Many moons ago Uranus itself had not even been discovered; never mind all of the moons orbiting around it. The moons are still popping up! The Solar System seems to be losing planets, but the planets that still have their status as planets are gaining moons like there’s no tomorrow. Of course, planets like the Earth are not going to acquire new moons, but the planets that are farther away still have new discoveries waiting for us here on Earth. For example, it was recently decided that Pluto is not actually a planet—too bad for everyone whose favorite planet was Pluto. Likewise, just when you thought you had Uranus’s moons memorized, a few more pop up.

The question many are asking now is if no one even knew that Pluto wasn’t a planet (and some experts still maintain that it is, indeed a planet) how sure can we be of the number of moons that Saturn, Uranus or Neptune actually have? Since these moons are, in some cases, much smaller than Pluto, how can astronomers be certain of their existence and their composition? Granted, existence is a much easier question to answer than composition, but both questions deserve lots of research and time. Of course, astronomers across Earth are enthusiastically seeking new research grants. Some people thought in the mid-60s that as soon as a flag was planted on the moon the hype and the fervor around astronomy would calm down. Of course, that has far from been the case. More and more satellites are bringing civilians and NASA specialists alike a multitude of new knowledge in the form of pictures from very far away places. Like many other things in modern society, having more pictures and more information is not fulfilling the need; it is making the need grow larger and larger.

At last count, Uranus has at least 27 moons. This is quite impressive when we consider that the Earth has, of course, only one moon and when we consider that Uranus’s largest moon (Titania) is only half the size that the Earth’s moon is. That means that there are more than a couple dozen moon-lets orbiting around Uranus; it seems a wonder that they don’t crash into one another at some point in their orbits. One of the ‘discovered’ moons of Uranus has not yet been given official status as a moon because astronomers cannot agree on whether or not it is actually a moon. Either way, the amount of moons is high.

Although Uranus’s moons may be smaller than the Earth’s moon and much smaller than the Earth itself, some of its moons exhibit truly mysterious and fascinating phenomena. For example, Miranda has a cliff face of 12 miles (more than twice the height of Mount Everest). This is impressive on its own, but when it’s considered in light of the relative size of Miranda compared to the Earth—the size of this cliff face is just beyond belief. Miranda is one of Uranus’s small moons. Astronomers have figured out that if this cliff face on the surface of Miranda were scaled (if Miranda were scaled up to the size of the Earth) the cliff face (12 miles) would reach all the way into, from the Earth’s surface, the area where spacecraft orbit the Earth.

The story of Uranus’s moons is not a simple one, not in number and not in features. In addition, when you consider what little is actually known about Uranus’s moons at present due to the sheer distance from here to there, it is obvious that there are many more astounding surprises just waiting to be uncovered.

Possibilities of life on other planets? Statistically we know it’s highly probable - but a new discovery is making it even more of a reality… NPR reports on this new earth-like planet:

Scientists have discovered a new planet in the constellation Libra. The small, rocky planet is special because it appears to have mild temperatures, like Earth. Researchers believe it looks like the first planet outside of our solar system that could be home to liquid water, and maybe even life.

Full story: NPR

In 2007 Japan plans to launch a space probe to Venus. This spacecraft will be the first of its kind. It will be unmanned, and is predicted to start orbiting Venus in 2009. Japan will be the third country to send a probe to Venus, following the United States and former Soviet Union. The Japanese trip to the planet will be different, because its primary focus will be on the carbon dioxide rich atmosphere.

The Japanese probe will be equipped with an infrared camera to aid in the investigation of the atmosphere. Scientists are hoping that the pictures will help them understand the three dimensional structure of the atmosphere.

They are also planning to explore the rapid rotation of the atmosphere on Venus. Venus rotates every 243 days. Though Venus’s atmosphere rotates in the same direction as the planet it is said to do so at a speed 60 times faster than the planet.

The probe will also explore the possibility of active volcanoes on Venus.

There are many reasons why probing the mysterious environment of Venus is important. Venus is the closest planet to Earth and in many ways the two planets are very similar. It is similar in size and mass. Many fear that Earth will become a planet like Venus if global warming continues. It is hoped that by researching the evolution of the atmosphere of Venus we might be able to use that information to predict what will be in store for Earth.

Despite their similarities Venus and Earth are very different. For example, the atmosphere of Venus is 90 times denser than that of Earth’s. Also, Venus’ atmosphere is carbon dioxide rich and because of global warming has an average temperature of almost 900 degrees Fahrenheit.

