Friday, August 25, 2006

12 planets not 9!!!


About 2,500 scientists meeting in Prague have adopted historic new guidelines that see the small, distant world demoted to a secondary category.

The researchers said Pluto failed to dominate its orbit around the Sun in the same way as the other planets.

The International Astronomical Union's (IAU) decision means textbooks will now have to describe a Solar System with just eight major planetary bodies.

Pluto, which was discovered in 1930 by the American Clyde Tombaugh, will be referred to as a "dwarf planet".

There is a recognition that the demotion is likely to upset the public, who have become accustomed to a particular view of the Solar System.

Without a new nomenclature, these discoveries raised the prospect that textbooks could soon be talking about 50 or more planets in the Solar System.

Amid dramatic scenes in the Czech capital which saw astronomers waving yellow ballot papers in the air, the IAU voted to block this possibility - and in the process took the historic decision to relegate Pluto.

The scientists agreed that for a celestial body to qualify as a planet:

  • It must be in orbit around the Sun.
  • It must be large enough that it takes on a nearly round shape.
  • It has cleared its orbit of other objects.

Pluto's status has been contested for many years. It is further away and considerably smaller than the eight other "traditional" planets in our Solar System. At just 2,360km (1,467 miles) across, Pluto is smaller even than some moons in the Solar System.

In addition, since the early 1990s, astronomers have found several objects of comparable size to Pluto in an outer region of the Solar System called the Kuiper Belt.

Some astronomers have long argued that Pluto would be better categorized alongside this population of small, icy worlds.

The critical blow for Pluto came with the discovery three years ago of an object currently designated 2003 UB313 (sedna). After being measured with the Hubble Space Telescope, it was shown to be some 3,000km (1,864 miles) in diameter: it is bigger than Pluto.

2003 UB313 (Sedna) will now join Pluto in the dwarf category, along with Pluto's major moon Charon, and the biggest asteroid in the Solar System Ceres.

An US spacecraft called New Horizons is due to fly by Pluto and the Kuiper belt in 2015.

Tuesday, August 22, 2006

Sedna

Astronomers have been conducting an ongoing survey of the outer solar system using the Palomar QUEST camera and the Samuel Oschin Telescope at Palomar Observatory in Southern California. This survey has been operating since the fall of 2001, with the switch to the QUEST camera happening in the summer of 2003. To date they have found around 40 bright Kuiper belt objects. To find objects, Astronomers have taken three pictures of a small region of the night sky over three hours and look for something that moves. The many billions of stars and galaxies visible in the sky appear stationary, while satellites, planets, asteroids, and comets appear to move. Objects in the inner Oort cloud are extremely distant and so move extremely slowly.

(The Oort cloud is a hypothetical shell of icy proto-comets in very loose orbits around the sun that extends to a distance of almost halfway to the nearest star. The existence of Sedna is evidence that the Oort cloud actually extends much further in towards the sun than previously thought).

These are two slightly differently processed views of the same 3 discovery images. The total area of sky shown in the bottom image is equivalent in size to the head of a pin held at arm's length. Incidentally, that is how big the Sun would appear from Sedna:


Even more interestingly, the orbit of Sedna is extreme elliptical, in contrast to all of the much closer planets, and it takes 10,500 years to circle the sun.

Here is an image of the orbit and position compared to all the known solar system objects:

In our discovery images, we see only a point of light. We can't directly measure the size of Sedna from this point. The light that we see has traveled from the sun, been reflected off the surface of Sedna, and come back to us where we can see it in the images like the discovery images below. So a small icy object and a large coal-covered object, for example, would both look about the same brightness in the discovery images, because both objects could reflect about the same amount of sunlight.


