May 18, 2010

Wednesday, May 19th. The Moon glides past the Beehive


Tonight the waxing crescent Moon moves past the zodiacal constellation of Cancer, the crab. Cancer is one of the less obvious constellations when viewed with the naked eye.

The crab consists of six relatively faint stars roughly in the shape of the letter X. There’s a visual treat in Cancer however. M44, the Beehive or Praesepe open cluster of stars is stunning.

You’ll need binoculars or a telescope for this one unless you have exceptional vision and are observing under very dark skies far from urban light pollution.

Tonight the Beehive will appear roughly 14 degrees west (to the right of) the Moon. If you trace an imaginary line from the Moon to the star Pollux, M44 is about one third of the distance from the Moon to Pollux.

For me M44 resembles a sparkling ball of diamonds. The Beehive is much more impressive without the glare of the Moon. Tonight use the Moon as a finder and once you know how to locate M44 come back to it on a night without glare from the Moon.

If you’d like to give your significant other the gift of diamonds a “gift that keeps on giving” show them M44.

Click to enlarge the chart I prepared with the Stellarium planetarium freeware.

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Tuesday, May 18th. The Moon meets Gemini


 First of all I want to say “Happy Birthday” to our twin daughters Sasheen and Checole. Happy Birthday girls, I love you!

Tonight’s observing project is finding the star Pollux which will be about 7 degrees NNE (to the right) of the waxing crescent Moon. Pollux is the brighter of the two “head stars” of constellation Gemini, the twins. Castor, the other “head” is about 4 degrees north (right) of Pollux.

Gemini is one of the more easily spotted constellations. The “bodies” of the twins stretch out to the west, at this time of year, below the head stars. These late spring evenings the twins feet are just about touching the western horizon as darkness falls. The Castor twin’s left foot points down to the right toward Venus.

My other “twins”, two chocolate Labs, are named Cass and Polly after Castor and Pollux because I adopted them in late spring when Gemini was prominent in the evening sky much like the current view. I should have named them “Thelma and Louise”!

Castor and Pollux may appear to be close together. Actually they are about 18 light years apart. Pollux is 33 LY distant from us, Castor 51 light years away and is a double star. Because Castor is about 33% more distant it appears smaller than Pollux.

See if you can make out the Gemini twins “stick figures” with the aid of the chart which I made using Stellarium.  Click on the image for a larger version/

Clear skies.

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May 15, 2010

If skies are clear Saturday night, May 15th

Go out at sunset, around 9 pm, and see if you can spot the two day young Moon about 4 degrees below and to the right of Venus.


Bring your binoculars. The Moon will be a very thin crescent with most of it’s disc bathed in earth glow. Refer to the chart which I prepared using the Stellarium planetarium freeware program. Venus and the Moon will appear between the “horns” of Taurus, the bull some 8 degrees above and to the right of the red giant star Aldeberan. Aldeberan is the “eye” of the bull and will be hugging the horizon.

Try and spot Taurus’ horn-tip stars Zeta and Beta Tauri. Click on the close up chart for a better view.


As the Moon is setting a little after 9:30 keep your eyes skyward. Observers in the Louisville area will be treated to a spacecraft “convoy” as the International Space Station streaks over followed by Atlantis which will be playing catch-up with the station. ISS will approach at about 9:32 from the NW to SE peaking about 50 degrees above the NE horizon. STS-132 will follow ISS by about 10 minutes appearing to the west (left) of where you saw ISS at 9:49 pm peaking at 66 degrees above the SW horizon.

Atlantis will appear to the west of ISS and much higher than ISS because it is flying about 50 miles below ISS’ altitude. The Station is orbiting at about 220 statute miles up, Atlantis about 175. That’s how the Shuttle catches up with the Station.

The other reason Atlantis will appear to the west of where you saw ISS is because YOU will have moved east some 150 miles in the 10 minutes since the Station passed. You’re standing on the Earth’s surface which, here in Kentuckiana, is spinning eastward at about 900 mph!


Atlantis was launched Friday afternoon and will dock with ISS around 10 am Sunday morning. STS-132 is delivering the Russian Mini Research Module called Rassvet which is the Russian word for “dawn”. The MRM will add an additional docking port and airlock to the Russian segment of ISS. On the trip up it’s packed full of supplies. The STS-132 crew will replace six batteries which store power from the Station’s solar panels and deliver a spare communications dish during three planned spacewalks. STS-132 will be Atlantis’ 32nd and final trip into space.

Over those 32 flights Atlantis has travelled about 115 million miles. That’s a lot of miles but, to put Solar System distances into perspective, Mars is about 130 million miles from Earth now.

Find STS-132 updates from NASA

I’ll see you at the Blackacre event.

Clear skies!

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May 14, 2010

Catch a very young Moon and the ISS Friday night!

The new lunar cycle, lunation 1081, began at 9:05 pm ET on Thursday evening. Observing very old and very young Moons is one of my favorite observing activities.

See if you can “catch” the very young Moon this evening. You’ll need binoculars. The Sun will have set and the sky darkened enough by about 8:40pm local time. The Moon will be about 8 degrees above where the Sun set.

The Moon will be about 4 degrees west (to the right) of the reddish star Aldeberan in Taurus. Aldeberan is the red “eye” of the bull.

The Moon will be about 15 degrees (remember hands and fists?) below and to the right of the very bright Venus.

Scan the sky low above the WNW horizon with your binoculars being very careful to avoid the Sun if it hasn’t already set. You can permanently blind yourself if you’re not careful.

You may be able to spot the earthlit disc of the Moon and a very, very slender crescent.

NASA launched STS-132, Atlantis, on a supply and servicing mission to ISS this afternoon. While you’re out looking for the Moon we’ll be treated to a visible pass of the ISS as it pops up above the western horizon for about two minutes from 8:43-8:45 pm.


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