Strangely, though Venus is closer in distance to the Sun, it absorbs less solar heat than Earth does. Venus orbits closer in proximity to the Sun than Earth does, it is considered just beyond the habitable zone. The habitable zone is defined as the distance from the Sun where liquid water can exist. Scientists are hoping that Japan’s mission to Venus will help them determine where the most inner edge of the habitable zone lies. Studying the climate of Venus may also help determine the future habitability of Earth.

The surfaces of Earth and Venus are also very different. Venus has huge smooth plains and a dense layer of sulfur rich clouds produced from volcanic activity on the planet.

Venus’ weather is also quite different from Earth’s. There are hurricane force winds that can sweep over the entire surface of the planet in just four days.

In order to understand what is happening on Earth and predict what should be expected in the future, it is vital that he explore the neighbor planet which has already made the transition that seems likely to be in store for Earth. By studying Venus, hopefully one will have a better understanding of the greenhouse effect and be able to plan accordingly. It is anticipated that Japan’s mission to Venus will be able to help answer some of the more puzzling questions surrounding the planet and its atmosphere. And with any luck we will be able to predict to what extent the Earth is going to move to be more like Venus.

Japan is not the only country interested in unraveling the mystery of Venus. Japan’s mission to Venus has been in the shadows of a more widely publicized European mission known as the Venus Express, which launched in 2005. And though there are no firm plans for an American mission, NASA discussed sending a robot in 2007 to collect surface samples to study.

This is a beautiful and interesting video on the history of science.

The planet Mercury is the first in the Solar System line-up, meaning it is closet to the Sun.  It moves very quickly across the sky and so was named Mercury, which in Roman mythology was the god of commerce, travel, and thievery. 

Mercury is small and rocky and makes its trip around the Sun once every 88 days.  Faster than any other planet, mercury travels at almost 50 km per second.  Its highly elliptical orbit places Mercury between 47 million km and 70 million km from the sun at different positions.  This causes temperatures on the surface to reach as high as 467 degrees Celsius, and as low as -183 degrees Celsius, due to the very small atmosphere.  This highly eccentric orbit confused 19th century astronomers until Einstein’s General Theory of Relativity was found to correctly predict the motions of Mercury.  These accurate predictions were important in the early acceptance of Einstein’s theory.

Mercury is always very near the sun and therefore, difficult to see in the twilight sky, but it is often visible with binoculars and sometimes can be seen with the naked eye.  The illumination of Mercury’s disk varies when viewed with a telescope from Earth because it is closer to the Sun than the Earth. 

The Mariner 10 is the only spacecraft that has visited the planet.  In 1974 and 1975 it flew by only three times and mapped 45% of the surface.  Mercury is too close to the Sun to be safely imaged by HST.  NASA launched the MESSENGER, a new discovery-class mission, in 2004, which is expected to orbit Mercury starting in 2011.  This spacecraft will investigate a set of key scientific questions using miniaturized instruments.

The surface of Mercury has many similarities to the Moon.  It is heavily cratered and has no plate tectonics.  Mercury is very old and is the second densest major body in the solar system after Earth.  The majority of the planet is composed of mostly iron, as is Mercury’s core; therefore it has only a thin silicate mantle and crust.  The core’s radius is 1800 to 1900 km and the mantle and crust is only 500 to 600 km thick.  Some of the enormous escarpments on Mercury’s surface are hundreds of kilometers in length and 3 km high.  Some were formed through compression indicated by the way the rings of the craters are cut through.  Mercury’s surface area actually shrank by almost 0.1% due to this compression.

Mercury’s surface has many smooth areas in addition to the craters.  One of the largest features was the result of an asteroid impact early in the solar system’s history and is called the Caloris Basin.  It is 1300 km in diameter and over the next half a billion years the planet shrank from 2-4 km as it cooled from its formation.  The surface cooled and compressed preventing the planet’s magma from reaching the surface.  This ended the period of geologic activity on Mercury. 

Mercury’s atmosphere is constantly being replenished, as opposed to Earth and Venus whose atmospheres are stable.  The atmosphere of Mercury is very thin and consists of atoms that were blasted off the surface by solar winds.  These atoms quickly escape into space.

Mercury is now the smallest planet in the solar system, now that Pluto is no longer a planet.  If Earth were compared to the size of a baseball, Mercury would be the size of a golf ball.  The sun looks almost three times the size it does from Earth, when viewed from the surface of Mercury. 

Mercury has no known satellites and has a magnetic field approximately 1% of that of Earth.  There is still much to be known about the solar system’s least explored planet and scientists will hopefully continue to learn about its history and future.

 

After years of debate about Pluto’s status as a planet, hundreds of the world’s most prominent astronomers voted to totally redefine what classifies a planet.  And guess what? Pluto no longer qualifies.  Now, Pluto has a lowly position as a dwarf planet. Millions of textbooks will have to be re-written and toys galore are now outdated with this declassification.

