Lagniappe Observing

Jul 5, 2018

The asteroid 2018 MW6 on 2018-07-04

The asteroid 2018 MW6(Classification: Apollo [NEO, PHA])
on 2018-07-04 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stacks of 10-60 second luminance BIN2 images
taken with iTelescope.net's
(T27 TEL 0.70-m f/6.6 reflector + CCD)
By Steven M. Tilley

NASA Jet Propulsion Laboratory (JPL) Orbit Diagram for The asteroid 2018 MW6(2018-07-04 12:30 UTC)

Background

(as of 2018-07-04)

Object: 2018 MW6
Orbit Type: Apollo [NEO, PHA]
Approximate Diameter: 310 m - 770 m (1017.06 feet to 2526.25 feet)(Absolute Magnitude: H= 19.436)
On the Sentry Risk Table: No (Removed 2018-06-26 14:03:18)
On the NEODyS CLOMON2 risk page: No (Removed)
Discovery observation was made: 2018 06 19.26519
Discovery observation was made by Mt. Lemmon Survey (MPC Code G96) The Discovery M.P.E.C.:MPEC 2018-M81 : 2018 MW6
Last Observation (publish): 2018 07 03.24029 (at Steward Observatory, Mt. Lemmon Station (MPC Code I52 ))
Data-Arc Span (publish): 14 days
Number of Optical Observations(published):68
Observatories Reporting (Published) Observations(MPC Code):

(246) Klet Observatory-KLENOT, Czech Republic.
(291) LPL/Spacewatch II, US/Arizona.
(691) Steward Observatory, Kitt Peak - Spacewatch, US/Arizona.
(G96) Mt. Lemmon Survey, US/Arizona.
(H01) Magdalena Ridge Observatory, Socorro, US/New Mexico
(H21) Astronomical Research Observatory, Westfield, US/Illinois.
(I52) Steward Observatory, Mt. Lemmon Station, US/Arizona.
(J77) Golden Hill Observatory, Stourton Caundle, UK.
(J95) Great Shefford, UK.
(L01) Višnjan Observatory, Tičan, Croatia.
(Q62) iTelescope Observatory, Siding Spring, Australia/NSW.
(T12) Mauna Kea-UH/Tholen NEO Follow-Up (2.24-m) US/Hawaii.

Perihelion Distance:0.7684431568362392(AU)
Aphelion Distance: 6.056415878243476(AU)

Useful Links:

Space Situational Awareness(ESA) -- 2018 MW6
Near Earth Objects Dynamic Site--2018 MW6
(MPC) Observations --2018 MW6
JPL Orbit Diagram --2018 MW6
NEO Earth Close Approaches (JPL) (upcoming)
JPL's NEO Earth Close-Approaches (Between 1900 A.D. and 2200 A.D- limited to encounters with reasonably low uncertainty)
The Tracking News
NEO Coordination Centre
Speed of Light - Space - Distance Calculator
Asteroid Hazards: The View from Space(MPC)
Don’t fear apocalyptic asteroids: you’re safer than you think
Understanding Risk Pages By Jon Giorgini
Revised asteroid scale aids understanding of impact risk
Near Earth, Objects Scale Helps Risk Communication
Dealing With the Impact Hazard: An International Project
The Palermo Technical Impact Hazard Scale
An Asteroid as Entered the Blogosphere… Should I Be Worried? A commentary by Steven M. Tilley
International Asteroid Warning Network
Impact Risk Assessment: An Introduction - Near-Earth Object Program
Hazardous NEO Technical Reviews
Frequently Asked Questions For Impact Risk Assessment
How to Find an Impact Orbit for the Earth-Asteroid Collision
The Asteroid/Comet Impact Hazard
Whom should we call? Data policy for immediate impactors announcements
NEO Search & Follow-Up
NEOs' Science pages by Livia Giacomini
Torino Scale(JPL)
Find_Orb --- Orbit determination software - Project Pluto
Guide to Minor Body Astrometry(MPC)
Asteroid - Impact Simulator (Impact Earth!) by Purdue University,
On-line Find_Orb

Jun 24, 2018

The asteroid 2018 MW6 on 2018-06-23

The asteroid 2018 MW6(Classification: Apollo [NEO, PHA])
on 2018-06-23 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 22-60 second luminance BIN2 images taken with
iTelescope.net's
(T17 TEL 0.43-m f/6.8 reflector + CCD)
By Steven M. Tilley

The asteroid 2018 MW6(Classification: Apollo [NEO, PHA])
on 2018-06-23 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 15-60 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

NASA Jet Propulsion Laboratory (JPL) Orbit Diagram for The asteroid 2018 MW6(2018 Jun 23 13:00)

Background

(as of 2018-06-24)

Object: 2018 MW6
Orbit Type: Apollo [NEO, PHA]
Approximate Diameter: 310 M - 750 m (1017.06 feet to 2460.63 feet)(Absolute Magnitude: H= 19.489)
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 more information read Understanding Risk Pages by Jon Giorgini

Torino Scale 0

"The likelihood of a collision is zero, or is so low as to be effectively zero. Also applies to small objects such as meteors and bodies that burn up in the atmosphere as well as infrequent meteorite falls that rarely cause damage.."

On the NEODyS CLOMON2 risk page: Yes
Discovery observation was made: 2018 06 19.26519
Discovery observation was made by Mt. Lemmon Survey (MPC Code G96) The Discovery M.P.E.C.:MPEC 2018-M81 : 2018 MW6
Last Observation (publish): 2018 06 23.67253 (at iTelescope Observatory, Siding Spring (MPC Code Q62 ) )
Data-Arc Span (publish): 4
Number of Optical Observations(published):48
Observatories Reporting (Published) Observations(MPC Code):

(246) Klet Observatory-KLENOT, Czech Republic.
(291) LPL/Spacewatch II,US/Arizona.
(691) Steward Observatory, Kitt Peak - Spacewatch,US/Arizona.
(G96) Mt. Lemmon Survey, US/Arizona.
(H01) Magdalena Ridge Observatory, Socorro,US/New Mexico
(I52) Steward Observatory, Mt. Lemmon Station, US/Arizona.
(J77) Golden Hill Observatory, Stourton Caundle, UK.
(J95) Great Shefford,UK. Observer
(L01) Višnjan Observatory, Tičan, Croatia.
(Q62) iTelescope Observatory, Siding Spring, Australia/NSW.

Perihelion Distance:0.7678873680374123(AU)
Aphelion Distance: 6.093862873564613 (AU)

Useful Links:

Jun 9, 2018

Confirmation Images of the COMET C/2018 L2 (ATLAS) on 2018-06-07

...

A confirmation image of the COMET C/2018 L2 (ATLAS)
on 2018-06-07 from Siding Spring Observatory,
Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 5 - 60 second luminance BIN2 images taken
with iTelescope.net's (T27 TEL 0.70-m f/6.6 reflector + CCD)
By Steven M. Tilley

Object: COMET C/2018 L2 (ATLAS)
Orbit Type:Parabolic Comet
Discovery observation was made by:ATLAS-MLO, Mauna Loa (MPC Code T08)
The Discovery M.P.E.C.: MPEC 2018-L37 : COMET C/2018 L2 (ATLAS)
JPL Orbit Diagram

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

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

{MPML} ZLAF9B2 = priority target (from Bill Gray):
Based on eleven observations from Catalina, this is
looking to be coming quite close, probably about 50000
km or so. It's mag 17.2 and getting brighter, too, so it shouldn't be
too tough to get.
— Asteroid Initiatives (@AsteroidEnergy) June 2, 2018

A tiny (3-metre?) asteroid, ZLAF9B2, making a close approach to Earth within twice GEO distance, perhaps much closer. Some solutions by Bill Gray suggest possible impact over Indonesia around now - look out for fireball reports! Not big enough to be a worry.
— Jonathan McDowell (@planet4589) June 2, 2018

It looks like there is a good probability the newly discovered small object ZLAF9B2 will impact the Earth's atmosphere within the next few hours. (Plot from MPML and Peter Birtwhistle) https://t.co/As7RgDseLA
— Asteroid Initiatives (@AsteroidEnergy) June 2, 2018

It looks like there is a good probability ZLAF9B2 will impact the Earth within the next few hours. (Plot from MPML and Peter Birtwhistle) https://t.co/As7RgDseLA pic.twitter.com/XKktXbLNFn
— Asteroid Initiatives (@AsteroidEnergy) June 2, 2018

ZLAF9B2 is very close.
— Neil Norman FRAS. (@telescopecomet1) June 2, 2018

and then there's ZLAF9B2 https://t.co/YXiBEdQqqC
— Asteroid Initiatives (@AsteroidEnergy) June 2, 2018

Update of the possible times of impact (UTC) for ZLAF9B2 from Bill Gray. pic.twitter.com/TEp9oF4Dcw
— Asteroid Initiatives (@AsteroidEnergy) June 2, 2018

