<p><a href="https://www.space.com/the-universe/asteroids/james-webb-space-telescope-finds-smallest-asteroids-ever-seen-between-mars-and-jupiter" rel="nofollow noreferrer">It does.</a> As a complementary science.</p>
<p>While JWST observes galaxies and stars far far away, small bodies of Solar System are a &quot;foreground noise&quot;. The closest asteroids to Earth can be moving too fast on the sky (have too fast angular velocity), and smear to dim unrecognizable tracks because of long exposures. But asteroids in Main asteroid belt are distinguishable.</p>
<p>The authors in the link found 138 <strong>new</strong> asteroids analysing 10000 images made during the study of TRAPPIST-1 star. It's more than they expected, as they say.</p>
<p>So yes, despite the small field of view JWST can be used to study asteroids. Not as dedicated program, maybe, but as complementary science (the future <a href="https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope" rel="nofollow noreferrer">NGR</a> space telescope will have much wider field of view for example).</p>
<p>About &quot;estimate populations that can endanger Earth&quot; - looks like JWST can help to estimate populations of the smallest and dimmest asteroids, but mostly in Main belt. It's not suited to search for asteroids that can actually endanger Earth. Also because of the short &quot;observation arcs&quot; on JWST images the orbits of new asteroids will have high uncertainties. For many of the new asteroids it can be impossible to say are they &quot;potentially dangerous&quot; or not, and organising the follow-up observations to refine the trajectories can be hard because the targets are very dim.</p>
<p>There is an enother infrared space telescope <a href="https://en.wikipedia.org/wiki/NEO_Surveyor" rel="nofollow noreferrer">NEO Surveyor</a> being developed explicitly for this. It will have a large field of view 11.5 square degrees - about 50 times more than Moon's area as seen from Earth. It will continuously observe the sectors where most NEOs can be found.</p>

CC BY-SA 4.0
2024-12-11T09:00:29.527Z
2024-12-11T10:59:29.253Z
2024-12-11T10:59:29.253Z
Heopps
<p>the James Webb Telescope is incredibly sensitive to warm objects. But it has a lot more important things to do than a survey of the outer solar system looking for objects that might fall close to Earth.</p>
<p>But will they ever use it to examine just a sample of the empty solar system to get an estimate of how many NEO's there actually are?</p>

CC BY-SA 4.0
2024-12-05T16:31:19.857Z
Such data exists on every JWST image.  Probably, someone is looking at them.
eshaya
CC BY-SA 4.0
2024-12-05T17:06:32.197Z
It's hard to track bodies in the outer Solar System and determine their orbits, because they are hard to see and they move slowly. A body with mean orbital radius $a$ au has period $a\sqrt{a}$ years, so at 50 au the period is ~350 years. So an accurate comprehensive survey would be tricky...
PM 2Ring
CC BY-SA 4.0
2024-12-05T17:21:09.967Z
Virtually all (~94%) of the Near-Earth Objects come from within 3 au, only about 6% is thought to come from the Kuiper Belt [Morbidelli et al 2002](https://www.boulder.swri.edu/~bottke/Reprints/Morbidelli-etal_2002_AstIII_NEOs.pdf). Also JWST has a tiny field of view and makes a terrible survey telescope.
astrosnapper
CC BY-SA 4.0
2024-12-05T19:10:19.333Z
FWIW, Horizons currently knows 237 bodies with mean orbital radius a: 0.99<a<1.01 au. https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27A%3E0.99%3BA%3C1.01%27 The query takes ~25 seconds because it searches through its small body database of ~1.4 million bodies.
PM 2Ring
CC BY-SA 4.0
2024-12-05T21:32:39.883Z
@PM2Ring OMG! .01 au Is less than a million miles away! 237  of them? That's terrible! I'm suprised they aren't raining down on us.
Miss Understands
CC BY-SA 4.0
2024-12-05T21:52:24.577Z
A lot of them are companion bodies to Earth in resonant orbits with us. Horseshoe orbits, tadpole orbits, and bean-shaped quasisatellite orbits aren't really a danger to us because they're in orbit with us almost as much as the Moon is.
Darth Pseudonym
CC BY-SA 4.0
2024-12-06T06:47:15.610Z
A solar distance of 1AU does not mean near Earth either - it could be 2AU from us. A million kilometers is also a journey 25 times around the Eartn or twice to the moon and back.
planetmaker
<james-webb-space-telescope><near-earth-object><outer-solar-system>
Will Webb observe a sample of the outer solar system to estimate the population of objects that might endanger Earth?
Miss Understands
# Will Webb observe a sample of the outer solar system to estimate the population of objects that might endanger Earth?

