Caribbean Sky - June 29 - July 5

Today, June 29, the moon is in first quarter and speaking of the moon the United States has returned to the moon with an interesting spacecraft. The Lunar Reconnaissance Orbiter is now in a 200km high polar orbit of the moon. In this orbit the moon is basically spinning under the orbiter as the orbiter goes round and round in a north south plane allowing it to map the entire terrain of the moon to incredible detail. Should be able to see the peanut shells that Neil Armstrong left behind.

Take a look at the moon on Tuesday. That bright star just off to the right is Spica in the constellation Virgo. One of the brightest stars in the sky.


(Click on the pic for larger version.)




On Friday the 3rd the earth will be at aphelian. That’s the point in it’s orbit where it is the farthest from the sun. Yes this happens now and not in winter! Seasons are controlled by the angle of the sun and not how far away it is.




IF you’re up early on the 4th you’ll see a nice grouping in the eastern sky just before sun rise. The brightest thing you see is Venus. Just above it is Mars and to the left is the good old Pleides or seven sisters the most famous of the star clusters. The bright star just below Venus is Aldebaran the bright start in the Taurus constellation. NASA's Pioneer 10 spacecraft, which flew by Jupiter in 1973 will reach and pass by Aldebaran in about two million years. Mark your calendars!

Wow, if the Pleides are rising again I guess we’re sneaking up on being in Grenada for about a year since I featured the Pleides in an early report.

The Nearest Star

You know how when you were a kid there were just some things you knew and you couldn’t remember when or how you came about knowing them. For example: Rhode Island is the smallest state or England is an island or Ernie Banks hit 512 home runs or specifically for us today that Alpha Centauri is the closest star. Right. Well nearly.

The official name of that nearest star is Rigel Kentaurus and it is in the constellation Centaurus. What I didn’t know growing up in South Bend Indiana was that I couldn’t see this nearest star from there and not just because I wasn’t allowed outside. But you can see it from Grenada.

Take a look to the south anytime after dark and you should be able to easily identify the southern cross. Follow the cross bar on the cross to the left to a pair of bright stars. The one on the right is Hadar, part of the Centaurus constellation and the one the left is Rigel Kentaurus (or Alpha Centauri). . . the nearest neighbor to our sun. AND although it is a binary system, the main star is a near twin of our sun. Those of you listening for awhile have heard me talk of things being hundreds or thousands or even millions of light years away. This guy though is only 4.4 light years away. Hey let’s go!

Hmmm… we might be able to get a rocket up to 100,000 km/hour. Ok, 4.4 light years, carry 3...divide by pie. . .Ok then. Trip would only take about 4000 years. Much longer by sailboat! I think we’re staying put!

Well enjoy the sighting anyway and just in case the centurians are watching - wave nicely.

Click on the picture below for a bigger version.

The imaga above is from Starry Night software. It is a really fun program for searching about the night sky. It's what I use for these astronomy minutes and for the Compass column. Oh, I go outside now too and look around! Check it out.

Finally, Now that I've successfully lured you to the end of this blog here's a blatant plug for my book, The Why Book of Sailing. It's either a sailing book about physics or a physics book about sailing. Here's some testimonials from other cruisers:

"I read it and then I sleep"
Exodus

"It is a book I've ever read"!
Puddle Jumper

"It's got pictures"!
Dionysus

I could go on and on. Here's a link to the book on Amazon.

See you next week!