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At a glance
- Width
- 19 to 43 m
- about 155 bananas
- Speed
- 19.20 km/s
- 69,109 km/h · 42,942 mph
- Misses us by
- 183.1 lunar
- 70,404,198 km · 43,747,127 miles
- First spotted by us
- 13th November 2026
- 2 page views
How far is "close"?
Same gap, ranked against places you have heard of, on a log scale because the Sun is awkwardly far away.
How big is it, really?
NASA only estimates the width, so we show the biggest guess. Log scale again. Everest is just there to make everything else look reasonable.
How fast is it going?
Speed relative to Earth at closest approach. The International Space Station is the fastest thing most of us will ever stand under. This lot would lap it.
If it hit (it will not)
Rough impact energy at the biggest size estimate, assuming solid rock, in tonnes, kilotons and megatons of TNT, which is how everyone who has to do this maths measures it. Treat it as a ballpark. The point stands: no impact is scheduled.
Where it actually lives
A top-down view of the orbit, to scale, with Earth's and Mars's orbits for company. The tilt of the orbit is ignored, so treat the shape as right and the exact position as roughly right. The Sun is the orange dot in the middle.
- Orbit class
- ATEAten: crosses Earth's orbit while spending most of its time inside it, between us and the Sun.
- Year length
- 0.74 Earth years (269 days)One lap of the Sun. Your commute is shorter, and so is your patience.
- Eccentricity
- 0.364How squashed the orbit is. 0 is a perfect circle, 1 is "leaving". Noticeably oval. Mildly dramatic.
- Tilt
- 10.7°The angle of its orbit against the flat plane the planets share. Slightly tipsy.
- Closest to the Sun
- 0.52 AU78 million km. One AU is the distance from Earth to the Sun.
- Furthest from the Sun
- 1.11 AU166 million km. Never leaves the inner solar system.
- Closest orbit-to-orbit gap
- 0.019 AUIf you only compare the two orbits, not where the planets are, they come within 7 lunar distances. The rock is rarely there at the same time as us, which is the entire reason we are still here.
- Observations used
- 135NASA has measured this one 135 times. It has been stalked thoroughly.
- Watched for
- 14 days2018-04-20 to 2018-05-04. Not long, so the orbit is still being refined and the rock is still a bit of a stranger.
- Orbit uncertainty
- 6 out of 90 means we know exactly where it is going. 9 means a shrug. Lower is better.
Is it actually hazardous?
This one fails at least one test, so it is not on the list. It is comfortably, boringly harmless.
Not on NASA's Sentry impact-risk watch list. No further action, no thoughts, head empty.
Its history with us
Every known pass this rock makes, 1900 to 2200. Dim dots are the past, green dots are still to come, the big orange ring is this one. The dashed line is the Moon's distance, so anything below it is closer than the Moon. Almost nothing is.
| Date | Miss distance | Speed |
|---|---|---|
| 17th December 1998 | 181.3 LD · 69,705,255 km | 17.7 km/s |
| 20th June 1999 | 135.5 LD · 52,108,001 km | 18.1 km/s |
| 28th April 2001 | 185.6 LD · 71,373,504 km | 24.2 km/s |
| 10th November 2001 | 182.6 LD · 70,228,787 km | 19.1 km/s |
| 16th April 2004 | 54.5 LD · 20,974,336 km | 13.6 km/s |
| 4th October 2004 | 166.0 LD · 63,852,168 km | 15.5 km/s |
| 13th May 2007 | 49.1 LD · 18,884,277 km | 8.2 km/s |
| 6th January 2010 | 171.6 LD · 65,979,808 km | 14.7 km/s |
| 24th June 2010 | 82.8 LD · 31,843,368 km | 12.5 km/s |
| 29th November 2012 | 184.2 LD · 70,832,064 km | 19.1 km/s |
By the numbers
- Estimated mass
- 11,215 tonnes to 125,383 tonnesVolume of a sphere at NASA's smallest and largest width estimates, times 3,000 kg per cubic metre (typical rock). Real shapes are lumpier, so treat it as a ballpark.
- Swimming pools of rock
- 6 Olympic poolsSphere volume at the middle width estimate, divided by 2,500 cubic metres per Olympic pool.
- Impact energy, if it hit
- 494 kilotons to 5.5 megatonsHalf mass times speed squared, at the small and large width estimates, converted to TNT (1 kiloton is 4.184 trillion joules). A rock this far away is not going to do this.
