Mars rover detailed

A detailed close-up of a Mars rover, highlighting its wheels and scientific instruments on the red Martian soil.

About this subject

Mars rovers are robotic vehicles designed to explore the surface of Mars. Since the first successful rover, Sojourner, in 1997, NASA has sent increasingly sophisticated robots such as Spirit, Opportunity, Curiosity, and Perseverance. Each carries scientific instruments to analyze rocks, soil, and atmosphere, searching for evidence of past life and conditions for future human exploration.

Opportunity operated for over 14 years, traveling 45 km, far beyond its expected 90-day mission. Curiosity, which landed in 2012, discovered evidence of ancient lakes in Gale Crater. Perseverance, launched in 2020, collects samples to be returned to Earth by future missions. These rovers are powered by solar or nuclear energy, with wheels designed for rocky terrain.

Their engineering involves protection against radiation, extreme temperatures, and fine dust. Wheel designs, for example, include spiral grooves for traction and to prevent particle buildup. Cameras and spectrometers enable remote analysis, while robotic arms perform drilling. Missions cost billions but greatly expand our knowledge of the neighboring planet.

Frequently Asked Questions

How many rovers have landed on Mars?

As of 2025, five rovers have successfully operated on Mars: Sojourner (1997), Spirit and Opportunity (2004), Curiosity (2012), and Perseverance (2021). China also has the Zhurong rover, which landed in 2021.

What is the difference between Curiosity and Perseverance?

Perseverance is more advanced: it has a sample collection system for future return missions, a companion helicopter (Ingenuity), and instruments to detect biosignatures. Both are about the size of a car.

How do rovers communicate with Earth?

They use high-gain antennas to send data to orbiters, which relay it to Earth. The communication delay ranges from 8 to 42 minutes due to distance.