The Night Sky Guy

Moon Pairs with Cluster and Mars

Find star cluster easily thanks to the Moon this Wednesday before dawn

Early bird skywatchers this coming week get a chance to see the crescent Moon join a beautiful bright open cluster and then the Red Planet in two back to back mornings.

First up on August 24th look towards the eastern horizon for the moon about 5 am local time. It is sitting in the constellation Gemini, the twins for the next couple of days.  If you have binoculars or a small telescope check out that faint fuzzy patch to the Moon’s left – that’s M35, and open star cluster.

M35 up close Image Copyright © Bob Christmas

This cluster which sits at 2,800 light years away was first observed by Charles Messier in August 1764 while he was searching for comets.

The cluster is quite large, spanning about 20 light years across with at least a good couple hundred member stars. Brightest member stars shine at 8 and 9 magnitude and first impressions when you view it up close is that the stars form a rectangular formation with a tighter, more packed core.

When the Moon is not in the area – later on the week try your hand at glimpsing M35 with the unaided eye. You may need to be away from the light polluted city in cottage country to really see this faint fuzzy patch that appears about as wide as a full Moon disk. With binoculars M35 is quite east to spot, even from the city.

Then the following morning of August 25 you will notice that the Moon has slide down to the lower left in the sky. Look closely to its left you will notice a faint orange-red star – that is planet Mars. Also you will see the two brightest stars in Gemini that mark the heads of the twins 51 light year Castor (top) and 37 light year Pollux (bottom).

The 4th planet in the solar system is looking real puny in the sky these days and that’s because it’s about as far away from our planet as it can get in its track around the Sun – at about 300 million km from Earth. It’s so far away that it takes light about 8 minutes to travel one way between our two worlds. So that means that when the Mars rover Opportunity and its orbiter cousins whirling around the planet send us those amazing images – it takes that long for us to receive them here on the ground stations. Despite its faintness in the sky you can still make out the orange hue imparted on the  planet by sunlight reflecting off the iron-oxide rich sand dunes and dust that cover much of the planet’s surface.

Moon sits beside planet Mars about an hour before sunrise in the east this Thursday.

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Montreal Meteor Shower Party

Well the Perseid meteor shower peak is almost here and reports from around the world are looking good with on average 20 shooting stars per hour. Of course with the full moon blocking out the fainter meteors the show won’t be as spectacular as in some years but the event should be a crowd pleaser.

For a viewer’s guide to the Perseids check out my National Geographic story .

If you are in Montreal tonight and there is clear skies then why not join me for a Perseid meteor shower party!  The Royal Astronomical Society of Canada, Montreal centre is hosting a public star party at the Morgan Arboretum in Ste. Anne-de-Bellevue, starting at 9 pm with a brief talk given by your truly. And if the weather permits volunteers will have telescopes t view the Moon and stars. and of course for the meteor shower I recommend bring a blanket and/or reclining lawn chairs to enjoy the Perseids.

You will find directions here

Wishing everyone a great sky show!

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Star Eclipsed by Moon Wednesday Night

Anyone In eastern North America looking up at the waxing gibbous Moon on Wednesday night at 10:30 pm ET will get a chance to see a naked eye star wink out before your eyes as it disappears behind the disk of the Moon. Known as a lunar occultation in astro lingo, when a stellar object gets covered by the Moon – it’s not everyday that you get to see a fairly bright star – magnitude 2.9 Pi Sagittarii in this case – slip behind the Moon.

Eastern north American observers can see naked eye star in Sagittarius eclipsed by Moon this Wednesday

What makes it worth watching is that Pi Sagittarii also known as Albadah in southern constellation Sagittarius is in fact a triplet of stars – too tight to resolve with small backyard scopes – but what we may see is that there may be not one but two noticeable dimming events as each star, one-by-one goes behind the moon. Skychart below shows what the southern sky should look like and the location of the star and Moon. Because the glare of the Moon will be very bright I suggest using binoculars or telescope to view the occultation. check out times for specific locations here.

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Mars Meets Star Cluster

Sky chart showing where to find Mars in the sky credit: Starry Night Software

Over the next few days the Red Planet will appear in the sky to glide past a beautiful pack of stellar gems known as M35. Mars will be fairly easy to spot with the naked eye – looking like a faint orange star,  but the star cluster may need the magnification of binoculars to really see them well.

Both planet and star cluster are in the constellation Gemini-located at the twin’s feet. While the cluster is visible to the naked-eye from a dark sky, a pair of binoculars will really bring out the details in the 2,800 light year distant cluster nicely, especially from a light polluted suburban backyard.

This open star cluster consists of several hundred stars and measures about 24 light years across. In our Earthly skies it takes up about the same chunk of sky as the full Moon does. M35 is one of the eternal favourite targets of beginner stargazers looking for deep sky treasures.

telescope view of Mars only 1/2 degree from star cluster; Click image to enlarge

Your best bet is to look towards the low eastern sky about an hour before local sunrise while skies are still dark.

On the morning of Sunday, Aug.7th Mars will only appear to be 0.5 degrees from the cluster – that’s about the width of one full Moon – the closest they will get to each other. don’t worry if you get clouded out – you can see the Mars-cluster pair for a few mornings after this weekend.

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Asteroid Vesta Brightest in Sky Now

Not until the  year 2018 will an asteroid appear as bright in our sky as Vesta will the next couple of weeks. The second largest asteroid int he solar system will appear like a bright star in a pair of binoculars and be just visible from cottage country with the naked eye. You can actually see it move over a the course of a few hours. How cool is that!

Best time to see it is late night in the constellation Capricornus low in the south around midnight. Here are a couple of star charts to help you hunt Vesta down yourself.  Sky and Telescope also has a nice magnified chart here.

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