What is the rate of ejecta deposited between planets?

In summary, there is a lot of talk about how many rocks are ejected from Mars each year, but it is hard to verify the claims. Scientific American reports that there are around 15,000 tonnes of rocks ejected from Mars each year, which is much lower than the 500 kg/year that the wokeists claim. However, the mechanism for ejection from a planet has to be a collision as some other mass comes in and collides with the surface.
  • #1
swampwiz
571
83
I was reading this (which is notable for its non-science content, but I am only referring to this part):
https://www.nationalreview.com/2020/11/wokeists-assault-space-exploration
... it is estimated that every year, approximately 500 kilograms of rocks ejected from Mars via meteoric impact land on our planet.
Is there a matrix that shows the amount that goes between the planets? (And here, I consider a moon to be a "planet".)
 
Astronomy news on Phys.org
  • #2
BUMP

No one has any idea?
 
  • #3
It is not that simple. Try this search on google scholar 'estimates of planetary ejecta hitting earth'

Lots of good hits. You need to decide your parameters, the diversity of topics is not small.
 
  • #4
swampwiz said:
I was reading this (which is notable for its non-science content, but I am only referring to this part):
https://www.nationalreview.com/2020/11/wokeists-assault-space-exploration

Is there a matrix that shows the amount that goes between the planets? (And here, I consider a moon to be a "planet".)
I would like to see references for their claims for the "billions of tons" and the 500kg/yr
They both seem extreme.
 
  • Like
Likes 256bits
  • #5
Let’s assume 10^9 metric tons. Surface density of 2000kg/m^3. That gives a 793m cube removed per year. That seems big, but not obscenely big. It could even be right. One is integrating over a lot of impacts.

I would also check out LPSC extended abstracts.
 
  • #6
caz said:
Let’s assume 10^9 metric tons. Surface density of 2000kg/m^3. That gives a 793m cube removed per year. That seems big, but not obscenely big. It could even be right. One is integrating over a lot of impacts.

I would also check out LPSC extended abstracts.
I could believe the figures for ALL meteorites, but just for Martian material, a bit hard to swallow

The rate for ALL meteoritic material is an avg of 50,000 tonnes / year
Wiki at ~ 15,000 tonnes / yr is very low compared to other sites
 
  • Like
Likes 256bits
  • #8
davenn said:
I would like to see references for their claims for the "billions of tons" and the 500kg/yr
They both seem extreme.

The numbers all seem to be huge but intuition can be very misleading.
The mechanism for ejection from a planet has to be a collision as some other mass comes in and collides with the surface. I would imagine there would have to be unusual circumstances for this to happen as most of the Kinetic Energy of the incident mass would be shared.

If the incident mass were to arrive from the Kuiper belt, say, it could have enough energy to eject a similar size mass into a much lower orbit - to collide with another inner (rocky) planet. But you would think that there would be far fewer rocks ejected than arriving. These events would all be pretty newsworthy on Earth but probably no one would be aware of an ejection event.

Having a rarified atmosphere and moderate gravity, Mars would perhaps be a better candidate for supplying rocks to Earth than the other way round. The Moon, even better.
 

1. What is ejecta?

Ejecta is material that is thrown out or ejected from a planetary surface during an impact event, such as a meteorite impact or a volcanic eruption.

2. How is the rate of ejecta deposition between planets measured?

The rate of ejecta deposition between planets can be measured through various methods, such as analyzing impact craters and their size-frequency distribution, studying the composition and age of ejecta deposits, and using computer simulations to model the impact process.

3. What factors affect the rate of ejecta deposition?

The rate of ejecta deposition can be influenced by several factors, including the size and velocity of the impacting object, the target planet's surface composition and gravity, and the angle of impact.

4. Why is understanding the rate of ejecta deposition important?

Studying the rate of ejecta deposition can provide valuable insights into the history and geology of a planet, as well as the frequency and magnitude of impact events in the solar system. It can also help us better understand the potential hazards of impacts on Earth and other planets.

5. Are there any ongoing studies or missions focused on measuring the rate of ejecta deposition between planets?

Yes, there are several ongoing studies and missions that are dedicated to studying the rate of ejecta deposition, such as the Lunar Reconnaissance Orbiter and the Mars Reconnaissance Orbiter. These missions use advanced instruments and techniques to collect data and images of impact craters and ejecta deposits on the Moon and Mars.

Similar threads

  • Sci-Fi Writing and World Building
Replies
21
Views
1K
  • Astronomy and Astrophysics
Replies
5
Views
3K
  • Sci-Fi Writing and World Building
Replies
2
Views
2K
  • Astronomy and Astrophysics
2
Replies
48
Views
12K
  • Astronomy and Astrophysics
Replies
14
Views
14K
  • Science Fiction and Fantasy Media
Replies
8
Views
3K
  • Sci-Fi Writing and World Building
Replies
1
Views
3K
  • Beyond the Standard Models
Replies
18
Views
3K
Replies
89
Views
34K
Replies
22
Views
57K
Back
Top