Eliminating Virtual Asteroids and Virtual Impactors for 2017 BL30

Astrometrica object verification window-- the NEO 2017 BL30

from Siding Spring Observatory, Coonabarabran, NSW, Australia. (MPC Q62)

a stack of 6 - 60-second luminance BIN2 images taken with iTelescope.net's

(TEL T27 0.70-m f/6.6 reflector + CCD)

(C) Steven M. Tilley

NOTE with only a five days data-arc span there is "little" known about the NEO 2017 BL30, and the information in this post may become outdated. So one should always check the links for updates. Whenever an object is listed on one the risk lists (especially if it has a Torino Scale 1 or greater) and it is observable, observers will take a particular interest in it. In the coming days, it is possible there will be more follow-up observations and a search in archives for precovery observations. It is MOST likely this object will be removed from the risk lists. It could take observations over one or more orbital periods before we can reliably say where it will be from 2029 to 2088

Why observe asteroids? 

One of the purposes of observing an asteroid is to reduce the orbital uncertainty of the asteroid. Each observations records were in the sky the asteroid was seen from the given location at the given time. Given that an asteroid's orbit and position within its orbital path determines where in the sky the asteroid can be seen from a location at a given time, many observations over an extended period of time can significantly reduce the orbital uncertainty. 

Each asteroid will be found somewhere within its uncertainty region. If the asteroid as a well-known orbit the uncertainty region will be tiny however if the asteroid as a poorly known orbit the uncertainty region will be enormous and may wrap around the solar system more than once. The question is will the "uncertainty region" of the asteroid and the Earth collide, and if so what is the percentage of the uncertainty region will be taken up by the Earth. The greater the percentage, the greater the risk of impact. As more observations come in the size of the uncertainty region will get smaller this may increase the proportion of the uncertainty region that will be taken up by the Earth. Therefore the "risk" may increase before dropping to zero.

To this end observers from around the world painstakingly take observations of asteroids on the risk lists. Each set of observations eliminates many possibilities(virtual asteroids) where the asteroid may be in the future. Most likely after more observations come all the virtual impactors will be eliminated and 2017 BL30 will be removed from the risk lists. 

Background

(as of 2017-02-03) 

NOTE 99.93500000% chance 2017 BL30 will miss the Earth(i.e. NOT worry about it)

• Object: 2017 BL30
• Approximate Diameter:  56 m - 130 m ( 183.727 feet to feet 426.509)(Absolute Magnitude: H= 23.384)
• Orbit Type: Apollo [NEO]- Potentially Hazardous Asteroid
• On the Sentry Risk Table: yes
•  NOTE this is NOT a prediction of an impact but rather a statement there is insufficient observational data rule out an impact -- for information read  Understanding Risk Pages by Jon Giorgini
•  Torino Scale(JPL): 1 
• "A routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. Current calculations show the chance of collision is extremely unlikely with no cause for public attention or public concern. New telescopic observations very likely will lead to re-assignment to Level 0."
• On the NEODyS CLOMON2 risk page: yes
• Torino Scale(NEODyS CLOMON2): 1
• Discovery (First) observation was made: 2017 01 28.37792 
• Discovery (First )observation was made by: Pan-STARRS 1, Haleakala (MPC Code  F51 ) The Discovery M.P.E.C.:  MPEC 2017-B125: 2017 BL30
• Last Observation(publish) was made: 2017 02 02.61107 (by iTelescope Observatory, Siding Spring   (MPC Code Q62 )
• Data-Arc Span(publish) :  5 days
• Number of Optical Observations(published) : 60
• Observatories Reporting (Published) Observations(MPC Code):
• (246) Klet Observatory-KLENOT. Czech Republic.
• (595) Farra d'Isonzo, Italy.
• (691) Steward Observatory, Kitt Peak - Spacewatch, US/Arizona.
• (F51) Pan-STARRS 1, Haleakala, US/Hawaii.
• (H06) RAS Observatory, Mayhill, US/New Mexico.
• (I52) Steward Observatory, Mt. Lemmon Station, US/Arizona.
• (K88) GINOP-KHK, Piszkéstető, Hungary.
• (Q62) iTelescope Observatory, Siding Spring, Australia/NSW.
• (T12) Mauna Kea-UH/Tholen NEO Follow-Up (2.24-m), US/Hawaii.
• (U69) iTelescope SRO Observatory, Auberry, US/California.
• Perihelion Distance: 0.862683125221094 (AU)
• Aphelion Distance: 1.404699667514954  (AU)
• Earth MOID:  9.67363E-5 AU ( 0.038 (LD)) or 8,992.201 miles (14,471.544 (KM))-- to put things in perspective "If" the Earth Was the Size of a Basketball this would be 10.65(27.06 CM)
• Next Close-Approach to Earth:  Will safely pass Earth on 2017-Mar-09  at a Nominal Distance of  0.0629444338149308 (AU) (24.496 (LD)) or 9,416,353.271 5,851,050.658 miles (9,416,353.271 KM)) -- to put things in perspective "If" the Earth Was the Size of a Basketball this would be 577.63 feet(176.06)

Useful Links:

• Space Situational Awareness(ESA) -- 2017 BL30
• Near Earth Objects Dynamic Site--2017BL30
• (MPC) Observations --2017 BL30
• JPL Orbit Diagram --2017 BL30
• NHATS Object/Trajectory Details