at the RAO

Later in the evening, after 11pm and throughout the night, the aurora put on an amazing show.  Unfortunately I had already packed it in and was cruising home to bed.  A moderate G2 geomagnetic storm decided to dazzle everyone with a beautiful display of the Northern Lights.

2017 Week 22: (May 28-June 3)

June is coming up really fast and with it the Summer Solstice.  There are a few conjunctions happening next week that will be interesting to check out.  The list of astronomical events for Week 22 is shown below.

Date	Event
May 31	Regulus 0.3°N of Moon
June 1	First Quarter
June 2	Venus 1.8°S of Uranus
June 3	Venus greatest elongation West
June 3	Jupiter 2°S of Moon

The month ends with Regulus hanging out right on top of the Moon.  This will be a great sight for the naked eye, binoculars or a telescope.  The next evening the Moon will be at its first quarter phase and great for finding interesting craters along the terminator.  I hope the clouds will stay away so I can capture some craters!  If you are a morning person Venus will be less than two degrees from Uranus.  This may be visible in a set of binoculars or a wide field telescope.  A map of the region is shown below.  As you can see they barely fit into my 8" telescope with a Panoptic 41mm eyepiece.

Venus and Uranus

Venus will be at its greatest elongation West on Saturday.  Also, if you add some power you will be able to see it at half phase.  The week finishes off with the Moon skipping below Jupiter in the southern sky.

If you are a Mars fan, I'm sorry but it will be tucking in behind the Sun for awhile.  It reaches superior conjunction on July 26.  It will become visible again nearer the end of September in the early morning prior to sunrise.  The good news is next year on July 27 it will be at opposition very close to Earth.  However, it will be low on the ecliptic and the big fat Full Moon will be cruising very close to the red planet.  Since it will be low on the ecliptic viewing it will be hindered by poorer seeing than if it were higher overhead.  I am hoping that it will be good enough to grab some images of the features on the planet, including Olympus Mons, the tallest mountain in our solar system.

Jupiter and Saturn will make for a great display throughout next week and into June.  Jupiter will appear in the South and Saturn will follow it up several hours later in the South East.

Uranus is still swimming around Pisces and Neptune is having fun tempering the water being pour out of Aquarius.  Good luck finding them.  Your best bet for Uranus is matching it up with Venus close to the June 2 conjunction.

Have fun observing the sky this upcoming week and keep your eyes peeled for exciting astronomy activities we host or volunteer at!  Join the group at www.facebook.com/simonjastronomy to stay informed!

Explore the Universe - M13

The great globular cluster in Hercules was the first Messier object I ever found.  Back in 2016 I first acquainted myself with the Hercules constellation and the keystone that forms the heart of it.  I knew Messier 13 was on one side of the keystone between two bright stars.  It took me nearly an hour to find it for the first time.  In my eyepiece it looked like a water molecule with the cluster forming the oxygen atom and two stars equally spaced away forming the hydrogen.

In Spring, Hercules is just coming back up to reside overhead for the next few months and it will give plenty of opportunity to go back to one of my old favourites.  With my red dot finder and knowledge today it only takes a few seconds to find.  This cluster serves as a milestone marker where once it took an hour now takes a matter of seconds.  The image below is the shot I took in May 2017.  I am hoping to learn how to use dark frames to get rid of noise from the photographs in the future.

Messier 13

In a dark sky it is barely visible to the naked eye and spans a diameter about two-thirds of the Moon.  The globular cluster contains more than a quarter millions stars packed into a region nearly 150 light years across.  The cluster lies more than 25,000 light years away from Earth.  It spanned approximately one-third of the way across my eyepiece and was circular in shape.  The record below shows my observation.

M13 Observation Record

This was the second of the three globular clusters I observed on May 21, 2017 and definitely the best.  I was planning on going to bed after this observation around midnight but stayed up another hour and a half to catch Messier 4.

