Comets
The so-called "astronomical unit" is often used for this. One AU (astronomical unit) is the average distance from Sun to Earth; it is about 150 million kilometers.
Earth gets hit by small space rocks and debris all the time, but most burn up in the atmosphere before reaching the surface. Larger impacts, like meteorites or asteroids, are rarer and can happen every few thousand to million years. Earth's atmosphere and magnetic field help protect it from many small objects.
Often the element helium (atomic symbol: He) often makes objects float, most commonly balloons.
metaloid and metal
Map scales often show distances in both miles and kilometers (kilometres in Australia).
It's not often you use a polygon with several million sides, so I don't believe it has a name.
Ideally: infinite. Practically: very high, at least 1000 often several million maybe billions.
Every year. There are also several other yearly showers in the link below. Besides which, there are many man-made objects that reenter the atmosphere, and many unique objects that surprise us.
Between the orbits of Mars and Jupiter, you will find the asteroid belt. This area - which is approximately 1AU (or 149,597,870.7 km) thick - consists of over 7,000 known asteroids of various sizes. Despite the large number of objects within the belt, it isn't anything like the crowded, dangerous space often depicted in Hollywood films; the distance between any two objects can easily be a million kilometres apart.
A gigagram is equal to one million kilograms, which is equivalent to 1,000 metric tons or roughly 2.2 million pounds. This weight is often used to measure heavy objects or materials like large vehicles, industrial equipment, or building materials.
every 3000 to 5000 kilometres, not sure how many miles that it every 3000 to 5000 kilometres, not sure how many miles that it every 3 to 5 thousand miles
Objects made by people are often called "man made objects".
1 in a million
every million years every million years
Objects that provide resistance are often referred to as obstacles, hindrances, or impediments. These objects can impede progress or hinder movement.
The so-called "astronomical unit" is often used for this. One AU (astronomical unit) is the average distance from Sun to Earth; it is about 150 million kilometers.
== == 4.97096954, it is often rounded to five for convenience when strict accuracy is not needed.