Analysis on the Minor Planet Mailing List suggests that the ZLAF9B2 object reentered and burnt up over Botswana at 1644UTC
— Jonathan McDowell (@planet4589) June 2, 2018

Newly-disovered asteroid #ZLAF9B2 likely hit the Earth a few hours ago.https://t.co/fwx3eAVMX7 pic.twitter.com/C3rBgE07js
— Tony Dunn (@tony873004) June 3, 2018

Strong infrasound detection of a bolide at station I47 in South Africa today at 1730 UT. Origin time between 1645-17 UT over Botswana. Yield 0.3-0.5 kT, corresponding to 2m diameter asteroid. #fireball #neoimpacts pic.twitter.com/fVe5GtwTtb
— Peter Brown (@pgbrown) June 3, 2018

Yes, this was ZLAF9B2. I obviously left Germany too early
— Peter Brown (@pgbrown) June 3, 2018

My Test with with Find_Orb and Guide 9--14 observations; 2018 June 2 (3.8 hr) (including newly added ATLAS observations) Monte Carlo noise set to 2 and Physical set to Standard #ZLAF9B2 pic.twitter.com/QqBBzXsOB2
— Steven M. Tilley (@StevearenoBR) June 3, 2018

Just for fun, here’s my estimated fireball track from the Deelpan video alongside the @StevearenoBR candidate line. 800km is a surprise (I guessed 400km) but it’s calculated correctly if 50km altitude burst & it’s a v bright fireball. Atmospheric speed from @tony873004. #ZLAF9B2 pic.twitter.com/b9DWcezuST
— Andy Cooper (@scute1133) June 3, 2018

{MPML} The object ZLAF9B2 is (given that it exploded in the air over Botswana yesterday) "posthumously" going to be named 2018 LA. https://t.co/JxTT8jwSGX
— Asteroid Initiatives (@AsteroidEnergy) June 3, 2018

Jun 1, 2018

Confirmation Images of the COMET C/2018 K1 (Weiland)

On 2018 05 25 Henry Weiland an observer with ATLAS-MLO(Asteroid Terrestrial-impact Last Alert System ---Mauna Loa) reported a possible comet to the Minor Planet Center in Cambridge, Massachusetts, USA. This possible comet was reported using the observer-assigned temporary designation "A1072Wf". It was posted to the Possible Comet Confirmation Page(PCCP) and came to the attention of observer around the world. On 2018-05-26 I woke up, check iTelescope.net and saw that their facility in Siding Spring Observatory, AU was open. So had T30 started an imaging run of 60 - 60-second luminance BIN2 images and went out to eat breakfast. I got back made four stacks of 5 so can work around "stars that were in the way." I submitted my observations, as more observations came in and as the morning change to the afternoon, I saw my observations had poor residuals, so I did imaging run of 60 - 60-second luminance BIN2 images on T27.

A confirmation image of COMET C/2018 K1 (Weiland)
[was the PCCP(Possible Comet Confirmation Page)object A1072Wf] on 2018-05-26
from Siding Spring Observatory, Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 5 - 60 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 COMET C/2018 K1 (Weiland)
[was the PCCP(Possible Comet Confirmation Page)object A1072Wf] on 2018-05-26
from Siding Spring Observatory, Coonabarabran, NSW, Australia. (MPC Q62)
a stack of 5 - 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 2018-05-31)

Object: COMET C/2018 K1 (Weiland)
Orbit Type: Halley-type Comet
First(Precovery) observation was made on: 2017 11 06.24388
First(Precovery) observation was made by: Pan-STARRS 1, Haleakala (MPC Code F51)
Discovery observation was made on: 2018 05 25.54194
Discovery observation was made by : ATLAS-MLO, Mauna Loa (MPC Code T08)
The Discovery M.P.E.C.: MPEC 2018-K117: COMET C/2018 K1 (Weiland)
Last Observation (publish): 2018 05 30.34974 (from Steward Observatory, Kitt Peak - Spacewatch (MPC Code 691) )
Data-Arc Span (publish): 205 days
Number of Optical Observations(published): 91
Observatories reporting (published) observations(MPC Code):

(349) Ageo, Japan.
(372) Geisei, Japan.
(691) Steward Observatory, Kitt Peak - Spacewatch, US/Arizona.
(E23) Arcadia, Australia/NSW.
(F51) Pan-STARRS 1, Haleakala, US/Hawaii
(H06) iTelescope Observatory, Mayhill, US/New Mexico
(H47) Vicksburg, US/Mississippi.
(I47) Pierre Auger Observatory, Malargüe, Argentina.
(I52) Steward Observatory, Mt. Lemmon Station US/Arizona.
(Q62) iTelescope Observatory, Siding Spring, Australia/NSW.
(T08) ATLAS-MLO, Mauna Loa, US/Hawaii.
(W88) Slooh.com Chile Observatory, La Dehesa, Chile.
(W96) CAO, San Pedro de Atacama (since 2013), Chile.
(Y00) SONEAR Observatory, Oliveira, Brazil.

