Decades ago, when observational techniques were not that technically advanced, scientists assumed and thus defined many objects in the Solar System according to their limited knowledge and expertise at that time. However, today’s advanced telescopes are questioning and demanding a newer look at all those researches and observations.
With each passing decade, or let’s say now with the latest observational instruments and telescopes, the universe is opening up to unveil an amazing variety of objects that were never seen or thought of by humans before.
The most interesting part is the discovery of the distant worlds that reside in the Milky Way. And to make it further intriguing, the ones found might just be like our very own Earth. All this is because today scientists understand planets and stars better than they did previously.
But stars do not come in as many varieties as planets do; these small worlds are becoming more complex to understand with every new observation. In our own Solar System, we have a unique array of worlds orbiting our Sun; from very hot to the very cold gas giants, to the perfectly beautiful green and blue planet — Earth. However, there are many more worlds out there within our own Solar System that are being discovered and are still waiting to be discovered. Especially, the ones which are in a region outside the orbit of Pluto, in an area called the Kuiper Belt, outside the orbit of Neptune.
This is an icy region made up of thousands of small rocky worlds that are cold and distant. These rocky worlds are called KBO’s or Kuiper Belt Objects. We know very little about them but as they are in the outskirts of our Solar System, so very much in our own backyard. Scientists and researches are too eager to know what KBO are and what they are up to which ultimately brings us closer to defining what exactly a planet is!
It all started when astronomers all around the globe gathered for the planet debate regarding Pluto’s status as a planet. In other words, does this tiny world in the outskirts of the Solar System deserves to be called a planet where so many other bodies like this one also roam?
Some argued that since Pluto fits the planet definition of being round, orbiting its host star and having its own moons around it, it deserved the status. Some said that we do not know enough about the outer reaches of the Solar System to be sure, while others argued that since there might be other objects out there like this one, they could be called ‘dwarf planets’ or ‘plutoids’.
In 2005, Pluto’s neighbourhood revealed another icy object named Eris. According to the 2006 definition of a planet by astronomers: “a body that circles a sun without being some other object’s satellite, is large enough to be rounded by its own gravity, and has cleared it’s neighbourhood of most other orbiting bodies”.
It was the last part regarding ‘clearing the neighbourhood’ that almost made Pluto lose the battle because of the discovery of many such icy bodies in its region. So Pluto and Eris were called dwarf planets, which means that we were left with just eight major planets — Mercury, Venus, Earth, Mars, Jupiter, Uranus, Saturn and Neptune.
The term ‘dwarf planet’ also appealed to some researchers as they felt that such a small world, so far out, with an outlandish orbit, too elliptical, did not belong to the family of the other eight larger ones. Astronomers feel that the only reason Pluto was called a planet was because when it was discovered back in 1930, they knew very less regarding the region where it was detected.
But then researchers found another flaw with the above definition regarding the other eight planets as well. None of the other eight planets had completely ‘cleared its neighbourhood’, which brings us back to where we started. But then again if all these far away bodies are called planets, we would lose count by finding out more and more with each new discovery.
Nevertheless, scientists also think that there really is no reason to label these unique new worlds as planets as the term is difficult to define due to the variety of objects out there in the Universe. For instance, the latest telescopic observations have shown strange planets that do not have a host star at all which means that they do not circle a sun but just move around on their own in pairs, etc.
So what do we call them? In our own Solar System, if we just stick to the fact that all the worlds that are round due to the gravitational pull inside their core and are thus rounded and circle our Sun are called planets, then their count will soar to thousands. So what definition should we require?
According to a leading astronomer, Neil deGrasse Tyson, who is the director of The Hayden Planetarium in New York, should one categorise such worlds as terrestrial planets or rocky worlds like Earth, Mercury, Mars and gas giants such as Jupiter, Saturn, Neptune and Uranus and Kuiper Belt objects such as Pluto, Eris and the rest and others as asteroids.
Interestingly, Pluto’s moons, Charon and Ceres orbit on their own and their centre of gravity is not inside Pluto like Earth’s Moon which is controlled by the gravity inside Earth’s core.
As researcher Tyson puts it in his interview to www.space.com, “The word ‘planet’ has far outlived its usefulness. It doesn’t celebrate the scientific richness of the Solar System.”
The universe is vast, complex and has much still left to be discovered. We have not even touched the tip of the iceberg, so to say. So, do we really need fixed definitions for a diverse group of objects or should we just marvel at their uniqueness?
We can only wait and see what further observations will reveal about the magnificent cosmos.