Explore the Universe - M5

Going into Friday, May 20, 2017 I required four more observations of deep-sky objects on the Explore the Universe list.  I was fortunate to have the opportunity to find three.  The first one I found was a globular cluster in a constellation known as Serpens.  Serpens is a strange constellation as it is split up into two non-contiguous sections bisected by Ophiuchus  Serpens contains Serpens Caput (head) and Serpens Cauda (tail) where the body of Serpens is represented going behind Ophiuchus.  This was just when I thought the constellations started to make sense.

For more information about globular clusters please see my blog post from January 18, 2017 linked below.

What is a Globular Cluster?

Messier 5 is an amazing globular cluster.  It spans 160 light years across and may contain up to half a million stars.  It is also one of the oldest globular clusters at an age of roughly 13 billion years.  An image I took of this cluster is shown below.

Messier 5

Its arclength in the sky is 23' and it spanned about a third of my field of view with my 25mm eyepiece.  After spending the Spring viewing open clusters it was a rewarding experience to come back to the Summer globulars.  The observation record is shown below.

M5 Observation Record

Messier objects are fun to find and the hunt is just as exciting.  It is like the thrill of finding Waldo in a difficult scene.  I am slowly working on the Messier certification however, it will be difficult and the work will likely span several years.  Also, I would like to get back into observing the Moon.  There is a new lunar observing program that is not as exhaustive as the Isabel Williamson Lunar Observing Program.  It might be a good place to start.

Explore the Universe - Alpha Librae

Last night was one of the first good nights for astronomy in a long time.  This Spring has recently been giving us 3 or 4 clear nights per month so last night was a treat.  I had a list of targets that I have been saving for a clear night.  I only require two more double stars and four deep-sky objects to complete my Explore the Universe Certificate.  I was fortunate to find two double stars and three deep-sky objects from the list last night.  A complete list of the Explore the Universe items can be found at the link below.

Explore the Universe

The first object on my list was Alpha Librae.  The bright star in the double is also known as Zubenelgenubi.  This name derived from the Arabic الزُبَانَى الجَنُوبِي which means* the 'southern guard' or 'southern police'.  I am assuming this is because Zubenelgenubi is the southernmost of the two bright stars of the justice constellation: Libra. (*Thank-you to a colleague who is well versed in Arabic).

This double star forms the second brightest object in the constellation Libra.  It is an easy naked eye object which made it exceptionally easy to find with a telescope.  When Libra was high in the sky just before midnight I could see Alpha Librae.  I placed my red dot finder onto the target and looked through my 25mm eyepiece.  I could clearly see two bright stars against a field of several dim stars.  I estimated the separation between the stars was approximately 5% across my field of view.  This would give an estimate of 3.13' separation which was close to the accepted value of 3.85'.  My observation record is posted below.

Alpha Librae Observation Record

I recently learned how to type in celestial coordinates to the goto mount and may begin imaging multiple star systems on the list.  They are not incredibly exciting so it may be a while before I attempt it.

The next deep sky objects on the list are either in or near Sagittarius which does rise above the houses until after 1 in the morning.  Messier 16 is more than 10° East of Saturn and would be the next feasible target on the list.  Approaching this target may be difficult as it is about two binocular fields away from an urban naked eye star: Nu Ophiuchi.  The Summer constellation Sagittarius is quite low in the sky and contains many deep-sky objects.  It may require spending a few late Summer evenings at the observatory to get a clearer view of the southern horizon.

It is unfortunate that the clouds seem to be rolling in this evening after an exceptionally clear night.  Long weekend evenings are typically very good for astronomy because you can sleep in after catching some great late night sights!  In future posts this week I will log another double star and three deep-sky Messier objects!

2017 Week 21: (May 21-27)

We are now approaching the 21st week of the year and there are some amazing things happening in the sky.  The table below showcases the conjunctions and the birth of a new lunar cycle on May 25.

Date	Event
May 22	Venus 2°N of Moon
May 23	Mercury 1.6°N of Moon
May 25	New Moon

The interesting thing in the sky is Comet C/2015 V2 Johnson in binocular range located in the bright constellation Boötes.  Currently the comet is at magnitude 6.9 less than 2° SW of Delta Boötis.  A sky map of the constellation is shown below for this evening.  The comet is labelled near the top.

