Screen shot from an online interactive sky chart viewer under development at A/CC to show the paths of objects that are passing Earth at less than ten lunar distances (LD). Objects in white are outside ten LD at the date and time shown, green inside ten LD, yellow inside Earth's Hill Sphere (except the Sun, of course), orange inside two LD, and red inside one LD of Earth -- all from JPL SSD Horizons data.
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Today's Traffic: There are three objects known to be moving within ten lunar distances (LD)1 of Earth today, January 6th. 2008 YG30 is outward bound, starting the day at 4.72 LD and finishing at 6.70 LD. 2008 YV32 is at 7.88-6.11 LD. And 2008 YY32 departs from within ten LD today.
Two objects are known to be approaching in the near future. 2008 YF29 will come inside ten LD on January 10th and 2002 AO11 on January 11th.
There are seven objects that recently flew past Earth at less than ten LD and remain of continuing interest. See their details below.
This report was refreshed at 0001 UTC.
Looking for recent impactor 2008 TC3? See news links.
1. Ten lunar distances: A "lunar distance" (LD) is the average distance between Earth and Moon (about 384,400 km.). Ten lunar distances has no special astronomical importance but is a useful arbitrary "bubble" within which to organize this report. An approach by a small Solar-System body starts to become interesting at less than four LD out from Earth as it encounters our planet's "Hill sphere" (distance indicated by the blue line in this illustration at about 3.9 LD). This is a region where the Earth exercises gravitational influence over passing objects and can change their orbital paths. The Moon also has a Hill sphere, outlined here as a gray circle. (The Earth and Moon are not shown to scale.)
2. Data credit: All data on this page derived from orbit solutions comes from the NASA JPL Solar System Dynamics (SSD) Group through its Horizons system. All information about optical observations comes from the IAU Minor Planet Center (MPC) and info about radar observations comes from JPL SSD. NASA, JPL, and the MPC are not associated with this page or A/CC, and responsibility for the interpretation of this information and its use here rests entirely with A/CC. Important note: Approach times presented here as to-the-minute may have unstated uncertainties of a few minutes, or many minutes or even hours for objects with old or very short observation spans. Therefore, actual encounter distances may also vary, occasionally by as much as ten lunar distances. See JPL's Close Approach Tables for nominal vs. minimum possible passage distances and times and their note about uncertainties.
3. Size estimates: Object diameters are rough approximations derived by standard formula from H, an object's "absolute magnitude" (brightness), where higher numbers represent dimmer (thus usually smaller) objects.
| 2008 YY32 - departing | |
| Approximate diameter: | 30 meters (H=25.25) |
| Closest Earth approach: | 6.15 LD at 1327 UTC on 3 Jan. |
| Inside ten LD of Earth: | 31 Dec. until today |
| Data based on: | JPL SSD orbit solution #3 downloaded 4 Jan. based on 43 observations spanning 2008-2009 |
| Optical observation: | observed from 9 locations during 3.7055 days discovered at 1201 UTC on 31 Dec. by the Catalina Sky Survey first observed at 1011 UTC on 31 Dec. by the Catalina Sky Survey last observed at 0307 UTC on 4 Jan. by Great Shefford Obs. |
| 2008 YG30 - departing | |
| Approximate diameter: | 40 meters (H=24.618) |
| Closest Earth approach: | 3.62 LD at 2007 UTC on 4 Jan. |
| Inside Earth's Hill sphere: | 4 Jan. until yesterday |
| Inside ten LD of Earth: | 1 to 8 Jan. |
| Data based on: | JPL SSD orbit solution #4 downloaded 4 Jan. based on 33 observations spanning 2008-2009 |
| Optical observation: | observed from 7 locations during 3.6467 days discovered at 0633 UTC on 31 Dec. by the Catalina Sky Survey last observed at 2204 UTC on 3 Jan. by Great Shefford Obs. |
| 2008 YV32 - approaching | |
| Approximate diameter: | 19 meters (H=26.312) |
| Closest Earth approach: | 2.75 LD at 1941 UTC on 9 Jan. - Note: JPL reports an approach uncertainty of 5 minutes. |
| Inside Earth's Hill sphere: | 8 to 11 Jan. |
| Inside ten LD of Earth: | 4 to 14 Jan. |
| Data based on: | JPL SSD orbit solution #3 downloaded 4 Jan. based on 33 observations spanning 2008-2009 |
| Optical observation: | observed from 6 locations during 2.9281 days discovered at 0517 UTC on 31 Dec. by the Mt. Lemmon Survey last observed at 0333 UTC on 3 Jan. by the Spacewatch 1.8m telescope |
| Note: | risk |
| 2008 YF29 - approaching | |
| Approximate diameter: | 50 meters (H=24.143) |
| Closest Earth approach: | 9.68 LD at 0822 UTC on 11 Jan. |
| Inside ten LD of Earth: | 10 to 12 Jan. |
| Data based on: | JPL SSD orbit solution #5 downloaded 4 Jan. based on 42 observations spanning 2008-2009 |
| Optical observation: | observed from 9 locations during 4.5426 days discovered at 0558 UTC on 30 Dec. by the Catalina Sky Survey last observed at 1900 UTC on 3 Jan. by Guidestar Obs. |
| Note: | risk |
| 2002 AO11 - approaching | |
| Approximate diameter: | 95 meters (H=22.75) |
| Closest Earth approach: | 7.68 LD at 1003 UTC on 15 Jan. - Note: JPL reports an approach uncertainty of 5 hours and 25 minutes. |
| Inside ten LD of Earth: | 11 to 19 Jan. |
| Data based on: | JPL SSD orbit solution #2 downloaded 30 Dec. based on 11 observations spanning 3 days |
| Optical observation: | none recent |
These objects either departed from ten LD during the last week or were reported observed.
