Do the Moon and planets make their own light? Nope, it’s all reflected light from the Sun. Stars however are light and heat furnaces like our Sun
I answer a lot of questions from kids and adults when doing an outreach presentation. Here are a few of the more frequently asked questions. Let’s start with a question from the adults: What’s the difference between the asteroid belt and the Kuiper Belt?
A few years ago that question wouldn’t have been asked. The Kuiper Belt was just an idea put forward by Gerard Kuiper (Ky-per). But now that we have been to the Kuiper Belt via New Horizons’ Pluto mission, it’s a popular one to. The answer has to do with the positioning of the two belts and their composition.
The asteroid belt lies between Mars and giant Jupiter. It is composed of the rocky remains of a planet that failed to pull itself together due to a gravitational tug-of-war between its companion planets. All the material was there for the planet to coalesce, but the gravitational pull of the two planets, especially massive Jupiter was too much for it. As a result all the material had the velocity to keep it orbiting the Sun, but there was too much pulling on it to allow the material to form into a planet.
The Kuiper Belt was proposed in the 1950s and was thought to be the ice and rocks left over after the solar system coalesced. It is much farther out than the asteroid belt – right on the fringe of what was traditionally called our solar system. Now that we are discovering minor planets in the Kuiper Belt it has been included in our solar system.
Kids frequently want to know if there really are Martians. I tell them that none have been discovered yet, but Mars has all the necessities for life to take hold. There’s water, carbon, a thin atmosphere and all the elements for life, but it has eluded us so far. Perhaps it is lurking just beneath the surface of Mars, or in one of the Martian lava tubes. We won’t know until humans go there and can do some digging around. But we don’t expect to find any Martians in spaceships with deadly death rays. Disappointing isn’t it?
Black holes are another kid’s favourite. Most want to know the gory details of what would happen if you fell into one. The answer to that would depend on whether it was a large black hole or a small one. In a small one you would fall down the centre and be stretched until you popped apart. The gravitational pull at your feet would be so great verses that at your head, you’d be pulled in half, then that half would be pulled apart and on and on until you were just atoms. The technical term for that (and I’m not kidding) is spaghettification. Fall into a big black hole (like the one in my wife’s purse) and you’d be flung against its walls like those rides at the county fair. Only this one would crush the life out of you. Take your pick, either is equally unpleasant.
And there you have it. Don’t forget to keep your lights aimed and dimmed down. You’ll save energy, money and our starry Kawartha night sky.
Have a question? Contact johnstargazer@nexicom.net.
