<blockquote>
<p>Does a lunar occultation of Mars happen twice a year?</p>
</blockquote>
<p>No, in the sense that the number of lunar occultations of Mars per year is quite variable and not always two.</p>
<p>I do not have a reference handy, but I am sure that there are some years with no occultations.</p>
<p>And we can see that in other years the number can be both less than and much greater than two:</p>
<ul>
<li>In 2019, there was one lunar occultation of Mars according to the <a href="http://asa.hmnao.com/SecA/olist19.html" rel="nofollow noreferrer">Astronomical Almanac Online 2019 Lunar Occultations</a>.</li>
<li>In 2020, <em>there were five!</em> See <a href="http://asa.hmnao.com/SecA/olist20.html" rel="nofollow noreferrer">2020 Lunar Occultations</a>.</li>
</ul>

CC BY-SA 4.0
2020-12-22T05:02:23.213Z
Well this seems quite conclusive, thanks! I've edited a bit to make it clearer (to me at least) but feel free to edit further or roll back.
uhoh
CC BY-SA 4.0
2020-12-22T01:56:10.453Z
2020-12-22T05:00:00.393Z
2020-12-22T05:00:00.393Z
JohnHoltz
<h2>Moon-Mars Occultations occur every 174 to 188 Days</h2>
<p>Average worldwide interval (based on 500 years) between occultations is 180 days. In a calendar year, zero to five occultations can occur. Annual occultation doesn't occur on average about once in 15 years. (<a href="http://climate.gi.alaska.edu/Curtis/astro3.html" rel="nofollow noreferrer">Source</a>)</p>
<p>Moon will occult Mars 3 times in 2021. <a href="http://www.lunar-occultations.com/iota/planets/mars.png" rel="nofollow noreferrer">Here is the map</a></p>

CC BY-SA 4.0
2020-12-22T06:27:24.943Z
2020-12-22T06:27:24.943Z
Nilay Ghosh
<p>The Space Exploration SE question <a href="https://space.stackexchange.com/q/49219/12102">When our Moon is hiding Mars, is it possible to create a radio communication between Earth and Mars?</a> links to this short article in the popular press <a href="https://massivesci.com/notes/mars-moon-occultation-eclipse-february-2020/" rel="nofollow noreferrer">Mars is hiding behind the Moon this morning</a> with the sub-headline</p>
<blockquote>
<p>It’s a twice-a-year occultation; like the eclipse, but it’s Mars, and there’s no shadow</p>
</blockquote>
<p>As answer(s) to the question mention, the Moon is smaller than Earth so an occultation would not be visible everywhere on Earth, so let's just consider it an occultation if it happens <em>anywhere</em> on Earth.</p>
<p><strong>Question:</strong> Does a lunar occultation of Mars happen twice a year? Is the Moon's diameter big enough and it's orbit's inclination with respect to the ecliptic small enough that it can pass between Mars and some place on Earth twice a year?</p>

<the-moon><mars><occultation>
Does a lunar occultation of Mars happen twice a year?
uhoh
# Does a lunar occultation of Mars happen twice a year?

(Asked by: username_0 on 2020-12-21)

The Space Exploration SE question [When our Moon is hiding Mars, is it possible to create a radio communication between Earth and Mars?](https://space.stackexchange.com/q/49219/12102) links to this short article in the popular press [Mars is hiding behind the Moon this morning](https://massivesci.com/notes/mars-moon-occultation-eclipse-february-2020/) with the sub-headline

> It’s a twice-a-year occultation; like the eclipse, but it’s Mars, and there’s no shadow

As answer(s) to the question mention, the Moon is smaller than Earth so an occultation would not be visible everywhere on Earth, so let's just consider it an occultation if it happens *anywhere* on Earth.

**Question:** Does a lunar occultation of Mars happen twice a year? Is the Moon's diameter big enough and it's orbit's inclination with respect to the ecliptic small enough that it can pass between Mars and some place on Earth twice a year?

**Tags:** the-moon, mars, occultation


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## 2 answers

### Answer by username_1 on 2020-12-22. Score: 2 | Accepted answer

> Does a lunar occultation of Mars happen twice a year?

No, in the sense that the number of lunar occultations of Mars per year is quite variable and not always two.

I do not have a reference handy, but I am sure that there are some years with no occultations.

And we can see that in other years the number can be both less than and much greater than two:

* In 2019, there was one lunar occultation of Mars according to the [Astronomical Almanac Online 2019 Lunar Occultations](http://asa.hmnao.com/SecA/olist19.html).
* In 2020, *there were five!* See [2020 Lunar Occultations](http://asa.hmnao.com/SecA/olist20.html).

> **Comments:**
> **username_0**: Well this seems quite conclusive, thanks! I've edited a bit to make it clearer (to me at least) but feel free to edit further or roll back.  

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### Answer by username_2 on 2020-12-22. Score: 2

## Moon-Mars Occultations occur every 174 to 188 Days

Average worldwide interval (based on 500 years) between occultations is 180 days. In a calendar year, zero to five occultations can occur. Annual occultation doesn't occur on average about once in 15 years. ([Source](http://climate.gi.alaska.edu/Curtis/astro3.html))

Moon will occult Mars 3 times in 2021. [Here is the map](http://www.lunar-occultations.com/iota/planets/mars.png)


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