<p>The smallest <strong>natural</strong> object that I know of that has been detected from an Earth-bound telescope is <a href="http://en.wikipedia.org/wiki/2011_CQ1" rel="nofollow">2011 CQ1</a>, a one-meter asteroid observed while <a href="http://en.wikipedia.org/wiki/Catalina_Sky_Survey" rel="nofollow">specifically looking for NEOs</a>.</p>

<p>As DeerHunter mentions in a comment, smaller artificial objects are identified and tracked, mostly by <a href="http://en.wikipedia.org/wiki/North_American_Aerospace_Defense_Command" rel="nofollow">NORAD</a> and some other national defence centers.</p>

CC BY-SA 3.0
2014-12-20T10:00:06.337Z
2014-12-20T10:00:06.337Z
dotancohen
<p>What is the minimum size of an object that can be observed from Earth with our most powerful telescope? </p>

<p>I understand that the answer depends on how far the object is from Earth. For the sake of  discussions let us consider distances less the orbit of Neptune.</p>

CC BY-SA 3.0
2014-12-19T12:38:35.827Z
About 10 cm in diameter at Low Earth Orbit. Capability for anything less is **classified**.
Deer Hunter
CC BY-SA 3.0
2014-12-19T13:02:36.463Z
wow! 10cm object from LEO? Amazing
Sathish
CC BY-SA 3.0
2014-12-19T19:01:00.587Z
Sathish is asking how small an object, at the distance of Neptune, can be resolved by a telescope on the earth's surface. Does anyone know what scope holds the current record for angular resolution? That and simple geometry would answer this question.
Wayfaring Stranger
CC BY-SA 3.0
2015-01-02T06:20:10.053Z
As Wayfaring Stranger says, the telescope with the lowest angular resolution can lead to the answer
Sathish
<telescope>
Smallest body that can be observed from Earth?
Sathish
# Smallest body that can be observed from Earth?

(Asked by: username_0 on 2014-12-19)

What is the minimum size of an object that can be observed from Earth with our most powerful telescope?

I understand that the answer depends on how far the object is from Earth. For the sake of discussions let us consider distances less the orbit of Neptune.

**Tags:** telescope

> **Comments:**
> **username_1**: About 10 cm in diameter at Low Earth Orbit. Capability for anything less is **classified**.  
> **username_0**: wow! 10cm object from LEO? Amazing  
> **username_2**: username_0 is asking how small an object, at the distance of Neptune, can be resolved by a telescope on the earth's surface. Does anyone know what scope holds the current record for angular resolution? That and simple geometry would answer this question.  
> **username_0**: As username_2 username_2 says, the telescope with the lowest angular resolution can lead to the answer  

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## 1 answers

### Answer by username_3 on 2014-12-20. Score: 3

The smallest **natural** object that I know of that has been detected from an Earth-bound telescope is [2011 CQ1](http://en.wikipedia.org/wiki/2011_CQ1), a one-meter asteroid observed while [specifically looking for NEOs](http://en.wikipedia.org/wiki/Catalina_Sky_Survey).

As username_1 mentions in a comment, smaller artificial objects are identified and tracked, mostly by [NORAD](http://en.wikipedia.org/wiki/North_American_Aerospace_Defense_Command) and some other national defence centers.


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