Archive for the ‘The Moon’ Category

Port Douglas, North Queensland, Australia
Wednesday, 14 November 2012

Earlier this year we told our friends in Sydney that we were going to Cairns to see the Solar Eclipse. Some thought we were mad; others said we were smart.

Yesterday, looking out of our Virgin airlines plane from 38 thousand feet, we wondered if we were indeed crazy, because the Queensland coast was covered in wads of cotton-wool clouds!

view from the plane

View of cloud bank over Queensland

But, buoyed by the good wishes of all our friends, we hoped that we’d see at least a few minutes of this very special celestial spectacle. “Well”, said Dom, trying to console me, “it’s our holiday, so let’s enjoy it whatever happens.”

The briefing on Tuesday evening
“Beware of snakes and cow dung!” Melissa said with a smile. No one from our tour group smiled back. We had come prepared for mud and mosquitoes, not snakes! 

Melissa, Education Officer from Sydney Observatory, our tour guide, had done her homework and visited the location for plan B, so we took her words seriously.

Why location B?  Location A, ten minutes from where we were staying at Port Douglas, was a no-no. Clouds were about, and clouds were forecast for eclipse morning. So Melissa had to make a rapid change of plans. She consulted a weather forecast company that film makers consult, and they had directed her beyond the Great Dividing Range.  

Cairns and Port Douglas are on the sea-front. Their weather is at the mercy of winds blowing in from the Pacific. Fortunately for us, the Great Dividing Range is inland from Port Douglas, and the mountains form a natural barrier for clouds rolling in from the sea.

So Melissa had to choose a location just past the shoulder of the Great Dividing Range. The place had to be reasonably flat, have a clear view of the east and be as close as possible to Port Douglas. She had personally driven around before we arrived, scouting for suitable places, and finally found one. There was only one catch. It was 160 km away.

So this morning we boarded the coach at the unearthly hour of 2 AM. Orion, bold and beautiful, was straight overhead. I considered it a good omen.

While we napped, Phil our coach captain drove very carefully on the Mulligan Highway that snakes its way over the Great Dividing Range. Two hours later, we reached the location in total darkness. The skies were wondrously clear. As we got off the coach and looked up, we oohed and aahed at the Milky Way spread out like a brilliant carpet overhead. The Southern Cross and the Pointers were to the south. Then, torches on, we carefully walked around cowpats and anthills to find a spot where we could set up our cameras. We noticed other cars there—at least 20 other astronomers had arrived before us.

The land was semi-cleared. To our great relief, resident snakes had taken off into the bush on hearing the footfalls of a platoon of men and women carrying torches, cameras and telescopes.

The spot was fairly level with low hills and a few trees which would be the foreground to the action. Venus was peeking over a mountain, so we set up our cameras aimed at her for we knew the drama would take place in that region.

The view of the east with Venus

The view of the east with Venus (Click on image to enlarge)

Melissa had warned us we’d miss the first stages of partial eclipse, but it was a small price to pay for a good view of the rest of the extravaganza.

We started setting up our equipment—telescopes, cameras—in the dark. Each group chose a different vantage a point from which to view and photograph. We chose a spot from where the landscape would lend enchantment to the view and interest to our photos.

Daphne sets up one of our cameras

Daphne sets up one of our cameras

As the sky began lightening, the stars began to fade. The brightness grew; anticipation was palpable … and soon Venus vanished.

We talked to others in our group. Many had been to other solar eclipses—some had even been to four! Many said previous eclipses had been non-events due to bad weather. We were among a few first timers. We sure hoped we’d be first time lucky!

Slowly, one spot in the sky began to grow brighter. Someone called out, “Put on your solar glasses!”

A bright spot apears between the mountains

A bright spot apears between the mountains (Click on image to enlarge)

The show had begun! All attention was focussed on the rising sun.

Dom views the eclipse with special solar glasses

Dom views the eclipse with special solar glasses

From the top left, the moon had taken a clean bite out of the sun!

