[ FirstLight Astronomy Club ] The Skies Above

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Well, That's a Load of Bull

Observing >

Rising in the eastern skies in the early evening now is a great horned beast. It is the great constellation of the bull of the heavens, Taurus, and is a scenic point for several reasons, all of which are visible with the naked eye.

There are many myths and stories featuring bulls from both the Greeks and Romans and the peoples before them who influenced their sky.

One famous story involves Europa, a princess in Canaan, and Jupiter, the oversexed, adulterous, and politically incorrect Big God On Campus for the Romans. The story goes that Jupiter, enamored with Europa, disguised himself as a beautiful white bull in a field where Europa and her friends were frolicking about.

Apparently he was so gentle that the trusting Europa decided to climb onto the back of her new Taurus and give it a spin. Jupiter, seizing the opportunity, sprang into the sea and swam all the way to Crete, his latest victim still clinging to his back. She would later become the mother of Minos, a future king of Crete.

As the constellation of the Bull rises in the east the first prominent part of it to be seen is the Pleaides, the tiny trove of stars often incorrectly identified as The Little Dipper. It represents to some the heart of Taurus, but has a story all its own.

Actually many, many stories if you consider cultures all over the world. We'll deal with some of those at a later date. But for now let's glance at the most well known story in the west --- that of the Seven Sisters.

These seven daughters of Atlas and Pleione were once accosted by Orion the Hunter. Zeus, the Greek counterpart of Jupiter, heard their cries and tossed them up in the heavens where they still twinkle today.

To astronomers they represent a classic "open" cluster, a collection of hundreds of stars all born at essentially the same time and in the same delivery ward. Look at them through a pair of binoculars and you see many more than seven sisters. You'll see more sisters, and brothers, and uncles and aunts and cousins ...

Born just millions of years ago, they were not here when dinosaurs ruled the Earth, but were here when ancient civilizations like the Sumerians were beginning to rock the land of Mesopotamia.

At that time, about 5000 years ago, the Pleaides were probably used as an extraterrestrial town crier. Back then the Sisters rose just before the sun in the first weeks of spring, which would have provided a reliable sky marker announcing the coming of the season for the people of the region.

Sadly, the whole group is actually moving away from us and in about a million years, plus or minus, the Sisters will be invisible to the naked eye.

After the heart of the Bull comes the big, easily recognizable V-shaped head of the Bull, also known as the Hyades. But like the Pleaides, these, too, have a story of their own.

Like the Pleiades, the Hyades were another brood of sisters fathered by the apparently very busy Atlas. (Free trivia: The Pleaides and the Hyades are known collectively as the Atlantides.)

In one mythical story these seven were very upset at the death of their brother Hyas and they wept and wept which, according to meteorologists at the time, was the cause of a one major rainfall. So, now guilty by association, both sailors and farmers for centuries blamed the Hyades for any nasty storms on sea and land.

The Hyades, like their half-sisters the Pleaides, are also an open cluster, the brightest of which trace out that famous V-shape. And they are very close to us, a mere 150 light years away.

Look closely at the Big V and you'll see a bright reddish star. That's Aldebaran, from the Arabic "Al Dabaran" meaning "the follower," probably because it follows the Pleaides through the night skies. This giant is not a sibling of the Hyades. It is actually only about 65 light years away --- and enormous.

Aldebaran, often seen as the red eye of the Bull, is nearly 100 times bigger than our sun and bleeds out more than 1000 times more energy! It is a red giant, doomed soon to die a violent death.

Taurus the Bull is a fascinating and feature-filled constellation. Go out and take a test drive through it yourself sometime soon.

Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com.

Posted by Administrator at 2004.11.27 11:55 AM | Comments (0)

Be Thankful for a 'Thin' Universe

A Perfect Balance >

Thanksgiving is here again, but because it is such a throwaway word nowadays in our hyper-busy society, allow me to remind us all that Thanksgiving was meant to be a time for giving thanks. And the study of the cosmos gives us plenty to be thankful for.

Many of us will eat our fill on this holiday. In fact, we will probably eat too much of all that food laid out on the table --- I know I probably will. I will probably put on a few extra pounds as a result of my lack of control.

The universe is more controlled than most of us, believe it or not. And that is reason for thanksgiving right there. For if the multitude of objects in the universe were more massive, if they were stuffed to excess, that would spell utter disaster for us on this planet.

