- Object
- Object primary designation
- Close-Approach (CA) Date
- Date and time (TDB) of closest Earth approach. "Nominal Date" is given to appropriate precision. The 3-sigma uncertainty in the time is given in the /- column in days_hours:minutes format (for example, "2_15:23" is 2 days, 15 hours, 23 minutes; "< 00:01" is less than 1 minute).
- View CA
- Open the close-approach viewer and render the high-precision trajectory during the close approach.
- CA Distance Nominal (au)
- The most likely (Nominal) close-approach distance (Earth center to NEO center), in astronomical units.
- CA Distance Minimum (au)
- The minimum possible close-approach distance (Earth center to NEO center), in astronomical units. The minimum possible distance is based on the 3-sigma Earth target-plane error ellipse.
- V relative (km/s)
- Object velocity relative to Earth at close-approach.
- V infinity (km/s)
- Object velocity relative to a massless Earth at close-approach.
- H (mag)
- Asteroid absolute magnitude (in general, smaller H implies larger asteroid diameter). Undefined for comets.
- Diameter
- Diameter value when known or a range (min - max) estimated using the asteroid's absolute magnitude (H) and limiting albedos of 0.25 and 0.05.
- Rarity
- A measure of how infrequent the Earth close approach is for asteroids of the same size and larger: 0 means an average frequency of 100 per year, i.e., roughly every few days or less, 1 corresponds to roughly once a month, 2 to roughly once a year, 3 to roughly once a decade, etc. 'n/a' means that a frequency estimate is not available. See note for details.
- au
- One Astronomical Unit (au) is approximately 150 million kilometers (see glossary for definition).
- LD
- One Lunar Distance (LD) is approximately 384,000 kilometers (see glossary for definition).
