NASA Space Telescope Finds Fewer Asteroids Near Earth

New observations by NASA's Wide-field Infrared Survey Explorer (WISE), show there are significantly fewer asteroids near Earth in the mid-size range than previously thought. These new findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids. Astronomers now estimate there are roughly 19,500 (not 35,000 as previously thought) mid-size near-Earth asteroids. Scientists say this improved understanding of the population could mean the hazard to Earth could be somewhat less than previously thought. However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (objects between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth. Near-Earth asteroids fall under the category of any space rock that orbits within 195 million kilometers of the sun into Earth's orbital vicinity. Though the WISE data reveal only a small decline in the estimated numbers for the largest near-Earth asteroids, which are 1 kilometer and larger, they show 93 percent of the estimated population have been found. This fulfills the initial "Spaceguard" goal agreed to with Congress in 1998.

Bibliography:
 www.sciencedaily.com
It is reported that Copernicus' parents said the following to him at the age of twelve: "Copernicus, young man, when are you going to come to terms with the fact that the world does not revolve around you." 

Blog 2 - Jupiter's Little Red Spot

Scientists have recently discovered a change in Jupiter's makeup. The "Red Eye" of Jupiter (a steadily shrinking red coloured storm) now has some competition. A smaller "Little Red Spot" has now shown up due to increased wind speeds which scientists believe stirred up material that was exposed to ultraviolet radiation, causing a chemical change to make it look red. The "Little Red Spot" storm was formed by the merger of three separate storms observed since the 1930's. In 1998 two of them came together and were joined in 2000 by a third to form a storm roughly the size of Earth. Both The "Red Eye" and "Little Red Spot" are anti-cyclones, meaning they spin in a counterclockwise motion. Unlike hurricanes, which rotate around a center of low pressure, anti-cyclones rotate around centers of high pressure. That means that air at lower elevations is forced away from the center, creating an opening that pulls cold air down from above. That leads to low humidity and few clouds. Their wind speeds have been recorded to reach up to 385 miles per hour, far exceeding the 156 mph mark that would make it a category five storm on Earth.

Bibliography

Milky Way's Spiral Arms Are the Product of an Intergalactic Collision Course; Models Show Dark Matter Packs a Punch

A dwarf galaxy called Sagittarius has collided twice with our Milky Way Galaxy, according to telescope data and detailed simulations, and is lined up to run into us again. When these galaxies collide, it sends stars shooting out in long loops which eventually build up to form a familiar ringed arm. Each time this collision has occured though, Sagittarius has been torn to pieces by about 80 to 90 percent and loses much of it's dark matter to form new arms for the milky way and its greater gravity. Although this may seem alarming, we do not have to worry at the moment, as scientists predict that the next collision will occur in about 10 million years.

http://www.sciencedaily.com/releases/2011/09/110914131338.htm