Asteroids which came closer to Earth than the Moon in 2017 by time of discovery Below is the list of asteroid close approaches to Earth in 2017.

Timeline of known close approaches less than one lunar distance from Earth in 2017

A list of known near-Earth asteroid close approaches less than 1 lunar distance () from Earth in 2017, based on the close approach database of the Center for Near-Earth Object Studies (CNEOS).

For reference, the radius of Earth is approximately or 0.0166 lunar distances.Geosynchronous satellites have an orbit with semi-major axis length of or 0.110 lunar distances. In 2017, four known asteroids have traveled nearer than this: 2017 GM, 2017 UJ2, 2017 EA, and 2017 WE30. Unconfirmed asteroids YU95BEF, P10ELNY and A104Vqx probably have traveled nearer, but knowledge of their orbits is too poor to be sure.

The CNEOS database of close approaches lists some close approaches a full orbit or more before the discovery of the object, derived by orbit calculation. The list below only includes close approaches that are evidenced by observations, thus the pre-discovery close approaches are only included if the object was found by precovery.

This list and relevant databases do not consider impacts as close approaches, thus this list does not include any of the 29 objects that collided with Earth's atmosphere in 2017, none of which were discovered in advance, but were observed visually or recorded by sensors designed to detect detonation of nuclear devices.NASA.gov

Date ofclosestapproach Datediscovered Object Nominal geocentricdistance (AU) Nominalgeocentric (LD)Size (m)(approx.) (H)() ClosertoMoon? 2017-01-09 2017-01-07 0.543 16–36 26.1 2017-01-25 2017-01-20 2017 BX 0.693 6.7–15 28.0 2017-01-30 2017-01-29 0.135 4.6–10 28.8 2017-02-02 2017-01-30 0.423 8.1–18 27.6 2017-02-23 2017-02-21 0.358 3.7–8.2 29.3 Yes 2017-02-25 2017-02-22 0.581 3.8–8.6 29.2 2017-03-02 2017-03-02 2017 EA 0.054 1.8–4.1 30.8 2017-03-05 2017-02-27 0.919 16–35 26.2 2017-03-17 2017-03-16 = 0.317 5.6–13 28.4 2017-03-17 2017-03-19 0.468 7.7–17 27.7 2017-03-19 2017-03-17 2017 FS 0.284 4.4–9.9 28.9 2017-03-20 2017-03-21 0.707 4.3–9.5 29.0 2017-03-20 2017-03-20 0.165 2–4.5 30.6 2017-03-20 2017-03-20 0.333 3.3–7.5 29.5 2017-03-30 2017-03-25 0.846 4.8–11 28.3 2017-04-02 2017-03-29 0.569 4.8–11 28.7 2017-04-04 2017-04-03 2017 GM 0.042 2.8–6.2 29.9 2017-04-16 2017-04-17 2017 HJ 0.353 8.3–19 27.5 2017-04-21 2017-04-27 0.927 8.4–19 27.5 2017-04-22 2017-04-26 0.607 7.7–17 27.7 2017-04-23 2017-04-22 0.326 4.4–9.9 28.9 2017-05-02 2017-05-01 2017 JA 0.259 4–9 28.9 2017-05-04 2017-05-02 0.442 3.7–8.2 29.4 2017-05-04 2017-05-06 0.145 3.8–8.6 29.0 2017-07-21 2017-07-23 0.332 33–75 24.4 2017-08-14 2017-08-16 0.163 37–83 24.3 2017-08-20 2017-08-18 0.563 5.8–13 27.9 2017-08-29 2019-02-26Precovery around this close approach: 2017-08-16 to 2017-08-28 0.159 26–58 25.1 2017-09-03 2017-08-31 0.928 3.7–8.2 29.3 2017-09-14 2017-09-18 0.517 18–41 25.8 2017-09-20 2017-09-17 0.806 9.2–21 27.3 2017-09-20 2017-09-21 0.535 3.8–8.4 29.3 Yes 2017-09-20 2017-09-20 0.243 5.1–11 28.6 2017-09-24 2017-09-26 0.720 6.7–15 28.0 2017-09-24 2017-09-25 0.670 10–23 27.0 Yes 2017-09-30 2017-10-01 0.269 3.6–7.9 29.4 2017-10-02 2017-09-29 0.227 5.8–13 28.3 2017-10-10 2017-10-14 0.730 21–47 25.5 2017-10-12 2012-10-04 0.130 12–27 26.7 2017-10-15 2017-10-16 2017 UF 0.991 7–16 27.9 2017-10-16 2017-10-15 0.260 5.6–12 28.4 2017-10-17 2017-10-19 0.829 7.7–17 27.7 2017-10-19 2017-10-11 0.497 9.7–22 27.2 Yes 2017-10-20 2017-10-21 0.047 1.8–3.9 30.9 2017-10-21 2017-10-25 0.511 5.3–12 28.5 Yes 2017-10-28 2017-10-27 0.155 1.1–2.4 32.0 2017-10-30 2017-10-29 0.588 6.1–14 28.2 2017-11-04 2017-11-05 2017 VE 0.885 13–28 26.6 2017-11-09 2017-11-10 0.306 16–36 26.1 2017-11-13 2017-11-15 0.796 5.3–12 28.5 2017-11-21 2017-11-20 0.367 3.1–6.8 29.7 2017-11-21 2017-11-22 0.246 8.8–20 27.4 2017-11-26 2017-11-26 0.078 1.2–2.6 31.8 2017-12-28 2017-12-25 0.582 6.4–14 28.1 2017-12-30 2017-12-28 0.801 5.3–12 28.5