Be full of thanks, for instance, that the sun isn't any heavier. When it was forming in its stellar womb about five billion years ago, it was given just enough hydrogen and helium with just a pinch of dirt to burn just the way it is now --- which is perfectly.

If the sun had collected more gas in its initial stages of creation it would burn faster and brighter. Both those consequences are deadly. Burning faster means it uses up its fuel much faster and would be dead or dying by now, and dying more violently. Burning brighter means it spews out not just more visible light but much more of the lethal ultraviolet and X-rays, too, more than our atmosphere can handle.

Be full of thanks that Old Jupiter, our big brother protector off in the distance, has no overeating problem. Jupiter, when it was just a toddler, vacuumed up just enough gas from the early solar nebula to be the fit and trim planet it is today. Had it swept up much more gas its increased gravity would have destabilized orbits of nearby planets, including ours.

Worse, had it swept up a lot more gas, had it gone for seconds and thirds and fourths at the cosmic dinner table, Jupiter would have erupted into a star. And no life-inhabited planet could endure that.

Two stars just don't allow the safe, perfectly designed, nearly circular orbit a life planet like our own demands. The constant tug-of-war between the two star's gravitational pulls usually ends up throwing a planet into one of the stars (bad) or flinging it out of the system altogether (just as bad). Either way, it's curtains.

I'm full of thanks that our own planet is no overindulgent body. There was a day when we were actually less massive and had a horribly thick atmosphere. But all the latest evidence leads us to believe that some rogue, Mars-sized planet came drifting by and smacked into an infant Earth at such an angle that we actually absorbed some of that planet's mass in the collision, but also threw a lot of debris into orbit around us.

This event thinned our atmosphere and gave us the Moon, both great blessings. And as a result of the collision, we now have a perfectly thin crust and the ideal tectonic plate activity.

But we also ended up, miraculously, with a planet of exactly the correct weight for the health of all future life on the planet. We have now the ideal mass, which means the ideal gravity, to hold on to the life-support gases like oxygen and nitrogen and water. But we don't have enough gravity to hold on well to lighter life-threatening gases like ammonia and methane.

I could go on and on and on about the flawless sizes and masses of all kinds of heavenly bodies and systems, but suffice it now to summarize here with two important points.

Perhaps the universe can be a model for us in that everything we see around us has the perfect weight for a healthy life here. From tiny atoms in your finger to the immensity of the universe itself, all are wonderfully sized for life here. Maybe we can use the universe as a model for healthier eating this Thanksgiving.

And of course, this Thanksgiving we can all be thankful for these and many, many more perfect heavenly ìparameters,î those cosmic guidelines and limits that make this planet one fantastically beautiful and paradisiacal place to live.

Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com.

Posted by Administrator at 2004.11.20 11:57 AM | Comments (0)

Palomar Shows Off New Laser

Observing >

Our favorite local --- and world famous --- observatory has just showed off a new toy, one that will allow it to continue to do premiere astronomy for a while to come.

Palomar Observatory, on Palomar Mountain in north San Diego County, for decades was The Place to go to do cutting-edge astronomy. The 200-inch mirror on the Hale Telescope (pictured at right) was the biggest in the world.

Then came bigger, more sophisticated telescopes, like the twin Keck Telescopes atop Mauna Kea in Hawaii, and Palomar's bright star began to fade.

One of Palomar's biggest problems, one in fact that assails every earthbound telescope, is that darned atmosphere of ours. For everything else our envelope of air is a pure godsend.

We need the atmosphere to provide us with oxygen, and pressure, and protection from deadly photons from space. It transports life-giving water, allows flight, warms us like a blanket, and so on.

But it makes an absolute mess of observing things in space. Why?

Have you ever looked at some distant object down a long street in the heat of the day? What you may remember seeing is what appeared as waves rippling above the asphalt making the distant object tough to see well. Look down that street with binoculars and the problem is just magnified. It's plain difficult to resolve much detail with all that distortion.

The same goes for anything above us. Trying to see through our atmosphere at night with the naked eye seems like no problem. We see the Moon and the planets and twinkling stars. But looking at them with a scope reveals that the same problem we have looking down the street at a distant tree rears its ugly head when we look up at distant stars.

Above us are tiny areas of warmer air next to cooler air moving invisibly through the skies. Such is the nature of our airy covering. The problem is that air pockets of even slightly different temperatures bend light differently, making the celestial object we are looking at appear to move about slightly.

So one may be looking at a star in the eyepiece of a telescope and the tiny point of light will literally jump around. (By the way, this atmospheric inference is why stars appear to twinkle.)

Planets are big enough in the eyepiece that they don't jerk about, but the details on their surfaces sure do, making them appear fuzzy or out of focus. Unfortunately, the way we learn in astronomy is to see more, not less, of the detail in objects, detail which reveals more and more of the way things are working up there.

What to do?! One possibility is to send a telescope above the atmosphere altogether, as was done with the famous Hubble Space Telescope, the satellite that has provided us with some of the most stunning images ever seen.

Obviously the Hale telescope at Palomar can't be sent into space. But maybe we can find a way to work with the atmosphere! How?

The latest, greatest thing in observational astronomy is called adaptive optics (AO). This method actually reads light coming in from a star and, via computer, "adapts" or reshapes a special mirror to compensate for the shaky atmosphere.

At the moment, Palomar and many other observatories use stars very near the object they are observing as corrective stars. As the image of the nearby moves about, the computer makes over 2000 corrections a second to try and steady it. The problem, though, is that you need a helper star really close to what you are observing. What if there is no star there?

You make your own star! And that's what's new at Palomar, where astronomers just recently, and successfully, tested their new star-making machinery. It works like this:

They fire off a beam of sodium laser light, just 4 watts, into the night sky right about where they are observing. When the sodium laser beam gets to about 60 miles up into the atmosphere it causes a tiny amount of sodium gas up there to glow --- just like a faint star. You can't even see it with the naked eye, it is that faint.

This convenient porta-star can be seen by the telescope, the AO system can correct for the distortion of the atmosphere, and --- ba-da-bing! --- it's almost like there isn't an atmosphere at all. Your images are sharp and information-filled, nearby star or not.

The whole system --- telescope, computers, and the new laser system --- should be working in unison by next year, breathing new life into the old and venerable Hale Telescope. It is indeed the Great Scope that just keeps getting better.

Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com.

Posted by Administrator at 2004.11.13 12:00 PM | Comments (0)



Looking for something?	« October 2004 \| Main \| December 2004 » Well, That's a Load of Bull Observing > Rising in the eastern skies in the early evening now is a great horned beast. It is the great constellation of the bull of the heavens, Taurus, and is a scenic point for several reasons, all of which are visible with the naked eye. There are many myths and stories featuring bulls from both the Greeks and Romans and the peoples before them who influenced their sky. One famous story involves Europa, a princess in Canaan, and Jupiter, the oversexed, adulterous, and politically incorrect Big God On Campus for the Romans. The story goes that Jupiter, enamored with Europa, disguised himself as a beautiful white bull in a field where Europa and her friends were frolicking about. Apparently he was so gentle that the trusting Europa decided to climb onto the back of her new Taurus and give it a spin. Jupiter, seizing the opportunity, sprang into the sea and swam all the way to Crete, his latest victim still clinging to his back. She would later become the mother of Minos, a future king of Crete. As the constellation of the Bull rises in the east the first prominent part of it to be seen is the Pleaides, the tiny trove of stars often incorrectly identified as The Little Dipper. It represents to some the heart of Taurus, but has a story all its own. Actually many, many stories if you consider cultures all over the world. We'll deal with some of those at a later date. But for now let's glance at the most well known story in the west --- that of the Seven Sisters. These seven daughters of Atlas and Pleione were once accosted by Orion the Hunter. Zeus, the Greek counterpart of Jupiter, heard their cries and tossed them up in the heavens where they still twinkle today. To astronomers they represent a classic "open" cluster, a collection of hundreds of stars all born at essentially the same time and in the same delivery ward. Look at them through a pair of binoculars and you see many more than seven sisters. You'll see more sisters, and brothers, and uncles and aunts and cousins ... Born just millions of years ago, they were not here when dinosaurs ruled the Earth, but were here when ancient civilizations like the Sumerians were beginning to rock the land of Mesopotamia. At that time, about 5000 years ago, the Pleaides were probably used as an extraterrestrial town crier. Back then the Sisters rose just before the sun in the first weeks of spring, which would have provided a reliable sky marker announcing the coming of the season for the people of the region. Sadly, the whole group is actually moving away from us and in about a million years, plus or minus, the Sisters will be invisible to the naked eye. After the heart of the Bull comes the big, easily recognizable V-shaped head of the Bull, also known as the Hyades. But like the Pleaides, these, too, have a story of their own. Like the Pleiades, the Hyades were another brood of sisters fathered by the apparently very busy Atlas. (Free trivia: The Pleaides and the Hyades are known collectively as the Atlantides.) In one mythical story these seven were very upset at the death of their brother Hyas and they wept and wept which, according to meteorologists at the time, was the cause of a one major rainfall. So, now guilty by association, both sailors and farmers for centuries blamed the Hyades for any nasty storms on sea and land. The Hyades, like their half-sisters the Pleaides, are also an open cluster, the brightest of which trace out that famous V-shape. And they are very close to us, a mere 150 light years away. Look closely at the Big V and you'll see a bright reddish star. That's Aldebaran, from the Arabic "Al Dabaran" meaning "the follower," probably because it follows the Pleaides through the night skies. This giant is not a sibling of the Hyades. It is actually only about 65 light years away --- and enormous. Aldebaran, often seen as the red eye of the Bull, is nearly 100 times bigger than our sun and bleeds out more than 1000 times more energy! It is a red giant, doomed soon to die a violent death. Taurus the Bull is a fascinating and feature-filled constellation. Go out and take a test drive through it yourself sometime soon. Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com. Posted by Administrator at 2004.11.27 11:55 AM \| Comments (0) Be Thankful for a 'Thin' Universe A Perfect Balance > Thanksgiving is here again, but because it is such a throwaway word nowadays in our hyper-busy society, allow me to remind us all that Thanksgiving was meant to be a time for giving thanks. And the study of the cosmos gives us plenty to be thankful for. Many of us will eat our fill on this holiday. In fact, we will probably eat too much of all that food laid out on the table --- I know I probably will. I will probably put on a few extra pounds as a result of my lack of control. The universe is more controlled than most of us, believe it or not. And that is reason for thanksgiving right there. For if the multitude of objects in the universe were more massive, if they were stuffed to excess, that would spell utter disaster for us on this planet. Be full of thanks, for instance, that the sun isn't any heavier. When it was forming in its stellar womb about five billion years ago, it was given just enough hydrogen and helium with just a pinch of dirt to burn just the way it is now --- which is perfectly. If the sun had collected more gas in its initial stages of creation it would burn faster and brighter. Both those consequences are deadly. Burning faster means it uses up its fuel much faster and would be dead or dying by now, and dying more violently. Burning brighter means it spews out not just more visible light but much more of the lethal ultraviolet and X-rays, too, more than our atmosphere can handle. Be full of thanks that Old Jupiter, our big brother protector off in the distance, has no overeating problem. Jupiter, when it was just a toddler, vacuumed up just enough gas from the early solar nebula to be the fit and trim planet it is today. Had it swept up much more gas its increased gravity would have destabilized orbits of nearby planets, including ours. Worse, had it swept up a lot more gas, had it gone for seconds and thirds and fourths at the cosmic dinner table, Jupiter would have erupted into a star. And no life-inhabited planet could endure that. Two stars just don't allow the safe, perfectly designed, nearly circular orbit a life planet like our own demands. The constant tug-of-war between the two star's gravitational pulls usually ends up throwing a planet into one of