Boötes

A zoomed in map is provided below with the fields of view.  As you can see a pair of 15x70 binoculars will easily fit Delta Boötis and C/2015 in the same field of view.  Also useful is a wide field eyepiece will be able to capture the comet in the same field of view this evening.

C/2015 V2 Johnson is a hyperbolic comet so it does not orbit our Sun.  It is probably a traveler from outside the solar system or it has been gravitationally kicked out by the interaction with another body in our solar system.

If you would like to find the comet seek out Arcturus.  This is a bright (4th brightest in the night sky) red star that will be sitting just southeast over overhead.  Follow the bright stars shown in the first image on this blog to the naked eye star near the comet.  Stick this star in your binoculars and peak southwest keeping the bright star in your field of view.  If you are lucky you will see a fuzzy patch of light.  This will be the comet.  For more information about Boötes please see my previous blog post linked below.

Constellation Profile - Boötes

Last night we had an astronomy open house at our home.  There were 12 people in attendance and we had the opportunity to discuss the objects that are currently in the sky.  Even though the Moon was just past last quarter the phases were discussed and when to view them.  After the presentation and the snacks the clouds parted to have a great view of Jupiter.  All four Galilean Moons were visible and the seeing was good enough to see the North and South Equatorial belts at 171x power.  A link to the powerpoint presentation is given below.

Astronomy Night - May 19, 2017

Based on the success of the open house we hope to continue these evenings regularly throughout the year.

Free Astronomy Software: Virtual Moon Atlas

The Moon is the closest celestial object in our sky.  Although it may seem like a simple sphere there are many features on it that can be observed from Earth.  In order to correctly identify them a Moon atlas is required.  I have the Atlas of the Moon book by Antonín Rükl that provides an amazing profile of all the areas on the front side of the Moon.  You can access a version of this book online at the following link.

http://www.refractorland.org/HMA/Moon_Map.htm

There is a free software package online that can be downloaded which provides an excellent interactive map of the Moon.  It is called Virtual Moon Atlas and I am just learning some of the great things that can be done with it.  A link to the program is provided below.

https://www.ap-i.net/avl/en/start

You can download associated image databases to view some of the amazing photography amateurs around the world have done.  The main screen of the program is shown below.

Virtual Moon Atlas

It can be zoomed in to see greater details.

Virtual Moon Atlas (Zoom)

You can add your own image database and customize a journal of your observations.  The current phase of the Moon can be shown and suggested targets along the terminator are displayed.

A great function of the program is that it can show you the libration of the Moon.  The libration is essentially its 'wobble' occurring due to its elliptical orbit.  Depending on its current libration you can see further to the East or West.  The video below shows the phases of the Moon throughout 2018.  Notice it seems to tilt East and West to show a greater degree in either direction throughout the year.

https://www.youtube.com/watch?v=FBWeSN66z9M

Distances on the Moon can be easily measured using the Virtual Moon Atlas.  Also, similar to Cartes Du Ciel, eyepiece target windows can be placed on the image.  This helps to choose the correct eyepiece for what you would like to observe.  A complete encyclopedic write-up is provided for the objects on the Moon that you can access just by clicking on the feature of interest.

Textures can be downloaded to overlay historical mapping of the Moon from centuries ago or up to date information from the Lunar Reconnaissance Orbiter.  The information from the LRO allows for amazing closeup shots.  Plato is again shown below.

Virtual Moon Atlas (High Zoom)

If you have a mild curiosity about the Moon or are a dedicated selenographer this program will be useful.  It is also free!  Check it out and learn more about our closest neighbour!

Free Astronomy Software: Cartes Du Ciel

There are some amazing astronomy programs that you can download for free.  In this post I will highlight my favourite: Cartes Du Ciel.  A link to the homepage is given below.

https://www.ap-i.net/skychart/en/start

An outline of the description is provided below.

"This program enables you to draw sky charts, making use of the data in many catalogs of stars and nebulae. In addition the position of planets, asteroids and comets are shown.

