<p>Ganymed's Mars approach in 2176 is only moderately close: 4.4 times Mars's <a href="https://en.wikipedia.org/wiki/Hill_sphere" rel="nofollow noreferrer">Hill sphere</a> radius or 11 times the average Earth-Moon distance.
JPL <a href="https://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&amp;body_group=sb&amp;sstr=1036" rel="nofollow noreferrer">HORIZONS</a> predicts these heliocentric <a href="https://en.wikipedia.org/wiki/Orbital_elements" rel="nofollow noreferrer">orbital elements</a> (J2000) before and after the encounter:</p>
<div class="s-table-container">
<table class="s-table">
<thead>
<tr>
<th style="text-align: center;">Date</th>
<th style="text-align: center;">e</th>
<th style="text-align: center;">a</th>
<th style="text-align: center;">i</th>
<th style="text-align: center;">Ω</th>
<th style="text-align: center;">ω</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: center;">2176-12-06</td>
<td style="text-align: center;">0.525078</td>
<td style="text-align: center;">2.65922 au</td>
<td style="text-align: center;">27.7778°</td>
<td style="text-align: center;">212.085°</td>
<td style="text-align: center;">136.031°</td>
</tr>
<tr>
<td style="text-align: center;">2176-12-26</td>
<td style="text-align: center;">0.525093</td>
<td style="text-align: center;">2.65922 au</td>
<td style="text-align: center;">27.7772°</td>
<td style="text-align: center;">212.085°</td>
<td style="text-align: center;">136.025°</td>
</tr>
</tbody>
</table>
</div>
<p>The change is slight.</p>
<p>With respect to <a href="https://cneos.jpl.nasa.gov/glossary/PHA.html" rel="nofollow noreferrer">Potentially Hazardous Asteroid</a> criteria,
Ganymed is large enough (H = 9.4 &lt; 22)
but can't get close enough to Earth (MOID = 0.34 au &gt; 0.05 au).</p>

CC BY-SA 4.0
2021-01-08T15:07:48.737Z
2021-01-08T15:07:48.737Z
Mike G
<p>In 2176, the asteroid Ganymed will come as close as <a href="https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Ganymed;cad=1#cad" rel="nofollow noreferrer">0.02868 AU</a> (4,290,000 km / 2,670,000 mi) from Mars. That's pretty close to Mars imho. Can Mars' gravity alter Ganymed's orbit significantly in 2176 and if so, how much would it change? Just curious. Ganymed is a near-Earth object after all, and one at global killer size.</p>

CC BY-SA 4.0
2021-01-07T15:48:02.990Z
Would you mind adding a link to the source for this close pass?
Connor Garcia
CC BY-SA 4.0
2021-01-07T16:13:09.307Z
@ConnorGarcia Why, don't you believe me? If not, just assume it's a hypothetical encounter: "What would happen if Ganymed came as close as 0.02868 AU from Mars?" A source is unnecessary to answer the question (except for orbital direction which I dunno either).
Greenhorn
CC BY-SA 4.0
2021-01-07T16:20:03.127Z
I believe you, but I am curious if there is more information like the angle between their orbital paths or an exact date, etc...  More information might help narrow the scope of the answer.
Connor Garcia
CC BY-SA 4.0
2021-01-07T16:27:46.943Z
@ConnorGarcia https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Ganymed;cad=1#cad
Greenhorn
CC BY-SA 4.0
2021-01-08T17:03:01.693Z
How do you define a "significant" change?
jng224
<orbit><gravity><mass><near-earth-object>
Will 1036 Ganymed's orbit be changed by its close encounter with Mars in 2176?
Greenhorn
# Will 1036 Ganymed's orbit be changed by its close encounter with Mars in 2176?

(Asked by: username_0 on 2021-01-07)

In 2176, the asteroid Ganymed will come as close as [0.02868 AU](https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Ganymed;cad=1#cad) (4,290,000 km / 2,670,000 mi) from Mars. That's pretty close to Mars imho. Can Mars' gravity alter Ganymed's orbit significantly in 2176 and if so, how much would it change? Just curious. Ganymed is a near-Earth object after all, and one at global killer size.

**Tags:** orbit, gravity, mass, near-earth-object

> **Comments:**
> **username_1**: Would you mind adding a link to the source for this close pass?  
> **username_0**: @ConnorGarcia Why, don't you believe me? If not, just assume it's a hypothetical encounter: "What would happen if Ganymed came as close as 0.02868 AU from Mars?" A source is unnecessary to answer the question (except for orbital direction which I dunno either).  
> **username_1**: I believe you, but I am curious if there is more information like the angle between their orbital paths or an exact date, etc...  More information might help narrow the scope of the answer.  
> **username_0**: @ConnorGarcia https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Ganymed;cad=1#cad  
> **username_2**: How do you define a "significant" change?  

---

## 1 answers

### Answer by username_3 on 2021-01-08. Score: 4

Ganymed's Mars approach in 2176 is only moderately close: 4.4 times Mars's [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere) radius or 11 times the average Earth-Moon distance.
JPL [HORIZONS](https://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=1036) predicts these heliocentric [orbital elements](https://en.wikipedia.org/wiki/Orbital_elements) (J2000) before and after the encounter:

| Date | e | a | i | Ω | ω |
| --- | --- | --- | --- | --- | --- |
| 2176-12-06 | 0.525078 | 2.65922 au | 27.7778° | 212.085° | 136.031° |
| 2176-12-26 | 0.525093 | 2.65922 au | 27.7772° | 212.085° | 136.025° |

The change is slight.

With respect to [Potentially Hazardous Asteroid](https://cneos.jpl.nasa.gov/glossary/PHA.html) criteria,
Ganymed is large enough (H = 9.4 < 22)
but can't get close enough to Earth (MOID = 0.34 au > 0.05 au).


---

