Friday, February 22, 2013

Moon Transits Earth

Check out this video made by the Deep Impact spacecraft.

These images were taken in 2008 when the spacecraft was 50 million kilometers away.  It's a loop of one day - one rotation of the Earth - and the Moon crosses right in front.  This is called a transit (just like when Venus transited the Sun in June 2012).  Since the Moon is 240,000 miles away from the Earth, Deep Impact had to be in exactly the right place to see this alignment.  Although the pictures aren't crystal clear, you can make out the African continent in there.  For more moons transiting planets in our solar system check out Emily Lakdawalla's Planetary Society blog:

Thursday, February 7, 2013

Asteroid Coming - Earth Safe

On February 15 at 2:25pm EST, a 150-foot long asteroid will zoom harmlessly by the Earth.  Let me repeat -
it will NOT hit the Earth.
But it will be wicked-close to us!

For a brief time on Friday, Asteroid 2012 DA14 will be the closest thing to Earth.  The Moon is, on average, about 240,000 miles from Earth while this asteroid (I will nickname Dan) will pass just 17,200 miles above our atmosphere – the closest pass by any asteroid known in advance.  That’s definitely a close shave, but it has absolutely no chance of hitting the Earth.

Astronomers can track the positions of asteroids with amazing accuracy. The Cincinnati Observatory was in charge of collecting data on asteroids and comets from 1947-1978. Dr. Paul Hegret ran the internationally recognized Minor Planet Center out of the Cincinnati Observatory in Mount Lookout.

Unfortunately Dan (Asteroid 2012 DA14) will not be visible from the Cincinnati area when it makes its closest approach (we’ll be facing the other way and it'll be daylight).  It’s so small that even at its closest it will be a 7th magnitude object - so dim that observers in Europe, Asia, and Australia will still need binoculars or a telescope just to see it.  
For more coverage on Dan, go to:  There'll be a link to a live webcast on February 15.
I can't wait to see the video amateur astronomers make of it!

Monday, February 4, 2013

Orion Myth Part II...

We left off our myth as the Pleiades, now doves, flew into the sky to escape Orion and turned into stars. Orion's love was scorned but he was not humbled. Orion was a great boaster which angered some of the gods. They thought it would be ironic for a tiny creature to slay the great hunter so they sent a scorpion, Scorpius, which dealt Orion a fatal bite on his heel.

For his greatness, Orion was allowed a place in the sky. He asked the gods to placed as far away as possible from the Scorpion that killed him. So the Scorpion is best seen in the summer while Orion reigns over the winter near the Pleiades. This way, Orion never sees Scorpius and at the same time he can try more pick-up lines on the Sisters.

The Sisters hated this so much that the gods placed a protector in between the two. That's where you can find Taurus the Bull. Now the Seven Sisters are riding safely on the bull's back while Taurus tramples poor Orion every night. That's what you get for asking seven sisters to marry you!

To find these stars, use Orion's belt stars.  Connect the dots and continue the line to the right.  When you do, you'll pass through a "V" shape of stars (that's Taurus' face).  If you keep going you'll run into the Seven Sisters.

But wait, there's more!  Not only is there a giant hunter being trampled by a bull with 7 women on its back... Orion asked the gods if he could have some help with the Bull.  The gods agreed and allowed him to bring his two best hunting dogs up to become stars. 

Next week, I'll show you where to find the dogs AND the Unicorn, AND the bunny rabbit, AND the river.