About (137427) 1999 TF211
(137427) 1999 TF211 is a common neo. It swings within 0.947 AU of the Sun at perihelion.
An Apollo-class object: its orbit is wider than Earth's but crosses it. Most known Earth-crossers belong to this family.
Common neo 21 EP
(137427) 1999 TF211
Position computed live · sbdb
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Live ephemeris
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Score breakdown
· 4 badgesCommon 22 pts → Uncommon
- Potentially hazardous +12
- Near-Earth object +5
- Apollo: crosses Earth's orbit +4
- Catalogue designation only +0
Total score 21
1 more point to reach Uncommon.
Badges
- Near-Earth object · +5
- Potentially hazardous · +12
- Catalogue designation only
- Apollo: crosses Earth's orbit · +4
Trivia
Handle with care
- What 'hazardous' means. 'Potentially hazardous' is bookkeeping, not a prediction: it means the orbit passes within 0.05 AU of Earth's and the body is big enough to matter. Nothing on that list is known to be on a collision course.
- If it ever hit. A rock this size arriving at a typical 20 km/s would release around 2 million megatons — the same league as the impact that ended the age of the dinosaurs.
What it actually is
- Its orbit family. An Apollo-class object: its orbit is wider than Earth's but crosses it. Most known Earth-crossers belong to this family.
- Closest approach. At its nearest it comes within 0.95 AU of the Sun — inside the orbit of Earth.
- One lap. A single orbit around the Sun takes it about 3.8 years.
- How far it roams. Its orbit swings between 0.95 and 3.93 AU from the Sun.
Sense of scale
- Sense of scale. In everyday terms it is roughly 0.4× the height of Mount Everest.
By the numbers
- Estimated size. Nobody has measured its size directly. Assuming it reflects light like a typical asteroid, its brightness implies something roughly 3.1 km across.
Properties
- aphelion au
- 3.93
- designation
- 137427
- eccentricity
- 0.6119
- full name
- 137427 (1999 TF211)
- h mag
- 15.28
- inclination
- 39.51
- mean motion deg day
- 0.2587
- moid au
- 0.0283
- name
- (137427) 1999 TF211
- number only
- yes
- orbit class
- APO
- perihelion au
- 0.947
- pha
- yes
- semi major au
- 2.439
How to see it
Like any astronomical target, (137427) 1999 TF211 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. Because it moves against the background stars, the live position panel on this page tracks where it is right now. The visibility panel above works out tonight's viewing window for your saved location.
Why (137427) 1999 TF211 is a common neo
(137427) 1999 TF211 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.
That score comes from 4 science badges — Near-Earth object, Potentially hazardous, Catalogue designation only and Apollo: crosses Earth's orbit — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.