- Speed against escape velocity
- 1.7 timesIts speed relative to Earth, divided by the 11.186 km/s needed to leave Earth's gravity. It is travelling a lot faster than we can throw things.
- Speed against Earth in orbit
- 0.64 timesDivided by Earth's own orbital speed of 29.78 km/s around the Sun.
- Time to cross the UK
- 50.5 secondsLand's End to John o' Groats is about 970 km in a straight line. Divided by its speed.
- Time to fly the miss distance
- 42.4 daysThe miss distance divided by its speed. This is how long it needs to cover a gap of that size, which is a measure of how near or far the pass is.
- Light takes to cross the gap
- 234.8 secondsMiss distance divided by the speed of light.
- Width from brightness alone
- 19 to 43 mAstronomers estimate size from how bright an asteroid is (H 25.7) and how reflective it is. A shiny rock (albedo 0.25) is smaller than a dark one (0.05) for the same brightness. NASA's own estimate above uses the same idea.
- Laps of the Sun since first spotted
- 0.114 days of observation divided by its 269-day year.
- Known close approaches, 1900 to 2200
- 1010 inside the Moon's orbit and 4 within ten lunar distances.
- Closest pass in that period
- 7.96 lunar distancesOn 18th April 2018.
- Next visit after this one
- 17th April 2029At 65.4 lunar distances. Closer than this time.
- Average gap between visits
- 3.0 yearsThe span of the record divided by the number of gaps between approaches.
- Rank by size
- 34 of 42Among every asteroid this site has tracked, biggest first.
- Rank by closeness
- 36 of 42Among every asteroid this site has tracked, using each one's most recent pass, closest first.
- Rank by speed
- 8 of 42Among every asteroid this site has tracked, fastest first.
How reliable are these?
Width, speed, miss distance and orbit come straight from NASA. Mass, energy, volume and the rankings are our own arithmetic on top, and the assumptions are written beside each one. NASA publishes a range for width because nobody has seen most of these rocks up close, so wherever we show one number it uses the biggest estimate and says so.
Will asteroid 2018 HU hit Earth? Questions answered
Will asteroid 2018 HU hit Earth?
No. 2018 HU passes Earth on 14th November 2026 at 183.1 lunar distances (70,404,198 km), which is 183.1 times the distance to the Moon. It is not on NASA's potentially hazardous list. It is not on NASA's Sentry impact-risk watch list.
How big is asteroid 2018 HU?
NASA estimates it is between 19 m and 43 m wide, which at the top end is about 0.4 football pitches long. Nobody has seen it up close, so the width is an estimate from its brightness.
How fast is asteroid 2018 HU travelling?
19.2 km/s relative to Earth at closest approach, about 69,109 km/h (42,942 mph). That is 2.5 times the speed of the International Space Station.
Is 2018 HU a potentially hazardous asteroid?
No. NASA gives the label to asteroids whose orbit comes within 0.05 astronomical units of Earth's (about 7.5 million km) and which are bigger than roughly 140 m. 2018 HU has an absolute magnitude of 25.7 and its orbit comes within 0.019 AU of Earth's.
When is asteroid 2018 HU's next close approach?
After this pass, the next one in NASA's record is on 14th November 2026, at 183.1 lunar distances.
Unhelpful facts
- About 0.41 of a football pitch long. VAR would be unimpressed.
- 179 basketballs wide. Somebody in the NBA has already asked for the numbers.
- If this one did hit Earth, your next meeting would be cancelled. Look on the bright side.
- 0.11 Empire State Buildings tall, if you insist on laying New York on its side.
- About 123 wheels of Gouda across. A brave scientist would call that a dairy event.
- If it did hit, that would release roughly 5.5 megatons of TNT, assuming solid rock. It will not, so enjoy the number.
- It is moving 197 times faster than a sports car, and has never once paid a congestion charge.
- As fast as 1,545 Usain Bolts at top speed, none of whom have been told.
- That is 1,431 times the speed limit on a 30 zone. Nobody has fined it yet.
- In the 42.4 days it takes to fly a gap that size, you could drink 3,056 cups of tea. Most would go cold.
- 121 large pizzas wide. Delivery in thirty minutes or it is free (it will not be free).
- Misses by 183.1 times the distance to the Moon. The Moon has not filed a complaint.