Our Changing Solar System

As they keep searching, astronomers learn more and more about how our Solar System formed. There is a good amount of understanding on how things happened, but a lot of the finer details of just why things appear the way they do still have to be answered.

Our Solar System is like a giant cosmic puzzle, and we are constantly finding new clues about the course of its evolution.

This week a few amazing findings that are redefining the way we understand our Solar System, planet formation, and what we might expect to find in other star systems.

An artistic rendition of the impact that created the Moon.

The idea that our Earth-Moon configuration is a rare occurrence has been challenged by simulations. Our Moon is considered to be disproportionally large, at over a quarter of the Earth's diameter. The Moon was formed from a large impact between a young Earth and a Mars-sized planet. The simulations run by researchers from the University of Zurich's Institute of Theoretical Physics in Switzerland and the Laboratory for Atmospheric and Space Physics at the University of Colorado show that these kinds of impacts might actually be much more common, perhaps as many as one in 10 rocky planets around a Sun-like star may host a large moon.

What is even better about this news, it is a way to help identify possible habitable planets. The Moon plays a large role in making the Earth a livable place between blocking would-be impactors and stirring the tides. Other planets with large moons could be ripe for life.

In this artist's conception, gas and dust—the raw materials for making planets—swirl around a young star. The planets in our solar system formed from a similar disk of gas and dust captured by our Sun. Credit: NASA/JPL-Caltech

The planet-sized object that glanced the Earth might have gotten its gravitational push from Jupiter. In another piece of news, researchers from around the world and NASA have developed a new model about the early motions of planets in our Solar System. The biggest news in this is the roaming of Jupiter, at one point it would have wandered almost as close to the Sun as Mars (before Mars was there), it would have only been stopped by the counter pull of Saturn.

The effects of Jupiter's motions have a profound impact. Over millions of years, Jupiter would have pushed around objects in our neighborhood. The nature of the asteroid belt would owe itself to these gravitational interactions. And probably the biggest impact is that Jupiter prevented Mars from growing to a larger planet. Jupiter either absorbed or scattered most of the material in the region Mars exists in, leaving slim pickings for planet formation.

A previous concept about the edge of our Solar System, which may be changing with new findings. Credit: NASA

And the last story about our amazing Solar System doesn't quite flow with the other two as well, but is still important. NASA is holding a teleconference on June 9 to discuss conditions at the edge of the Solar System. Based on data from the Voyager probes, the view of the edge of our Solar System needs to be changed.

The discussion will be about "a new computer model that shows the edge of our solar system is not smooth, but filled with a turbulent sea of magnetic bubbles." Since this is a poorly understood and previously unexplored region, there is much to be learned. Understanding is important though, this is a region that protects us from galactic cosmic rays.

Another reason why I am interested in this particular conference is because one of the panelists I have met before. Merav Opher used to be an assistant professor at my alma mater, George Mason University. She is wonderfully intelligent and I have found her work with the Voyager probes absolutely fascinating.

Posted in Earth,Jupiter,Mars,Moon,Solar System,Voyager 33 comments