Name: Asteroids - Sixty Symbols
Uploaded: 2020-04-13T16:55:03.000Z
Duration: 6 min 36 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Adverbs of manner

an asteroid is a big chunk of rock, a lump of rock in space, which is big enough to be very readily observable, but small enough that no one wants to give it the honor of being a planet.

But it's not quite a planet, and it's bigger than a bit of dust.

Adverbs of degree

Obviously, when you first discover something, you're very excited about it.

You give it a name, you come up with a nice fancy symbol for it.

And so, for example, the first minor planet was discovered with Siri's in 18 01 and Siri's is the Roman goddess off agriculture.

And so it was actually given symbol as well as the name, and the symbol it was given was kind of a little sick sickle symbol with a cross on the water of the sickle, making it like the Venus symbols are female agricultural symbol.

And so when your first discovering the first of these, you know, obviously you have time to think about it, and you can come up with a nice, appropriate looking symbol for it.

But obviously, as time goes on you more and more of these things were discovered, and by the time you know, there are up into the tens to hundreds off them.

At that point, it starts getting a little city trying to come up with symbols for them.

So at that point they sort of admitted defeat and just started using numbers for the mall.

And now we're up to 1/4 of a 1,000,000 of the things that actually have numbers.

That's obviously most of them don't even have names that alone symbols.

At this point, I can see the outer planet.

And if you zoom in thistles the Earth orbit and re newsman Mercury.

Now I want to switch on the asteroids, and this is where all the streets are.

This is, of course, not all every history.

There's millions of asteroids and this is just, you know, the biggest ones are the most famous ones, and I think it's around 40 years.

So there is ah kind of a belt of asteroids in the solar system, and it's thought to be classically thought to be a kind of a failed planet.

That little this rubble was sort of collected there.

And because of the title influences of the other planets it never will collected together to form a planet.

The first time we I got very close to an asteroid was in 1991.

And so we went up Thio an asteroid called Gasparilla and then in 1993 again.

Then we went toe Ida and this was the Galileo probe and it just went quite close to them as they as it went on towards Jupiter.

And we didn't really know what they would look like if we could only see them with ground based telescopes.

They're kind of elongated, and they have a bunch of pot marks in him.

So it looks like other things have hit them.

Eso This is if you look here, this is the mass orbit, and this is the Jupiter's orbit.

And then there's this this asteroid belt where most of the asteroids actually orbit the sun.

It's kind of one planet's worth of stuff that's kind of spread out around the entire orbit.

So actually, the amount, the total amount of material although a planet's worth is quite a lot of material.

So actually you could fly quite happily through the asteroid belt and the chances of you bumping into anything actually pretty low, because that was the other thing.

I always wondered when I read about probes like the voyage is being sent to the outer planets.

I always wondered how they made sure they didn't hit something in the asteroid belt.

And, of course, with a space probe, you don't need anything very big to hit it for something bad to happen.

And so you know, the only ones we actually see the only ones we have documented of the big ones.

And so there is always a risk that any kind of space probe can run into a chunk of rock out there in space.

Fortunately, space is a very big place, so the johns ever happening, really is very low.

There's nothing very much you can do about it, but most of the orbits you can see if it tilted to the side.

Most of the orbits are in the in the planetary plane But there's some like this one, for example, which is tilted towards it.

Well, I think most people will think that they're interesting because there's a chance that some asteroids could actually hit Earth.

So that's a bit frightening and a bit exciting all at the same time.

We can see Meteors, media craters throughout the earth.

There's some that we've discovered with satellite images, and there's some that are just completely obvious when you walk past him.

There's a meteor crater in Arizona, which is just fascinating.

Never actually been there in person, but the photos are incredible.

It's a classic problem in that the chances of an asteroid smashing into the earth during your lifetime he's actually pretty low.

But if one did, it could be catastrophically bad and quite how much you want to worry about things where there's a very low probability of it happening.

But if it does happen, it's very, very bad.

It's not really a world define problem, but yes, potentially, you know, there could be an asteroid that will come along and wipe us all out.

Do asteroids excite astronomers, or are they just rubbish in between, the interesting stuff depends which astronomy you talk to.

If he talked to a cosmologist, they'll probably have very little interest at all in an asteroid.

If you talk to somebody who's interested in asteroids, they'll tell you they're the most fascinating objects in the universe.

And with a kind of growing interest in the formation of planets, it's pretty clear that asteroids are sort of either the rubble left over from when you've been building planets or the sort of raw material from which you might build a planet.

So actually, you know, if you're interested in planet formation studying asteroids probably some of the most interesting things you can study.

So if if we assume out basically and beyond Neptune somewhere, one off these red ones is actually polluter, there's these are again many, many objects.

They orbit further out in the solar system, and this is called the Kuiper Belt.

This probably goes out a few screens, a so by now for example, there is set now, which is quite a famous asteroid, which is this outer orbit.

I consume out a bit more so you can see how vast that orbit actually is.

I suppose most even people are interested in asteroids probably would would be prepared to concede that they really are just love to rock.

The interesting point is where they are in the solar system, what they're made off, how they might all come together to form planets, those kind of things.

So So they're kind of providing clues to how the solar system formed so individually, they're not that interesting.

Just as you know, if you're studying a galaxy, the individual stars are particularly fascinating.

But it's the fact is the kind of viewing them as a whole.

Andi what they mean for help, planets might form.

So this is game from, I guess, the late 19 seventies, where so the quality of graphics was appropriate to the late 19 seventies little line drawings and you had this little spaceship.

So the idea was to try and eliminate these Asteroids Rover than bumping into them.