The different Mars Rovers and what we learned
First rover to successfully land on Mars. Defined by NASA as a "micro-rover" due to its small size, Sojourner had a speed of maximum of 0.4 meters pr. minute. It was active for about 80 days on the surface of Mars.
Sojourner carried three cameras, an Atmospheric Structure Instrument (Meteorology Package) and an Alpha Proton X-ray Spectrometer. There instruments.
From Sojourner, NASA learned about the surface and weather conditions of Mars.
Sojourner found rounded rocks at the landing site, which suggests that running water could have been on Mars. The radio-tracking of Pathfinder (mission name) also gave an estimate of Mars' metal core's size (1300 kilometers to 2000 kilometers). It also discovered that the dust that is in the air on Mars is magnetic and possibly made up of mahemite. Sojourner also observed dust devils, ice clouds in the lower atmosphere and temperature fluctuations on the surface of Mars.
Spirit (2004-2010) and Opportunity (2004-2018)
Spirit was one of two Mars rovers launched in 2003 (mission started in 2004). The wheels on Spirit and Opportunity were about double the size of Sojourners. The weight of both rovers was about 17 times Sojourners, and more than double the size. Their goal on Mars was to search the surface for traces of past water. In 2009, Spirit got stuck in soil (in the area called Troy). In 2010, Spirit stopped communications, and the mission ended in 2011.
Opportunity was launched in 2004 along with Spirit but lasted much longer than their twin. Setting the record for the longest-lasting Mars rover, Opportunity stopped communications in 2018. Opportunity also set the record for the longest distance traveled by a rover, around 45 kilometers.
Like Sojourner, Spirit provided data about Mars' weather conditions, especially the wind. Both Spirit and Opportunity found evidence of possible conditions on Mars that could allow microbial life.
Spirit and Opportunity both had panoramic cameras, a thermal emission spectrometer, a Moessbauer spectrometer, an alpha particle X-ray spectrometer, and a microscopic imager.
Curiosity is currently the oldest active Mars rover (as of 21/07/2023) The main purpose of Curiosity is to figure out if Mars has the right environment for microbial lifeforms. Curiosity is currently exploring Gale Crater and had the most advanced instruments at the time. Curiosity has found evidence of water having been on Mars in the past, found old organic material, and discovered that Mars has had a thicker atmosphere in the past.
Curiosity can climb over knee-high obstacles and can go up to 30 meters per hour.
Curiosity carries a radioisotope power system to generate electricity, which gives the rover a steady electricity flow. Curiosity also carries 17 cameras, a laser, a drill, and 10 different instruments.
Perseverance (2021-present)
Perseverance is the newest Mars rover from NASA. The main goal for Perseverance is to research habitable conditions on Mars, but also for signs of past microbial life. The mission also tests possible options for future human expeditions on Mars (ex. improved landing techniques, producing oxygen from the atmosphere and environmental conditions).
The drill Perseverance used can collect samples and then set them aside for collection on the surface.
Launched by the CNSA, Zhurong is the first Chinese Mars rover. In 2022 it became inactive due to sandstorms and the winter, which prevented it from waking at an appropriate temperature and good sunlight conditions.
Zhurong's mission was to study the topography, examine the surface (soil and elements), and take samples of the atmosphere. To do this it had a RoPeR (Mars Rover Penetrating Radar), RoMAG (Mars Rover Magnetometer), MCS (Mars Climate Station), MarSCoDE (Mars Surface Compound Detector), a multispectral camera and navigation and topography cameras. It also had a remote camera on board.