the stars (bad) or flinging it out of the system altogether (just as bad). Either way, it's curtains. I'm full of thanks that our own planet is no overindulgent body. There was a day when we were actually less massive and had a horribly thick atmosphere. But all the latest evidence leads us to believe that some rogue, Mars-sized planet came drifting by and smacked into an infant Earth at such an angle that we actually absorbed some of that planet's mass in the collision, but also threw a lot of debris into orbit around us. This event thinned our atmosphere and gave us the Moon, both great blessings. And as a result of the collision, we now have a perfectly thin crust and the ideal tectonic plate activity. But we also ended up, miraculously, with a planet of exactly the correct weight for the health of all future life on the planet. We have now the ideal mass, which means the ideal gravity, to hold on to the life-support gases like oxygen and nitrogen and water. But we don't have enough gravity to hold on well to lighter life-threatening gases like ammonia and methane. I could go on and on and on about the flawless sizes and masses of all kinds of heavenly bodies and systems, but suffice it now to summarize here with two important points. Perhaps the universe can be a model for us in that everything we see around us has the perfect weight for a healthy life here. From tiny atoms in your finger to the immensity of the universe itself, all are wonderfully sized for life here. Maybe we can use the universe as a model for healthier eating this Thanksgiving. And of course, this Thanksgiving we can all be thankful for these and many, many more perfect heavenly ìparameters,î those cosmic guidelines and limits that make this planet one fantastically beautiful and paradisiacal place to live. Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com. Posted by Administrator at 2004.11.20 11:57 AM \| Comments (0) Palomar Shows Off New Laser Observing > Our favorite local --- and world famous --- observatory has just showed off a new toy, one that will allow it to continue to do premiere astronomy for a while to come. Palomar Observatory, on Palomar Mountain in north San Diego County, for decades was The Place to go to do cutting-edge astronomy. The 200-inch mirror on the Hale Telescope (pictured at right) was the biggest in the world. Then came bigger, more sophisticated telescopes, like the twin Keck Telescopes atop Mauna Kea in Hawaii, and Palomar's bright star began to fade. One of Palomar's biggest problems, one in fact that assails every earthbound telescope, is that darned atmosphere of ours. For everything else our envelope of air is a pure godsend. We need the atmosphere to provide us with oxygen, and pressure, and protection from deadly photons from space. It transports life-giving water, allows flight, warms us like a blanket, and so on. But it makes an absolute mess of observing things in space. Why? Have you ever looked at some distant object down a long street in the heat of the day? What you may remember seeing is what appeared as waves rippling above the asphalt making the distant object tough to see well. Look down that street with binoculars and the problem is just magnified. It's plain difficult to resolve much detail with all that distortion. The same goes for anything above us. Trying to see through our atmosphere at night with the naked eye seems like no problem. We see the Moon and the planets and twinkling stars. But looking at them with a scope reveals that the same problem we have looking down the street at a distant tree rears its ugly head when we look up at distant stars. Above us are tiny areas of warmer air next to cooler air moving invisibly through the skies. Such is the nature of our airy covering. The problem is that air pockets of even slightly different temperatures bend light differently, making the celestial object we are looking at appear to move about slightly. So one may be looking at a star in the eyepiece of a telescope and the tiny point of light will literally jump around. (By the way, this atmospheric inference is why stars appear to twinkle.) Planets are big enough in the eyepiece that they don't jerk about, but the details on their surfaces sure do, making them appear fuzzy or out of focus. Unfortunately, the way we learn in astronomy is to see more, not less, of the detail in objects, detail which reveals more and more of the way things are working up there. What to do?! One possibility is to send a telescope above the atmosphere altogether, as was done with the famous Hubble Space Telescope, the satellite that has provided us with some of the most stunning images ever seen. Obviously the Hale telescope at Palomar can't be sent into space. But maybe we can find a way to work with the atmosphere! How? The latest, greatest thing in observational astronomy is called adaptive optics (AO). This method actually reads light coming in from a star and, via computer, "adapts" or reshapes a special mirror to compensate for the shaky atmosphere. At the moment, Palomar and many other observatories use stars very near the object they are observing as corrective stars. As the image of the nearby moves about, the computer makes over 2000 corrections a second to try and steady it. The problem, though, is that you need a helper star really close to what you are observing. What if there is no star there? You make your own star! And that's what's new at Palomar, where astronomers just recently, and successfully, tested their new star-making machinery. It works like this: They fire off a beam of sodium laser light, just 4 watts, into the night sky right about where they are observing. When the sodium laser beam gets to about 60 miles up into the atmosphere it causes a tiny amount of sodium gas up there to glow --- just like a faint star. You can't even see it with the naked eye, it is that faint. This convenient porta-star can be seen by the telescope, the AO system can correct for the distortion of the atmosphere, and --- ba-da-bing! --- it's almost like there isn't an atmosphere at all. Your images are sharp and information-filled, nearby star or not. The whole system --- telescope, computers, and the new laser system --- should be working in unison by next year, breathing new life into the old and venerable Hale Telescope. It is indeed the Great Scope that just keeps getting better. Mark Ritter teaches astronomy at Temecula Valley High School and can be reached at mritter@firstlightastro.com. Posted by Administrator at 2004.11.13 12:00 PM \| Comments (0)
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