Saturday, April 30, 2011
BASIC ASTRONOMY COURSE
Basic astronomy is now available for those residing in UAE specifically in Abu Dhabi. If you are interested email to: abudhabiastronomy@gmail.com
Thursday, April 21, 2011
Six Tips for Perfect Stargazing
Excerp from Discovery News
Guest contributor Mark Thompson shares his top recommendations for you to get started as an astronomer.
For northern hemisphere folk, the dark nights of winter are almost upon us.
If, like many thousands of people around the world, you find the sight of a dark, star-filled sky inspiring -- or perhaps you've read some of the many fascinating articles here and want to see the objects with your own eyes -- then there is no better time than the nights of winter to get started as an astronomer.
Many years ago I was just starting out, and in the following years I have learned there are a few essential things you can do right now to start enjoying the night sky in all its glory.
Here are my six steps to start stargazing -- surprisingly, the first isn't to rush out and buy a telescope!
Step 1: Buy a Red Torch
It takes between 40 minutes and an hour for your eyes to become fully adapted to seeing in the dark, but even astronomers need a little light to read a chart or tend to equipment. Unfortunately, any exposure to bright lights will instantly ruin your eye's acclimatization to the dark.
The solution to this problem is to use a red light that won’t affect your ability to see in the dark. It's best to resist using a rear bicycle light as bright red lights can be just as bad as any other color. A better idea is to buy a purpose-built red torch, just for astronomers.
Step 2: Buy a Planisphere OR Download an App!
Along with a red torch, the other item most astronomers have is a planisphere. These are very versatile star charts made of plastic that show you the night sky from your location, at any time of year. Some will even show you how to locate the planets. They are cheap and can be bought from most book shops.
Alternatively, there are a vast range of products online to help out. Internet applications and computer software are great but hard to use in the field, so a better option if you have a smartphone is to download an app. For the iPhone, "StarWalk" is by far the best application in my opinion.
Step 3: Subscribe to an Astronomy Magazine
There is no better way to keep up to date with what's going on in the world of astronomy than subscribing to an astronomy magazine. Most countries have at least one or two good ones dedicated to the subject. Inside the covers, you will find news, equipment reviews, classified adverts and even monthly sky charts.
Be warned though, the monthly sky charts will be specific to the country of origin of the magazine. For the beginner, "Astronomy" is great in the US, and "Astronomy Now" in the UK. For more experienced astronomers, "Sky and Telescope" has more in-depth detail.
Step 4: Join Your Local Astronomical Club or Society
Whether you intend to stick with casual stargazing or want to get more involved, a great and very enjoyable way to enhance your new hobby is to seek out your local astronomical society.
These are excellent places to go for advice and help, and eventually you'll find that observing with your new-found friends makes your observing sessions much more enjoyable. You will more than likely have the opportunity to try different types of telescopes so you can make an informed decision before you buy your own.
Step 5: Get Outside and Start Observing
Now it's time for the most exciting bit: Get outside and start learning your way around the night sky. You will be amazed what you can see; those bright stars that aren't on your planisphere are probably planets and on your first night under the stars you may have already spotted satellites, meteorites and the occasional passing aircraft. Time spent now familiarizing yourself with the sky will make your future enjoyment of the Universe much easier.
Step 6: Consider Future Equipment Purchases
Eventually you will want to see more and the only solution is to make that all-important purchase and buy yourself a pair of binoculars or even a telescope. The only words of advice here are to take your time and make sure you spend wisely. Time spent now learning your way around the sky and seeing what equipment is available, and hopefully trying it out at your local society, will be very well spent.
Mark Thompson is a writer and astronomy presenter for the UK's BBC One Show. He also writes for his own website The People's Astronomer and you can follow him on Twitter: @PeoplesAstro.
Tuesday, April 19, 2011
ORGANIZING EVENTS (Meteor Shower)
April 22 is about to come and there will be a meteor showers... any one from Abu Dhabi who wants to stay late night and be a part of meteor shower watch, we'll be in corniche area, along public beach and we will watch the shower, if interested send email to us: abudhabiastronomy@gmail.com. See you...
Monday, April 18, 2011
FULL MOON AT ABU DHABI
OBSERVING THE FULL MOON ALONG THE CORNICHE AREA IN ABU DHABI, UAE USING CELESTRON EQ 130 AND SONY E1090 CAMERA
Monday, April 4, 2011
Our endangered sky
We live in a really amazing-looking galaxy. It's too bad we can't see it.
1 Comment
Because you're taking the time to read this column, I will assume you know that the Milky Way is not only a candy bar.
But have you ever actually seen it?
For an increasing number of people, the answer is "no." More on that in a moment. First, some background.
The Milky Way is the galaxy―the gravitational grouping of more than 100 billion stars―to which our Sun belongs. It's what's known as a barred spiral galaxy. Most of the stars in it are located in the central, bar-shaped region from which two long, spiral shaped arms protrude.
