Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

The smallest object you've ever observed

  • Please log in to reply
20 replies to this topic

#1 Spaceman Spiff

Spaceman Spiff

    Explorer 1

  • -----
  • topic starter
  • Posts: 61
  • Joined: 27 Dec 2020

Posted 24 January 2021 - 08:52 PM

From comets, to asteroids, to moons, what are some of the smallest astronomical objects you've seen? 


Edited by Spaceman Spiff, 25 January 2021 - 07:12 PM.

  • happylimpet likes this

#2 Dynan

Dynan

    Fly Me to the Moon

  • *****
  • Vendors
  • Posts: 5,032
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 24 January 2021 - 09:08 PM

Does Hoag's Object count? - https://en.wikipedia...i/Hoag's_Object

 

2020_0616_HOAGS_OBJ_PI_ST_1_SM_2.jpg

 

Strange thing about Hoag's Object is that it is a VERY unusual formation for a galaxy...yet there is ANOTHER visible through the ring of Hoag's Object. (I couldn't get it but it's there in the Wiki pic.)

 

Actually the smallest thing I've seen since I started astronomy and AP is my bank balance.


Edited by Dynan, 24 January 2021 - 09:15 PM.

  • payner, Mirzam, AstroFrankMontana and 6 others like this

#3 cytan299

cytan299

    Viking 1

  • *****
  • Posts: 947
  • Joined: 24 Nov 2014

Posted 24 January 2021 - 10:34 PM

Well, I was photo bombed by an asteroid called Bali in my photo of the Pleiades on 21 Dec 2019. 

 

small_marked_M45.jpg

 

Here's the "proof" that it is Bali from Cartes du Ciel:

 

asteroid_rotated.jpg

 

You can see the linear smudge after I stacked all the frames for that evening, all (28 frames*5 min) = 140 min of it.

 

In the next post, you can see the movie of Bali crossing the sky when I zoom in and make a movie out of each 5 min frame.

 

cytan


  • Dynan, vdog, Enceladust and 1 other like this

#4 cytan299

cytan299

    Viking 1

  • *****
  • Posts: 947
  • Joined: 24 Nov 2014

Posted 24 January 2021 - 10:35 PM

Here's the movie of Bali crossing the sky  which is strongly cropped to meet file size requirements:

 

bali_optim1.gif

 

cytan


Edited by cytan299, 24 January 2021 - 10:41 PM.

  • chrysalis, emh52, Mr. Krabappel and 4 others like this

#5 Dynan

Dynan

    Fly Me to the Moon

  • *****
  • Vendors
  • Posts: 5,032
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 24 January 2021 - 10:50 PM

Nicely done!


  • Spaceman Spiff likes this

#6 Allan Wade

Allan Wade

    Aurora

  • *****
  • Posts: 4,912
  • Joined: 27 Jan 2013
  • Loc: Newcastle, Australia

Posted 25 January 2021 - 05:35 AM

Deimos at 12km in diameter.  Halley’s Comet at 11km. I’m sure many of the other comets I’ve seen are smaller. I’ve observed thousands of meteors the size of a speck of dirt. Does that count.


  • happylimpet, Dynan and Spaceman Spiff like this

#7 happylimpet

happylimpet

    Fly Me to the Moon

  • *****
  • Posts: 5,458
  • Joined: 29 Sep 2013
  • Loc: Southampton, UK

Posted 25 January 2021 - 05:47 AM

Outside the atmosphere, asteroid 2012DA14 is 45 metres across and I watched that fly by. Made a movie too, but dont seem to have put it online.

 

Here's 2003YT1 though, at 1km size, flying past Polaris:

 

https://vimeo.com/308000018


  • Allan Wade, chrysalis, emh52 and 3 others like this

#8 Stefano Delmonte

Stefano Delmonte

    Vostok 1

  • -----
  • Posts: 176
  • Joined: 17 Aug 2020
  • Loc: Salou (Spain) & Broni (Italy)

Posted 25 January 2021 - 06:34 PM

I think Allan has mentioned the smallest object nearly everyone has seen: dust entering the atmosphere, a meteor.  But if you mean through a telescope, I say Vesta the asteroid and I'll try Mars' moons in 2022, that I consider the smallest object visible at an eyepiece.

 

Ste


  • Dynan and Spaceman Spiff like this

#9 rhetfield

rhetfield

    Apollo

  • *****
  • Posts: 1,364
  • Joined: 14 Aug 2019
  • Loc: Suburban Chicago, IL, USA

Posted 25 January 2021 - 07:09 PM

The bat that flew through my fov one night.
  • happylimpet and Spaceman Spiff like this

#10 Alan French

Alan French

    Night Owl

  • *****
  • Posts: 6,107
  • Joined: 28 Jan 2005
  • Loc: Upstate NY

Posted 25 January 2021 - 07:26 PM

It may not count, but the most surprising thing I ever observed was the 2 - 3mm diameter tether connecting "Ralph" and "Norton," the two satellites making up the Tether Physics and Survivability Experiment (TiPS).  

 

The two satellites required binoculars, and I was very surprised to see light reflections caused the tether to sparkle and become "visible." I observed it several times. 

 

Otherwise, probably Deimos. 

 

Clear skies, Alan 


  • Dave Mitsky, happylimpet, Dynan and 1 other like this

#11 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 95,592
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 25 January 2021 - 09:20 PM

The smallest non-terrestrial objects that I've observed have been satellites, quite a few of them over the years.  The smallest non-man-made objects would be Deimos and various asteroids, again quite a few.  I've observed many comets too but their nuclei are impossible to resolve.  Even their pseudonuclei might be fairly large in size and their comae much larger, not to mention tails stretching for many thousands of kilometers.


