<p>2016 HO3 does not really orbit Earth.
It orbits the Sun in such a way that it happens to loop around Earth at distances of
<a href="http://www.skyandtelescope.com/astronomy-news/2016-ho3-a-new-minimoon-for-the-earth/" rel="noreferrer">0.1 to 0.25 AU</a>.
Earth's gravitational sphere of influence is much smaller,
about 0.01 AU at most; outside that radius, the Sun is the dominant attractor.</p>

<p>The Minor Planet Center has an
<a href="http://www.minorplanetcenter.net/db_search/show_orbit?utf8=%E2%9C%93&amp;object_id=2016+HO3&amp;epoch=2016-07-31.0&amp;number=469219&amp;designation=2016+HO3&amp;name=&amp;peri=307.2276436&amp;m=297.53221&amp;node=66.5132056&amp;incl=7.7714415&amp;e=0.104143476&amp;a=1.00123&amp;commit=Interactive+Orbit+Sketch" rel="noreferrer">orbital diagram</a>
which you can examine in 3D.
Earth's orbit is light blue.
2016 HO3's orbit is orange to the north of Earth's orbital plane and medium blue to the south.
A dark gray line passes through the Sun and the asteroid's perihelion and aphelion.
It's a moderately eccentric, moderately inclined orbit around the Sun with a 1.00 year period.</p>

<p>In the course of its solar orbit, the asteroid alternately moves slower, outside, and to the north of Earth's orbit; and faster, inside, and to the south.
In a rotating frame of reference fixed on Earth,
as in the <a href="https://www.youtube.com/watch?v=SbbAnVU4rmY" rel="noreferrer">video</a> you've seen,
this looks like an oddly shaped, highly inclined, retrograde loop around Earth, but it is not due to Earth's gravity.
Earth's slight influence helps to maintain this coincidental pattern
but is not nearly enough to capture the asteroid.</p>

CC BY-SA 3.0
2016-07-05T23:16:16.397Z
2016-07-05T23:16:16.397Z
Mike G
<p>It's not true; this object is not a moon of Earth's.</p>

<p><a href="http://www.jpl.nasa.gov/news/news.php?feature=6537" rel="noreferrer">Here's a NASA/JPL announcement</a> of it. <a href="https://en.wikipedia.org/wiki/(469219)_2016_HO3" rel="noreferrer">2016 HO3</a> is the "name" being used for it at the moment.</p>

<p>They're calling it a "quasi-moon". It's in an orbit that is in resonance with Earth's but is not permanently bound. (It's not the first object to be found with such properties too.)</p>

CC BY-SA 3.0
2016-07-05T07:52:58.317Z
Its current orbit is charted on the Wikipedia page I linked. These orbits are quite interesting really. But I stress it is **not** a moon of Earth's. People tend to write "quasi moon" etc. on their press releases to generate public interest.
Andy
CC BY-SA 3.0
2016-07-05T07:57:13.447Z
@Andy-what makes this object different than 2016 H03? The orbit right? <https://en.wikipedia.org/wiki/3753_Cruithne>
user5434678
CC BY-SA 3.0
2016-07-05T08:07:00.417Z
Right, Cruithne is also in an orbit that overlaps to Earth's though it's more eccentric than 2016 HO3. There are quite a lot of asteroids in these "horseshoe" orbits. (As far as I know those ones never get really close to Earth.)
Andy
CC BY-SA 3.0
2016-07-05T08:10:17.180Z
This statement by space.com    <http://www.space.com/33185-earth-quasi-moon-asteroid-2016-ho3.html> says the object is orbiting the sun right next to earth traveling at a speed similar to earths. This seems to make no sense due to its size 100ft or so.... and if the object is that close to earth it would of been captured in earth's gravity field along time ago, if not when will earth capture this asteroid forever and pronounce it a moon, or is this exactly what has happened and now they are announcing it?
user5434678
CC BY-SA 3.0
2016-07-05T08:19:54.463Z
It's a long way outside Earth's [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere) so I'd have trouble defining it as a true moon of Earth's. And that's all I think I can really say on this matter.
Andy
CC BY-SA 3.0
2016-07-06T02:40:33.307Z
@Andy-For it to be considered a Moon it has to be in orbit around a planet other wise it would be labeled a asteroid.Do you know its current orbit? And if it happens to be a permanent resident captured by earth's gravity shouldn't it be called a NEO or Trojan. Astrophysics really need to set a standard for what can be labeled a moon, if not by size how about a distance limit or the time spent in a planet's gravity field within one rotation of its star.
user5434678
CC BY-SA 3.0
2016-07-05T07:37:58.683Z
2016-07-05T07:37:58.683Z
Andy
<p>Several sites claim NASA has confirmed a second moon orbiting earth. This is the <strong>Asteroid 2016 HO3</strong>. One source states The newfound quasi-satellite/moon-2016 HO3, is likely larger than 120 feet (40 m) and smaller than 300 feet (100 m).</p>