In addition to the confirmed asteroids on the above list, which feature in the CNEOS close approach database, there have been well-observed unconfirmed or confirmed but poorly observed objects with a 50% or greater chance of passing within 1 LD of the Earth, which are listed separately below.

Date ofclosestapproach Datediscovered Object Nominal geocentricdistance (AU) Nominalgeocentric (LD)Size (m)(approx.) (H)() ClosertoMoon?2017-10-132017-10-21(Unconfirmed) YT80190 0.21 2–6 30.4 2017-10-22 2017-10-30(Unconfirmed) YU92F9B 0.47 3–10 29.2 2017-10-22 2017-10-30(Unconfirmed) YU95BEF 0.051 5–15 28.2 2017-11-14 2017-11-20(Unconfirmed) P10ELNY 0.083 4–12 28.8 2017-11-08 2017-11-16(Unconfirmed) A104Vqx 0.086 4–14 28.4

Warning times by size

This sub-section visualises the warning times of the close approaches listed in the table of confirmed close approaches, depending on the size of the asteroid. The sizes of the charts show the relative sizes of the asteroids to scale. For comparison, the approximate size of a person is also shown. This is based the absolute magnitude of each asteroid, an approximate measure of size based on brightness.

Absolute magnitude H ≥ 30 (smallest) (size of a person for comparison)

Absolute magnitude 30 > H ≥ 29

Absolute magnitude 29 > H ≥ 28

Absolute magnitude 28 > H ≥ 27

Absolute magnitude 27 > H ≥ 26

Absolute magnitude 26 > H ≥ 25

Absolute magnitude 25 > H (largest)

Notes

Timeline of close approaches less than one lunar distance from the Moon in 2017 The number of asteroids listed here are significantly less than those of asteroids that approach Earth for several reasons. Asteroids that approach Earth not only move faster, but are brighter and are easier to detect with modern surveys because: Asteroids that come closer to Earth are a higher priority to confirm, and only confirmed asteroids are listed with a lunocentric approach distance. Those that closely approach the Moon are frequently lost in its glare, making them harder to confirm. They are similarly hard to discover during the new moon, when the Moon is too close to the Sun to detect asteroids while they are near the Moon.