Astronomers measured Sedna's size using a thermal telescope, which measures the heat coming from the surface. They know how far away Sedna is, so they know that the surface temperature is about 400 degrees below zero Fahrenheit. A large object of that temperature will give off much more heat than a small object of that temperature. A 30 meter diameter IRAM telescope and a Spitzer Space Telescope were used. Sedna was too small to be detected in either. This tells us that Sedna is at most about 1800 km in diameter: about halfway in size between Pluto and the largest known Kuiper belt object Quaoar. Even though all we know for certain is that Sedna is smaller than 1800 km, we have evidence which suggests that the size might be pretty close to this number. They are virtually certain that the size is larger than the 1250 km size of Quaoar, though this object has shown many unexpected characteristics, so they can't completely rule out a smaller size.

Sedna is about 20.5 magnitudes in R, considerably fainter than 2004 DW and Quaoar. It is beyond the reach of almost all amateurs astronomers (though, interestingly, the first confirmation of the existence of Sedna was made at Tenagra Observatory, an extremely high-end amateur telescope run by Michael Schwartz in southern Arizona).

In March 2004, the location of Sedna is easily found in the evening sky to the southwest just after sunset. It is almost directly below Mars, and forms a triangle with the very bright Venus.



When astronomers first announced the discovery of Sedna, we noted that circumstantial evidence suggested that there is a moon around Sedna. Soon after, we acquired the images below with the Hubble Space Telescope. Much to our surprise no moon is visible!


But In December 2005 astronomers finally discovered a moon for sedna they called it (Gabriel).

Saturday, August 12, 2006

Symbols of planets


The symbols for the planets, Moon and Sun (along with the symbols for the zodiac constellations) were developed for use in both astronomy and astrology. The astronomical symbol for the Sun is a shield with a circle inside. Some believe this inner circle represents a central sun spot. The symbol for Mercury represents the head and winged cap of Mercury, god of commerce and communication, surmounting his staff. The symbol for Venus is designated as the female symbol, thought to be the stylized representation of the hand mirror of this goddess of love. The symbol for Earth shows a globe bisected by meridian lines into four quarters. These for quarters represents the four seasons. The symbol for the Moon is a crescent. The symbol for Mars represents the shield and spear of the god of war, Mars; it is also the male or masculine symbol. The symbol for Jupiter represents a hieroglyphic symbol of the eagle, or the initial letter of Zeus with a line drawn through it to indicate its abbreviation. The symbol for Saturn is thought to be an ancient scythe or sickle, as Saturn was the god of seed-sowing and also of time. The symbol for Uranus is represented by combined devices indicating the Sun plus the spear of Mars, as Uranus was the personification of heaven in Greek mythology, dominated by the light of the Sun and the power of Mars. The symbol for Neptune is the trident (long three-pronged fork or weapon) of Neptune, god of the sea. The symbol for Pluto is a monogram made up of P and L in Pluto (and also the initials of Percival Lowell, who predicted its discovery).

for more information visit this website:

http://en.wikipedia.org/wiki/Astronomical_symbol

Saturday, August 05, 2006

How Observant are you?

Read out loud the text inside the triangle below.


More than likely you said, "A bird in the bush" and

If this is what you said, then you failed to see

That the word THE is repeated twice!

Next, let's play with some words.

What do you see?


In black you can read the word GOOD, in white you can read the word EVIL. It's all very physiological too, because it visualizes the concept that good can't exist without evil (or the absence of good is evil).

Now, what do you see?

You may not see it at first, but the white spaces read the word optical, the blue landscape reads the word illusion. Look again! Can you see why this painting is called an optical illusion?


What do you see here?


This one is quite tricky!

The word TEACH reflects as LEARN

Last one.

What do you see?



You probably read the word ME in brown, but.......

when you look through ME

you will see the word

YOU!


ALZHEIMERS EYE TEST


Count every " F " in the following text:

FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC Studies COMBINED WITH THE EXPERIENCE OF YEARS.


HOW MANY ?

WRONG! THERE ARE 6 , no joke.
READ IT AGAIN !

The brain cannot process "OF".

Anyone who counts all 6 "F's" on the first go is a genius!

Only smart people can read this!


The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and the lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh?