::: I have been compiling these answer for more than 6 months, hope it's useful for you ::

"How far is the closest Black Hole from Earth?"

Astronomers think there is a black hole in the center of our galaxy. Relatively speaking, that is pretty close. But it's far enough away that we aren't in any danger of being sucked in by it.

"What would happen if a comet hit our earth?"

There are lots of scenarios. Comets have hit the Earth before and caused no major damage. Here is a list of some possibilities, listed in order of likelihood (in my opinion) with the first one being the most likely.

1. Comet might burn up in Earth's atmosphere.

2. Comet might arrive mostly whole, but land in an ocean with no consequences.

3. Comet might arrive mostly whole, but land in an ocean and create a tidal wave.

4. Comet might arrive mostly whole and hit the land in an unpopulated area.

5. Comet might arrive mostly whole and hit the land in a populated area.

6. Comet might be large enough to cause major destruction, either directly by smashing or by landing in an ocean or by causing tremors.

"Is the moon moving closer or farther from the Earth and if so at what rate and why? "

The moon is moving away from Earth at a distance of only a couple of centimeters per year. When the moon was formed, it was a lot closer to Earth than it is now, and it is continuing to move away. This means that the length of the Earth day is increasing. Too bad it is only by a miniscule amount, because some days I sure could use more time!

"what would happen if the earth didn't have gravity"

We'd float away into space, I suppose. But think about it: if the Earth didn't have any gravity, that would mean it didn't have any mass. If the Earth had no mass, would it exist at all?

"I wanted to know what would happen on earth if it did not have an axis?"

When something rotates, the point around which everthing spins is called the axis. It is not a concrete thing. So if the earth didn't have an axis, it wouldn't be spinning.

"What is the shape of the earth? Why?"

This is a really good question. It may seem that the earth is round because it "just is," like all the other heavenly bodies. But the question you have asked deals with laws of physics. You see, matter has mass and gravitational pull. The larger the mass, the more gravitational pull it has. So the particles that made up the earth attracted one another and clumped together. Then they attracted more and more matter, until an entire planet was formed. Earth has lots of gravity that pulls all its matter towards the center. So a sphere is the most efficient shape. If Earth had corners, that would mean that gravity was not pulling equally in all directions. Luckily, Earth's gravity is not SO strong that it prevent mountains from existing, or pulls us into flat little pancakes.

"What do earth worms eat"

Earthworms eat humus. This decayed organic matter (usually plant) in the soil. Thanks for writing. Dr. Universe

"what is the age of earth" About four and a half billion years, give or take a couple hundred thousand.

"If Adam and Eve were first on the earth and the animals came right after. But the animals came after dinosaurs but adam and eve were first. where do dinosaurs come in? "

Dinosaurs were on Earth before people, but they died out before humanity existed. In biblical days, they probably hadn't unearthed dinosaur bones, nor could they date them if they had. This is why dinosaurs are not described in Genesis