TOKYO (AP) — Japan's space agency says more than 200 photos taken by two small rovers on an asteroid show no signs of a smooth area for the planned touchdown of a spacecraft early next year.

The Japan Aerospace Exploration Agency said Thursday the two solar-powered rovers have become inactive and are probably in the shade, but are still responding to signals after three months, exceeding their projected life of several days.

The rovers were dropped by the unmanned Hayabusa2 spacecraft onto asteroid Ryugu, about 280 million kilometers (170 million miles) from Earth, in September.

Many of the photos show a rocky surface on the asteroid, presenting challenges for Hayabusa2's planned touchdown.

JAXA says it still plans to attempt the touchdown to collect samples.