Sometimes we hear warning messages asteroids near Earth, with the potential for catastrophic results if there were direct intervention.
However, most experts agree that there is little chance that a large asteroid or other cosmic object will hit Earth and cause great destruction.
Many organizations are aware of the real risk of such an event. One example is NASA, the United States Space Agency. NASA and its international partners are constantly looking for heaven behind what scientists call NEOs. These objects include asteroids and comets that fall within 50 million kilometers of Earth's orbit.
This week, NASA will team up with the US Federal Emergency Management Agency (FEMA) and international experts to study the possibility that NEO would hit Earth. There will be scientists at a conference near Washington, D.C. simulate Asteroid made to explore what can happen if you defend yourself against real life.
What is an asteroid?
The asteroid is a rocky, airless object. Asteroids are sometimes called smaller planets. The original formation of our solar system has remained about 4.6 million years ago. Most asteroids can be found in the orbit of the Sun between the planets Mars and Jupiter. NASA says researchers have identified more than 795,000 asteroids.
A comet is a small, occasionally active object that contains ice. There may be ice in the sun evaporate create an atmosphere of dust and gas.
NASA says a car-sized asteroid enters Earth's atmosphere about once a year. Such objects turn into a fireball and burn before reaching the surface of the Earth.
About every 2000 years, a much larger object hits Earth and causes great damage. However, NASA experts claim that an object large enough to threaten Earth's civilization comes only every few million years.
The meeting this week – from April 29 to May 3 – is called the Planetary Defense Conference. Participants from NASA, FEMA and other government agencies and experts from around the world take part in a simulated test exercise.
The "table exercise" will consider the false threat from the asteroid invented by NASA's Jet Propulsion Laboratory (JPL). Groups explore possible emergency and defense measures to address the human-caused asteroid threat.
Lindley Johnson is a NASA planetary defense officer. He said the exercise would be a chance to create a better international process of preparation and response in case of a real threat. "This… will help us develop more effective communication with each other and with our governments," he added.
The exercise is based on the NEO discovery that the conference organizers said it would hit Earth in 2027. The exercise estimates the chance that NEO will hit the planet.
NASA officials say the international community has decided that in 1: 100, the chance at 1: 100 will be big enough to consider taking defensive and emergency measures.
In a press release, the organizers said the asteroid in real life is to go near Earth in 2029. This asteroid, called Apophis, is one of the most important discovered NEOs.
NASA predicts Apophis will pass Earth on Friday, April 13, 2029, at a distance of 31,300 kilometers above Earth's surface. This is closer than where meteorological satellites orbit our planet.
From end to end, it is estimated that Apophis is about 340 meters long. Experts say that if such an asteroid hit Earth, it would cause great damage to the planet's surface and our civilization.
However, NASA has made it clear that it does not believe Apophis will hit Earth in 2029. However, a close flyby will give scientists a great chance to study an asteroid, NASA says.
In the future, the world community could decide to send a spacecraft to watch Apophis, the press release said.
I'm Bryan Lynn.
Bryan Lynn wrote this story for VOA Learning English based on NASA reports and the International Academy of Astronautics. The editor was George Grow.
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Words in this story
asteroid – n. A rocky object that goes around the sun like a planet
simulate – against. create something that behaves or looks like something real but not
evaporate – against. from solid or liquid to gas