which of the following objects in space appear to be shooting stars once they enter earth's atmosphere?
A. Asteroids
B. Meteoroids
C. Comets
B. Meteoroids
B. Meteoroids
The correct answer is B. Meteoroids.
To understand why meteoroids appear as shooting stars when they enter Earth's atmosphere, let's break down the objects mentioned in the question:
A. Asteroids: These are rocky objects made of metals and silicates that orbit the Sun. They are generally larger than meteoroids and can vary in size from a few meters to hundreds of kilometers in diameter. When asteroids enter Earth's atmosphere, they produce bright and fiery streaks called fireballs, but they are not typically seen as shooting stars.
B. Meteoroids: These are smaller rocky or metallic objects, ranging in size from tiny specks to several meters in diameter. They are usually fragments of asteroids or comets that orbit the Sun. When meteoroids enter Earth's atmosphere, they burn up due to the intense heat generated by the friction of air molecules. The bright light they emit during their rapid descent is what we commonly call shooting stars or meteors.
C. Comets: These are icy bodies that orbit the Sun in elongated elliptical orbits. Comets are composed of dust, rock, and frozen gases, such as water, carbon dioxide, methane, and ammonia. When a comet gets close to the Sun, its heat causes the frozen gases to vaporize, creating a glowing coma (a bright, fuzzy, cloud-like region) and often a tail that can be seen from Earth. However, it is important to note that comets are not considered shooting stars, as the visible tail is caused by sunlight reflecting off the released gas and dust particles, rather than the comet itself burning up in the atmosphere.
In summary, when meteoroids enter Earth's atmosphere and burn up, they create the visual phenomenon known as shooting stars.