The purpose of this program is to prepare different sky maps for a particular observation. A large number of parameters help you to choose specifically or automatically which catalogs to use, the colour and the dimension of stars and nebulae, the representation of planets, the display of labels and coordinate grids, the superposition of pictures, the condition of visibility and more. All these features make this celestial atlas more complete than a conventional planetarium."

I can not begin to describe how useful the program has been to me over the past year.  A lot of astronomical observation begins with a plan.  It is important to know which part of the sky you would like to look and how to get there.  In order to understand the sky it is best to use a manual telescope without the crutch of a mount driving the scope to the location.  This requires a great deal of skill and knowledge of the sky.

When you download Cartes Du Ciel you can input your exact coordinates for an accurate model of the sky.  You can choose any date to research future observation plans.  An interesting feature of the program is that it allows you to program in your eyepieces to make field of view targets on your skymap.  An example of this is shown below during my research of the Leo triplet.

Leo Triplet

As you can see the 25mm eyepiece for my 8" reflector telescope will display all three deep sky objects in the same field of view.

You can create a map of the entire sky if you are interested in naked eye viewing for the evening.

All sky map

A feature I find interesting is you can see the alignment of planetary moons and which face of Jupiter is pointing at us.

Jupiter

This is useful if you would like to identify the moons through binoculars or a telescope.  Also, if you are imaging Jupiter you will know when you can capture the great red spot.

Advanced settings of Cartes Du Ciel let you control a computerized mount directly from your laptop.  You can add light pollution boundaries if you are near an urban center that may disrupt your viewing.  Detailed information about every object in the sky is provided and you can download more catalogs depending on what you are interested in.  A favourite function of mine is the comet viewer.  You can view a comet and determine its magnitude throughout various times.  The below image shows comet C/2015 V2 (Johnson) in the same field of view as Mu Boötes, a double star I recorded about a month ago.

C/2015 V2 (Johnson)

This will be an interesting target to find during the next few evenings.  Without a program like this it would be more difficult to learn and navigate the sky.

Another neat thing I discovered this evening is the picture add-on.  It provides nearly 10,000 images of deep sky objects as you zoom in.  This can help pinpoint your location in galaxy rich areas such as the Virgo Cluster or the Leo Triplet, shown below.

Leo Triplet (with images)

If you get this program and need some advice as you use it do not hesitate to contact me.  Whether you are a casual observer who may look up with the naked eye once a year or a dedicated astronomer seeking out the faintest objects, this program is for you.

2017 Week 20: (May 14-20)

We are officially moving into the 20th week of 2017 with a few nighttime sky events.

Date	Event
May 15	Double shadow transit on Jupiter
May 17	Mercury greatest elongation West (26°)
May 18	Last Quarter
May 18	Double shadow transit on Jupiter
May 20	Neptune 0.5°N of Moon

As mentioned last week the set of double shadow transits of Jupiter's moons has begun.  The evening of the 18th will be a great opportunity to witness this phenomenon.  Assuming good weather and no clouds I may open my backyard for a viewing opportunity.  Mercury will reach its greatest elongation West on Wednesday and will allow for prime viewing the following morning in the dawn sky.  The Moon will be waning back to a New Moon only visible in the early morning as it reaches Last Quarter.  Fortunately we had some good nights where the Full Moon was brightly beaming in the southern sky.  Finally, Neptune will be pretty close to the Moon next weekend.

When Mercury was approaching its greatest elongation East I was able to get a few pictures of this elusive planet.  Unfortunately it was with my non-tracking Dobsonian during a public viewing night.  I did not have enough time to properly capture the half phase that would be showing.

Mercury

For the people who like to stay up very late, Saturn will be prominent in the low southern sky.  It will look like an elongated sphere through binoculars.  If you have the chance to view it through a telescope the rings will be extremely conspicuous along with many of its moons.  It currently rises at quarter to Midnight and will be visible above the houses about an hour later.  Saturn will reach opposition on June 15 where it will be at its biggest and brightest as viewed from Earth.  Great time for imaging.

