As highlighted in a recent Live Science article, our solar system, which has existed for 4. Though that might sound like an unimaginably long period, it's but a fleeting moment in the grand 13. 8 billion-year history of the universe. . If you're counting on solar to deliver long-term savings, it pays to understand what “lasting 25 years” actually means, and what you can do to make every one of those years count. 8. . The Solar System is the gravitationally bound system of the Sun and the masses that orbit it, most prominently its eight planets, of which Earth is one. [11] The system formed about 4. If Jupiter was a hollow shell, 1,000 Earths could fit inside.