Research from NASA’s Spitzer Space Telescope reveals that asteroids somewhat near Earth, termed near-Earth objects, have a wide array of compositions. Compared to a box of chocolates filled with every type of filling, asteroids come in various assorted colors, shapes and compositions.
NASA’s Spitzer Space Telescope has observed 100 known near-Earth asteroids. The data is helping astronomers to identify near-Earth objects as a whole; however, the asteroids physical properties are still not known. Infrared data provides one method to read an object’s temperature, which will give an astronomer more information about the actual size and composition of an asteroid.
“These gigantic asteroids are educating us about the places they are from,” said David Trilling of the Northern Arizona University, Flagstaff, and lead researcher for his new paper based on asteroids physical characteristics and will appear in the September issue of The Astronomical Journal.
“Larger, dark rocks have a higher temperature than a smaller light one, because it absorbs more sunlight,” explained Timothy Spahr, director of the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics. (The Minor Planet Center serves as the worldwide clearinghouse for asteroid and comet observations. It collects data and disseminates observations and calculates orbits.)
“Very little is known about the physical characteristics of near-Earth objects,” said Trilling. “Our data will tell us more about the stray asteroids, and the study will show that the smaller objects have surprisingly high albedos (an albedo is a measurement of how much sunlight an object can reflect).
Asteroid surfaces become darker with time due to exposure to solar radiation, the presence of lighter, brighter surfaces of asteroids indicate that they are relatively young. In addition, the asteroids presently observed have a greater degree of diversity indicating they are from many different origins.
Some may come from the main Asteroids Belt between Mars and Jupiter, and others come from farther out in the solar system. This diversity suggests the materials that went into making the asteroids are the same materials that make up our planets, and they were formed early in our solar-system’s history.
The more that we know about asteroids, we may discover how to defend ourselves from a possible killer asteroid. Several months ago, the earth had a near miss of an enormous sized asteroid by only a matter of miles. All of our global neighbors to include the U.S. were unaware of its presence until it had already passed by the earth, and we were alerted by one amateur astronomer.