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Showing posts with label Apollo. Show all posts
Showing posts with label Apollo. Show all posts

Jun 19, 2020

A Foofaraw Over a NEO Designated 2018 VP1

Artist's concept of a near-Earth object. ImageCourtesy NASA/JPL-Caltech
Commentary 
Over the years, the tabloids as shown a propensity for raising a foofaraw over Near-Earth Objects. The Close-Approach of 2018 VP1 is only about four months away, and an internet search will reveal several clickbait stories. Many times it appears that tabloid writers pick a random asteroid and writes a "story" about it. At times one must have some background or do some research to see what the more accurate story is.

There is a low probability, 1 in 240, that the two-meter 2018 VP1 will strike the Earth's atmosphere and create spectacular fireballs on 2020-11-02. A test with the Imperial College London's Earth Impact Effects Program reports, "The average interval between impacts of this size somewhere on Earth is 0.2 years". In other words, it would be safe to assume objects the size of 2018 VP1 has impacted Earth's atmosphere since 2018-Nov-03, the date of discovery. The Earth Impact Effects Program also suggests that the fireball is unlikely to do any significant damage. NASA JPL list kinetic energy at impact from 2018 VP1[IF ANY] as ~ 0.00042 MegaTons of TNT. The Chelyabinsk event was 0.4 to 0.5 MegaTons of TNT.

Four times in the past, NEOs were observed by observers of asteroids before impact. These four asteroids(2008 TC3,2014 AA, 2018 LA, and 2019 MO) all were on the safe side when it comes to size.

 Object Date of discovery Date of Impact Size(M)
 2008 TC32008-10-06 2008-10-07 4.1
 2014 AA2014-01-01 2014-01-02 2–4
 2018 LA2018-06-02 2018-06-02 2.6–3.8
 2019 MO2019-06-22 2019-06-22 3–10

One of the programs available to the amateur observers of asteroids and comets is Find_Orb.[By Bill Gray] It is useful for calculating approximate ephemeris, determining approximate orbits, generating virtual asteroids, virtual impactors, predicting impact locations, and many other things. It should be noted IF one uses the wrong setting, one gets an incorrect solution. Find_Orb can generate an "asteroid risk corridor" with the help of Guide 9.1.[By Bill Gray]

Find_orb computing  Monte Carlo variant orbits  for the NEO 2018 VP1. One can use Monte Carlo method to  create virtual asteroids. By using orbits of  the virtual asteroids one can can see where the "real" asteroid could go. If any of virtual asteroids impact the Earth they become  known as  virtual impactors and the is 'Non-Zero' probability of  the real  asteroid hitting the Earth 

My Find_orb Setting

 Selecting perturbers All
 Epoch 2020-11-01.051
 Monte Carlo noise 2
 Physical model Include  SRP
 Filler out 3 worst observations

As a test of concept, I obtained the observations of 2018 VP1 for the Minor Planet Center. I loaded the observations into Find_Orb and had it run the Monte Carlo method all night. Find_orb generated the following files MPCOrb.datstate.txt, and  virtual.txt. These files had orbits for 129,659 virtual asteroids 200 were virtual impactors( about 0.15%). I place a copy of the virtual.txt file in the Guide directory along with a copy of impact.tdf.(Project Pluto) Then Guide could generate a map of an asteroid risk corridor.

An asteroid (fireball) risk corridor of potential impact for the NEO 2018 VP1, the orange dots is where 200 virtual impactors strike the Earth's atmosphere.

Note: Because there were more than 9 observations, I had to edited virtual.txt to do a workaround. I replace "18 of 21" with "U of O" see edited virtual.txt; this keeps the columns in the right place. I also edited impact.tdf(My) file where I can have more than one risk corridor.



Peter Thomas @ptastro1 also  this path of risk for 2018 VP1 on Twitter

Background

(as of 2020-06-13 )

 
Also see
 

Note this has been edit to fix links and know typos.

Jun 14, 2020

2018 VP1 Information Sheet-- "1 in 240" Odds of a Fireball on 2020-11-02 or ."99.59% chance the asteroid will MISS the Earth"

2018 VP1 Information Sheet-- "1 in 240"  Odds of a Fireball on 2020-11-02 or ."99.59% chance the asteroid will MISS the Earth"

This artist's concept shows a broken-up asteroid. Image: Courtesy NASA/JPL-Caltech
This artist's concept shows a broken-up asteroid.
ImageCourtesy NASA/JPL-Caltech

Throughout the year, very small rocks strick the Earth's atmosphere and creating spectacular fireballs.  Most of these rocks travel through space unknown to habitats of Earth until they strick the atmosphere.   If we are lucky, the fireball will be seen and reported.  If we are really lucky, the fireballs will be capture on film.  The most vast majority of fireballs are of no danger what so ever. Most fireballs are like rainbows in that they are cool.  Four times in the past, these rocks travel through the field of vision of an asteroid observer before impact. Observation was taken. The rocks were given designations, like 2014 AA( i.e., the first discovery of the first half of January in 2014), and the rocks "became" asteroids.  These four asteroids were on the safe side when it comes to size.

