Meteor Crater

Great craters like this cover the surface of Mars and the moon, but this one just happens to be on our home planet, Earth.

Meteor Crater is one of (if not the) best preserved crater in the world. Formally one of the Seven Wonders of the World, Meteor Crater is located in Arizona not far from the Grand Canyon, another natural wonder.
Meteor Crater was discovered in 1871 by a man named Franklin who was a scout for General Custer. For years it was thought to be a volcanic crater until a shepherd found iron-nickel meteorites there in 1886. However, the shepherd thought that he had found silver and did not report his discovery for 5 years.
In 1902 Barringer purchased the land containing the crater and began looking for the main body of the meteor  that had created Meteor Crater. At first he started drilling at the bottom of the crater, but after a wile he reasoned that the meteor had come in at an angle and the surviving meteorite was located under the south rim. Sadly 26 year of searching, Barringer died without finding his meteorite.
Today, the common theory in the scientific community about how the Meteor Crater was formed is this: a huge meteoroid 150 feet across entered the Earth's atmosphere at 26,000mph and slammed into the desert plain of Arizona. On its trip through the atmosphere, the half a million ton projectile lost little speed and less the one percent of its mass. The result was tremendous impact releasing more energy then a 20 megaton atomic bomb. During the impact, 175 million tons of rock was flung out of the creator and the surrounding bedrock was uplifted over 150 feet. Most of the meteorite was liquidized in the process and solidified in small spheres after penetrating the crater's floor. The remaining chunks of meteorite where hurled over the rim and landed in the debris field surrounding Meteor Crater. Today, the largest piece of meteorite discovered is only about three feet across and is on display at the Meteor Crater Visitor Center.
Watch an animation of Meteor Crater being created!


Sources:

www.meteorcrater.com
World Book Encyclopedia, 1997 Edition
Meteor Crater Visitor Center

All photos courtesy of www.meteorcrarer.com

Fluorine

Florine is arguably the most volatile and reactive element in the universe. And yet it's in our toothpaste!

When purified fluorine is a pale yellow gas, however it does not stay around very long because it is so reactive. Fluorine will react with almost any element, sometimes in an explosive manner. Under most conditions pure fluorine will burn with other substances on contact, but for other substances (such as hydrogen) it will explode violently. This property makes it extremely difficult to store.

The reason fluorine is so reactive is found in the shape and behavior of the atomic structure itself. Fluorine is the 9th element on the Table of Elements its atomic number is also 9, which means it has 9 electrons. If you remember learning about the Bohr model of the atom, you might recall that the first electron orbit can contain 2 electrons and the second orbit can contain 8. This means that all but one spot in the outer electron orbit of fluorine is filled.

Now for a little review on molecular structure: in order for atoms to combined themselves into a molecule, they need to share electrons. This happens when one atom's electron fills the "hole" of another. (From hole to whole, get it?) The fewer electron holes an atom has, the more it "wants" to fill them. (This wanting is called electronegativity.)This means that elements like oxygen (which has two holes) is more reactive then elements like carbon (which has four), while elements that have no holes (like helium and neon) are inert and will not form molecules with other elements. This also means that fluorine (with only one hole) really wants that hole filled. When it burns or explodes, what it is really doing is stealing another atom's electron. In fact, fluorine is such a thief it can even steal from some of the noble gases! (The ones with no holes.) However this trick requires some special conditions first, because no one gets away with stealing from the nobles!

Because fluorine is very reactive you might think it is harmful to people, but you would be wrong. Just because an element is reactive does not necessarily mean it is dangerous, as long as it is exposed to the correct area of the body in a semi-stable form. Oxygen and hydrogen are also very reactive, and both are essential to life. Fluorine makes enamel harder and more resistant to decay. A word of cation though: fluorine may cause damage to developing permanent teeth, and will harm you if taken in large doses. City water typically contains less then 2ppm fluoride.

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Fun fact: an average human's body contains about 2-3 grams of fluorine.

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Sources:

Exploring Creation with Chemistry, Second Edition

World Book Encyclopedia, 1997 Edition.

www.webelements.com

All pictures courtesy of www.webelements.com

Exploding Magnets

Exploding things is always fun, but did you know there is a reason for it when it comes to magnets? Scientist have been on a quest for stronger and stronger magnets ever since they knew what magnetism was. It started with perminet magnets like loadstone and neodymium. After that it was electromagnets. Although electromagnets can produce extreamly strong magnetic fields, they generate an enormus amount of heat. Because of this, electromagnets can only produce about 50,000 gauss before they melt, even with special cooling systems.

So what did scientist do to make a more powerful magnet? Well, they stuck with the electromagnet and pumped several times as much power through them as they normally would. The result was an electro magnet so powerful that it actually blew itself apart rather than just melting. After carefully analyzing the magnet power fluctuation during its short existence scientist concluded that as the magnet flew apart it lost a large amount of energy. To fix this problem, the experimenters placed high explosives around the electromagnet before they turned it on. Then, they light the explosives and turn on the magnet at the same time. The result is a magnetic field of 1000 Tesla! (That's 10,000,000 gauss!) Of course, it's gone in about 10 microseconds.

Watch this magnet in action!

Sources:

National High Magnetic Field Laboratory:

http://www.magnet.fsu.edu/
World Book Encyclopedia, 1997 Edition

Photo courtesy of the National High Magnetic Laboratory

Rock Eating Cacti

Did you know there are cacti that live on bare rocks? It's true! The giant cardon cactus of Baja Mexico not only lives on rocks, but drills its roots into them for anchorage!