Our Sun is not in the center, but out in one of the arms. In celestial terms, we're out in the sticks. What's more, all the other stars you can see in the night sky are out in the spiral arms with us. The rest of the Milky Way's stars―and remember, that's most of them―are in the bar-shaped region of the galactic center, much too far away for us to see them individually with the naked eye.
But we can see them collectively. That big, dense region of stars―think of it as "the big city" to us folks living out here in the sticks―is visible as a soft river of light that seems to flow across the night sky. That's why it came to be called the "Milky Way," or the Via Lactea if you lived in ancient Rome. The word galaxy, itself, is derived from the ancient Greek word gala: milk.
As a skygazing object, the "Milky Way" is really the disk shape of our galaxy, as viewed from the edge. That's our vantage point, out here in one of the spiral arms.
Not so milky these days
The trouble is that for people living in densely populated regions like ours, the Milky Way has all but disappeared.
It's not quite completely gone. In a clear sky during a new moon (the "new" moon is the phase when no moon is visible), you can still see it, especially if you stand outside for at least 15 minutes and let your eyes adjust to the dark. It's then that you should be able to perceive a dim ribbon that crosses the whole sky...and is just a little bit less dark than the sky on either side of it. There you have it: the Milky Way.
Expecting more? Underwhelmed? You should be. 250 years ago, Ben Franklin enjoyed a much better view from our region. The photograph accompanying this column gives you an idea of the Milky Way he would have seen during his hundreds of astronomical observations.
Unfortunately, with the lights of Philadelphia to our east, Reading to our west, and thousands of shopping centers, ball fields, and other sources of artificial light in our own towns, we don't give the Milky Way much of a chance to show itself. The Dark Sky Finder illustrates the severity of the problem in the eastern U.S., particularly in the Northeast (the warmer the color, the harder it is to see stars).
Taking back the night
Local governments in some areas have taken steps to combat the problem of "light pollution," as it's known to astronomers. Streetlamps and other outdoor lighting fixtures that are designed to limit the amount of "waste" light that goes into the sky are available. In Tucson, Arizona, where I once lived, lighting fixtures on public property and many large business sites are required to be astronomy-friendly. The Kitt Peak National Observatory, about 50 miles west of Tucson, is a major beneficiary of these codes and has yielded a number of important astronomical discoveries.
Closer to home, Cherry Springs State Park in Potter County is home to one of the darkest skies east of the Mississippi River and one of only four official "dark sky preserves" in the United States. For a small park fee (about $4.00), you can take your own telescope there and set up for the evening. Public stargazing events are also held.
What can you do about light pollution in your own backyard? For starters, you can reduce your own home's light pollution by turning off external lights or even replacing them with fixtures that direct the light at the ground. Such fixtures also save money and energy by requiring less power to illuminate the same amount of ground as typical light fixtures. The International Dark Sky Association maintains a list of outdoor lighting fixtures that have received its seal of approval.
If you're not ready to dive into dark sky preservation with both feet, that's okay. There's still something you can do.
The GLOBE at Night project, sponsored by NASA and the National Science Foundation, among others, is inviting stargazers around the world to help them get a handle on the problem of light pollution between now and April 4.
For the most part, all you have to do is go outside between 8-10pm and look at the stars.
Then you provide the GLOBE at Night web site with your latitude and longitude―use a GPS device or one of the map tools on their web site―and compare your view of the constellation Leo with their magnitude charts. Pick the one that looks most like the Leo you see. (Most people in our area will probably pick something between "Magnitude 2" and "Magnitude 4.") Report your observations, then browse results from other skygazers around the world.
If you happen to be an elementary school teacher or a parent whose child has taken an interest in the night sky, the GLOBE at Night folks have all sorts of materials to help kids become Dark Skies Rangers.
It's not just about pretty stars
Lest anyone think all this handwringing over light fixtures is solely for the benefit of a bunch of telescope-collecting nerds like me, consider that until about 110 years ago, none of the animal species on the planet had ever encountered artificial light.
So, what? Well, humans might be used to living with it, but wildlife is not. Watch this video of migratory birds flapping around in disoriented circles in the "Tribute in Light" periodically turned on at the site of the World Trade Center to commemorate the terrorist attacks of September 11, 2001.
An abundance of artificial light at night confuses birds, noctural insects, bats, sea turtles, and any number of other creatures that rely on the sun, moon, and stars to know when to be awake, when to reproduce, or where to go.
Think of that before you leave your porch light on tonight.
But have you ever actually seen it?
For an increasing number of people, the answer is "no." More on that in a moment. First, some background.