The moon had taken a bite out of the sun

The moon had taken a bite out of the sun (Click on image to enlarge)

Slowly the environs became darker. A bird called out. The air turned chill.

As the moon moved more over the sun, an unnatural hush descended. The vanished Venus and a few stars reappeared. The sun and moon slipped behind a tree giving me a unique photo of sun, moon and gum leaves.

The action takes place behind gum trees

The action takes place behind gum trees (Click on image to enlarge)

We watched the sun becoming a crescent …

The sun as a crescent

The sun as a crescent (Click on image to enlarge)

… and then a slim sliver. One of the kids called out, “It’s like a smiley!”

A sliver like a smiley

A sliver like a smiley (Click on image to enlarge)

Eventually the sun was barely a thread of orange.

The sun a slendar thread of orange

The sun a slendar thread of orange (Click on image to enlarge)

Then it happened! Total eclipse!  A shout went up from the crowd!

 “I can’t see a thing,” cried someone.

“Take off your solar glasses!”

“Ahhhh! That’s better. Look at that!”

This was the climax of the drama. The sun and moon were in perfect alignment. What did it matter that this event can be explained mathematically in celestial geometry? It was a moment of bliss and magic—a poetic moment to remember with all its sights, sounds and feelings.

Two stages rapidly followed. First came Baily’s Beads—sunlight, like coloured beads, shining through mountain valleys on the rim of the moon—

Baily's beads

Baily’s beads (Click on image to enlarge)

—then total eclipse when the sun’s disk was fully obscured, but its corona was visible like a halo.

Total eclipse

Total eclipse (Click on image to enlarge)

The two minutes of total eclipse felt like 40 seconds.

And then—oh wow! For a brief second the diamond ring flashed!

The diamond ring

The diamond ring (Click on image to enlarge)

How we savoured the moment!

And all too quickly it was over. Slowly, the sun emerged from the shadow of the moon. The exposure of the sun began anew.

Sliver of sun appears

Sliver of sun appears (Click on image to enlarge)


As the sun waxed, sunspots were clearly evident.

Three quarters revealed with sun spots

Three quarters revealed with sun spots (Click on image to enlarge)

With the return of the light, we noticed how green the trees around looked.

The trees glow green

The trees glow green (click on image to enlarge)

The shadow of the moon over the sun was all but gone.

Nearly full

Nearly full (Click on image to enlarge)

The show was over, but people were reluctant to go home!

Eclipse worshippers reluctant to leave

Eclipse worshippers reluctant to leave (Click on image to enlarge)

Post eclipse

Sydney Observatory regulars who have chased solar eclipses in Turkey, Russia and Easter Island, all agreed that today’s Solar Eclipse was the best they’ve ever seen.

We two were indeed first time lucky!


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17 June 2012

Woke up this morning and looked out of Bedroom Observatory. There was the crescent Moon hanging off the palm tree like a slice of silver fruit!

Crescent Moon

Crescent Moon (Click on image to enlarge)

I moved to get a better view and two bright sparks came into view! Jupiter and Venus! Gorgeous! And all before sunrise!
How quickly Venus has moved across!

Crescent Moon with Jupiter and Venus

Crescent Moon with Jupiter and Venus (Click on image to enlarge)

18 June 2012

We are really out of practice of waking at 4 AM and throwing off the feather doona, our warm nest for the night.  But jump out of bed we did, and looked out of Bedroom Observatory.  The sky overhead was clear, but it was too dark to judge whether there were low clouds in the eastern horizon.  A clear horizon was crucial for today’s pre-dawn viewing.  The only way to find the answer was to check from Clifftop Observatory.  So we had a quick cuppa, rugged up, gathered our camera gear, and drove to North Bondi.  The temperature was 9 deg C, and a cold wind from the south pole was about.  From where we parked we had to climb about 100 metres, and our fingers froze holding the cold metal of the camera tripod.

When we reached Clifftop Observatory, we stood stunned, breathless and motionless.   Jupiter was lined up with the Pleiades; the new moon was below lined up with Venus.  And Venus was pretending to be the brightest object in Taurus!