Perihelion Distance 1.879151252869776 (AU)
Aphelion Distance: 57.90074646767503 (AU)

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:

NEO Confirmation Page(NEOCP) and Possible Comet Confirmation Page (PCCP)
The Impact Risk Monitoring lists(See Jon Giorgini's "Understanding Risk Pages" for more inofmation)

The Radar Support Lists (Arecibo or Goldstone)
Near-Earth Object Human Space Flight Accessible Targets Study (NHATS)
ESA's NEO Coordination Centre (NEOCC) Priority List

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)

May 21, 2018

A Scale Model of the Earth if the Earth was the Size of a Basketball as of 2018-05-20

A Scale Model of the Earth if the Earth was the Size of a Basketball - Radius 12.0275 CM(4.73523622 inches)

Top of the Troposphere--0.038cm (0.015inches) 0.001 Ft
Top of the Stratosphere--0.113cm (0.045inches) 0.004 Ft
Top of the mesosphere--0.227cm (0.089inches) 0.007 Ft
STS-1(Perigee)--0.453cm (0.178inches) 0.015 Ft
STS-1(apogee)--0.474cm (0.187inches) 0.016 Ft
ISS(Perigee)--0.757cm (0.298inches) 0.025 Ft
ISS(apogee)--0.770cm (0.303inches) 0.025 Ft
Top of the Thermosphere--1.133cm (0.446inches) 0.037 Ft

The 50 closest observed NEO Earth close approaches as of 2018-05-20

01. The 2011-Feb-04 fly by of 2011 CQ1--10.347cm (4.074inches) 0.339 Ft
02. The 2008-Oct-09 fly by of 2008 TS26--11.816cm (4.652inches) 0.388 Ft
03. The 2004-Mar-31 fly by of 2004 FU162--12.351cm (4.862inches) 0.405 Ft
04. The 2016-Feb-25 fly by of 2016 DY30--14.978cm (5.897inches) 0.491 Ft
05. The 2017-Apr-04 fly by of 2017 GM--18.681cm (7.355inches) 0.613 Ft
06. The 2017-Oct-20 fly by of 2017 UJ2--21.756cm (8.565inches) 0.714 Ft
07. The 2011-Jun-27 fly by of 2011 MD--23.184cm (9.127inches) 0.761 Ft
08. The 2014-Jun-03 fly by of 2014 LY21--25.810cm (10.161inches) 0.847 Ft
09. The 2009-Nov-06 fly by of 2009 VA--26.590cm (10.469inches) 0.872 Ft
10. The 2012-May-29 fly by of 2012 KT42--27.263cm (10.734inches) 0.894 Ft
11. The 2017-Mar-02 fly by of 2017 EA--27.420cm (10.795inches) 0.900 Ft
12. The 2016-Sep-11 fly by of 2016 RN41--32.749cm (12.893inches) 1.074 Ft
13. The 2015-Sep-22 fly by of 2015 SK7--38.208cm (15.043inches) 1.254 Ft
14. The 2016-Jan-12 fly by of 2016 AH164--38.293cm (15.076inches) 1.256 Ft
15. The 2013-Dec-23 fly by of 2013 YB--39.225cm (15.443inches) 1.287 Ft
16. The 2017-Nov-26 fly by of 2017 WE30--44.815cm (17.644inches) 1.470 Ft
17. The 2016-Mar-11 fly by of 2016 EF195--47.677cm (18.771inches) 1.564 Ft
18. The 2008-Oct-20 fly by of 2008 US--50.052cm (19.705inches) 1.642 Ft
19. The 2004-Dec-19 fly by of 2004 YD5--51.949cm (20.452inches) 1.704 Ft
20. The 2013-Feb-15 fly by of 367943 Duende (2012 DA14)--52.259cm (20.574inches) 1.715 Ft
21. The 2015-Nov-15 fly by of 2015 VY105--53.303cm (20.985inches) 1.749 Ft
22. The 2016-Jan-14 fly by of 2016 AN164--57.900cm (22.795inches) 1.900 Ft
23. The 2010-Nov-17 fly by of 2010 WA--61.321cm (24.142inches) 2.012 Ft
24. The 2018-Jan-18 fly by of 2018 BD--61.859cm (24.354inches) 2.030 Ft
25. The 2015-Feb-17 fly by of 2015 DD1--62.075cm (24.439inches) 2.037 Ft
26. The 2014-Sep-07 fly by of 2014 RC--63.313cm (24.927inches) 2.077 Ft
27. The 2011-Feb-06 fly by of 2011 CF22--63.839cm (25.134inches) 2.094 Ft
28. The 2016-Sep-07 fly by of 2016 RB1--64.398cm (25.354inches) 2.113 Ft

