# Calculating Radius of Crater from Meteor Impact

• ChrisVer
Hoops wrote:Most of the times, when people refer to these things, they refer to their age and their diameter/radius. My question is mainly about the radius. Is there a dynamical way to solve for the shape and radius of a crater such an impact can cause?Eg if I said that a meteor of mass 0.001 the mass of the earth, and initial velocity of 200 km/s falls horizontally on the ground, would I be able to calculate the radius of the crater?Well, you know the mass and the velocity, so you can start by calculating the kinetic energy of the steller object. This energy will have to be dissipated upon impact ( upon impact there is a

#### ChrisVer

Gold Member
When a stellar object falls into the Earth's surface, it creates a crater on the ground.
Most of the times, when people refer to these things, they refer to their age and their diameter/radius. My question is mainly about the radius. Is there a dynamical way to solve for the shape and radius of a crater such an impact can cause?
Eg if I said that a meteor of mass 0.001 the mass of the earth, and initial velocity of 200 km/s falls horizontally on the ground, would I be able to calculate the radius of the crater?

Well, you know the mass and the velocity, so you can start by calculating the kinetic energy of the steller object. This energy will have to be dissipated upon impact ( upon impact there is a horizontal and vertical component to the velocity of the object ). The heat produced will liquify and/or vaporizie some, or all of the object and some of the earth. Correlation between the initial kinetic energy and size of the crater produced most likely does not follow in a linear fashion.

ChrisVer said:
falls horizontally on the ground, would I be able to calculate the radius of the crater?
You're wanting to model a glancing/grazing impact? Of an object a tenth of Earth's diameter? Trajectory of COM is tangent to Earth's surface? Cuts a chord 0.1 Earth radii below the surface, passes 0.1 radii above the surface?
You might have meant .001 Earth diameter?

• ChrisVer
oops...I wrote horizontally, I meant vertically (like a falling apple)

The ground type at the impact site would also have an effect on the crater size produced
solid rock is likely to produce a smaller crater than soft ground for a given size meteorite impact
Also the type of meteor ... nickel/iron or rocky ( chondrite) and its velocity at impact

also let's get you velocity into a better range ---- 10 - 70km/s is the avg range for meteors entering the atmosphere
your 200 km/s is a bit high

its estimated that the meteor that produced the Barringer Crater in Arizona was still traveling at ~ 11 km/s when it impacted
This was a ~ 50 metre diameter nickel/iron type and produced a crater of about 1.2 km in diameter

Dave

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## 1. How is the radius of a crater from a meteor impact calculated?

The radius of a crater from a meteor impact can be calculated using the following formula: r = (g * t2) / (2 * π), where r is the radius of the crater, g is the acceleration due to gravity (typically 9.8 m/s2 on Earth), and t is the time since the impact.

## 2. What factors can affect the accuracy of the calculated radius?

Several factors can affect the accuracy of the calculated radius, including the angle and speed of impact, the composition of the meteor and the surface it impacts on, and the presence of any pre-existing structures or topographical features in the impact area.

## 3. Can the size of the meteor be determined from the radius of the crater?

No, the size of the meteor cannot be accurately determined from the radius of the crater alone. Other factors, such as the density and speed of the meteor, as well as the composition and properties of the impacted surface, also play a role in the size and shape of the crater.

## 4. How do scientists use crater radius calculations in their research?

Scientists use crater radius calculations to study the impact history and geology of a certain area or planet. By analyzing the size and distribution of craters, they can estimate the frequency and intensity of past impacts, which can provide valuable insights into the formation and evolution of celestial bodies.

## 5. Can the radius of a crater be used to determine the age of a meteor impact?

Yes, the radius of a crater can be used to estimate the age of a meteor impact. By comparing the size of a crater to other known impact events and using models of impact crater formation, scientists can estimate the age of the crater and therefore the age of the corresponding meteor impact.