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Designation: 2013 ET · NASA id: 3629117
Estimated diameter: 64 – 143 meters
These describe where an object sits in a catalogue, not how dangerous it is. The full ranked list is on the impact risk page.
2.8 megatonnes – 105.5 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.
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:
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.
Orbit class: APO — Near-Earth asteroid orbits which cross the Earth’s orbit similar to that of 1862 Apollo
a (semi-major axis) > 1.0 AU; q (perihelion) < 1.017 AU
| Orbital period | 483.5 days (1.32 years) |
| Eccentricity | .3842859405625196 (0 = circular, closer to 1 = more elongated) |
| Semi-major axis | 1.205572015056196 AU |
| Inclination | 4.851498761996817° (tilt of its orbit vs. Earth's) |
| Perihelion distance | .7422876393344734 AU (closest approach to the Sun) |
| Aphelion distance | 1.668856390777918 AU (farthest from the Sun) |
| Minimum Orbit Intersection Distance | 0.00411 AU = 614,834 km (closest its orbit path ever comes to Earth's, regardless of timing) |
| Ascending node longitude | 171.3027210987275° |
| Argument of perihelion | 81.93783681112767° |
| Mean anomaly / motion | 121.702386971912° / .7445850921808969°/day |
| Jupiter Tisserand invariant | 5.202 (helps distinguish asteroids from comets) |
| Reference epoch / equinox | JD 2459000.5 / J2000 |
| Orbit determined | 2017-04-06 08:46:37 |
| Observed | 2013-03-03 to 2013-03-10 (7 day arc, 523 observations used) |
| Orbit uncertainty | 3 (0 = best known, 9 = least certain) |
Every close approach NASA has on record for this object — 86 total.
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. 70 of them were approaches to Earth, 10 of them were approaches to Venus, 5 of them were approaches to Mars and 1 of them were approaches to Moon.
This one’s path runs from 0.742 AU at its closest to the Sun out to 1.669 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 483.5 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 (0.0041 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: 2030-09-19
| Date | Passed near | Velocity (km/h) | Miss distance |
|---|---|---|---|
| 2131-03-02 | Earth | 61037.34 | 25,089,193 km 65.3 LD |
| 2127-03-08 | Earth | 49440.00 | 8,763,612 km 22.8 LD |
| 2123-03-13 | Earth | 40785.74 | 3,480,679 km 9.05 LD |
| 2122-05-22 | Mars | 26869.39 | 10,211,888 km 26.6 LD |
| 2119-03-28 | Earth | 28572.19 | 23,040,886 km 59.9 LD |
| 2111-10-17 | Earth | 33483.04 | 74,500,313 km 194 LD |
| 2111-02-10 | Earth | 28486.48 | 61,621,300 km 160 LD |
| 2107-10-05 | Earth | 28812.23 | 63,099,355 km 164 LD |
| 2107-01-28 | Earth | 33498.76 | 73,488,393 km 191 LD |
| 2103-07-12 | Earth | 35299.97 | 37,336,220 km 97.1 LD |
| 2103-06-03 | Venus | 39253.44 | 13,985,679 km 36.4 LD |
| 2099-08-10 | Earth | 27722.61 | 27,189,970 km 70.7 LD |
| 2095-08-30 | Earth | 36021.91 | 10,582,493 km 27.5 LD |
| 2095-07-17 | Venus | 42453.45 | 22,111,516 km 57.5 LD |
| 2091-09-07 | Earth | 47793.97 | 7,013,907 km 18.2 LD |
| 2087-09-14 | Earth | 62780.22 | 28,076,476 km 73.0 LD |
| 2083-09-20 | Earth | 78214.53 | 49,565,899 km 129 LD |
| 2079-09-27 | Earth | 93696.99 | 70,949,543 km 185 LD |
| 2078-04-13 | Venus | 27093.12 | 13,072,892 km 34.0 LD |
| 2074-02-20 | Earth | 82426.31 | 54,558,034 km 142 LD |
| 2070-02-27 | Earth | 64822.05 | 30,366,543 km 79.0 LD |
| 2066-03-07 | Earth | 47912.60 | 6,723,401 km 17.5 LD |
| 2062-03-15 | Earth | 34913.12 | 11,830,963 km 30.8 LD |
| 2061-01-13 | Venus | 23911.82 | 11,087,136 km 28.8 LD |
