how big would a asteroid comet etc have to be for it to inundate most of the uk, if it landed in the north sea

Answer 1

Do you mean covering the Highlands, the Pennines, the Welsh mountains, the Lake District? To get a tsunami that big, tsunami would be the least of your worries - the flash would incinerate evreything and blow everything away, the crater would be hundreds of kms across, and UK would be covered by many meters of debris. That one would be about 10 km wide.

But to get a tsunami that simply swamped most of the lowlands (mainly east of England) would probably only need one a hundred or so meters wide.

Please ignore the first very stupid answer.

Answer 2

To put it simple, it depends on a lot of factors. First, what is it made of. If it were made of mostly iron, than it would survive the friction of the atmosphere. The more perpendicular to the earth would not slow it down as much as coming in at an angle and most important, how fast is it going to hit. If it was as big as a building going say 3 miles a second, it would make a moderate tsunami. But is it was as big as a building and hit at 15 miles a second, it would be 100 times as destructive. How much damage a meteorite causes depends on material,size and speed with speed being the most important factor.

Answer 3

Most comets, and potentially some asteroids, have orbits that bring them close to Earth only once every 200 years or longer. These are known to astronomers as long-period objects.

The rate of long-period comet impacts on Earth is on the order of one every 32 million years, whereas the rate of comparably-sized asteroid impacts is more like one per every 500,000 years.

When we find a comet which has some potential to hit Earth, it might cause an even bigger sensation than potential asteroid impactors,

The consequences of comet and asteroid impacts on Earth are roughly comparable. Both would cause widespread destruction and loss of human life.

Big chunks of rock with a little ice, an asteroid, or big chunks of ice with a little rock, a comet, create a lot of damage when they impact Earth like getting hit on the head by a stone with an icy coating or an iceball with a lot of rock in it—it's going to hurt your head.

A key difference is that long-period objects, like comets, will impact Earth with much greater speed than short-period objects

Nasa has a Near Earth Objects Program. which you might find interesting for more information

Answer 4

It would have to be perhaps a mile or more in diameter to create a tsunami of that magnitude.

Answer 5

about the size of a golfball i think