Jupiter, the Moon, Venus

As the sky brightened, some of the little stars got swallowed up in the dawn light, but the main players were still there, keeping us riveted.

Jupiter, the Moon and Venus

Jupiter, the Moon and Venus (Click on image to enlarge)

Before we left, a photo with our favourite tree and my favourite man was mandatory!

Dom the tree and the planets

Dom the tree and the planets (Click on the image to enlarge)

When we came home, we could still see the triangle of Jupiter, Moon and Venus over the roof of our house. 

Final look at Jupiter, the Moon and Venus

Final look at Jupiter, the Moon and Venus (Click on image to enlarge)

The weather man says the rain has gone to Spain for a few days.  So here’s cheers to clear weather and more good viewing.

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3 May 2012

Since we wrote the last blog, we have joined a Star Hoppers group led by our US mentor Greg. Most of the members are on the east coast of the US. We are the only two, as far as I know, Down Under. The aim of the group is to apply the classic advice of Sherlock Holmes – learn to “observe,” not simply to “see.”

And what should we observe in the first two weeks of May?

 “Good targets for viewing under dark skies are the Beehive (with binoculars or a low power scope), several double stars in Cancer and Leo or the galaxies in Leo.”  

We have to pick 3 – 5 targets on any given night.

The targets for May are fortunately also in constellations in our southern sky.

Constellations of Cancer and Leo

Stellarium image of constellations of Cancer and Leo (click on image to enlarge)

Waiting, waiting

Primed and ready – we waited for the weather to give us a break.

When weather reports of the last few months promised clear skies, they often didn’t mention the evening clouds that creep in, uninvited, and destroy any chance of viewing the stars.  So we’ve invented a new game to amuse ourselves: it’s called “Wither goes the weather?”

On the evening of the 3rd May, around 8 pm, we were pleasantly surprised to find the sky was clear of pesky clouds. When we walked out on to car deck observatory the panorama was breath-taking even with lights on everywhere and moonlight bathing the street. And the air was cool and calm. Perfect for viewing!

Dish of the sky

Stellarium image: Dish of the sky (click on image to enlarge)

Sure our view wasn’t quite as detailed as this, but with all those fairly large objects in view, we were very excited.

Starting from north – Mars was pretending to be one of the stars of Leo, forming a neat triangle with Regulus and Algieba.

Moving past the fat Gibbous Moon, and going east was Saturn, a golden brooch on the skirt of Virgo.

Looking south over Francis Street were the Pointers doing their job of showing us the Southern Cross.

Southern Cross and Pointers

A slide along the Milky Way and we were looking west at Canis Major (Big Dog) lying on his back wearing Sirius like a trophy on his chest. And caught in the moonlight (or should I say despite the moonlight) a hare, Lepus, being chased by the Big Dog. What a beautiful constellation this is! A neat curve of stars.

Just below the Big Dog is his master Orion slipping down sideways behind the trees!

View of western sky

Our photo: View of western sky (Click on image to enlarge

Spoilt for choice

How to choose three targets? Spoilt for choice, weren’t we? So we did what one does at a smorgasbord crammed with too many delectable dishes. We decided for our first night of star hopping to sample every big star and planet we could see and look for doubles and galaxies and clusters before we committed ourselves to three.

 Using our binoculars we star-and-planet hopped. With the Moon between Leo and Virgo, we were lucky to see Regulus and Algieba, but swinging to the Cross we saw the Jewel Box displaying its contents near Beta Crucis. And in the vicinity was the king of globular clusters – Omega Centaurus.

Going down the Milky Way, watered down by the light of the Moon and the lights on in every home in Francis street (people don’t believe in curtains or blinds), we looked for M41 in Canis Major, and found it rather faint. Caught M42 in Orion’s sword just before the Hunter slipped off on his perpetual chase of the Scorpion.

With the sky still clear at 8.30 pm we decided it was time to bring out the scope and look at the planets. Mars was a nice round reddish disk, but Saturn, despite the light of the Moon, beat the god of war in the beauty stakes. Saturn is certainly the pin-up boy of the planets! We could just see its moon, Titan; the other moons were drowned out by the light of the Moon.