| 2058-04-14 | Earth | 30858.19 | 30,978,466 km 80.6 LD |
| 2054-05-16 | Earth | 38901.04 | 40,113,835 km 104 LD |
| 2054-02-14 | Earth | 25987.57 | 56,698,306 km 147 LD |
| 2050-10-07 | Earth | 30098.51 | 65,902,251 km 171 LD |
| 2050-06-10 | Earth | 40619.76 | 42,097,748 km 110 LD |
| 2050-01-29 | Earth | 32468.00 | 70,996,127 km 185 LD |
| 2046-09-15 | Earth | 21521.99 | 49,844,346 km 130 LD |
| 2046-07-07 | Earth | 36165.71 | 38,253,085 km 99.5 LD |
| 2043-10-22 | Venus | 23536.71 | 10,714,624 km 27.9 LD |
| 2042-08-15 | Earth | 27475.07 | 24,941,943 km 64.9 LD |
| 2041-07-03 | Mars | 29286.72 | 9,125,088 km 23.7 LD |
| 2038-09-03 | Earth | 42804.46 | 2,357,638 km 6.13 LD |
| 2034-09-11 | Earth | 58975.10 | 22,798,557 km 59.3 LD |
| 2030-09-19 next | Earth | 75885.28 | 46,508,851 km 121 LD |
| 2026-09-26 | Earth | 93136.99 | 70,330,128 km 183 LD |
| 2026-08-10 | Venus | 27404.15 | 13,177,573 km 34.3 LD |
| 2021-02-20 | Earth | 79927.60 | 51,317,048 km 133 LD |
| 2017-02-28 | Earth | 60538.72 | 24,495,046 km 63.7 LD |
| 2013-03-09 | Moon | 41412.69 | 1,066,425 km 2.77 LD |
| 2013-03-09 | Earth | 42754.95 | 975,490 km 2.54 LD |
| 2009-05-04 | Earth | 36533.93 | 37,755,209 km 98.2 LD |
| 2009-02-24 | Earth | 21661.77 | 49,488,203 km 129 LD |
| 2005-09-27 | Earth | 26357.83 | 57,063,087 km 148 LD |
| 2005-06-26 | Earth | 38880.51 | 40,788,208 km 106 LD |
| 2001-08-30 | Earth | 35357.91 | 11,434,664 km 29.7 LD |
| 1997-09-15 | Earth | 66846.21 | 33,803,586 km 87.9 LD |
| 1992-02-17 | Earth | 88727.80 | 63,244,847 km 165 LD |
| 1989-08-06 | Venus | 47332.55 | 20,121,855 km 52.3 LD |
| 1988-03-02 | Earth | 56407.08 | 18,672,874 km 48.6 LD |
| 1984-03-26 | Earth | 28331.64 | 23,615,960 km 61.4 LD |
| 1980-10-15 | Earth | 33388.72 | 73,497,734 km 191 LD |
| 1980-05-26 | Earth | 40526.15 | 41,825,765 km 109 LD |
| 1980-05-15 | Venus | 45678.44 | 18,818,234 km 49.0 LD |
| 1980-02-06 | Earth | 29259.77 | 63,154,989 km 164 LD |
| 1979-06-10 | Mars | 30632.08 | 11,080,845 km 28.8 LD |
| 1976-07-12 | Earth | 35026.89 | 37,145,698 km 96.6 LD |
| 1972-09-02 | Earth | 40268.91 | 4,651,893 km 12.1 LD |
| 1968-09-14 | Earth | 65339.40 | 31,706,764 km 82.5 LD |
| 1964-09-25 | Earth | 90580.89 | 66,732,548 km 174 LD |
| 1959-02-23 | Earth | 73426.63 | 42,240,389 km 110 LD |
| 1955-03-07 | Earth | 47858.29 | 6,659,509 km 17.3 LD |
| 1951-03-28 | Earth | 28358.77 | 24,039,557 km 62.5 LD |
| 1947-05-15 | Earth | 38829.09 | 40,054,149 km 104 LD |
| 1947-02-14 | Earth | 25846.59 | 56,296,536 km 146 LD |
| 1944-10-08 | Venus | 24407.46 | 11,092,648 km 28.9 LD |
| 1943-10-01 | Earth | 28016.24 | 60,709,481 km 158 LD |
| 1943-06-20 | Earth | 39869.59 | 41,520,161 km 108 LD |
| 1939-08-07 | Earth | 27937.24 | 28,237,258 km 73.5 LD |
| 1935-09-05 | Earth | 46443.27 | 5,250,660 km 13.7 LD |
| 1935-06-21 | Venus | 37450.53 | 12,226,687 km 31.8 LD |
| 1931-09-17 | Earth | 72316.32 | 41,367,940 km 108 LD |
| 1926-02-15 | Earth | 91028.11 | 66,296,598 km 172 LD |
| 1922-02-26 | Earth | 64985.83 | 30,579,062 km 79.6 LD |
| 1918-03-11 | Earth | 39551.88 | 5,275,938 km 13.7 LD |
| 1917-05-16 | Mars | 30799.56 | 11,145,630 km 29.0 LD |
| 1914-05-01 | Earth | 35760.99 | 36,884,536 km 96.0 LD |
| 1910-10-04 | Earth | 29179.44 | 63,126,141 km 164 LD |
| 1910-06-15 | Earth | 40410.83 | 42,032,283 km 109 LD |
| 1910-01-25 | Earth | 33607.43 | 73,660,042 km 192 LD |
| 1906-08-12 | Earth | 27414.01 | 26,603,677 km 69.2 LD |
| 1904-03-22 | Mars | 24786.06 | 12,544,782 km 32.6 LD |
| 1902-09-08 | Earth | 52053.03 | 12,927,432 km 33.6 LD |
Looked up from NASA's NeoWs API and cached — last refreshed 2026-09-23T02:58:38.948192+00:00.