Legend - object IDs plus links to more info
Data compiled at 1619 UTC on 24 July 2014 for three known objects during a period of seven days from 21 to 27 July 2014. Orange is for objects with a new JPL orbit solution (usually from new observation).
Object Details - Skychart objects presented in reverse designation order, newest first
("designation assigned to" indicates unofficial discovery credit)
|2013 RZ53 - approaching|
|Approximate diameter||2 meters (H=31.1)|
|Closest Earth approach||1.90 LD at 0403 UT on 9 Sept. 2014 - Note: JPL reports an approach uncertainty of +/- 20 minutes|
|Inside Earth SOI||4 to 13 Sept. 2014|
|Inside ten LD of Earth||5 Aug. until 12 Oct. 2014|
|Closest Moon approach||2.26 LD at 0407 UT on 5 Sept. 2014|
|Data based on||JPL SSD orbit solution #6 downloaded from JPL on 21 July 2014 UTC (dated 13 June 2014 local)|
based on 31 observations spanning 3 days
previous passage Sept. 2013 at 0.63 LD
|2011 PU1 - departed|
|Approximate diameter||34 meters (H=25.)|
|Closest Earth approach||8.51 LD at 0234 UT on 17 July 2014|
|Inside ten LD of Earth||12 to 21 July 2014|
|Data based on||JPL SSD orbit solution #20 downloaded from JPL on 24 July 2014 UTC|
based on 64 observations spanning 2011-2014
|Notes||radar target, potential mission destination|
previous passage July 2011 at 0.87 LD
|2007 AB2 - distant observation|
|Approximate diameter||295 meters (H=20.3)|
|Distance from Earth||217.6 - 217.7 LD min-max during the observation period|
|Data based on||JPL SSD orbit solution #39 downloaded from JPL on 23 July 2014 UTC|
based on 430 observations spanning 2007-2014
|Notes||previous passage Dec. 2006 at 5.4 LD, observation Feb. 2010, and observation May 2013|
1. Ten lunar distances: A "lunar distance" (LD) is the average distance between Earth and Moon (about 384,400 km., the same as 238,855 miles or nearly ten [9.59] times around Earth's equator). Ten lunar distances has no special astronomical importance but is a useful arbitrary "bubble" within which to organize this reporting. 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 within which Earth's gravitational influence can change the orbits of passing objects. The Moon also has a Hill sphere, outlined here as a gray circle. (Earth and Moon are not shown to scale.) The "Earth-Moon system" is generally defined as that region of space within a radius of one lunar distance from Earth, so an object can pass very close to the Moon yet not be described as coming "inside" the E-M system.
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. The MPC, NASA, and JPL 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, which is significant because the Earth moves through its own diameter in about seven minutes. Thus actual encounter distances may 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 for 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.