Mars, unfortunately is approaching conjunction with the Sun late in July and is currently fairly dim and small as viewed from Earth.  Its next opposition is July 27, 2018 in what will be close to a perihelic opposition (Mars will be very close to us due to its elliptical orbit).  2003 had a great perihelic opposition not seen in the past 60,000 years.  These oppositions provide the best time for seeing Martian features including the polar ice caps and Mons Olympus, the tallest mountain and volcano in the entire solar system.

If the sky is clear, look up, enjoy the spring constellations and the bright, beautiful planet Jupiter in the southern sky!

Explore the Universe - Virgo

Virgo is quite a bright constellation high in the sky during the Spring. Virgo is the second largest constellation in the sky narrowly missing that title by 8 square degrees.  Its brightest star, Spica, is the 16th brightest in the sky and forms a sheave of wheat in the left hand of Virgo.

Virgo is a zodiacal constellation representing the dates between August 23 and September 23.  Virgo also has many myths associated with it.  A myth that has been discussed in previous blog entries is that of Icarius who was killed by the shepherds.  His daughter, Erigone, was so overcome with grief she hanged herself.  Dionysus, the god of the grape harvest, placed both of them in the sky as Boötes and Virgo.  Virgo has been known to be Astraea, the virgin goddess of purity and innocence.  Astraea was always associated with the goddess of justice, Dike.  These two companions share the sky as Virgo and Libra.

Virgo (Artist Interpretation)

 The Virgo cluster of a couple thousand galaxies lies partially within the constellation's borders.  Due to this fact, eleven Messier objects can be found in Virgo.  I've only given the constellation a cursory scan with my telescope and I could see many galaxies.  The image below shows my observation record from May 2, 2017.

Virgo Observation Record

The arms are quite easily navigated with the naked eye.  The Virginids form a set of meteor showers radiating from various locations in Virgo throughout the year.  The maximum hourly rate among them barely reaches ten per hour so they are not really discussed a lot.

Explore the Universe - Clavius

The final crater I observed on May 4, 2017 is called Clavius.  This has become one of my favourite craters due to its distinctive pattern.  There are a set of craters inside Clavius arranged in a half-circle with progressively smaller diameters.

Clavius

Clavius' diameter is a colossal 225km which is approximately the distance between Calgary and Cardston.  It is also one of the oldest craters dating back nearly 4 billion years.  The diminishing craters inside Clavius have diameters (50, 28, 21, 13, 12, 8)km.  These craters are well known for being a test of a telescope's resolution.  How many of these craters can you see?

Clavius is named after the German astronomer named Christopher Clavius.  He was a strict adherent to the geocentric view of the universe with the Earth at the center.  However, this did not let him get in the way of a great friendship with Galileo.  Clavius is probably best known as one of the architects of the Gregorian Calendar.  The Gregorian Calendar replaced the Julian Calendar throughout civil society beginning in 1582.  It is worth noting that some countries have yet to accept the Gregorian Calendar.  The Julian Calendar is still used by some Orthodox Churches most notably the Russian Orthodox Church.  The last country to use it was Greece until they switched over in 1923.

A wide field image of Clavius shows how close it is to the more famous Tycho.  The large crater between the two is known as Longomontanus who was Tycho Brahe's assistant in Denmark.  The crater on the Northeast rim is known as Porter or Clavius B.  The first of the diminishing craters is called Rutherfurd after an American astronomer famous for his Sun and Moon photography.  The central peaks in Rutherfurd seem to look like eyes in the image below.

Clavius Wide Field

Enjoy the sight of the Moon and take a closer look to see if you can see any remarkable features on its surface!

Explore the Universe - Tycho

Tycho is probably one of the most famous craters on the entire Moon.  Between first quarter and third quarter Tycho is likely the crater the naked eye immediately goes to.  Tycho is the obvious crater located on the southern reaches of the Moon that has the long ejecta lines.  The nearly Full Moon in the image below showcases this crater.

Tycho on a nearly Full Moon

The diameter of the crater is 86km, smaller than the previous craters examined in the Explore the Universe certificate.  It reaches nearly 5km deep and has prominent central peaks.  The walls are terraced and ejecta lines are easily visible later in the lunar cycle.  Tycho is a very young crater with an estimated age of only 108 million years.  Compare this to Plato which dated back nearly 4 billion years.

