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

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(2013 ET)

Designation: 2013 ET · NASA id: 3629117

Estimated diameter: 64 – 143 meters

≈ a football pitch
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 = 23.1) · JPL Small-Body Database →

Earth impact concern
No identified impact threat
Why?
  • Its closest recorded pass was 2.5 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

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.

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: 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 period483.5 days (1.32 years)
Eccentricity.3842859405625196 (0 = circular, closer to 1 = more elongated)
Semi-major axis1.205572015056196 AU
Inclination4.851498761996817° (tilt of its orbit vs. Earth's)
Perihelion distance.7422876393344734 AU (closest approach to the Sun)
Aphelion distance1.668856390777918 AU (farthest from the Sun)
Minimum Orbit Intersection Distance0.00411 AU = 614,834 km
(closest its orbit path ever comes to Earth's, regardless of timing)
Ascending node longitude171.3027210987275°
Argument of perihelion81.93783681112767°
Mean anomaly / motion121.702386971912° / .7445850921808969°/day
Jupiter Tisserand invariant5.202 (helps distinguish asteroids from comets)
Reference epoch / equinoxJD 2459000.5 / J2000
Orbit determined2017-04-06 08:46:37
Observed2013-03-03 to 2013-03-10 (7 day arc, 523 observations used)
Orbit uncertainty3 (0 = best known, 9 = least certain)

Close Approach History

Every close approach NASA has on record for this object — 86 total.

Why does it pass Earth, Venus, Mars and Moon? 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. 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.