The whole rigmarole about what to define the now former planet Pluto started once scientists and astronomers recognized that it was littler than it appeared when first encountered in 1930.  Back then, Pluto was thought to be large enough to mess with the orbits of Uranus and Neptune.  Years later, this hypothesis was chalked up to human error.

Over the years, scientists have always believed that there was something distinct and solid about our remaining eight planets in the solar system – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. However, until recently, there was no real classification of what a planet constituted. It was a matter of that principle of “knowing it when we see it.”

The first alternative would be to name any object that was orbiting the sun and that was bigger than a predetermined size would be a planet.  Of course, if the minimum measurement were small enough, it would encompass Pluto and be back to planet status.  Then again, if this minimum measurement scenario were incorporated, it would include another hunk of rock dubbed Xena, which is further out than Pluto and bigger to boot.

Another option would be to define a planet as any orbiting thing that is big enough to have gravity form it into a round shape.  If this was the definition then not only would our recently dismissed Pluto make the cut but also Xena and another object called Ceres, which makes an orbit between Jupiter and Mars.

With the vote from hundreds of astronomers around the world, the definition for planet became to be generally defined as an object that dominated their own orbits but also taking smaller things before them. That general description knocked Pluto out of the solar system running for planet status. 

Pluto is now considered a dwarf planet.  A dwarf planet can be defined as a celestial mass that is in orbit around the Sun in our solar system.  In addition, a dwarf planet can also be defined as having sufficient weight to create its own gravity while conquering unyielding powerful forces that mold its shape into a round format. Another aspect to dwarf planets is that they are not satellites (an object that orbits a mass larger than itself) nor have they totally followed a complete orbital path.

Some of the classifications of what makes a dwarf planet are what disqualified Pluto from planet status.  For instance, Pluto does not have a round orbit.  Rather is it oblong-shaped and gets into Neptune’s territory.  There are some naysayers in the astronomy community that think that Pluto should remain a planet.  However, a large contingent of the same community says that most of the controversy stems not from the reclassification but discovering what you’ve always learned is no longer.

With better tools in which to gaze upon the heavens, it is no wonder that there is some definition shuffling in the astronomy community.  It stands to reason that everyone is going to discover new things that are bound to challenge the tradition thinking of the community and even the public in general.  And many believe that is what has happened with the demotion of Pluto to a dwarf planet. As one scientist has said, “Progress is simply the growing pains of an existing theory.”

Photo Credit:  Eliot Young (SwRI) et al., NASA

Source:  http://antwrp.gsfc.nasa.gov/apod/ap010319.html

Explanation: Pluto is mostly brownish-green. The above picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. No spacecraft has yet visited this dwarf planet in our Solar System. The above map was created by tracking brightness changes from Earth of Pluto during times when it was being partially eclipsed by its moon Charon. The map therefore shows the hemisphere of Pluto that faces Charon. Pluto’s brownish-green color is thought dominated by frozen methane deposits metamorphosed by faint but energetic sunlight. The dark band below Pluto’s equator is seen to have rather complex coloring, however, indicating that some unknown mechanisms may have affected Pluto’s surface.

Thinking of taking a trip to Science World? Here’s a mini tour to help you decide…

Perpetual motion sculpture at Science World planetarium, then a walk through Plaza of Nations to the city library… one of the finest architectural buildings in Vancouver.

The late Dr Carl Sagan speaks about 4 billion years of evolution. Footage taken from the COSMOS series.

When categorizing hurricanes, cyclones, and typhoons scientists had to find a way to identify the different levels of intensity in regards to damage and severity.  Based upon the maximum wind speeds and storm surge, a hurricane scale was created, which ranges from Level One to Level Five.  The Saffir-Simpson Hurricane Scale was created to monitor and categorize the intensities of hurricanes, cyclones, and typhoons. 

When analyzing the intensity of these storms, meteorologists review their maximum wind speeds and the storm surge.  A storm surge is the rush of water that comes onshore from a low-pressure storm, like those in a tropical cyclone.  Usually, it is the high winds of the storm that push the water further onshore.  The Saffir-Simpson Hurricane Scale is used to categorize hurricanes affecting the United States, but other places in the world use other means of rating their storms.  The scale does not take into consideration the amount of rainfall or location, which means that a Level 2 hurricane that hits a major city will likely do more damage than a Level 5 hurricane that hits a rural area. 