<p><a href="http://www.physics-astronomy.com/2016/06/nasa-just-confirmed-that-earth-has-new.html#.V3tdaNIrLIU" rel="nofollow">http://www.physics-astronomy.com/2016/06/nasa-just-confirmed-that-earth-has-new.html#.V3tdaNIrLIU</a> </p>

<p><strong>Question</strong>
Is this claim true circling the internet and can anyone post a link from NASAs offical web site to conclude this is true?</p>

CC BY-SA 3.0
2016-07-05T12:33:06.727Z
The article says very clearly that it is a **quasi-**moon.  "It's that simple." It's not a moon.
Fattie
CC BY-SA 3.0
2016-07-05T17:29:57.667Z
For future reference, you should avoid using the word "theory" in the context you did here; a theory is a very well tested hypothesis in the field of science.
nataliaeire
CC BY-SA 3.0
2016-07-05T23:28:20.167Z
Medias like to play with words, so be careful. ;)
Archa
CC BY-SA 4.0
2019-04-08T03:14:13.723Z
Related: [How was Earth's “quasi-satellite” 2016 HO3 “first spotted” and it's orbit determined?](https://astronomy.stackexchange.com/q/16303/7982) and also [What (actually) is a 1:1 resonance, and is 2016 HO3 in one with the Earth?](https://space.stackexchange.com/q/16772/12102)
uhoh
CC BY-SA 4.0
2019-04-08T06:28:26.053Z
"That's no moon"—Kenobi, O.
PM 2Ring
<orbit><near-earth-object><the-moon><asteroids>
Has NASA confirmed earth now has a second moon orbiting the planet?
user5434678
# Has NASA confirmed earth now has a second moon orbiting the planet?

(Asked by: username_0 on 2016-07-05)

Several sites claim NASA has confirmed a second moon orbiting earth. This is the **Asteroid 2016 HO3**. One source states The newfound quasi-satellite/moon-2016 HO3, is likely larger than 120 feet (40 m) and smaller than 300 feet (100 m).

<http://www.physics-astronomy.com/2016/06/nasa-just-confirmed-that-earth-has-new.html#.V3tdaNIrLIU>

**Question**
Is this claim true circling the internet and can anyone post a link from NASAs offical web site to conclude this is true?

**Tags:** orbit, near-earth-object, the-moon, asteroids

> **Comments:**
> **username_1**: The article says very clearly that it is a **quasi-**moon.  "It's that simple." It's not a moon.  
> **username_2**: For future reference, you should avoid using the word "theory" in the context you did here; a theory is a very well tested hypothesis in the field of science.  
> **username_3**: Medias like to play with words, so be careful. ;)  
> **username_4**: Related: [How was Earth's “quasi-satellite” 2016 HO3 “first spotted” and it's orbit determined?](https://astronomy.stackexchange.com/q/16303/7982) and also [What (actually) is a 1:1 resonance, and is 2016 HO3 in one with the Earth?](https://space.stackexchange.com/q/16772/12102)  
> **username_5**: "That's no moon"—Kenobi, O.  

---

## 2 answers

### Answer by username_7 on 2016-07-05. Score: 5 | Accepted answer

It's not true; this object is not a moon of Earth's.

[Here's a NASA/JPL announcement](http://www.jpl.nasa.gov/news/news.php?feature=6537) of it. [2016 HO3](https://en.wikipedia.org/wiki/(469219)_2016_HO3) is the "name" being used for it at the moment.

They're calling it a "quasi-moon". It's in an orbit that is in resonance with Earth's but is not permanently bound. (It's not the first object to be found with such properties too.)

> **Comments:**
> **username_7**: Its current orbit is charted on the Wikipedia page I linked. These orbits are quite interesting really. But I stress it is **not** a moon of Earth's. People tend to write "quasi moon" etc. on their press releases to generate public interest.  
> **username_0**: @username_7-what makes this object different than 2016 H03? The orbit right? <https://en.wikipedia.org/wiki/3753_Cruithne>  
> **username_7**: Right, Cruithne is also in an orbit that overlaps to Earth's though it's more eccentric than 2016 HO3. There are quite a lot of asteroids in these "horseshoe" orbits. (As far as I know those ones never get really close to Earth.)  
> **username_0**: This statement by space.com    <http://www.space.com/33185-earth-quasi-moon-asteroid-2016-ho3.html> says the object is orbiting the sun right next to earth traveling at a speed similar to earths. This seems to make no sense due to its size 100ft or so.... and if the object is that close to earth it would of been captured in earth's gravity field along time ago, if not when will earth capture this asteroid forever and pronounce it a moon, or is this exactly what has happened and now they are announcing it?  
> **username_7**: It's a long way outside Earth's [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere) so I'd have trouble defining it as a true moon of Earth's. And that's all I think I can really say on this matter.  
> **username_0**: @username_7-For it to be considered a Moon it has to be in orbit around a planet other wise it would be labeled a asteroid.Do you know its current orbit? And if it happens to be a permanent resident captured by earth's gravity shouldn't it be called a NEO or Trojan. Astrophysics really need to set a standard for what can be labeled a moon, if not by size how about a distance limit or the time spent in a planet's gravity field within one rotation of its star.  

---

### Answer by username_6 on 2016-07-05. Score: 5

2016 HO3 does not really orbit Earth.
It orbits the Sun in such a way that it happens to loop around Earth at distances of
[0.1 to 0.25 AU](http://www.skyandtelescope.com/astronomy-news/2016-ho3-a-new-minimoon-for-the-earth/).
Earth's gravitational sphere of influence is much smaller,
about 0.01 AU at most; outside that radius, the Sun is the dominant attractor.

The Minor Planet Center has an
[orbital diagram](http://www.minorplanetcenter.net/db_search/show_orbit?utf8=%E2%9C%93&object_id=2016+HO3&epoch=2016-07-31.0&number=469219&designation=2016+HO3&name=&peri=307.2276436&m=297.53221&node=66.5132056&incl=7.7714415&e=0.104143476&a=1.00123&commit=Interactive+Orbit+Sketch)
which you can examine in 3D.
Earth's orbit is light blue.
2016 HO3's orbit is orange to the north of Earth's orbital plane and medium blue to the south.
A dark gray line passes through the Sun and the asteroid's perihelion and aphelion.
It's a moderately eccentric, moderately inclined orbit around the Sun with a 1.00 year period.

In the course of its solar orbit, the asteroid alternately moves slower, outside, and to the north of Earth's orbit; and faster, inside, and to the south.
In a rotating frame of reference fixed on Earth,
as in the [video](https://www.youtube.com/watch?v=SbbAnVU4rmY) you've seen,
this looks like an oddly shaped, highly inclined, retrograde loop around Earth, but it is not due to Earth's gravity.
Earth's slight influence helps to maintain this coincidental pattern
but is not nearly enough to capture the asteroid.


---

