When a meteor hit the surface of a planet, it creates an impact crater. When an meteor hit the surface of a planet at an angle, like it usually happens in the movies, what do you call the long "ditch" that is formed before the actual crater where the meteor came to rest?
I think the answer to this is that it doesn't have a name because such "ditches" don't occur for real meteor impacts. In movies and tv shows, these ditches are often shown as being caused by the meteor first hitting the ground at some angle, then sliding across the ground, digging out a ditch along the way, until they come to their final resting point where the crater is.
When you stop to think about it, this scenario doesn't really make sense. These types of images (e.g., this one or this one) usually show a thin tail or ditch where the meteor first impacts which gets wider and deeper as the meteor scrapes on the ground, resulting in a final, large crater. But, the most energy a meteor imparts to the ground comes from the first instance it hits. If it were to scrape along the ground as portrayed in many movies, the crater would come from the point it hit the ground and the tail would be in the direction the meteor was traveling. The "ditch" or "tail" would get thinner and shallower as the meteor lost energy scraping across the ground. Generally the opposite is shown in movies.
But all that is moot anyway because meteors don't scrape along the ground at impact. That would just violate conservation of momentum and energy. You really have one of two scenarios.
- The meteor hits the ground with such force and energy that it mostly destroys itself and you wind up with just a crater. Such an example is the meteor crater in Arizona - in a stroke of brilliance called Meteor Crater. I would hazard a guess that almost all meteor impacts are of this form, be it on Earth or elsewhere.
- The other option is that the meteor isn't destroyed when it hits the ground. In this case, rather than dragging or scraping on the ground, your meteor will skip like a rock on water and create another crater on its second impact. In theory, it will keep skipping until it is finally destroyed or runs out of energy. This scenario requires that the impacting meteor is hitting at a very shallow angle with very little force and generally means that it is hitting a smaller body (but larger than itself) such as an asteroid/comet/moon. An example would be the Messier Crater on the Moon, linked by Andy in his comment. These types of craters are unlikely though, as they require pretty specific conditions to occur.
They considered a type of crater. If you dislike the word crater, you could describe it as an elongated impact structure.
These are known on the Moon and Mars, but are rather rare. On the Earth, an impactor at a lower angle will have to travel through a lot of air before reaching the ground. Making it more likely that the impactor will be broken up, and destroyed in the air, and so not form a crater.
Even in very shallow impacts, you won't get "ditch" being dug. That is only for the movies.
Whilst it is admittedly not a scientific text, here's a quotation from the 1977 novel Lucifers Hammer by Larry Niven and Jerry Pournelle:
"Dr. Sharps says that all craters are circular." Harvey posed above the cake pan with a lug nut in his fingers; he let it drop. Flour sprayed. "Whatever the velocity or the mass or the angle of flight of a meteor, it leaves a circle. I think he's right.