Geosynchronous orbit--67.559cm (26.598inches) 2.216 Ft

29. The 2008-Nov-03 fly by of 2008 VM--75.248cm (29.625inches) 2.469 Ft
30. The 2004-Mar-18 fly by of 2004 FH--80.665cm (31.758inches) 2.646 Ft
31. The 2017-Oct-12 fly by of 2012 TC4--82.650cm (32.540inches) 2.712 Ft
32. The 2010-Oct-12 fly by of 2010 TD54--85.742cm (33.757inches) 2.813 Ft
33. The 2017-Jan-30 fly by of 2017 BH30--85.850cm (33.799inches) 2.817 Ft
34. The 2010-Nov-30 fly by of 2010 XB--87.847cm (34.586inches) 2.882 Ft
35. The 2013-Apr-18 fly by of 2013 HT25--89.662cm (35.300inches) 2.942 Ft
36. The 2017-May-04 fly by of 2017 JB2--93.008cm (36.617inches) 3.051 Ft
37. The 2014-Aug-31 fly by of 2014 RA--95.026cm (37.412inches) 3.118 Ft
38. The 2016-Apr-04 fly by of 2016 GN134--95.974cm (37.785inches) 3.149 Ft
39. The 2012-May-28 fly by of 2012 KP24--96.122cm (37.843inches) 3.154 Ft
40. The 2015-Apr-21 fly by of 2015 HD1--99.566cm (39.199inches) 3.267 Ft
41. The 2017-Oct-28 fly by of 2017 UL6--100.460cm (39.551inches) 3.296 Ft
42. The 2014-Mar-06 fly by of 2014 EC--104.224cm (41.033inches) 3.419 Ft
43. The 2009-Feb-27 fly by of 2009 EJ1--104.330cm (41.075inches) 3.423 Ft
44. The 2017-Aug-14 fly by of 2017 QP1--106.229cm (41.823inches) 3.485 Ft
45. The 2017-Mar-20 fly by of 2017 FN1--107.355cm (42.266inches) 3.522 Ft
46. The 2012-Mar-26 fly by of 2012 FS35--109.577cm (43.140inches) 3.595 Ft
47. The 2012-Jan-27 fly by of 2012 BX34--111.432cm (43.871inches) 3.656 Ft
48. The 2008-Mar-10 fly by of 2008 EF32--112.584cm (44.324inches) 3.694 Ft
49. The 2009-Oct-01 fly by of 2009 TB--119.071cm (46.878inches) 3.907 Ft
50. The 2007-Oct-17 fly by of 2007 UN12--119.600cm (47.087inches) 3.924 Ft

Light-second. 566.000cm (222.820inches) 18.568 Ft
Lunar distance (perigee)--673.000cm (265.000inches) 22.095 Ft
Lunar distance--714.000cm (281.000inches) 23.414 Ft
Lunar distance (apogee)--766.000cm (302.000inches) 25.128 Ft
Light-minute--34000.000cm (13400.000inches) 1114.101 Ft

Moon Equatorial radius--3.280cm (1.292inches) 0.108 Ft
Moon Equatorial radius Diameter--6.560cm (2.584inches) 0.215 Ft
Moon Equatorial Circumference--20.600cm (8.117inches) 0.676 Ft

Earth radius--12.000cm (4.735inches) 0.395 Ft
Earth (Equatorial) diameter--24.100cm (9.470inches) 0.789 Ft
Earth (Equatorial) Circumference--75.600cm (29.752inches) 2.479 Ft

See the spreadsheet The 50 closest observed NEO Earth close approaches as of 2018-05-20.xlsx

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Jul 5, 2018

Jun 24, 2018

Jun 9, 2018

Jun 3, 2018

Jun 1, 2018

May 29, 2018

May 21, 2018

A Scale Model of the Earth if the Earth was the Size of a Basketball - Radius 12.0275 CM(4.73523622 inches)

The 50 closest observed NEO Earth close approaches as of 2018-05-20

Geosynchronous orbit--67.559cm (26.598inches) 2.216 Ft