(Asked by: username_0 on 2024-12-05)

the James Webb Telescope is incredibly sensitive to warm objects. But it has a lot more important things to do than a survey of the outer solar system looking for objects that might fall close to Earth.

But will they ever use it to examine just a sample of the empty solar system to get an estimate of how many NEO's there actually are?

**Tags:** james-webb-space-telescope, near-earth-object, outer-solar-system
> **Comments:**
> **username_1**: Such data exists on every JWST image.  Probably, someone is looking at them.  
> **username_2**: It's hard to track bodies in the outer Solar System and determine their orbits, because they are hard to see and they move slowly. A body with mean orbital radius $a$ au has period $a\sqrt{a}$ years, so at 50 au the period is ~350 years. So an accurate comprehensive survey would be tricky...  
> **username_3**: Virtually all (~94%) of the Near-Earth Objects come from within 3 au, only about 6% is thought to come from the Kuiper Belt [Morbidelli et al 2002](https://www.boulder.swri.edu/~bottke/Reprints/Morbidelli-etal_2002_AstIII_NEOs.pdf). Also JWST has a tiny field of view and makes a terrible survey telescope.  
> **username_2**: FWIW, Horizons currently knows 237 bodies with mean orbital radius a: 0.99<a<1.01 au. https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27A%3E0.99%3BA%3C1.01%27 The query takes ~25 seconds because it searches through its small body database of ~1.4 million bodies.  
> **username_0**: @PM2Ring OMG! .01 au Is less than a million miles away! 237  of them? That's terrible! I'm suprised they aren't raining down on us.  
> **username_4**: A lot of them are companion bodies to Earth in resonant orbits with us. Horseshoe orbits, tadpole orbits, and bean-shaped quasisatellite orbits aren't really a danger to us because they're in orbit with us almost as much as the Moon is.  
> **username_5**: A solar distance of 1AU does not mean near Earth either - it could be 2AU from us. A million kilometers is also a journey 25 times around the Eartn or twice to the moon and back.  

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## 1 answers

### Answer by username_6 on 2024-12-11. Score: 4

[It does.](https://www.space.com/the-universe/asteroids/james-webb-space-telescope-finds-smallest-asteroids-ever-seen-between-mars-and-jupiter) As a complementary science.

While JWST observes galaxies and stars far far away, small bodies of Solar System are a "foreground noise". The closest asteroids to Earth can be moving too fast on the sky (have too fast angular velocity), and smear to dim unrecognizable tracks because of long exposures. But asteroids in Main asteroid belt are distinguishable.

The authors in the link found 138 **new** asteroids analysing 10000 images made during the study of TRAPPIST-1 star. It's more than they expected, as they say.

So yes, despite the small field of view JWST can be used to study asteroids. Not as dedicated program, maybe, but as complementary science (the future [NGR](https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope) space telescope will have much wider field of view for example).

About "estimate populations that can endanger Earth" - looks like JWST can help to estimate populations of the smallest and dimmest asteroids, but mostly in Main belt. It's not suited to search for asteroids that can actually endanger Earth. Also because of the short "observation arcs" on JWST images the orbits of new asteroids will have high uncertainties. For many of the new asteroids it can be impossible to say are they "potentially dangerous" or not, and organising the follow-up observations to refine the trajectories can be hard because the targets are very dim.

There is an enother infrared space telescope [NEO Surveyor](https://en.wikipedia.org/wiki/NEO_Surveyor) being developed explicitly for this. It will have a large field of view 11.5 square degrees - about 50 times more than Moon's area as seen from Earth. It will continuously observe the sectors where most NEOs can be found.


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