Newton’s 2nd Law of Motion states that if you apply a force to an object, it will accelerate at a rate proportional to its mass, and to the amount of force applied, and that the acceleration will be in the same direction as the force. We write this mathematically as: F = MA (Force = Mass times Acceleration). This makes sense, because we all know that it is easier to move a light object than a heavy one. A heavy … Continue reading →
Newton’s first law of motion says that an object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. What does this mean, in plain english? Every object in the universe hates change: If it’s stationary, it will not just start moving by itself. If it is moving, it won’t change that movement by … Continue reading →
Dark energy is the name used by scientists to describe whatever it is that is pushing the universe apart. Since the 1920’s, astronomers have been able to see that the universe is expanding, and this knowledge led them to the Big Bang Theory. One of the Hubble Space Telescope’s most amazing discoveries was that this expansion is not slowing down (as you would expect, because of gravitational attraction), but actually speeding up. Nothing that we know about physics can explain … Continue reading →
When you have two bodies orbiting each other (For example, the Earth and the Moon), we call the smaller of the two the Satellite of the larger. Thus the planets are satellites of the Sun, the Moon is a satellite of Earth, and so on. But when most people talk about satellites, they are referring to artificial satellites. These are manufactured objects which have been launched into space and carefully maneuvered into orbit around something much more massive like a … Continue reading →
Current total: 95. I’ll keep updating this page as more get discovered. Details in the UPDATES section below As of 2 February 2012, we know of 67 moons around Jupiter. We will probably continue to find more and more, as we keep looking, since Jupiter is large enough that it constantly captures passing asteroids and comets, turning them into moons. The smallest ones are so hard to see, and have such big irregular orbits, that astronomers sometimes lose them, until … Continue reading →
