Asteroid 17851 Kaler (also known as 1998 JK) was discovered on May 1, 1998 by NASA's Near Earth Asteroid Tracking (NEAT) project. Only 5-10 kilometers across, at its brightest it is 16th magnitude, some 10,000 times fainter than the human eye can see.
Averaging 2.40 Astronomical Units from the Sun (the AU the average distance between Earth and Sun, 149.6 million km), Asteroid Kaler is on the inner portion of the main asteroid belt and takes 3.72 years to orbit. With an eccentricity of 0.144, it stays within the main belt, changing its solar distance from 2.744 AU to 2.054 AU, which keeps it at its closest just over 1 AU from Earth. A low inclination of 3.2 degrees keeps it close to the ecliptic.