How many asteroids are out there?

¿Cuántos asteroides hay allá afuera?

Have you ever wondered how many asteroids are out there? But more importantly, how many of them are potentially dangerous to Earth? In this page, we will try to answer these questions. And we will do so by using the latest data provided by the NASA Small Body Database and state-of-the-art population models.

NEOs1 discovered to March 12 2025 23:00
Total number of discovered NEOs	38091
Number of NECs2	210 [0.55%]
Distribution by classes3	Amor, 13353 [35.06%] Apollo, 21481 [56.39%] Aten, 3017 [7.92%] Encke-type Comet, 6 [0.02%] Halley-type Comet*, 36 [0.09%] Atira, 34 [0.09%] Jupiter-family Comet*, 11 [0.03%] Jupiter-family Comet, 153 [0.4%]
Number of discovered NEAs4	37881
Numbered of undiscovered NEAs5	420 000 000 [99.99%]
We know all asteroids in the range	D ≳ 0.51+0.85-0.23 km (H ≲ 19.25)
NEO is the acronym of Near Earth Object. See science page for details. NEC is the acronym of Near Earth Comet. It includes cometary nuclei and cometary fragments. See science page for details. For a list of NEO classes and their definitions see this link. NEA is the acronym of Near Earth Asteroid. See science page for details. This is the number of asteroids larger than 2 meters.

Technical information

In the following paragraphs we will provide some technical details about the data and the methods used to obtain the results presented above.

Cumulative distribution of NEAs

Distribución acumulada de NEAs

One of the most important aspects of the NEO population is its size distribution. The cumulative distribution of NEAs is shown in the figure below.

NEAs albedo distribution

Distribución de albedo de NEAs

The albedo of an asteroid is a measure of its reflectivity. The albedo distribution of NEAs is shown in the figure below.