| 2008 XU2 - departed | |
| Approximate diameter: | 26 meters (H=25.565) |
| Closest Earth approach: | 2.13 LD at 1028 UTC on 30 Nov. |
| Inside Earth's Hill sphere: | 29 Nov. until 1 Dec. |
| Inside ten LD of Earth: | 26 Nov. until 4 Dec. |
| Closest Moon approach: | 1.98 LD at 0043 UTC 30 Nov. |
| Data based on: | JPL SSD orbit solution #7 downloaded 4 Jan. based on 44 observations spanning 2008-2009 |
| Optical observation: | observed from 6 locations during 27.9970 days discovered at 0616 UTC on 6 Dec. by the Mt. Lemmon Survey last observed at 0612 UTC on 3 Jan. by Astronomical Research Obs. |
| Note: | risk |
| 2008 WY94 - departed | |
| Approximate diameter: | 26 meters (H=25.615) |
| Closest Earth approach: | 3.16 LD at 0941 UTC on 5 Dec. |
| Inside Earth's Hill sphere: | 3 to 7 Dec. |
| Inside ten LD of Earth: | 25 Nov. until 14 Dec. |
| Data based on: | JPL SSD orbit solution #8 downloaded 30 Dec. based on 34 observations spanning 30 days |
| Optical observation: | observed from 6 locations during 29.9713 days discovered at 1257 UTC on 29 Nov. by the Siding Spring Survey last observed at 1216 UTC on 29 Dec. by Magdalena Ridge Obs. |
| 2008 YN2 - departed | |
| Approximate diameter: | 19 meters (H=26.281) |
| Closest Earth approach: | 7.57 LD at 1425 UTC on 14 Dec. |
| Inside ten LD of Earth: | 10 to 18 Dec. |
| Data based on: | JPL SSD orbit solution #6 downloaded 4 Jan. based on 46 observations spanning 2008-2009 |
| Optical observation: | observed from 8 locations during 12.9927 days discovered at 0326 UTC on 21 Dec. by the Mt. Lemmon Survey last observed at 0316 UTC on 3 Jan. by Astronomical Research Obs. |
| 2008 EV5 - departed | |
| Approximate diameter: | 344 meters (H=19.967) |
| Closest Earth approach: | 8.41 LD at 1516 UTC on 23 Dec. |
| Inside ten LD of Earth: | 18 to 29 Dec. |
| Data based on: | JPL SSD orbit solution #43 downloaded yesterday based on 371 observations spanning 2008-2009 including radar observation |
| Optical observation: | observed from 20 locations during 306.6329 days discovered at 0508 UTC on 4 March 2008 by the Mt. Lemmon Survey last observed at 2019 UTC on 4 Jan. by El Guijo Obs. |
| Radar observation: | observed 2 times from one location during 3.9306 days first observed at 0940 UTC 17 Dec. by Goldstone DSS-14 70m antenna last observed at 0800 UTC 21 Dec. by Goldstone DSS-14 70m antenna |
| Note: | radar target |
| Link: |
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| 2008 YH30 - departed | |
| Approximate diameter: | 14 meters (H=26.862) |
| Closest Earth approach: | 3.58 LD at 1424 UTC on 25 Dec. - Note: JPL reports an approach uncertainty of 3 minutes. |
| Inside Earth's Hill sphere: | 24 to 26 Dec. |
| Inside ten LD of Earth: | 21 to 29 Dec. |
| Data based on: | JPL SSD orbit solution #3 downloaded 3 Jan. based on 23 observations spanning 2008-2009 |
| Optical observation: | observed from 5 locations during 2.7627 days discovered at 0701 UTC on 31 Dec. by the Spacewatch 0.9m telescope last observed at 0120 UTC on 3 Jan. by Great Shefford Obs. |
| 2008 YB29 - departed | |
| Approximate diameter: | 25 meters (H=25.639) |
| Closest Earth approach: | 7.34 LD at 1438 UTC on 27 Dec. |
| Inside ten LD of Earth: | 23 to 31 Dec. |
| Data based on: | JPL SSD orbit solution #4 downloaded 3 Jan. based on 33 observations spanning 2008-2009 |
| Optical observation: | observed from 6 locations during 3.7774 days discovered at 0918 UTC on 30 Dec. by the Catalina Sky Survey last observed at 0358 UTC on 3 Jan. by Great Shefford Obs. |
| 2008 YC29 - departed | |
| Approximate diameter: | 29 meters (H=25.317) |
| Closest Earth approach: | 3.37 LD at 0030 UTC on 2 Jan. - Note: JPL reports an approach uncertainty of 32 minutes. |
| Inside Earth's Hill sphere: | 1 to 2 Jan. |
| Inside ten LD of Earth: | 29 Dec. until yesterday |
| Data based on: | JPL SSD orbit solution #1 downloaded 30 Dec. based on 18 observations |
| Optical observation: | observed from 3 locations during 0.1367 days discovered at 1008 UTC on 30 Dec. by the Catalina Sky Survey last observed at 1325 UTC on 30 Dec. by the Catalina Sky Survey |