25143 Itokawa (provisional designation 1998 SF36) is a sub-kilometer near-Earth object of the Apollo group and also a potentially hazardous asteroid.

[1] The peanut-shaped S-type asteroid has a rotation period of 12.1 hours and measures approximately 330 meters (1,100 feet) in diameter.

Due to its low density and high porosity, Itokawa is considered to be a rubble pile, consisting of numerous boulders of different sizes rather than of a single solid body.

Since its return to Earth in 2010, the mineralogy, petrography, chemistry, and isotope ratios of these particles have been studied in detail, providing insights into the evolution of the Solar System.

Hayabusa landed on 20 November for thirty minutes, but it failed to operate a device designed to collect soil samples.

On 16 November 2010, the Japan Aerospace Exploration Agency reported that dust collected during Hayabusa's voyage was indeed from the asteroid.

[18] Names of major surface features were proposed by Hayabusa scientists and accepted by the Working Group for Planetary System Nomenclature of the International Astronomical Union.

[23] The Hayabusa mission confirmed these findings and also suggested that Itokawa may be a contact binary formed by two or more smaller asteroids that have gravitated toward each other and stuck together.

The Hayabusa images show a surprising lack of impact craters and a very rough surface studded with boulders, described by the mission team as a rubble pile.

Analysis of the best-rated lightcurve by Mikko Kaasalainen gave a sidereal rotation period of 12.132 hours with a high brightness variation of 0.8 magnitude, indicative of the asteroid's non-spherical shape (U=3).

[33] Itokawa's composition was found to match the common type of meteorites known as "low-total-iron, low metal ordinary chondrites".

Smooth deposits of dust accumulate in depressions on the surface of the body (like craters), contrasting from the Rocky terrain around them.