The crater is named after the famous Danish astronomer Tycho Brahe.  Brahe (1546-1601) was one of the last astronomers to not use a telescope.  He is known for what is now known as a Tychonic Cosmological Model.  This model has both the Moon and Sun orbiting the Earth while the rest of the planets orbit the Sun.  Tycho was a devout Lutheran and interpreted the Bible literally that the Earth shall not be moved (1 Chr 16:30, Psa 93:1, Psa 96:10).  Even though Brahe did not have the technology of a telescope he made the most accurate naked eye measurements in history.  His published measurements had errors not typically larger than 3 arcminutes.  His observation notes had some errors less than a single arcminute.  He improved the sextant and most other measurement devices of the period.  He is also famous for being involved in a duel with a distant cousin where he lost most of his nose.  He wore a silver/gold prosthetic for the rest of his life.

The image below showcases this amazing crater, its central peaks and its terraced rim.  It is a composition of the top 10% of 2000 frames taken over 20 seconds.

Tycho

A wide field view showcases some of Tycho's conspicuous neighbours including the 163km wide Maginus to its South (up in this photograph).  The terminator can be seen to the West (right) in the image.

Tycho Wide Field

The next time you look at the Moon take a gander at Tycho and see how far you can see the ejecta lines spread across the surface.  Enjoy the Spring sky before the mosquitoes claim the outdoors to begin their evil reign over the twilight.

2017 Week 19: (May 7-13)

This upcoming week has several conjunctions, a Full Moon and a double shadow transit across the face of Jupiter.  The table below outlines all of these events.

Date	Event
May 7	Jupiter 2°S of Moon
May 7	Mercury 2°S of Uranus
May 10	Full Moon
May 11	Double shadow transit on Jupiter
May 13	Saturn 3°S of Moon

The double shadow transit on Jupiter is an interesting sight.  The Moons of Jupiter come between the Sun and the large planet many times a month.  When they do they cast a shadow on the planet's surface.  This is the same as when a solar eclipse casts a shadow on the face of the Earth.  Sometimes the alignment of Jupiter's Moons has two or even three casting a shadow at the same time.  Imagine the Earth having three solar eclipses occurring at the same time.

When I first looked at Jupiter through a telescope in April of 2016 I noticed two black spots on the surface.  Unbeknownst to me there was a double transit occurring and I was lucky to see it.  Due to the 2:1 orbital resonance of Io and Europa (two innermost Moons) a double transit will occur every 3-4 days until the end of June.  I am hoping to catch an image of this sometime in the next 6-8 weeks.  The image below was taken from by backyard on May 4 and shows two of Jupiter's Moons orbiting the big planet.

Jupiter and two Moons

May 10 brings a Full Moon to light up the evening sky and exacerbate insomnia sufferers.  I was unable to get a picture of the Full Moon last month due to clouds so I am hoping for clear skies.  It is looking promising!

Enjoy the sky while the bugs are not in full swing and take in the mid-Spring constellations!

Explore the Universe - Plato

We had a beautiful clear sky on May 5, 2017 that allowed for the opportunity to get a good view of the Moon.  I was able to record three of the twelve listed craters on the Explore the Universe certificate.  The first one I took a look at was Plato.  The crater is named after the Greek philosopher and father of western science.

Plato is an extremely old crater (as indicated by its lava filled interior) at an estimated 3.84 billion years old.  It sits just above the Sea of Rains (Mare Imbrium) which is only slightly older at 3.94 billion years.  To its East are the Montes Alpes (The Alps), a beautiful mountain range forming the northeastern border of Mare Imbrium.  It is a fairly large crater extending  101km in diameter.  The western rim consists of a landslide.  There are a few small craters located on the floor of Plato which show up as tiny light patches in the images below if you look carefully.

A close up image is shown below.  A smaller (20km) prominent crater is shown to its northwest with the name Bliss.