The Milky Way is the galaxy―the gravitational grouping of more than 100 billion stars―to which our Sun belongs. It's what's known as a barred spiral galaxy. Most of the stars in it are located in the central, bar-shaped region from which two long, spiral shaped arms protrude.
Our Sun is not in the center, but out in one of the arms. In celestial terms, we're out in the sticks. What's more, all the other stars you can see in the night sky are out in the spiral arms with us. The rest of the Milky Way's stars―and remember, that's most of them―are in the bar-shaped region of the galactic center, much too far away for us to see them individually with the naked eye.
But we can see them collectively. That big, dense region of stars―think of it as "the big city" to us folks living out here in the sticks―is visible as a soft river of light that seems to flow across the night sky. That's why it came to be called the "Milky Way," or the Via Lactea if you lived in ancient Rome. The word galaxy, itself, is derived from the ancient Greek word gala: milk.
As a skygazing object, the "Milky Way" is really the disk shape of our galaxy, as viewed from the edge. That's our vantage point, out here in one of the spiral arms.
Not so milky these days
The trouble is that for people living in densely populated regions like ours, the Milky Way has all but disappeared.
It's not quite completely gone. In a clear sky during a new moon (the "new" moon is the phase when no moon is visible), you can still see it, especially if you stand outside for at least 15 minutes and let your eyes adjust to the dark. It's then that you should be able to perceive a dim ribbon that crosses the whole sky...and is just a little bit less dark than the sky on either side of it. There you have it: the Milky Way.
Expecting more? Underwhelmed? You should be. 250 years ago, Ben Franklin enjoyed a much better view from our region. The photograph accompanying this column gives you an idea of the Milky Way he would have seen during his hundreds of astronomical observations.
Unfortunately, with the lights of Philadelphia to our east, Reading to our west, and thousands of shopping centers, ball fields, and other sources of artificial light in our own towns, we don't give the Milky Way much of a chance to show itself. The Dark Sky Finder illustrates the severity of the problem in the eastern U.S., particularly in the Northeast (the warmer the color, the harder it is to see stars).
Taking back the night
Local governments in some areas have taken steps to combat the problem of "light pollution," as it's known to astronomers. Streetlamps and other outdoor lighting fixtures that are designed to limit the amount of "waste" light that goes into the sky are available. In Tucson, Arizona, where I once lived, lighting fixtures on public property and many large business sites are required to be astronomy-friendly. The Kitt Peak National Observatory, about 50 miles west of Tucson, is a major beneficiary of these codes and has yielded a number of important astronomical discoveries.
Closer to home, Cherry Springs State Park in Potter County is home to one of the darkest skies east of the Mississippi River and one of only four official "dark sky preserves" in the United States. For a small park fee (about $4.00), you can take your own telescope there and set up for the evening. Public stargazing events are also held.
What can you do about light pollution in your own backyard? For starters, you can reduce your own home's light pollution by turning off external lights or even replacing them with fixtures that direct the light at the ground. Such fixtures also save money and energy by requiring less power to illuminate the same amount of ground as typical light fixtures. The International Dark Sky Association maintains a list of outdoor lighting fixtures that have received its seal of approval.
If you're not ready to dive into dark sky preservation with both feet, that's okay. There's still something you can do.
The GLOBE at Night project, sponsored by NASA and the National Science Foundation, among others, is inviting stargazers around the world to help them get a handle on the problem of light pollution between now and April 4.
For the most part, all you have to do is go outside between 8-10pm and look at the stars.
Then you provide the GLOBE at Night web site with your latitude and longitude―use a GPS device or one of the map tools on their web site―and compare your view of the constellation Leo with their magnitude charts. Pick the one that looks most like the Leo you see. (Most people in our area will probably pick something between "Magnitude 2" and "Magnitude 4.") Report your observations, then browse results from other skygazers around the world.
If you happen to be an elementary school teacher or a parent whose child has taken an interest in the night sky, the GLOBE at Night folks have all sorts of materials to help kids become Dark Skies Rangers.
It's not just about pretty stars
Lest anyone think all this handwringing over light fixtures is solely for the benefit of a bunch of telescope-collecting nerds like me, consider that until about 110 years ago, none of the animal species on the planet had ever encountered artificial light.
So, what? Well, humans might be used to living with it, but wildlife is not. Watch this video of migratory birds flapping around in disoriented circles in the "Tribute in Light" periodically turned on at the site of the World Trade Center to commemorate the terrorist attacks of September 11, 2001.
An abundance of artificial light at night confuses birds, noctural insects, bats, sea turtles, and any number of other creatures that rely on the sun, moon, and stars to know when to be awake, when to reproduce, or where to go.
Think of that before you leave your porch light on tonight.
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