So how on earth does a plant accomplish this feat? The answer lies in a symbiotic relationship between the giant cardon cactus (Pachycereus pringlei) and an endophytic bacterium. The bacteria produce an acid that breaks the rock down into the minerals the the cactus needs. In return, the cactus allows the bacteria to live in its roots, suppling them with water, carbon and shelter. The acid that the bacteria make also allows the cactus's roots to bore into the rock by dissolving it. This process not only benefits the cacti and bacteria, but also breaks the rock down into soil at an accelerated rate so that other vegitation can grow there.
To continue the mutual symbiosis, P. pringlei "packages" the bacteria with it seeds. The seeds are then spread via bat or bird droppings which supply the young cardon cacti with nutrients until the bacteria can establish themselves.

Sources:
http://thenewcreationism.wordpress.com/2009/09/02/rock-dissolving-bacteria-in-desert-cacti/
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8209000/8209687.stm
http://worldwidescience.org/
http://www.sciencedirect.com/science/journal/00988472

All images courtesy of BBC News

Quark Quirks

Can you imagine 3 marbles floating around the vastness of outer space? If you can, you can imagine the inside of a proton.

Protons, although tiny, are not the smallest particles around, the quark is. To give you an idea of just how small a quark is, imagine a pea orbiting a baseball 20 miles away. That is the atom. Now take that baseball, magnify to the size of the Milky Way, and drop a marble in there. The marble is the quark. Starting to get the picture? I'm just getting a headache! In fact, quarks are so small they may have no size at all! Scientist refer to them as point-like-objects.

Quarks come in 3 different varieties: up, down, charm, strange, top and bottom. Up and down quarks are the ones that make up protons and neutrons. The up quark has a positive charge of 2/3, and the down quark has a negative charge of 1/3. Quarks are never found alone, they always come sets. The most common sets are baryons, which are three quark combinations that include protons and neutrons. The neutron has 1 up quark and 2 down quarks giving it an overall charge of 0. A proton, on the other hand, has 2 up quarks and 1 down quark giving a positive change of 1.

The other four types of quarks are much more massive than up and down quarks, and therefore less stable. The top quark is the most massive of all quarks. It has a mass roughly equivalent to a gold atom, and can remain in existence for more than a billionth of a second!

Here's an fun thing to leave you pondering: according to leading theories, the three quarks in a proton are not alone, but surrounded by "virtual quarks" that blink in and out of existence!

Sources:

hyperphysics.phy-astr.gsu.edu/HBASE/Particles/

www.sudan.umn.edu/

World Book Encyclopedia, 1997 Edition

World Book Encyclopedia, 2008 Edition

Mass Concentrations

Back in 1967 NASA was shocked when they observed a new lunar satellite orbiting the moon in an irregular pattern. The satellite would be orbiting normally, and then dip toward the moon's surface without warning, gain speed, and shoot back up into normal orbit. Investigation of this problem led to the discovery of mass concentrations.
Mass concentrations or "mascons" are just that, concentrations of mass. The word can be used in different ways, but the most common refers to a large pocket of high density matter on or under the surface of a terrestrial body. In the moon's case, mascons are 6km thick sheets of basalt which form the maria.

Now that I have explained a little of what mascons are, I can tell you what they do. Because mascons have more mass than the surrounding crust, they have a greater gravitational pull. This is why things orbiting the moon dip and sway as they pass over a mare; the mare's mascon is pulling the satellite out of orbit. Because of this, spacecraft cannot safely orbit the moon for more than 2 months*. (Luckily NASA discovered this before they sent people to the moon.)
Believe it or not, the Earth has mascons too! They are not as extreme as the moon's, but still do change the weight of objects over them. Two of the largest and strongest are Hawaii and a large crater in Antarctica.

*There are four stable orbits around the moon that do not pass over mascons, and safe orbits can be achieved over mascons with the aid of computers and rockets.
Sources:
http://science.nasa.gov/headlines/y2006/06nov_loworbit.htm
http://earthobservatory.nasa.gov/IOTD/view.php?id=6862
Word Book Encyclopedia 1997 Edition
http://www.higp.hawaii.edu/

Top two photos courtesy of NASA
Lower photo from Google Earth

Phoebe's Ring

A new ring was discovered around Saturn last October with the help of the Spitzer Telescope. This new ring, called Phoebe's Ring, is the largest planetary ring now known. Phoebe's Ring begins about 6 Gigameters (3.7 million miles) away from the planet, and extends another 12Gm (7.4 million miles). This makes the ring nearly 35 times larger than the previously known ring system, and 300 times wider than Saturn!

Although Phoebe's Ring is a giant, it went undetected for many years  because it is comprised mostly of fine black dust. This dust is only visible very faintly in infrared. The ring gets its name from its source: Phoebe. Phoebe is one of Saturn's farthest moons (ok, natural satellites to be correct). It is also one of the darkest objects in our solar system. Space debris hitting Phoebe creates the dust in Phoebe's ring.
Fun Fact: If Phoebe's Ring were visible in the night sky, it would appear twice as wide as the moon!

Sources:
www.planetary.org/blog/article/00002165/
www.windows.ucar.edu/tour/link=/saturn/saturn_phoebe_ring.html
www.nasa.gov/mission_pages/spitzer/news/spitzer-20091006.html#

All pictures courtesy of NASA