Stories tagged earth

Best title for a science article, ever! All about efforts to track asteroids, comets and other outer space stuff that might hit the Earth, and to deflect or destroy it before it does.

Jul
08
2007

The Earth as it actually is: Here we see a revised map of the planet earth.    (Image by FuLL MoON on Flickr.com)
The Earth as it actually is: Here we see a revised map of the planet earth. (Image by FuLL MoON on Flickr.com)
Well… Maybe the home planet isn’t shrinking, exactly, but it’s slightly smaller than we used to think. So it’s kind of like it’s shrinking in our heads, which is just as bad, according to The Matrix.

Using a procedure called “Very Long Baseline Interferometry,” or just VBLI, scientists have been able to reevaluate previous estimates on the earth’s exact size. VBLI works by using a network of over 70 radio telescopes around the world to measure radio waves emitted by sources deep in space, like Quasars. Because each telescope is always going to be slightly closer or further away from the source of the radio waves, the signals are received with a slight time lag from telescope to telescope. By measuring that lag, scientists can tell the exact distances from each telescope to the Quasar, and then the distances between two telescopes “to the preciseness of two millimeters per 1,000 kilometers.” Through all this, they have discovered that the Earth is just slightly smaller than we used to think - just a matter of millimeters, though.

But what does a matter of millimeters mean on a global scale? The implications, I think, will startle you. For instance, the state of Rhode Island no longer exists. And Delaware is just a beach now. My bedroom, formerly a palatial 12’ by 13’ 6” is now a claustrophobic 11’ 11” by 13’ 5.9”. I had to throw some books out. It’s a scary world we live in, so dominated by concepts.

The Geodesists who have developed this world-measuring process are hopeful, however, that it will have the potential to make up for its grim introduction. By measuring the Earth’s size so exactly, VLBI will allow us to measure minute changes in sea level and track the progression of global warming, or to follow the exact movement of the tectonic plates (It turns out that the Swiss and us are moving 18 millimeters away from each other every year. I’m not sure how I feel about this.)

The March of VLBI

Mars and Venus may be our closest planetary neighbors, but astronomers have now identified a distant planet that might have potential to support life. Don't pack your bags just yet though—planet 581 c is 120 trillion miles away, and scientists are still determining if it has an atmosphere.

Mar
03
2007

Diagram of a lunar eclipse: Illustration NASA
Diagram of a lunar eclipse: Illustration NASA

The Earth will pass between the Sun and the Moon today, casting its shadow over the Moon and creating a total lunar eclipse.

The Moon starts to enter the Earth's shadow at 3:18 pm Eastern Time (US). It is fully in shadow from 5:44 pm to 6:57 pm, and then slowly leaves the shadow until it is clear at 9:24 pm.

Eclipse times in other US time zones:

Time Zone (US) Partial eclipse begins Total eclipse begins Total eclipse ends Partial eclipse ends
Eastern 3:18 pm 5:44 pm 6:57 pm 9:24 pm
Central 2:18 pm 4:44 pm 5:57 pm 8:24 pm
Mountain 1:18 pm 3:44 pm 4:57 pm 7:24 pm
Western 12:18 pm 2:44 pm 3:57 pm 6:24 pm
.


Photo of the Moon during a total eclipse in 2003: Photo NASA

In St. Paul, the Moon will rise tonight at 5:59 pm -- just after the total eclipse phase has ended. You can watch the Moon slowly emerge from the Earth's shadow. (Ancient astronomers watching lunar eclipses noticed that the Earth's shadow was always round -- thus proving that the Earth is round, too.)

To find out when the moon rises and sets in your town today, go to this site.

Note: it is perfectly safe to watch a lunar eclipse with your naked eye. All you are seeing is sunlight bouncing off the Moon's surface. It is no more dangerous than staring at a Full Moon. However, you must never look directly at the Sun, as during a solar eclipse. You can seriously damage your eyes.

To learn more about lunar eclipses, check out Wikipedia or NASA,

The last total eclipse was three years ago; the next will be later this year, on August 28.

Oct
02
2006


Pine Barrens Tree Frog: In this image the tympanum can be seen as the small round disk to the right of the eye. Image courtesy Bruce Means and the U.S. Fish and Wildlife Service.
Do frogs have ears?

Yes, they do, but they are different from the ears we have. Frogs do not have external ears, rather they have something called a tympanum. The tympanum are behind the eyes, and look like round disks. Some tympanum are easier to see than others. They receive sound waves for the frog just like the tympanic membrane (also known as the eardrum) does for us. Frogs not only use the tympanum to hear, but also use their lungs. The lungs help with hearing, and also protect the frog’s eardrums from the very loud noises frogs make by equalizing pressures between the inner and outer surfaces of the tympanum.

What does sublimation mean?

In physics, sublimation is the process by which a solid converts to a gas and bypasses a liquid stage in doing so. Have you ever seen dry ice? At room temperature, dry ice sublimates directly into a gas, skipping the liquid stage.

Where do Komodo Dragons live?

There are about 6,000 Komodo Dragons living in the wild. They live on the Lesser Sunda Islands in Indonesia.

What causes hiccups?

There are a variety of causes for hiccups, including eating too quickly, swallowing too much air, taking a cold drink while eating a hot meal, laughing, coughing, or drinking too much alcohol.

Hiccups are an involuntary spasm of the diaphragm, the large muscle that separates the chest cavity from the abdominal cavity. The sudden intake of air into the lungs is stopped by the glottis, which causes the “hic” sound.

Do you know how fast the Earth spins on its axis?

Well, if you figure the Earth does one full rotation on its axis about every 24 hours (23 hours, 56 minutes, and 04.09 seconds), and the Earth’s circumference is around 25,000 miles (24,901.55 miles), then it spins at roughly 1,040 miles per hour.

Illustration of the life-cycle of the Sun: Illustration courtesy Tablizer.
Illustration of the life-cycle of the Sun: Illustration courtesy Tablizer.Courtesy Tablizer
Will the sun explode?

No, but one day it will be large enough to push the Earth into a new orbit while eradicating the Earth’s atmosphere – but not for a long, long time. Our sun does not have enough mass to “go supernova” and explode. But, in about 5-6 billion years it will start becoming a red giant once it has used up its supply of hydrogen in its core and switched to fusing hydrogen in a shell outside of its core. While this is happening other processes will cause the sun to grow. Much, much later, the red dwarf will become a planetary nebula, and then a white dwarf. This is the standard stellar evolution for a star such as our sun.