Had we been able to see them, this is what we would have seen.

Saturn with moons

We’ll keep that treat for another night.

Turning our sights to the Moon

Having had our fill of stars and planets we turned the scope with the 6mm eyepiece on the Moon. OMG! The angle of the light from the sun lit up craters and mares perfectly, casting shadows to show them in 3D. We have never seen crater Aristarchus with Vallis Schroteri and  crater Herodotus  in such good light. It was the feature of the night.

Some features of the Moon

Another striking feature in this light was the Bay of Rainbows with crater Bianchini clearly visible as were the other four or five craters in the neighbourhood. And then looking toward the edge of the Moon was a rather angular crater with a prominent peak. I think it is Babbage, or perhaps Pythagoras.

We could even see the Rectii range, an unusually straight range in the Sea of Showers.

Blindingly brilliant were Copernicus, Kepler and up at the top Tycho. But another crater that stood out very clearly, so that we could even discern where its rim is broken, was Gassendi on Mare Humorum. With Gassendi A, this crater looks like an engagement ring with a big diamond.

After a month’s starvation of night sky viewing, we feasted on this evening’s gifts of a clear and still night.  An hour and a half of uninterrupted viewing was more than we hoped for, so when the clouds came over at 9.30 pm, we folded our scope without a word of complaint.

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20 April 2012

After many, many days, the evening sky looked reasonably clear, so we went to Dover Heights, a suburb adjacent to Bondi, which faces the west. There from the platform of a large playing field we get a spectacular view of three suburbs, Bondi, the City and North Sydney. I hope the developers never, ever think of building here as it gives the public, in a crowded suburb, a place where children can play, people can walk their dogs and star gazers can come and enjoy the beauty of the night sky (despite the light pollution) against the background of our glittering city.

Somehow Dom and I have been forgetting about this grandstand view of the western sky – put it down to “senior” memory.

We went there this evening, carrying our cameras, and parked ourselves on a bench. A thick bank of clouds lay on the horizon up to about 10 degrees where the sun was setting and we thought we’d miss what we had come to see – Venus, the Evening Star – because it would be chasing the sun and soon drop below the horizon.

Anyway, we thought we’d just sit there and enjoy the cool evening and see which stars would pop out in the darkening sky. We saw headlights of planes flying this way and that. Then looking towards the north we saw two planes approaching, but as we watched we realised that one was not moving.

It is the higher one in this image. 

Venus and plane in evening sky

Venus and plane in evening sky (click on image to enlarge)

“Can’t be Venus”, we decided, though as it got darker, it kept getting brighter! “It is a bit more than 20 degrees – 21, I’d say!” estimated Dom with confident exactness. I had to agree.

“Must be Jupiter!” I tentatively suggested as it got brighter and brighter. “Now that’s brighter than any plane’s headlights,” said Dom.

Stars began to appear – Sirius was high up. The belt of Orion was becoming visible.

Convinced we’d missed Venus behind that huge bank of clouds near the setting sun, we picked up our gear and went home. We spied the big headlight in the sky in between buildings and above streets as we wound our way home. “Should have brought the binoculars,” I said. “Might have seen Jupiter’s Moons.”


Back at my computer I checked on Stellarium – it wasn’t Jupiter, was it? It was Venus! Not the King, but the Queen of the evening sky!

It was much higher than we expected and not as near to the sun as we had imagined.

But it sure was bright and beautiful!

21 April 2012

 We were drawn again to see Venus, this time with binoculars. Venus has phases like the Moon, so we wanted to see it as a crescent.

Planet Venus over Sydney, Australia

Planet Venus over Sydney, Australia (click on image to enlarge)

24 April 2012

We had a thunderstorm this afternoon and I thought our hopes of going to see Venus were zilch!

However, on our way back from our evening walk we spied the crescent Moon in the West against a clearing sky.

As soon as we got home, we took our gear and went to the platform which looks out west.

