At a glance
- Width
- 139 to 312 m
- about 1,128 bananas
- Speed
- 10.48 km/s
- 37,711 km/h · 23,432 mph
- Misses us by
- 42.5 lunar
- 16,326,166 km · 10,144,606 miles
- First spotted by us
- 15th November 2026
- 9 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
- APOApollo: crosses Earth's orbit, but spends most of its time further out than us. The most common troublemaker type.
- Year length
- 1.21 Earth years (444 days)One lap of the Sun. Your commute is shorter, and so is your patience.
- Eccentricity
- 0.232How squashed the orbit is. 0 is a perfect circle, 1 is "leaving". Noticeably oval. Mildly dramatic.
- Tilt
- 17.5°The angle of its orbit against the flat plane the planets share. Slightly tipsy.
- Closest to the Sun
- 0.87 AU131 million km. One AU is the distance from Earth to the Sun.
- Furthest from the Sun
- 1.40 AU210 million km. Never leaves the inner solar system.
- Closest orbit-to-orbit gap
- 0.065 AUIf you only compare the two orbits, not where the planets are, they come within 25 lunar distances. The rock is rarely there at the same time as us, which is the entire reason we are still here.
- Observations used
- 53NASA has measured this one 53 times. It has been stalked thoroughly.
- Watched for
- 6.0 years2010-04-20 to 2016-04-20. Not long, so the orbit is still being refined and the rock is still a bit of a stranger.
- Orbit uncertainty
- 2 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 |
|---|---|---|
| 12th April 2095 | 89.8 LD · 34,544,147 km | 10.6 km/s |
| 3rd October 2099 | 191.5 LD · 73,660,605 km | 21.6 km/s |
| 16th June 2100 | 173.6 LD · 66,773,193 km | 9.9 km/s |
| 6th November 2105 | 31.0 LD · 11,926,025 km | 11.6 km/s |
| 12th May 2106 | 121.4 LD · 46,671,955 km | 10.0 km/s |
| 9th August 2111 | 183.6 LD · 70,625,932 km | 6.3 km/s |
| 11th April 2112 | 90.9 LD · 34,945,136 km | 10.7 km/s |
| 4th October 2116 | 190.2 LD · 73,157,105 km | 21.6 km/s |
| 16th June 2117 | 173.4 LD · 66,674,780 km | 9.9 km/s |
| 5th November 2122 | 33.5 LD · 12,895,242 km | 11.8 km/s |
By the numbers
- Estimated mass
- 4.3 million tonnes to 47.7 million 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
- 2,408 Olympic poolsSphere volume at the middle width estimate, divided by 2,500 cubic metres per Olympic pool.
- Impact energy, if it hit
- 56 megatons to 625 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
- 0.9 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
- 0.35 timesDivided by Earth's own orbital speed of 29.78 km/s around the Sun.
- Time to cross the UK
- 92.6 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
- 18.0 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
- 54.5 secondsMiss distance divided by the speed of light.
- Width from brightness alone
- 139 to 312 mAstronomers estimate size from how bright an asteroid is (H 21.4) 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
- 4.92,192 days of observation divided by its 444-day year.
- Known close approaches, 1900 to 2200
- 1070 inside the Moon's orbit and 0 within ten lunar distances.
- Closest pass in that period
- 31.01 lunar distancesOn 6th November 2105.
- Next visit after this one
- 30th April 2027At 102.5 lunar distances. No closer than this time.
- Average gap between visits
- 2.8 yearsThe span of the record divided by the number of gaps between approaches.
- Rank by size
- 14 of 47Among every asteroid this site has tracked, biggest first.
- Rank by closeness
- 10 of 47Among every asteroid this site has tracked, using each one's most recent pass, closest first.
- Rank by speed
- 33 of 47Among 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 2010 HG20 hit Earth? Questions answered
Will asteroid 2010 HG20 hit Earth?
No. 2010 HG20 passes Earth on 22nd November 2026 at 42.5 lunar distances (16,326,166 km), which is 42.5 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 2010 HG20?
NASA estimates it is between 139 m and 312 m wide, which at the top end is about 3.0 football pitches long. Nobody has seen it up close, so the width is an estimate from its brightness.
How fast is asteroid 2010 HG20 travelling?
10.5 km/s relative to Earth at closest approach, about 37,711 km/h (23,432 mph). That is 1.4 times the speed of the International Space Station.
Is 2010 HG20 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. 2010 HG20 has an absolute magnitude of 21.4 and its orbit comes within 0.065 AU of Earth's.
When is asteroid 2010 HG20's next close approach?
After this pass, the next one in NASA's record is on 22nd November 2026, at 42.5 lunar distances.
Unhelpful facts
- 1,299 basketballs wide. Somebody in the NBA has already asked for the numbers.
- About 3.0 football pitches long. Still no better than a mid-table side.
- Flying a gap that size takes it 18.0 days, which is 1,298 twenty-minute naps. Recommended.
- Roughly 479 car tyres wide. Check the tread before you worry about the rock.
- In the 18.0 days it takes to fly a gap that size, you could drink 1,298 cups of tea. Most would go cold.
- It could overtake 41 commercial jets, and it would not even signal.
- 0.82 Empire State Buildings tall, if you insist on laying New York on its side.
- That is 781 times the speed limit on a 30 zone. Nobody has fined it yet.
- A UK train would take 18.6 years to cross the same gap, plus delays "due to a train being late".
- Light crosses the gap in 54.46 seconds. That is not enough time to say "what was that".
- 877 large pizzas wide. Delivery in thirty minutes or it is free (it will not be free).
- It passes in 7 days, which is 49 dog days. Your dog is already nervous, mostly about the post.