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Every day, Earth is bombarded with more than 100 tons of dus
Transcript of Every day, Earth is bombarded with more than 100 tons of dus
By Jacob Korkue
Every day, Earth is bombarded with more than 100 tons of dust and sand-sized particles.
About once a year, an automobile-sized asteroid hits Earth's atmosphere, creates an impressive fireball, and burns up before reaching the surface.
Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the area.
Only once every few million years, an object large enough to threaten Earth's civilization comes along. Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences.
Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences.
This 10.5-billion-year-old globular cluster, NGC 6496, is home to heavy-metal stars of a celestial kind! The stars comprising this spectacular spherical cluster are enriched with much higher proportions of metals — elements heavier than hydrogen and helium are curiously known as metals in astronomy — than stars found in similar clusters.
A handful of these high-metallicity stars are also variable stars, meaning that their brightness fluctuates over time. NGC 6496 hosts a selection of long-period variables — giant pulsating stars whose brightness can take up to, and even over, a thousand days to change — and short-period eclipsing binaries, which dim when eclipsed by a stellar companion.
The nature of the variability of these stars can reveal important information about their mass, radius, luminosity, temperature, composition, and evolution, providing astronomers with measurements that would be difficult or even impossible to obtain through other methods.
NGC 6496 was discovered in 1826 by Scottish astronomer James Dunlop. The cluster resides at about 35,000 light-years away in the southern constellation of Scorpius (The Scorpion).
Space rocks smaller than about 25 meters (about 82 feet) will most likely burn up as they enter the Earth's atmosphere and cause little or no damage.
If a rocky meteoroid larger than 25 meters but smaller than one kilometer ( a little more than 1/2 mile) were to hit Earth, it would likely cause local damage to the impact area.
We believe anything larger than one to two kilometers (one kilometer is a little more than one-half mile) could have worldwide effects. At 5.4 kilometers in diameter, the largest known potentially hazardous asteroid is Toutatis.
By comparison, asteroids that populate the main asteroid belt between Mars and Jupiter, and pose no threat to Earth, can be as big as 940 kilometers (about 583 miles) across.
About once a year, an automobile -sized asteroid hits into Earths atmosphere ,creating an impressive sized fireball, burns up before reaching the surface.
There is a universe that is expanding 5 to 9 percent faster than NASA had expected,an important clue to understand those mysterious parts of the universe that make up 95 percent of everything and don't emit light.