When I started this article I knew nothing about asteroids. I just thought they were space rocks that floated around in outer space somewhere. It turns out there are a lot of interesting things to be learned by studying asteroids. After all, they are made of the stuff that built the solar system.
The Asteroid Belt is not a failed planet.
It was once believed by scientists that the Asteroid Belt was a planet that failed to form. However, further study showed that there is not enough material for this to be true. If all the material found in the Asteroid Belt were to be gathered into a planet, it would be a size even smaller than our moon. However, there is at least one dwarf planet drifting around in the Asteroid Belt. I will discuss this further below.
They can have moons.
Yes, some asteroids are big enough to have small bodies orbit them. Scientists have discovered that over 150 asteroids have a moon, and some are even big enough to have two.
NASA crashed into one.
This was part of the Double Asteroid Redirection Test or DART, which took place in September of 2022. The scientists were able to successfully divert the orbit of a large asteroid near Earth, though studies of its orbit are still ongoing at the time of this writing. This test brings up interesting ideas for how to defend Earth from an asteroid threat in the future.
Samples have been taken from them.
Japan was the first country who successfully retrieved a sample from an asteroid with the Hayabusa mission of 2010, which brought back carbon rich samples from the Itokawa asteroid. NASA has also sent a spacecraft to an asteroid, where they discovered that the surface of their target was covered with several centimeters of thick debris and rubble.
Some were thought to be planets when first discovered.
Three of these “planets” were named Pallas, Juno, and Vesta. The objects appear as stars in telescopes, so it was easy to mistake them for planets. Eventually astronomers discovered several similar objects orbiting in the same place, which became known as the Asteroid Belt. There are many planet-shaped asteroids that can be picked up on telescope, but none of them are big enough to be considered actual planets.
There are several different kinds.
Astronomers have three main classifications for asteroids, with many smaller classifications that I won’t go into today. About three quarters of those found in the Asteroid Belt are considered C-type, or chondrite, asteroids, which are thought to consist of clay and silicate rocks. S-type, or stony asteroids, are made up of silicate rocks and nickel-iron components. The third class is M-type, or metallic, which consist primarily of nickel and iron.
Some could be mined in the future.
Several near earth asteroids, or NEA, are being considered as future mining prospects. These asteroids are thought to be around 85% metal, and could be mined for nickel, iron, and cobalt. We just need the technology to get there and extract the material.
Asteroids and meteors are not the same.
An asteroid is a small, rocky object that orbits the Sun. A meteoroid is a small piece of an asteroid or comet that has broken off from the main body. If it falls to Earth and vaporizes in the sky, creating a streak of light, it is called a meteor. A meteorite is a rock that did not burn up in the atmosphere and falls to Earth.
They can act like comets.
That’s right, sometimes asteroids develop tails just like a comet. Scientists aren’t completely sure why. They think that this may occur in an asteroid that contains some water or ice. Another hypothesis is that these are actually old comets that are almost out of volatile material and are transforming to rocky bodies. Some asteroids are old comets.
Ceres is no longer considered to be one.
When it was first discovered in 1801, Ceres was thought to be an unusually large asteroid. It is about 476 kilometers across, which is bigger than any other body within the asteroid belt. Scientists reclassified Ceres as a dwarf planet in 2006 and it became the first one visited by a spacecraft in 2015. This planet contains water, which means it might hold life. It is currently being explored for this possibility.
My only experience with this phenomenon involved a meteor back in the late 1990s. I was sitting up late in my room with the windows open and all of a sudden I saw this giant white light erupt over the city. It streaked across the sky with such bright light that it reflected on the wall of my bedroom, then a gigantic ball of whiteness disappeared somewhere over the mountains north of me. My astronomy professor was excited, saying what I had seen was an extremely rare event. I can only imagine the size of the rock that came down, and what it may have broken away from in the first place.
The Planets- www.theplanets.org