The next time any of the planets will align with each other is predicted to be in October 2015. The last time at least three planets aligned was in 2011.
There will never be what is called an "exact" planetary alignment because of the different orbits of the planets. It is estimated that there will be another close alignment, meaning about 30 degrees within each other, of all eight planets in 2438, similar to the one that occurred in 1962. Beyond that, it could take millions of years before all eight of the planets ever align in perfect harmony again.Learn More
According to NASA, gravity is the reason why planets are round. Gravity causes any matter to attract toward any other matter. When planets began to form, the earth’s solar system was one big swirling disk that contained dust and gas, with the sun at its center. Particles of dust and gas pulled toward each other due to gravity.Full Answer >
Planets orbit around the Sun as a result of gravitational pull, or the natural attraction, between two masses. Earth has a velocity that is perpendicular to the force of the Sun's pull, causing it to move in a circular fashion.Full Answer >
In this solar system, Mercury and Venus have no moons. Mercury is the smallest planet in the solar system and only slightly larger than Earth's moon. It is the closest planet to the Sun. Venus is the second closest planet to the Sun and is slightly smaller than Earth.Full Answer >
All four of the gas giant planets in the solar system have rings. These are Saturn, Jupiter, Neptune and Uranus. The rings of Saturn are so prominent that they can be seen with binoculars on clear nights. The rings of the other planets are much more faint.Full Answer >