Plato

It was amazing to view the Alps to the East of Plato.  The Vallis Alpes is clearly visible between Mare Imbrium and Mare Frigoris.  The valley stretches early 170km through the famous lunar mountain range.  I'm sure if the weather was reasonable it would make a great several day hike.  The image below shows the region around Plato with the valley extending across the right side.

Plato Wide Field

Also shown in the images above is the mountain range known as Montes Teneriffe.  They extend for about 110km and rise more than 2km from the surface.  The name comes from the largest of the Canary Islands: Ternerife.  The mountain range points towards Mons Pico, a beautiful solitary peak named after the highest point of the Atlantic Islands: Pico von Teneriffe.

Just to the West of Montes Tereriffe is Montes Recti (Straight Range) that is barely poking out in the wide field image above.

The features on the Moon can be elusive month to month.  However, they can also put on an amazing show when the weather behaves.  I find it fascinating to imagine these features on the Earth and what it would look like up close.

Explore the Universe - Ptolemaeus

The sky cleared out on April 4, 2017 around 22:30 and the Moon shone brightly a day after first quarter.  I had in my calendar to watch out for the large crater known as Ptolemaeus.  The terminator had just recently passed the crater and it was prime for viewing and imaging.  Unfortunately the seeing was not too great and I was too tired to polar align the scope properly.  I still got a couple good images to go along with this post.

Ptolemaeus

In the image above Ptolemaeus is centered in the frame.  Inside the large crater is a smaller one known as Ammonius which is approximately 9km wide.  Ptolemaeus itself is a sizable 153km in diameter.  On the right side of the image is a crater known as Herschel named after the famed astronomer William Herschel.  The left side has the larger crater called Alphonsus which contains a central peak.

Ptolemaeus was named after the extremely famous Greek astronomer named Claudius Ptolemaeus 100-170AD), colloquially referred to as Ptolemy.  He wrote a landmark scientific treatise known as Almagest.  His geocentric model of the Universe was accepted until Copernicus discussed heliocentrism during the early Renaissance.  His work allowed for accurate predictions of the Moon, planets, Sun, eclipses and stars.  Ptolemy had a list of 48 constellations and most are still in use today.

A wider field of the region is shown below.

Ptolemaeus Wide Field

I am finding the Moon a more difficult target to view.  Certain regions have great visibility in the evening sky about once a month.  This gives a potential 12 opportunities each year to properly view certain lunar features.  With inclement weather this can drop to perhaps only 5 or 6.  Stellar objects are typically available for several months at a time so you're bound to have many good chances to see them.

Typically the day after Ptolemaeus you will be able to see the great craters of Tycho and Plato!  These are great in any set of binoculars or a telescope!

Explore the Universe - Mercury

The last Saturday of March 2017 had beautiful weather that coincided with an open house at the Rothney Astrophysical Observatory.  Mercury was a week away from being at its greatest elongation East and was high in the sky.  It also was the day of Venus' inferior conjunction with the Sun and we were actually able to view it minutes after the Sun set.  If you have not attended one of these open houses it is well worth the experience.  As members of the Royal Astronomical Society of Canada we have the opportunity to share our telescopes with the public.  Watching someone view Jupiter or Saturn for the first time is an amazing experience.

Volunteering at the RAO

The Explore the Universe certificate requires an observation of all the planets (excluding Earth).  I had waited a year for the opportunity to view Mercury and it did not disappoint.  Around 20:18 I observed a bright red disk in the twilight sky just a little over 10° above the horizon.  I only had my 8" untracked reflector so was limited in exposure time to about 1 second.  The image below is what I managed to capture.

Mercury - March 25, 2017

Mercury is the smallest planet in the Solar System.  Sorry, Pluto is not a planet, it is a dwarf planet.  However, there are two moons in the Solar System larger than Mercury.  Jupiter's largest moon Ganymede and Saturn's largest Titan beat out Mercury by a couple hundred kilometers in diameter.  However, Mercury has both of them beat by mass.  The gravity on Mercury is considered to be about 38% that of Earth.

Keep an eye on our blog for times throughout the year when Mercury will be easy to observe.