The sky was darkening and the Crescent Moon and Venus were getting brighter by the minute. The city lights came alive and the scene was breath-taking.

I wish I could say I got a good pic – sometimes it just does not happen.  This is the best of a bad lot.

Venus and crescent Moon

Venus and crescent Moon (click on image to enlarge)

The view is burned in my mind’s eye. It was just beautiful.

I sent emails to friends and family who do take the time to look at the night sky. Here’s what my niece Saritha had to say:

“So glad you sent us that information. We noticed it on the way home the other night. It was amazing – so low and bright that I was sure it was a plane, except that it wasn’t moving! Can’t believe it was actually Venus.

Feel quite excited about noticing the Evening Star – we may become star-gazers after all!”

As Greg, my US mentor says, it is wonderful when “people simply – and routinely – integrate  the night sky into their appreciation of nature.  It amazes me how many people are bird watchers, gardeners, or whatever – yet have no idea what is going on once the sun sets.”

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12 Mar 2012

Lately we have been getting an occasional glimpse of bright planets between clouds.

This evening a friend from Melbourne, who is also enthused about celestial happenings, excitedly rang to read us an item on the movements of Jupiter and Venus in the western sky. Thanks to that reminder we went out into Street Observatory at 8 o’clock. Our street runs east to west.

We had to walk up the street a little and stand near the middle of a traffic lane to get the best view.  Fortunately traffic was light, and Dom had a red torch to warn oncoming cars.  We looked west and beheld Venus and Jupiter – beautiful and bright.

As Greg, my mentor said, “Despite all my fascination with telescopes, I still get a thrill out of simply seeing the planets in the night sky and watching them change positions. It helps – for me, anyways – to understand what’s going on ‘backstage’. But people need to rediscover what you have found – simply look up at night – it’s a great show, we spend too much time in our caves!”

Venus and Jupiter on 12th March 2012

Venus and Jupiter on 12th March 2012 (Click on image to enlarge)

Having had our fill of Jupiter and Venus in the backdrop to our street, we folded the tripod and turned towards home. The celestial backdrop continued to the north.  We recognized Mars above the roof line of houses. Placing the tripod on a neighbour’s driveway I was focusing on Mars when a car stopped and the driver leaned out and said, “What are you photographing?” just in case we were spying into someone’s window.

“Mars”, Dom told the astonished man, “Right over the roof there!”

“So it is,” he said. “And it is red! Wow!”

Mars on 12th March 2012

Mars on 12th March 2012 (Click on image to enlarge)

We turned again and looked the other way downFrancis Street and lo and behold! The Cross and Pointers were looking down on us!

Southern Cross and Pointers

Southern Cross and Pointers (Click on image to enlarge)

I thought, hopefully, “Maybe at last, good sky watching times are here!”

After processing the photographs, I went to Bedroom Observatory at about 11 pm. Another planet, this time Saturn with the star Spica in Virgo were shining due east. Looking further east was the bright glow of the Gibbous Moon. I grabbed the binoculars and noticed that the angle of light had the section between Tycho and Mare Nectaris clearly outlining the craters.  I had not seen the SE sector so clearly. Craters everywhere. Several caught my eye and I tried to memorize their positions. Though the angle was awkward for the camera, I had to get a shot.

Gibbous Moon

Gibbous Moon (click on image to enlarge)

Dom and I pondered over the map a long while to identify Theophilus with the imposing central mountain. Tucked into the side of  Theophilus,  is Cyrillus.  The third in this neat threesome on the banks of Mare Nectaris is Catharina. The map is beautiful, but oh! how much more gorgeous is the real thing especially when the craters are in 3D.

Oh! what a night!

I need to spend more time studying some of the other craters that were clearly in the light.

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4 February 2012

When the weather forecast for the next three weeks promised only two clear nights, I knew those two were going to be very long nights glued to the binoculars. My patience was rewarded.  The Gibbous Moon shone splendidly outside Bedroom Observatory, and we photographed it easily. 

