The contemplation of asteroids is one of the least practiced tasks in observational astronomy , due to how elusive these celestial objects are. However, it is quite satisfactory when we have knowledge of the characteristics of the asteroid we are observing, as is the case with Vesta.
This gigantic asteroid, with a diameter of 525.4 kilometers, is the second largest solar system and concentrates approximately 9% of the mass of the entire main asteroid belt . Thanks to its large size and its ability to reflect sunlight (albedo = 0.4228), it can be observed with a small telescope, with binoculars or even with the naked eye when it is in opposition phase from very dark skies.
Vesta is one of the asteroids that has aroused the most interest among astronomers since its discovery in 1807 , for this reason, for many years, it has been in the focus of many studies and space missions. Thanks to this, it is one of the asteroids that we know best.
This asteroid has been studied with all the available technology: its light has been analyzed from terrestrial observatories using photometric techniques and spectrography, which has made it possible to know with complete accuracy its rotation period (5.343227 hours) and its approximately spherical shape; its composition and density, which stands at 3.5 grams per cubic centimeter (higher than that of marble, which is 2.6 grams per cubic centimeter).
Images obtained with the Hubble Space Telescope have made it possible to identify features such as the large Rheasilvia crater , which occupies 80% of its entire diameter, with a central mountain 18 kilometers high from the crater floor.
Thanks to the Dawn mission, launched in 2007, the entire surface of this asteroid has been mapped with great precision and revealed that this asteroid was subjected to three major impacts, which molded its shape to its current state. Fragments emerged from these impacts that gave rise to what we now know as the Vestoy family of asteroids.
The surface of Vesta is composed of different types of minerals such as diogenites, formed by magmatic processes under the asteroid’s crust. This mineral has also been identified in meteorites that have fallen on our planet and are suspected of coming from Vesta. In addition, howardites have been identified in Vesta, a type of surface rock composed of fragments from different materials ejected and mixed by the impact of meteorites. These rocks are the most abundant on this asteroid.
During the next few nights, this body will shine in magnitude 6 and we can observe it being aware of its most characteristic features.
Amadeo Aznar Macías
APT Observatories Group.
www.apt.com.es
