February 15, 2013
High Tech Computer Simulations May Help Determine Origin Of Solar System
Peter Suciu for redOrbit.com — Your Universe Online
Understanding past collisions between celestial bodies, including asteroids, could help researchers better understand the origins of our Solar System. After all, it was through a series of such collisions some four and a half billion years ago that our planetary system was formed. What started as a giant dusty gas cloud combined to form increasingly large clumps, and as these collided and combined, they grew into what we now know to our familiar planets.
However, between the planets of Mars and Jupiter, hundreds of thousands of fragments remained uncombined, and these resulted in the so-called asteroid belt. Here the composition of matter has hardly changed. Yet scientists have no way of witnessing those past events that created the asteroids nor can they take a quick flight to the asteroid belt to examine the asteroids firsthand. However, with state-of-the-art technology, they can now recreate those collisions on a computer.
Martin Jutzi, a scientist at Center for Space and Habitability (CSH) at the University of Bern, has utilized a three-dimensional computer simulation to reconstruct how an asteroid called Vesta collided with other asteroids — not just once but twice over a billion years ago.
What makes this particular study all the more unique is that Vesta is a so-called protoplanet, which has an internal structure and could have formed into a planet had the process of accretion continued. Vesta is the second largest celestial body in the asteroid belt and is also the only known asteroid to have an earth-like structure that includes a core, mantle and crust. It was discovered by German astronomer and physician Wilhelm Olbers in 1807 and is also the brightest asteroid in the heavens.
Vesta also stands out because of the two large craters on its surface. The oldest of these, Veneneia, is believed to have formed approximately 2 billion years ago. With a diameter of 245 miles, this crater also covers about three-fourths of Vesta´s equator. The second impact crater, Rheasilvia, partially obscures Veneneia.
Jutzi has now accurately reconstructed how Vesta collided with other asteroids, and his model shows that the protoplanet likely owes its elliptical shape to those collisions. The simulations have also enabled detailed conclusions on the composition and properties of Vesta´s interior. This in turn could help provide a better understanding of the origin and evolution of the entire solar system.
The goal of the simulation is to discover more about Vesta´s interior. Jutzi´s study was conducted in collaboration with researchers from France´s prestigious Ãcole Polytechnique FÃ©dÃ©rale de Lausanne (EPFL) and is featured as the cover story for the February 14 issue of Nature.
This recent simulation is just the latest study into the mysteries of Vesta. Previous observations from the Hubble Space Telescope provide initial evidence of the giant crater at the protoplanet´s south pole, while in 2011 NASA´s Dawn spacecraft entered orbit around the asteroid and analyzed the mineral composition on its surface. This indicated that the crater observed by Hubble is actually composed of two partially overlapping basins.
Jutzi took this information and with the simulation demonstrated exactly how two consecutive impacts may have led to the formation of those basins, which span almost the entire southern hemisphere. The final images of the simulations actually closely resemble the shape and topography of the actual asteroid as it was observed by the Dawn mission.
“This shows how reliable our method is,” said Jutzi in a statement.
More importantly, the simulations could reveal what Dawn wasn´t able to see, notably that the material exposed by the impacts came from depths of up to 60 miles. This could allow a deeper look into the mysteries of the universe as well.
“The fact that we can now look inside such protoplanets makes entirely new perspectives in the research on the history of our solar system possible,” added Jutzi in closing.