<p>From the website quoted in your question, the craters pictured here are on the order of 10s of meters wide:</p>
<blockquote>
<p>The small craters were likely formed when high-speed blocks of rock
were thrown out by a much larger impact (about 10-kilometers in
diameter) and fell back to the ground.</p>
</blockquote>
<p>The primary impact was to the right of this picture, and the secondary rock blocks were traveling from right to left.  When they landed, the resultant ejecta continued to travel left of the impacts.  We see similar physics from the track and field &quot;long jump&quot; landing where the ejected sand from the athlete's landing in the pit travels in the same direction as the jumper.</p>
<p>If we panned to the right of this picture, we would eventually expect to see symmetric crater/ejecta pairs on the opposite side of the primary impact crater with their ejecta to the right of the craters rather than the left.  Very high velocity impacts, like the primary impact, form nearly symmetrical ejecta cones, even if their impact angles are low.</p>

CC BY-SA 4.0
2021-09-23T15:32:36.693Z
2021-09-23T15:32:36.693Z
Connor Garcia
<p>I was browsing the HiRISE images and found <a href="https://www.uahirise.org/ESP_050250_1915" rel="nofollow noreferrer">this one</a></p>
<p><a href="https://i.sstatic.net/MX8lX.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MX8lX.jpg" alt="enter image description here" /></a></p>
<p>In this image, there are several craters with an ejecta blanket that is to the left of the crater. How did all the ejecta blankets end up on the same side?</p>

<mars><crater>
Why are all the ejecta blankets in the same direction in this image?
usernumber
# Why are all the ejecta blankets in the same direction in this image?

(Asked by: username_0 on 2021-09-23)

I was browsing the HiRISE images and found [this one](https://www.uahirise.org/ESP_050250_1915)

[![enter image description here](https://i.sstatic.net/MX8lX.jpg)](https://i.sstatic.net/MX8lX.jpg)

In this image, there are several craters with an ejecta blanket that is to the left of the crater. How did all the ejecta blankets end up on the same side?

**Tags:** mars, crater


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## 1 answers

### Answer by username_1 on 2021-09-23. Score: 1 | Accepted answer

From the website quoted in your question, the craters pictured here are on the order of 10s of meters wide:

> The small craters were likely formed when high-speed blocks of rock
> were thrown out by a much larger impact (about 10-kilometers in
> diameter) and fell back to the ground.

The primary impact was to the right of this picture, and the secondary rock blocks were traveling from right to left. When they landed, the resultant ejecta continued to travel left of the impacts. We see similar physics from the track and field "long jump" landing where the ejected sand from the athlete's landing in the pit travels in the same direction as the jumper.

If we panned to the right of this picture, we would eventually expect to see symmetric crater/ejecta pairs on the opposite side of the primary impact crater with their ejecta to the right of the craters rather than the left. Very high velocity impacts, like the primary impact, form nearly symmetrical ejecta cones, even if their impact angles are low.


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