These factors severely limit the amount of Moon-approaching asteroids, to a level many times lower than the asteroids detected passing as close to Earth. Date ofclosestapproach Object Nominal lunocentricdistance (AU) Nominal lunocentricdistance (LD)Size (m)(approximate) (H) Approachdistanceto Earth (LD)2017-01-25 0.73 5–16 28.1 1.122017-01-25 2017 BX 0.81 5–18 28.0 0.692017-01-30 0.73 4–12 28.8 0.132017-02-03 0.75 7–24 27.3 0.422017-02-24 0.22 3–9 29.3 0.362017-02-25 0.70 3–11 29.1 0.582017-03-02 2017 EA 0.87 1–5 30.8 0.0542017-03-17 0.92 6–20 27.7 0.472017-03-17 0.40 5–14 28.4 0.322017-04-04 2017 GM 0.88 2–7 29.9 0.0422017-04-21 0.69 6–21 27.6 0.612017-04-24 0.90 3–12 28.9 0.332017-05-02 2017 JA 0.98 3–13 28.9 0.262017-05-02 0.73 3–11 29.0 0.142017-05-03 0.96 3–9 29.4 0.442017-05-31 0.45 10–36 26.5 1.232017-07-21 0.92 25–90 24.5 0.302017-08-14 0.90 31–91 24.3 0.162017-08-21 0.69 5–22 27.9 0.562017-08-26 0.94 4–17 28.3 1.022017-09-03 0.95 3–9 29.3 0.932017-09-16 0.68 2–7 29.8 1.082017-09-20 0.50 3–9 29.2 0.532017-09-20 0.83 6–26 27.3 0.812017-09-24 0.12 8–27 27.0 0.672017-09-30 0.86 3–8 29.4 0.272017-10-02 0.68 4–16 28.1 0.222017-10-12 0.72 10–31 26.7 0.232017-10-13 YT80190 0.81 2–6 30.4 0.212017-10-17 0.55 4–18 28.2 0.262017-10-20 0.65 1–5 30.8 0.0472017-10-20 0.29 7–28 27.2 0.502017-10-20 0.11 4–15 28.3 0.512017-10-22 YU95BEF 0.19 5–15 28.2 0.0512017-10-24 0.80 7–28 27.2 1.382017-11-09 0.990 13–42 26.1 0.312017-11-09 A104Vqx 0.80 4–14 28.4 0.0862017-11-13 0.94 4–14 28.5 0.802017-11-14 P10ELNY 0.76 4–12 28.8 0.0832017-12-18 0.55 6–26 27.5 1.0442017-12-28 0.68 4–18 28.2 0.58

Notes

Additional examples

An example list of near-Earth asteroids that passed or will pass more than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2017. Object Size(meters) Lunardistances Date 653.34 6 January 2017 16 1.03 31 January 2017 1866.57 7 February 2017 7 1.005 23 February 2017 9 1.02 27 February 2017 313 8.34 16 March 2017 4 1.051.04 moon 3 April 2017 823 4.57 19 April 2017 890 7.96 1 June 2017 30 1.021.34 moon 6 June 2017 2017 MF 20 1.21 moon 19 June 2017 110 1.11 1.27 moon 14 July 2017 8 0.32 and 11 17–28 September 2017 394 7.88 29 September 2017YT83F29 4 2.60.73 moon 14 October 2017 685 5.77 22 October 2017(444584) 2006 UK 313 8.66 17 November 2017

Statistics

Virtual impactors

List of asteroids with a Palermo Technical Impact Hazard Scale greater than −6 that are listed on the Sentry Risk Table because they have short observation arcs with poorly constrained orbits and have a chance of impacting Earth in 2017. Given a short observation arc, many different orbits fit the observed data. could have approached Earth around May 2017 or could have been 9 AU from Earth on the way to a close approach with Saturn in 2018. A Palermo rating of −4 indicates an event that is 10,000 times less likely than the background hazard level of Earth impacts, which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact.

Date Object Estimateddiameter(meters) Obsarc(days) Impactprobability(1 in) Palermoscale JPL Horizonsnominal geocentricdistance (AU) NEODySnominal geocentricdistance (AU)2017-05-222010 GZ60 -- Earth Impact Risk Summary (4 missed virtual impactors) 2,000 1.3 830,000,000 -1.83 Not listed2017-05-252010 XB73 -- Earth Impact Risk Summary (2 missed virtual impactors) 110 1.1 120,000,000 -4.47 (Close Approaches)2017-08-192015 ME131 -- Earth Impact Risk Summary 500 1.8 420,000,000 -3.41 2017-09-182015 HV182 -- Earth Impact Risk Summary (4 missed virtual impactors) 157 0.9 7,700,000,000 -5.78 2017-11-182008 VS4 -- Earth Impact Risk Summary (21 missed virtual impactors) 45 0.083 100,000,000 -5.50 2017-11-292007 YM -- Earth Impact Risk Summary (3 missed virtual impactors) 2007 YM 20 0.13 2,000,000 -5.21 2017-12-01 2,000 1.3 10,000,000,000 -3.62 Not listed2017-12-132005 TM173 -- Earth Impact Risk Summary (17 missed virtual impactors) 53 1.9 230,000,000 -5.98 2017-12-20 2,000 1.3 83,000,000 -1.97 Not listed

Notes

See also List of asteroid close approaches to Earth List of asteroid close approaches to Earth in 2016 List of asteroid close approaches to Earth in 2018 List of bolides (asteroids and meteoroids that impacted Earth)

Notes

References

External links Near-Earth object close approaches ±30 days within 5 LD (JPL) Upcoming close approaches to Earth (ESA) Table of Asteroids Next Closest Approaches to the Earth (Sormano Observatory)