Gathering Information to Learn the Age of Planets and Stars
Modern astronomy has allowed astronomers to discover how the age of planets and stars can be established.
Modern astronomy has allowed astronomers to discover how the age of planets and stars can be established. By observing a variety of physical features, certain characteristics can be interpreted to estimate the age of a cosmic body. Mainly measuring the age of stars is done using the technique of stellar spectroscopy, while the age of planets can be calculated by various means depending on the type of planet.
Stellar spectroscopy is the process of analyzing the spectrum of a star’s light. By studying the type of wavelengths a star emits, the temperature, mass, size, luminosity and surface gravity can be determined. A relationship between age and color of a star can be established, which can be used to group stars together depending on age. Stars are generally divided into three categories; young, middle-aged and old.
The age of a planet can be calculated in two ways. For planets circling around a star, the age of the star can be used as an indication of the age of the planet. If the planet orbits around a star which is millions of years old, chances are the planet is about the same age. Additionally, certain features on the planet’s surface give indications of its age. Examples of these features are craters and mountains.
Planets which exist outside the Solar System are harder to determine the age of. For planets outside the solar neighborhood, the age can be estimated using the ages of stars in the same area. As these planets lack physical features, the age is determined only by the age of the star system or other methods such as the determination of the age of the metal content in the atmosphere.
By using various ways of collecting data, astronomers can make estimations of the age of stars and planets. Combining the various methods of spectral analysis and physical observations has allowed astronomers to gather data to present a better understanding of the age of cosmic bodies.