Solar Fields - When The Worlds Collide [UPD]
Theclose-knit stars are similar to the sun in size and are probably abouta fewbillion years old ?roughly the age ofour sun when life first evolved on Earth. But these stars spin muchfaster,and, as a result, have powerful magnetic fields. The magnetic activitydrivesstrong stellar winds ? gale-force versions of the solarwind ? that slow the stars down, pulling them closer togetherover time.And this is where the planetary chaos may begin.
Solar fields - When the Worlds Collide
Like all families, the members of our solar system family share a common origins story. Their story started even before our solar system formed 4.56 billion years ago. Their story started when the story started for every single thing in our universe. Our universe was born from the Big Bang about 13.5 billion years ago. The first stars lived out their lives and eventually exploded, sending "star stuff" out into the cosmos. That original stellar material was recycled as another generation of stars, and many of these, too, exploded at the end of their lives. Our Sun is thought to be a third-generation star and our entire solar system is made of the recycled star stuff of previous star generations.
Fortunately, vital clues are scattered throughout the solar system -- from the oldest rocks on the Earth, Earth's Moon, Mars and the asteroids to the frozen outer reaches of the Kuiper Belt. NASA robotic missions are examining these distant worlds, making new discoveries that will help to fill in the pages of this story. Ongoing research is examining the early solar nebula's composition and conditions such as radiation, by studying grains from comets, from the Sun, and the composition of Jupiter (for more information about comets, see Small Bodies / Big Impacts). Comets are made of the ices and dust from the original nebula that formed our solar system, and can tell us more about how our planets formed. The EPOXI mission, which will fly past Comet Hartley 2 on November 4, 2010, is studying the structure, composition and formation history of cometary nuclei, in order to learn more about the origin of the solar system.
Our understanding of the solar system's formation is also being guided by the new worlds discovered around distant stars. The unusual orbits of many of these distant planets have sparked a hot topic of research: that planets' orbits may shift -- migrate -- early after their formation. This "planetary migration" is the best explanation for these newly discovered "hot Jupiters"-- massive gas giants orbiting extremely close to their stars.
If life exists in Europa, it likely evolved entirely separate from life on Earth. And if life sprung forth separately on two worlds around the same star, humans could infer that life begins often and easily when the conditions are right. We could further reason that life is likely to be found throughout the cosmos.
At this year's British Mathematical Colloquium we talked to the French mathematician and Fields medallist Cédric Villani. He told us about dynamical systems: from the possibility that our solar system will one day become unstable and the planets collide, to chaos in gases, the unpredictability of the stock market and unruly children. He also told us what it's like being a mathematical superstar and why mathematicians should talk about their work more.
Understanding how the Earth and moon formed is important for piecing together the history of the solar system and answering questions like how long planets take to form, what planets are made of, and what makes a planet suitable for life. This also guides planetary scientists in their search for other habitable (or inhabited!) worlds in our solar system and beyond! 041b061a72