In the first half of November 2018, an asteroid was discovered and give the designation 2018 VP1.  This asteroid is very small[1.8 m - 3.9 m ( 5.90551 to 12.79528 feet) ]. This asteroid was only observed 21 times over 13 days. 

In orbit determination, one calculation what orbit will place the object in the sky where it was seen. If one knows an object's orbit, it knows where it is going and where it will be in the sky.  All observations are "imperfect," so there will be many similar orbits.  If one were to create virtual asteroids for each of the similar orbits and did a simulation, one would see over time. The virtual asteroids move apart from each other to create an uncertainty region.  The real asteroid is somewhere within the uncertainty region. When doing the simulation, if any of the virtual asteroids impact the Earth, they become virtual impactors, and there is 'Non-Zero' probability of the real asteroid hitting the Earth.  By calculating the percentage of virtual impactors to virtual asteroids, one can calculate the risk of impact.

There is a very low-risk impact 2018 VP1 will on 2020-11-02. However, it must be restarted this asteroid is very small[1.8 m - 3.9 m ( 5.90551 to 12.79528 feet) ]. We have a fireball this size about two times a year.


Find_orb computing  Monte Carlo variant orbits for the NEO 2018 VP1
Find_orb computing  Monte Carlo variant orbits  for the NEO 2018 VP1. One can use Monte Carlo method to  create virtual asteroids. By using orbits of  the virtual asteroids one can can see where the "real" asteroid could go. If any of virtual asteroids impact the Earth they become  known as  virtual impactors and the is 'Non-Zero' probability of  the real  asteroid hitting the Earth



Background

(as of 2020-06-13 )

Note: this was edited  to add links missing data formatting,  typos, replace, the image of Find_orb computing, fixing bad links .

Jun 3, 2018

A Rock Designated ZLAF9B2(now 2018 LA) Social Media and Fireball Reports

On  2018-06-02 Richard A. Kowalski, with the Catalina Sky Survey reported observations of a "new" object, given  the observ3er-assigned temporary designation "ZLAF9B2", to  Minor Planet Center in Cambridge, Massachusetts, USA.  It was posted to the NEOCP(NEO Confirmation Page) making the observations available to asteroid and comet  researcher around the world.   The data was analyzed and posted JPL's Scout: NEOCP Hazard Assessment, independently analyzed and posted to Bill Gray's  Current NEOCP summary page. Then emails  to mailing list post to social madia started going out. It was know to be small at the start.

When wroke up on 2018-06-02 I check iTelescope.net and saw their facility in Siding Spring Observatory, AU was clouded out than I went out to eat breakfast.  When got back just to see what I would observe if I could observe, I check the NEOCP and saw that ZLAF9B2 was "bright",  and  then  check "The Minor Planet Mailing List {MPML}" Some of the asteroid and comet researchers where talking.  The Bill Gray sent and a number of  carefully worded emails to email list  stating ZLAF9B2 should be a "Priority Target".
 
One of the programs available to asteroid and comet researchers is Find_Orb it is useful for calculating approximate ephemeris, determining approximate orbits, residuals,  generating virtual asteroids, virtual impactors, predicting impact locations, and many other things.  It should be noted  IF one uses wrong setting one get a totally wrong solution. One things Find_Orb can be use for is generating a "asteroid risk corridor" with the help of Guide 9.1. This should be done with care because of uncertainties in  observations how one sets the over-observing parameters as well with other setting can the effect the results.  Bill Gray posted post a risk corridor for ZLAF9B2 and I thought I would give it a try. I had Find_Orb generated  virtual asteroids and virtual impactors using a  monte carlo process. 


Here is my TEST with Find_Orb using a monte carlo process see the files here

Here is my TEST with Find_Orb using a monte carlo process see the files here
Before I share my results ZLAF9B2(now 2018 LA)  "impacted" the Earth over southern Africa creating a Fireball. around 2018-06-02 16:45 UT and posts about impact started making.  After the impact two (pre-impact) follow up observations from ATLAS-MLO(Asteroid Terrestrial-impact Last Alert System ---Mauna Loa) were posted to  the NEOCP(NEO Confirmation Page)  Then I did another  monte carlo process with the newly added ATLAS observations.

Test with the newly added ATLAS observations with Find_Orb
 using a monte carlo process see the files here
On 2018-06-04  the Minor Planet Center issues MPEC 2018-L04 : 2018 LA  Stating
"that the objectreached 50-km height above the Earth's surface around 16:51 UTC over southern Africa."

Timeline of SOME of the Post to Social Media














May 29, 2018

Re-Observing 2015 FP118 Another Look Almost Three Years later

When I am looking objects to observer, I try to find something within the capabilities of the telescope, interesting, and 'needing" observation. To these ends I check following lists:
On 2018-05-28 I saw  that 2015 FP118 was on both the Arecibo and Goldstone lists, needing astrometry,  and it was within the capabilities of iTelescope.net's (T27 TEL 0.70-m f/6.6 reflector + CCD) so I went for it. As I was create a directory so I could downloading the .FITS(Flexible Image Transport System) files I found out that I observed 2015 FP118  for  19.6 min on  2015-06-06.

The NEO 2015 FP118 on 2018-05-28 from
Siding Spring Observatory, Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 45 - 60 second luminance BIN2 images
taken with iTelescope.net's (T27 TEL 0.70-m f/6.6 reflector + CCD)
By Steven M. Tilley

The NEO 2015 FP118 on 2015-06-06 from
 Siding Spring Observatory, Coonabarabran, NSW, Australia. (MPC Q62)
 a stack of 22 - 60 second luminance BIN2 images
taken with iTelescope.net's (T27 TEL 0.70-m f/6.6 reflector + CCD)
By Steven M. Tilley
 Background
(as of 2018-05-29)
  • Object: 2015 FP118
  • Orbit Type: Apollo [NEO, PHA]
  • Approximate Diameter: 370 m - 820 m(1213.911 feet to 2690.289 feet) (Absolute Magnitude: H= 19.3)
  • On the Sentry Risk Table: NO( Removed 2015-04-02 15:53:35)
  • On the NEODyS CLOMON2 risk page: NO 
  • Discovery observation was made on: 2015 03 21.57498
  • Discovery observation was made by Pan-STARRS 1, Haleakala (MPC Code F51) The Discovery M.P.E.C.:MPEC 2015-F132: 2015 FP118
  • Last Observation (publish): 2018 05 28.56107 (at iTelescope Observatory, Siding Spring, Australia (MPC Code Q62) )
  • Data-Arc Span (publish): 1164 days (3.19 yr) 
  • Number of Optical Observations(published):133
  • Observatories Reporting (Published) Observations(MPC Code):
    • (204) Schiaparelli Observatory,Italy. 
    • (290) Mt. Graham-VATT,US/Arizona.
    • (291) LPL/Spacewatch II,US/Arizona. 
    • (568) Mauna Kea, US/Hawaii.
    • (691) Steward Observatory, Kitt Peak - Spacewatch US/Arizona.
    • (703) Catalina Sky Survey, US/Arizona.
    • (711) McDonald Observatory, Fort Davis, US/Texas.
    • (807) Cerro Tololo Observatory, La Serena, Chile.
    • (926) Tenagra II, US/Arizona.
    • (D29) Purple Mountain Observatory, XuYi Station 
    • (F51) Pan-STARRS 1, Haleakala US/Hawaii. 
    • (G96) Mt. Lemmon Survey, US/Arizona.
    • (Q62) iTelescope Observatory, Siding Spring
  • Perihelion Distance 0.9541884017671265 (AU)
  • Aphelion Distance: 3.28765938878308 (AU)
  • Earth MOID (Earth center to NEO center): 0.029858 AU ((11.62 LD)), ( 701.09 Earth radii) or 2,775,474.494 miles ( 4,466,693.22 ( KM))[If the Earth was the size of a Basketball this would be 276.261 Feet(84.204 Meters)]
  • Next Close-Approach to Earth: Will safely pass Earth on 2018-Sep-03:
    • Minimum Distance(Earth center to NEO center) of 0.0314378825351047 (AU) (12.235  (LD)),  (738.195 Earth radii) or  2,922,333.75 miles ( 4,703,040.286 (KM)) 
    • Nominal Distance(Earth center to NEO center) of   0.031438612821003 (AU) (12.235 (LD)), (738.212 Earth radii) or  2,922,401.634  miles (4,703,149.536 (KM))
    • Maximum Distance(Earth center to NEO center) of  0.0314393431490244 (AU) (12.235 (LD)), (738.229 Earth radii) or  2,922,469.522 miles (4,703,258.791 (KM))
  • Goldstone Asteroid Schedule: Yes 2018 Sep (Needs Astrometry: Yes Needs Physical Observations: Yes)
  • On the Arecibo Asteroid Schedule:  YES,  Dates 2018 Aug (Request Optical Astrometry: YES , Request Optical  Lightcurve:YES, Request Optical Characterization YES) 

Apr 23, 2018

Confirmation images of the NEO 2018 HC1

A confirmation image of the NEO 2018 HC1 on
2018-04-21 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 15 - 05 Second Luminance BIN2
images taken with iTelescope.net's
(T30 TEL 0.50-m f/6.8 reflector + CCD + f/4.5 focal reducer)
By Steven M. Tilley
A confirmation image of the NEO 2018 HC1 on
2018-04-21 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 15 - 05 Second Luminance BIN2
images taken with iTelescope.net's
(T30 TEL 0.50-m f/6.8 reflector + CCD + f/4.5 focal reducer)
By Steven M. Tilley
A confirmation image of the NEO 2018 HC1 on
2018-04-21 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 15 - 05 Second Luminance BIN2
images taken with iTelescope.net's
(T30 TEL 0.50-m f/6.8 reflector + CCD + f/4.5 focal reducer)
By Steven M. Tilley