Gibbous Moon

Gibbous Moon (click on image to enlarge)

The first thing I notice is there’s a smorgasbord of features. So, like a diet conscious eater, I am going to pick out just the most delectable. The maria, centre and left, are beautifully displayed, so I decide to start with them. Up the top is the small Sea of Nectar. In shape it looks like a big dark D with a cherry on top. The straight edge of the D is to our east where it abuts the terrae that separates it from the Sea of Fertility. In that terrae, several mountain peaks of the Pyrennes mountains sparkle in the light.

 The “cherry” on the top of the D of the Sea of Nectar, I discover, the Crater Fracastorius which is a flooded crater whose rim is disintegrating. More interesting is the bright spot to the north of Fracastorius which is Crater Rosse. With its high albedo, Rosse a mere 12 km across, stands out against the dark volcanic lava of the mare. A feature of the Moon does not have to be large to catch the eye! Rosse does not have its own rays, but notice the ray that comes all the way from Tycho, brushes past the western wall of Fracastorius and then points to Rosse – that’s quite a long ray – at least 1800 km!

 Crater Rosse was named after the Irish Astronomer William Parsons, the 3rd Earl of Rosse. His claim to fame: building the largest telescope in 1847 and cataloguing many galaxies.

Gibbous Moon with Sea of Nectar

Gibbous Moon with Sea of Nectar (click on image to enlarge)

On the other side of the Pyrenees range is the large Sea of Fertility. Tucked into its eastern side is a large white circle which is the Crater Langrenus. The Flemish Astronomer Michel Florent van Langren who was the first to draw a lunar map named this crater after himself. When Riccioli and the others renamed all the lunar features, they left Crater Langrenus be!

The features of Langrenus are not too clear in this light but I will look at it during other phases. Astronaut James Lovell described it during the Apollo 8 mission as “quite a huge crater; it’s got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down.”

Gibbous Moon with Sea of Fertility

Gibbous Moon with Sea of Fertility (click on image to enlarge)

To the west of the Sea of Fertility across a large terrae with several bright peaks is the Sea of Tranquility. The top (south) part of this sea looks like a clenched fist with an outstretched thumb on which balances the Sea of Nectar. There are many interesting features of the Sea of Tranquilityto investigate, but the one that catches my eye is the light grey patch which nestles along the north-eastern edge facing the Sea of Crisis.

Called Pauli Somni, (Marsh of Sleep), it has a higher albedo than the lunar mare and has a diameter of 143 km. In 1907 the marsh was described as having “a color which is unique upon the moon, a kind of light brown, quite unlike the hue of any of the other plains or mountain regions”. Not sure about the light brown as I just saw it as grey through the binoculars.

Hugging the top edge of the marsh is the curve of Sinus Concordiae (Bayof Harmony) and at the bottom edge, Sinus Amoris (Bayof Love). Sleep between Harmony and Love — sounds like a good recipe for Tranquility!

Gibbous Moon with Sea of Tranquility

Gibbous Moon with Sea of Tranquility (click on image to enlarge)

The Sea of Serenity is the last mare I am looking at tonight. Both Luna 21 and Apollo 17 landed near the east border of this sea, in the area of the Montes Taurus range.

As I look at the Sea of Serenity, I pick our two craters Menelaus and Posidonius.

Posidonius was a multi-talented Greek: a philosopher, politician, astronomer, geographer, historian and teacher. In astronomy, among other things, he worked on the size and distance of the sun and moon from Earth. All this in 90 BCE, and all without any of the sophisticated equipment we now have!

An interesting note:

“The Luna Society voted unanimously to designate a Lunar crater for Michael Jackson (formerly Posidonius J) in honor of the legendary entertainer and prominent Moon property owner.” Michael Jackson would have been pleased – he did perfect the moon walk!

With my binoculars I can’t see this tiny crater on the rim of Posidonius, but what caught my interest in this little item was that one can buy real estate on the Moon!

Crater Menelaus is on the southern shore of the Sea of Serenity. You can’t miss it with its high albedo and it’s amazing to see a ray from the crater clearly crossing the mare. The crater is named after Menelaus of Alexandria, mathematician and astronomer. Some suggest it could be the Menelaus in the Iliad, whom Helen ditched to take off with the handsomeParis, causing the Trojan War! Somehow I don’t think it is that Menelaus!

“I hope you are going to show where Apollo 17 landed! After all it was the last manned lunar landing!” Dom suggested

“Oh okay! I’ll put a little star at the approximate spot!” Little boys!

Gibbous Moon witih Sea of Serenity

Gibbous Moon witih Sea of Serenity (click image to enlarge)

Having identified 10 new features, I call it a night. More to-morrow – the second clear night promised!

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19 Jan 2012

Studying the Moon is a challenge when skies are cloudy. We often have to wait patiently for a quick break in the scudding clouds.  Those seconds are precious: we must have our binocs ready to find the sickle moon and scan its face.

At 4 am on the 19th we woke up to find the crescent Moon a little south of east – at a narrow angle to the window of Bedroom Observatory. The Moon was sitting just out of reach of the fangs of Scorpio. The crescent is my favourite phase – it is the one I remember from childhood as the illustration in fairy tales and nursery rhymes.

Crescent Moon near Scorpio

Stellarium image: Crescent Moon near Scorpio (Click on image to enlarge)

Taking in the view through the binoculars we were delighted to discover features of the Moon we hadn’t noticed before. During the waning phase, the edge along the terminator is more clearly defined as the slanting rays of the sun emphasise physical features by casting shadows of mountains and rims of craters.

At the lower end of the terminator was what appeared to be a small mare with a prominent rim on its lower bank.

Bay of rainbows (Click on image to enlarge)

Research showed it to be Sinus Iridium or the Bay of Rainbows, the remains of a 260 km diameter walled plain. The mountainous rim on the northern and western edges is the range called the Jura Mountains. Along the line of the terminator, peaks of this range catch the sunlight. The string of bright points is aptly called the ‘jewelled handle’ effect.

Looking closer, about halfway along this mountain range, we noticed the prominent crater Bianchini.

There are a few craters scattered in the area below; some of which are Mairan, Sharp, Harpalus. The Bay of Rainbows is certainly a prominent feature, but we noticed it only now in the crescent Moon.

Bay of rainbows
Bay of rainbows with craters and Jura Mountains (Click on image to enlarge)

Moving up (south) we saw the familiar crater Kepler whose rays are now prominent. Aristarchus was its bright self and Grimaldi its dark self.

But what was that fairly large mare with a prominent crater in the top half of the Moon?

Crescent Moon with Bay of Rainbows and craters
Crescent Moon (Click on image to enlarge)

I recognized the mare as the Sea of Moisture, but it is more prominent during this phase of the Moon than when I saw it before. The Sea of Moistureis a small circular mare 825 kilometers (275 miles) across. The frilly edge of the Sea of moisture is formed by the mountains of an old impact basin. This basin has been flooded and filled by mare lavas. We could see that the lavas had flowed through the basin rim particularly in the lower left into the southern part of Oceanus Procellarum or Ocean of Storms.

Crescent Moon with Sea of Moisture
Crescent Moon with Sea of Moisture (Click on image to enlarge)

And that crater on the lower (northern) edge, is the large crater Gassendi which was considered as a landing spot for the Apollo 17 mission.

The rim of Gassendi is pretty circular, but is eroded in parts – a big gap appears in the top (southern) end. From the shadow cast it appears that the rim varies in height. Research tells me it goes from as little as 200 meters to as high as 2.5 kilometers above the surface.

A smaller crater cuts into the northern rim, making Gassendi look like a ring with a single stone. We noticed a few central peaks in Gassendi becoming clear as they caught the light.

Click on the link below for a neat photo of Gassendi taken through a near-infrared filter when the moon was waning.


Here are all the features I identified in the crescent Moon.

Crescent moon with features
Crescent Moon with features (Click on image to enlarge)

The top part of the crescent Moon, where it narrows to a point, looks interesting with a collection craters, but it is really hard to work out what they are. So I’ll leave them for another time – another phase of the Moon.

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