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| Artist's concept of a near-Earth object. Image: Courtesy NASA/JPL-Caltech |
Commentary
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 TC3 | 2008-10-06 | 2008-10-07 | 4.1 |
| 2014 AA | 2014-01-01 | 2014-01-02 | 2–4 |
| 2018 LA | 2018-06-02 | 2018-06-02 | 2.6–3.8 |
| 2019 MO | 2019-06-22 | 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]
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| 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.dat, state.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.
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| 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
@kpheider asked me to calculate a path of risk for #2018VP1. It's only a few meters across but JPL's SENTRY has it at 1 chance in 240 of impacting on Nov 2, 2020 (ESA/NEODys has it at 1 in 400). Path of risk stretches across the Pacific. Calculated with SOLEX 12.1 pic.twitter.com/U8SGb8CvOl— Peter Thomas (@ptastro1) July 26, 2019
Background
(as of 2020-06-13 )
- Object: 2018 VP1
- Orbit Type: NEO Apollo
- Approximate Diameter: 1.8 m - 3.9 m ( 5.90551 to 12.79528 feet) (Absolute Magnitude: H=30.9)
- On the Sentry Risk Table: YES
- Impact Probability(2020-11-02.05) = 4.1e-3
- 0.41% chance of Earth impact
- 1 in 240 odds of impact
- 99.59% chance the asteroid will miss the Earth
- for more information read Understanding Risk Pages by Jon Giorgini
- On the NEODyS CLOMON2 risk page: YES
- (2020-11-02.051) 5.16e-3
- 0.516%
- 1 in 194
- 99.484% chance the asteroid will miss the Earth
- Possible Earth Impact Effects Program of 2018 VP1
- Listed on The Near-Earth Object Human Space Flight Accessible Targets Study (NHATS):NO
- Listed on the Goldstone Asteroid Radar Schedule:NO
- Listed on the Arecibo Asteroid Radar Schedule:NO
- Radar Observations: none
- Discovery observation was made: 2018 11 03.27284202 5 (By Palomar Mountain--ZTF (MPC Code I41)[ First precovery observation was 2018 11 03.27249502]
- Last Observation(publish) was made: 2018 11 16.24026503 (By Cerro Paranal (MPC Code 309))
- Data-Arc Span (publish): 13 days ( yr)
- Number of Optical Observations(published): 21
- Oppositions: 1
- Number of Observatories Reporting (Published) Observations :5
- Observatories Reporting (Published) Observations(MPC Code):
- (309) Cerro Paranal, Chile.
- (H01) Magdalena Ridge Observatory, Socorro, US/New
- (I41) Palomar Mountain--ZTF, US/California.
- (L01) Višnjan Observatory, Tičan, Croatia.
- (T12) Mauna Kea-UH/Tholen NEO Follow-Up (2.24-m)
- Perihelion Distance: 0.9051326626577225 (AU)
- Aphelion Distance: 2.270308947523921 (AU)
- Earth MOID: 5.54556E-5 (AU), 0.022 (LD), 1.30069951121949 (Earth Radii), (Miles), or 8,296.04 5,154.92 (KM)
- Close-Approach to Earth: Will pass the Earth on 2020-Nov-02 11:33 at a Nominal Distance(Best Fit) of 0.00280167254552464 (AU), 1.09 (LD), 65.71 (Earth Radii), 260,431.733 (Miles), or 419,124.247(KM). "IF" the Earth was the Size of a Basketball flyby would be 25.53 feet ( 7.78 meters) away
- Close-Approach to Earth Uncertainty:
- Distance (Maximum Distance (au) - Minimum Distance (au)): 0.0256085074009903 - 3.90766585857012e-05 = 0.02556943074(AU) 9.951(LD) or 3,825,132.39 KM( 2,376,827.07 Miles)
- Time Uncertainty: (minutes) 4750.56847240545 ( 3 Days 7 Hours 11
Minutes) - Object velocity relative to Earth at close-approach [V-relative] (KM/S): 9.71114662839966
- Object velocity relative to a massless Earth at close-approach[V-infinity](KM/S):9.61271582257126
- Visibility:
- Naked Eye Visibility:NO
- Peak Magnitude: 17.1
- 2018 VP1 Ephemerides(Near Earth Objects Dynamic Site - NEODyS - SpaceDyS)
Also see
Note this has been edit to fix links and know typos.