  • Spaceman Spiff likes this

#12 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 95,592
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 25 January 2021 - 09:42 PM

I've observed meteors through binoculars and telescopes on occasion so they would be the smallest natural objects that I've seen through an eyepiece or eyepieces.


  • Spaceman Spiff likes this

#13 Napp

Napp

    Mercury-Atlas

  • *****
  • Posts: 2,808
  • Joined: 26 Jul 2015
  • Loc: Northeast Florida, USA

Posted 25 January 2021 - 09:54 PM

Probably the smallest would be meteors and satellites through binoculars and scopes.  One night I watched a faint satellite appear from the left edge of the eyepiece field and slowly approach Jupiter's Galilean moons in a line.  It just missed transiting the first moon in the line and continued on just above Jupiter itself.  It was just really neat to watch the whole episode slowly play out.  The smallest object I was able to intentionally locate with a scope so far is probably Deimos.  I located it using an occulting eyepiece shortly after the Mars opposition this year.  Wasn't able to spot Phobos, though.


Edited by Napp, 25 January 2021 - 10:19 PM.

  • Dave Mitsky and Spaceman Spiff like this

#14 emh52

emh52

    Mariner 2

  • -----
  • Posts: 276
  • Joined: 14 Sep 2014
  • Loc: Arizona

Posted 25 January 2021 - 11:52 PM

Asteroid 2014 J025 that made a close pass to Earth on April 20 2017    this is the movement in 5 minutes with closest approach of 1 M miles- the asteroid is 650 m in diameter  

Attached Thumbnails

  • Asteroid 2014 J025.jpg

  • Dave Mitsky, happylimpet and Dynan like this

#15 Zorbathegeek

Zorbathegeek

    Vostok 1

  • -----
  • Posts: 131
  • Joined: 19 Jul 2019

Posted 26 January 2021 - 02:32 AM

46p/Wirtanen* at around 1.2km. However, my ongoing goal is to observe small asteroids. So far, in the lead for smallness is (135) Hertha, at around 77km. I'm looking forward to trying to find NEO (7482) 1994 PC1, which will be 10th magnitude next January and between 1-3 km.

 

Ray.

 

* Actually. do comets count? What we see is the gas cloud which is way larger than the invisible core.


Edited by Zorbathegeek, 26 January 2021 - 03:32 AM.


#16 RadioAstronomer

RadioAstronomer

    Ranger 4

  • *****
  • Posts: 347
  • Joined: 13 Jun 2018
  • Loc: Tucson, AZ

Posted 28 January 2021 - 03:00 AM

2020 CD3 aka Earth's transient minimoom. It's 1.2m in diameter.


  • happylimpet and Dynan like this

#17 happylimpet

happylimpet

    Fly Me to the Moon

  • *****
  • Posts: 5,458
  • Joined: 29 Sep 2013
  • Loc: Southampton, UK

Posted 28 January 2021 - 03:57 AM

46p/Wirtanen* at around 1.2km. However, my ongoing goal is to observe small asteroids. So far, in the lead for smallness is (135) Hertha, at around 77km. I'm looking forward to trying to find NEO (7482) 1994 PC1, which will be 10th magnitude next January and between 1-3 km.

 

Ray.

 

* Actually. do comets count? What we see is the gas cloud which is way larger than the invisible core.

I would only really count it if observed so far from perihelion that the coma/tail is insignificant and the bare nucleus is observed.


  • Zorbathegeek likes this

#18 t.r.

t.r.

    Fly Me to the Moon

  • ****-
  • Posts: 6,261
  • Joined: 14 Feb 2008
  • Loc: 1123,6536,5321

Posted 29 January 2021 - 03:34 PM

It may not count, but the most surprising thing I ever observed was the 2 - 3mm diameter tether connecting "Ralph" and "Norton," the two satellites making up the Tether Physics and Survivability Experiment (TiPS).

The two satellites required binoculars, and I was very surprised to see light reflections caused the tether to sparkle and become "visible." I observed it several times.

Otherwise, probably Deimos.

Clear skies, Alan

Ummm...I’m pretty sure that counts Alan...probably wins first place 🥇

#19 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 95,592
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 29 January 2021 - 06:07 PM

I saw another binocular meteor last night while I was doing a bit of binocular observing before the Moon rose very high.



#20 Alan French

Alan French

    Night Owl

  • *****
  • Posts: 6,107
  • Joined: 28 Jan 2005
  • Loc: Upstate NY

Posted 30 January 2021 - 07:30 PM

Ummm...I’m pretty sure that counts Alan...probably wins first place

I wondered "What was the angular size of the tether?" The orbit of TiPs was almost circular and its altitude just over 1000km, so we'll take it as 1000km and go with the larger 3mm diameter of the tether. That works out, assuming I did the math right, to an apparent diameter of 0.0006 arcseconds. Of course the tether itself was not visible, just random sparkles of sunlight reflecting off it, but they clearly revealed the existence of a tether between the satellites, Ralph and Norton.

 

We need another pair of tethered satellites to view. 

 

Clear skies, Alan


Edited by Alan French, 30 January 2021 - 07:32 PM.


#21 jrkirkham

jrkirkham

    Explorer 1

  • -----
  • Posts: 92
  • Joined: 22 Nov 2009
  • Loc: Illinois, U.S.A.

Posted 31 January 2021 - 12:25 AM

Of course my first response would be meteors no larger than a grain of sand. Then I think I would go for satellites, etc. If I go for the less obvious there were  two observations last year that stick out. 1) I followed Ceres for the first time last year. I may try for Vesta this year. It is half the size. 2) One afternoon this summer I locked the telescope on a Google Internet balloon in the stratosphere. I got a picture of it and the small instrument box it carried.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics