Illustration of Earth with several asteroids passing at different distances, one flagged as potentially hazardous

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(2011 EK47)

Designation: 2011 EK47 · NASA id: 3559782

Estimated diameter: 37 – 82 meters

≈ an airliner's wingspan
That comparison is of size only — what an impact would do depends on speed, angle, composition and where it arrives, none of which follows from width.
(absolute magnitude H = 24.3) · JPL Small-Body Database →

Earth impact concern
No identified impact threat
Why?
  • Its closest recorded pass was 13.3 lunar distances.
  • It is not on NASA/JPL’s Sentry list, which holds every object with a computed chance of impact above zero. Most objects are not on it.
What the four levels mean
  • No identified impact threat — not on any risk list. 98.8% of the objects here.
  • On a monitored risk list — a computed chance above zero, however small. 1.2% of the objects here.
  • Among the highest-ranked — Palermo at or above −2. Two objects worldwide qualify, both studied for decades and both centuries away.
  • Exceptional — Torino 1 or more, or Palermo at or above zero. No object anywhere currently qualifies.

These describe where an object sits in a catalogue, not how dangerous it is. The full ranked list is on the impact risk page.

Energy of motion, if it ever entered the atmosphere

741 kilotonnes – 27.6 megatonnes of TNT

This is not a forecast. Nothing here says this object will arrive, and almost nothing ever does — what is actually assessed, by people with far better data than this page has, is on the impact risk page. This is simply the kinetic energy such a body would carry, worked out from its size and its usual encounter speed.

The range spans a factor of 37, and it cannot be narrowed. Nobody has weighed this object. Its diameter is inferred from how bright it is under an assumed reflectivity, which carries a fixed factor of 2.24 — and because mass goes as the cube of diameter, that alone becomes a factor of 11. Density is then assumed somewhere between 1,500 and 5,000 kg/m³, from a loose rubble pile to dense rock. Quoting a tighter figure would be invented precision.

Megatonnes do not mean what the word suggests here. Most of this energy is spent high in the atmosphere, not on the ground, and the comparison with weapons misleads badly. The Chelyabinsk body released around 440 kilotonnes in 2013 — this same calculation gives it 166 to 904 — and the damage was broken windows across a city, from the shock wave of an airburst some thirty kilometres up. No crater, and nothing that reached the ground intact.

Why is one asteroid “hazardous” when closer ones are not?

Because the flag has nothing to do with how close it came on the day. NASA marks an object a Potentially Hazardous Asteroid only if both of these are true of its orbit and its size:

  • Its orbit can bring it within 0.05 AU of Earth’s — about 7.5 million km. This is the Minimum Orbit Intersection Distance, the closest the two paths ever come, not the distance on any given pass.
  • It is big enough to matter — absolute magnitude 22.0 or brighter, which is roughly 140 metres across and up. That threshold is a planning convention, not a physical boundary: it is about the size at which an impact could do regional damage. Smaller objects are not harmless, they are simply outside this definition — the Chelyabinsk object of 2013 was around 20 metres and injured about 1,500 people with the shock wave from its airburst, without ever reaching the ground intact.

The two terms: AU — astronomical unit, the average Earth–Sun distance, 149,597,871 km. 0.05 AU is about 7.5 million km.
MOID — minimum orbit intersection distance, the closest the two orbits ever come, whatever the timing. See the glossary for NEO, PHA and H.

So a large rock passing at 39 million km today can be flagged, because on some future orbit it could come far nearer — while a pebble skimming past at 4 million km is not, because it would never reach the ground.

Three objects that all passed Earth on 30 August 2026 make the point better than any definition:

Object Size Orbit’s closest to Earth’s Missed by, that day Flagged
2013 JR28 122–272 m 5.3 M km (0.035 AU) 39.2 M km Yes — both tests pass
2012 LE11 629–1,406 m 23.3 M km (0.156 AU) 26.1 M km No — orbit never gets near enough
2007 EK 3.7–8.2 m 198,000 km (0.0013 AU) 4.2 M km No — far too small

The middle one is five times larger than the flagged one and passed closer on the day, but its path can never come within 23 million km of ours. The last one’s orbit crosses inside the Moon’s distance — nearer than any other object here — and it is still not hazardous, because at a few metres across it would burn up long before it landed.

“Potentially hazardous” is a watchlist criterion, not a prediction. None of these is on a collision course; the label means an object is worth keeping precise track of over the coming centuries.

Orbital Data

Orbit class: ATE — Near-Earth asteroid orbits similar to that of 2062 Aten
a (semi-major axis) < 1.0 AU; q (perihelion) > 0.983 AU

Orbital period317.9 days (0.87 years)
Eccentricity.2787201492994434 (0 = circular, closer to 1 = more elongated)
Semi-major axis.9115209956305148 AU
Inclination10.82852359353989° (tilt of its orbit vs. Earth's)
Perihelion distance.6574617276388005 AU (closest approach to the Sun)
Aphelion distance1.165580263622229 AU (farthest from the Sun)
Minimum Orbit Intersection Distance0.03654 AU = 5,466,411 km
(closest its orbit path ever comes to Earth's, regardless of timing)
Ascending node longitude334.7617925038661°
Argument of perihelion44.00704069988895°
Mean anomaly / motion88.97428295286457° / 1.132541328505184°/day
Jupiter Tisserand invariant6.498 (helps distinguish asteroids from comets)
Reference epoch / equinoxJD 2461000.5 / J2000
Orbit determined2021-04-15 04:53:35
Observed2011-03-09 to 2011-03-12 (3 day arc, 15 observations used)
Orbit uncertainty7 (0 = best known, 9 = least certain)

Close Approach History

Every close approach NASA has on record for this object — 75 total.

Why does it pass Earth and Venus? Doesn’t it orbit just one?

It orbits the Sun. Not Earth, and not Venus. The column above does not say what the asteroid goes around — it says which planet a given close approach was to. 57 of them were approaches to Earth and 18 of them were approaches to Venus.

This one’s path runs from 0.657 AU at its closest to the Sun out to 1.166 AU at its farthest. For scale, Venus orbits at about 0.72 AU and Earth at 1.00 AU — so an orbit spanning that range crosses the path of every planet in between, once on the way out and once on the way back.

Crossing a planet’s path is not the same as meeting the planet. Almost every time the asteroid crosses, that planet is somewhere else along its own orbit. A close approach is logged only on the rare occasions when both happen to arrive at the crossing point at roughly the same time — which is why the dates below are scattered rather than regular. This object takes 317.9 days to go round, against Earth’s 365.25, so the two drift in and out of step over years rather than repeating on a neat cycle.

The Minimum Orbit Intersection Distance in the table above (0.0365 AU) is the closest the two paths ever come. The miss distances below are how far apart the two bodies actually were on the day, which is almost always very much larger.

next approach: 2031-02-14

Date Passed near Velocity (km/h) Miss distance
2200-10-13 Venus 52040.19 13,623,099 km
35.4 LD
2195-06-03 Earth 49153.81 38,708,416 km
101 LD
2194-11-13 Venus 33994.39 19,287,834 km
50.2 LD
2194-02-16 Earth 31179.71 6,913,345 km
18.0 LD
2187-02-15 Earth 40393.71 12,374,179 km
32.2 LD
2180-02-18 Earth 53371.19 30,583,382 km
79.6 LD
2173-02-22 Earth 68043.77 50,577,985 km
132 LD
2168-05-21 Earth 76622.42 70,388,382 km
183 LD
2166-02-28 Earth 84714.99 72,926,414 km
190 LD
2163-04-12 Venus 34637.36 6,885,240 km
17.9 LD
2161-05-29 Earth 59502.43 49,938,269 km
130 LD
2160-09-08 Earth 43851.07 48,751,258 km
127 LD
2160-02-25 Earth 27407.95 16,583,389 km
43.1 LD
2154-06-07 Earth 41472.98 32,178,936 km
83.7 LD
2153-02-14 Earth 37803.13 9,045,691 km
23.5 LD
2146-02-20 Earth 60493.75 40,385,424 km
105 LD
2141-05-20 Earth 78629.75 72,980,967 km
190 LD
2139-03-01 Earth 85316.59 73,812,821 km
192 LD
2134-05-31 Earth 54595.20 44,572,048 km
116 LD
2133-09-15 Earth 44973.30 50,109,116 km
130 LD
2133-02-19 Earth 29099.07 10,459,031 km
27.2 LD
2132-02-13 Venus 34669.45 19,110,794 km
49.7 LD
2127-07-28 Venus 53082.92 14,713,778 km
38.3 LD
2127-06-12 Earth 33033.56 28,067,259 km
73.0 LD
2126-10-13 Earth 45503.17 53,314,944 km
139 LD
2126-02-16 Earth 46318.09 20,859,378 km
54.3 LD
2121-08-29 Venus 42563.17 20,133,054 km
52.4 LD
2120-07-18 Earth 29391.86 34,885,814 km
90.8 LD
2119-11-10 Earth 39137.97 52,206,306 km
136 LD
2119-02-23 Earth 68026.28 50,685,817 km
132 LD
2117-02-13 Venus 44608.78 5,839,973 km
15.2 LD
2114-05-22 Earth 74371.53 67,640,591 km
176 LD
2113-08-19 Earth 39088.47 43,868,495 km
114 LD
2111-03-15 Venus 46091.62 21,592,051 km
56.2 LD
2107-05-30 Earth 56820.66 46,964,060 km
122 LD
2106-09-12 Earth 44455.14 49,378,154 km
128 LD
2106-08-30 Venus 45920.53 7,263,607 km
18.9 LD
2106-02-22 Earth 27847.36 14,658,157 km
38.1 LD
2100-09-28 Venus 37566.80 19,171,838 km
49.9 LD
2100-06-05 Earth 44199.74 34,310,030 km
89.3 LD
2099-09-26 Earth 46022.36 51,868,826 km
135 LD
2099-02-14 Earth 34559.97 5,881,887 km
15.3 LD
2096-03-10 Venus 57888.94 19,488,263 km
50.7 LD
2092-02-15 Earth 47748.08 22,770,660 km
59.2 LD
2090-04-14 Venus 30507.00 20,761,542 km
54.0 LD
2085-02-19 Earth 62885.18 43,681,182 km
114 LD
2078-02-25 Earth 78541.48 64,757,180 km
168 LD
2073-05-24 Earth 66698.04 58,281,225 km
152 LD
2066-05-31 Earth 51436.99 41,157,551 km
107 LD
2065-02-16 Earth 29894.96 9,117,605 km
23.7 LD
2059-06-07 Earth 38121.47 30,032,565 km
78.1 LD
2058-02-14 Earth 39994.96 12,141,204 km
31.6 LD
2052-06-26 Earth 25634.65 30,197,283 km
78.6 LD
2051-10-27 Earth 43194.65 53,330,276 km
139 LD
2051-02-18 Earth 57699.07 36,585,235 km
95.2 LD
2044-02-25 Earth 78475.09 64,762,349 km
168 LD
2039-05-26 Earth 62739.40 53,738,410 km
140 LD
2031-02-14 next Earth 37857.88 9,361,934 km
24.4 LD
2024-02-19 Earth 61362.14 41,673,349 km
108 LD
2022-12-24 Venus 60562.30 22,092,848 km
57.5 LD
2019-05-20 Earth 77669.46 71,800,483 km
187 LD
2017-02-27 Earth 85773.33 74,437,452 km
194 LD
2017-01-27 Venus 39044.41 19,299,926 km
50.2 LD
2012-07-14 Venus 45566.01 6,840,536 km
17.8 LD
2012-05-29 Earth 53535.10 43,434,397 km
113 LD
2011-09-15 Earth 45191.67 50,245,750 km
131 LD
2011-02-18 Earth 29190.51 10,507,244 km
27.3 LD
2006-08-13 Venus 46508.18 21,836,502 km
56.8 LD
2005-06-08 Earth 35631.36 28,959,119 km
75.3 LD
2004-02-14 Earth 43061.68 16,468,227 km
42.8 LD
2002-01-29 Venus 43945.00 5,107,160 km
13.3 LD
1997-10-28 Earth 42742.87 53,185,480 km
138 LD
1997-02-17 Earth 58725.55 38,024,215 km
98.9 LD
1996-02-27 Venus 41950.58 20,119,363 km
52.3 LD
1990-02-23 Earth 73915.93 58,586,751 km
152 LD

Looked up from NASA's NeoWs API and cached — last refreshed 2026-09-02T13:13:02.200847+00:00.