February 23, 2012

Posts Comments

How Many Planets Are There?

Mars (back left), Mercury (back right), Moon (... 

Image via Wikipedia

According to the International Astronomical Union (IAU), there are eight planets. These planets include Mercury, Venus, Mars, Neptune, Jupiter, Saturn, Uranus and Earth. Are you wondering what happened to Pluto?

Pluto is considered a dwarf planet. There are five dwarf planets, including Ceres, Haumea, Makemake, Eris and Pluto. This was clarified in August 2006. These five planets were potentially going to be considered IAU planets, but the definition of a planet was clarified with a formal defined by the IAU.

The IAU determined that a planet must have three qualifications in order to be considered a planet in the Solar System. First, it must orbit around the sun. Secondly, it must be big enough to be gravitationally dominant in it’s own orbit, so that no other large bodies are in the “neighborhood.” Thirdly, the planet must be large enough to be round (or, at least, almost round). If the planet does not meet all three of these qualifications, it’s considered a dwarf planet.

Not everyone agrees with this classification, of course. Some say that not all of the planets have actually cleared their own neighborhoods, for example. Many astronomers refuse to follow the classification. Also, scientists like Mike Brown say there are actually lots and lots of “dwarf planets” out there, soon to be discovered.

Naturally, many people in the non-scientific community have had trouble letting go of Pluto as a planet. Remember grade school? Or, perhaps the 1930′s discovery. Also, when Eris was first discovered it was called the “tenth planet” which has lead to much media attention and some confusion. Still, at this point, there are officially nine planets.

 

Filed Under: Astronomy, Planets Tagged With: , ,

Why Pluto Isn’t a Planet

In 2005, the solar system lost its smallest and newest planet. People who had grown up learning about the nine planets of the solar system as well as a host of memory devices for remembering them were shocked to learn that Pluto had dropped from its planet status. In 2006, Pluto officially became a dwarf planet rather than its own planet.

Pluto is the most recently discovered planet in the solar system. In 1930, Clyde Tombaugh discovered Pluto. It did not come as much of a surprise; for many years prior, scientists referred to a mystery “Planet X” that they believed would turn up.

Pluto and its moons are located in the Kuiper Belt. It was previously believed that Pluto was the only planet in that area, and the moons simply orbited it. However, the belief is now that Pluto and its moons are several of many astronomical objects floating around in the Kuiper Belt.

The International Astronomical Union has several criteria in place for determining whether a body is a planet. The first requirement is that the object orbits around the sun. Pluto does this. The second requirement is that the object has substantial gravity for turning into a sphere. The third requirement is what trips Pluto up. In order to be a planet, the body must have cleared the area of its orbit.

To do so, the planets must become the main gravity body in their particular orbit around the solar system. Upon encountering other objects, they either absorb them or throw them far away due to the gravitational pull. However, Pluto does not have enough mass to be the main gravitational body in its orbit. As a result of this finding, Pluto was downgraded from a planet to a dwarf planet. Eventually, Pluto may collide with another celestial object and gain enough mass to become a planet.

Filed Under: Astronomy Tagged With:

What Time Do You Have?

Have you ever thought about time, and how relative it is? Not in the form of what Einstein concluded, but rather what is a day, a month, or a year. If we say that we are 33 years old, we are basing that on a 365 day calendar. Here is a tough question, what if our day was no longer 24 hours long? Say it was only 12 hours long or even 60 hours long. Would our calendar and our age still be the same? These questions are important because on earth, our day is 24 hours long; our annual year is 365, approximate, days long. We have determined this to be the case not because it seemed like a good idea at the time, but because someone figured out that it takes 365 days to completely circle the sun, and at which time, we begin the cycle again.
Not every planet has the same time frame of completing their year, or even their day. The earth takes 24 full hours in order to complete a full revolution. Saturn takes just over 10 hours; however, Pluto can take over six earth calendar days in order to complete a full rotation. This difference also applies to completing a full rotation around the sun as well. Some planets can take over 650 days to complete, but Mercury only needs 88 days.
So, how old are we, and what time is it really? Depending on the planet, you could have a very mixed and confusing answer. Because our planet provides a consistent pattern, and it is all that way know as far as time is concerned, we have to stick with it. But, I think it would be fun if we used a Neptune calendar. It takes over 160 years for Neptune to make a full rotation around the sun.

Filed Under: Astronomy, Planets Tagged With: , , ,

Pluto No More

One of the most exciting astronomical decisions made in our lifetime is the decision to reclassify Pluto from the status of a planet, to the status of a dwarf planet. This has been a highly contested decision, and many astronomers do not necessarily agree with the decision. This landmark event comes after the definition of a planet is fully explained, and therefore Pluto does not fit the bill.
A planet is defined as a large star that is round in shape due to its own spinning and force. It also must be in control of the area near the planet. This would mean that any moons would have to be under the force of the spin of the planet of the orbit it shares. The original definition was that a large being had to have a moon within its orbit. The moon must also be somewhat smaller than the plant it orbits. In the case of Pluto, its moon is only half its size, and not necessarily under Plutos control.
The problem lies in that in order to be a planet, it is a rare claim. In fact, without Pluto, there are only eight planets in our solar system. With Pluto being added to the list of dwarf planet status, it joins a club of over 40 planets that are close by, and hundreds more that are known in our galaxy. The reclassification will bring about major changes on how the solar system is taught, how textbooks are written, and how the solar system is appears for school children.
All in all, what this means, is that there is a change within out galaxy, and that there will probably be many more to come. This is merely one instance of things that could affect the world we know in the future.

Filed Under: Planets Tagged With: , , ,

Fun Facts About Comets

If you’ve ever seen a shooting star, it’s most likely actually a comet or even an asteroid. Not many people understand what comets are, or even know much about them at all. There are some interesting facts about comets. Because of how a comet looks, the word comet actually comes originally from the word for hair in Greek. Comets are composed of rocky debris, ice, and dust. It’s believed that most comets come from some of the farthest areas of our solar system. In fact, they are so far out that even the orbit of Pluto doesn’t reach them. They are still in our solar system, though.

There is a chance that at some point in our futures a comet could hit earth and cause major destruction, but you are much more likely to win at your favorite sports betting sites than die from a comet crashing into the planet.

It was once believed that comets were a show of power from the gods. They were also seen by many as a curse, or a warning that something bad was about to happen. Others believe that a comet is the device which angels are carried through heaven.

You may see Halley’s comet again in your life, depending on your current age. It only comes around every 76 years. The next time it is estimated to come near our planet again is in the year 2061. There is at least a few meteor showers every year. In fact, the Perseid shower happens in August of each year.

Comets have been seen throughout recorded history. Some people have revered them, while others were terrified. We know today what comets are, and can track them through the skies. The orbits of comets are similar to earth’s orbit; an egg shape. Usually, these flying bits of rock and ice have a much, much larger orbit than earth.

Enhanced by Zemanta
Filed Under: Astronomy, Comets and Asteroids, General, Observatory Tagged With: , , , , , , ,