Level One storm’s are considered to be pretty weak and tend to create the least amount of damage to trees, shrubs, and mobile residences.  Storms within the Level One category will reach wind speeds between 74-95 miles per hour and their storm surge will reach 4 to 5 feet.  Level Two is considered to be a moderate storm and causes noticeable damage to trees and mobile residences, as well as piers.  This type of storm has been known to rip the shingles from roofs and cause further damage to the tops of houses.  The wind speeds in a Level Two storm can reach between 96-110 miles per hour and their storm surge reaches 6-8 feet. 

Level Three is considered strong and is known for blowing down trees or stripping the leaves from the branches.  Mobile residences are more likely to be destroyed within these types of storms and damage to other types of buildings is also likely.  Level Three storms reach wind speeds of up to 111-130 miles per hour and the storm surge reaches 9-12 feet.  Level Four storms are considered to be very strong with the ability to create extensive damage to houses, including the windows, doors, and roofs.  When living close to the shore, the damage will be much more devastating.  The chances of flooding are high when this type of storm hits.  Level Four storms reach wind speeds of up to 131-155 miles per hour and the storm surge reaches 13-18 feet. 

Level Five is considered to be the worst level of hurricanes, cyclones, and typhoons.  Small buildings will be overturned or blown away with the winds from a Level Five storm.  The structural damage received by this category hurricane or storm is very severe, with wind speeds reaching 156 plus miles per hour.  The storm surge in a Level Five storm is 19 plus feet.  It is within this category that Hurricane Katrina was placed with maximum wind speeds of over 175 miles per hour.  

The Saffir-Simpson scale is used to give an estimate of the potential property damage and flooding expected along the cost from a hurricane landfall.  Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region.  A category five, or “catastrophic” hurricane has wind speeds greater than 155 miles per hour and will cause complete failure on roofs of residences and industrial buildings and major damage to structures less than 15 feet above sea level within 1,500 feet of shore.  A category five storm requires evacuation of all residential areas on low-lying ground within 5 to 10 miles of shore. 

 

A new planet has been discovered and named HAT-P-1. The use of a network of telescopes known as a HAT discovered this planet. The HAT network consists of six telescopes, four at the Smithsonian Astrophysical Observatory’s Whipple Observatory in Arizona and two at its Submillimeter Array facility in Hawaii. These telescopes conduct robotic observations every clear night, each covering an area of the sky 300 times the size of the full moon with every exposure. This new planet orbits one member of a pair or stars in a constellation named Lacerta. Constellation Lacerta is 450 light years away.

 Astronomers spotted HAT-P-1 as it passed in front of, or transited its parent star. The parent star has been identified as one in a system called ADS 16402. HAT-P-1 revolves around its host star every 4.5 days in an orbit one-twentieth of the distance from Earth to the Sun. Once each orbit, it passes in front of its parent star, causing the star to appear fainter by about 1.5 percent for more than two hours, after which the star returns to its previous brightness. The two stars are separated by about 1500 times the Earth-Sun difference. These stars are 3.6 billion years old, making them younger than the Sun, which is 4.5 billion years old. When HAT-P-1 passed in front of its star it resulted in a small change in the starlight hitting Earth. This change allowed scientists to determine the new planets size and mass. HAT-P-1 is 1.76 times wider than Jupiter, (with a radius about 1.38 times that of Jupiter’s) but only posses half of the mass. This means it is one-third larger than Jupiter, but only weighs half as much. This is 24 percent larger than theory predicts.

 HAT-P-1 has been placed into a class of planets named “hot Jupiters”. These planets are roughly the size of Jupiter, but orbit much closer to their stars the Jupiter does to the Sun.

 HAT-P-1 is a real light weight planet. This new planet is one quarter the density of water and it is said that it would float like a cork (if there was a body of water large enough to hold it). The planet is being described as swollen or puffy.

HAT-P-1 is the largest low-density planet found outside of our solar system. The very first of these “light” planets was named HD209458b, and it was also discovered using the transit technique. HD209458b is 20 percent larger than predicted by theory.

The fact that two out of the eleven planets discovered by the transiting technique are bigger and lower in density than expected, has scientists questioning the current theory on how planets are formed. It is a mystery on what causes these planets to puff up to their large size. It is assumed that the cause is additional heat seeping into the interior of the planets, but astronomers cannot agree on how this may be happening. Simple heating of the surface due to the host star’s proximity would not work. (If it could, all close in transiting giant planets should be expanded, not just two of them.)

There are a few other theories on what might be causing the planets to swell up. According to Dimitar Sasselov one explanation for the large sized planets was tidal heating due to an eccentric orbit (an orbit that deviates from the standard circle). However, recent observations have pretty much ruled out this theory.

There is another theory that energy can be injected into the center interior of a planet by tipping it on its side (similar to Uranus). However, most astrologists agree that this seems highly unlikely.