First discovered on images from Mars Global Surveyor, they may be the site of recent liquid water.
Images from Mars Express, Mars Global Surveyor, and the Mars Reconnaissance Orbiter have revealed ancient river valleys and deltas.
Dark streaks can be seen in the images below, as seen from Mars Global Surveyor.
It was discovered, on the basis of data from Mars Global Surveyor, to be a low-relief shield volcano, but was formerly believed to be a plain, and was then known as Syrtis Major Planitia.
By analyzing a map of crustal magnetic anomalies compiled with data from Mars Global Surveyor, scientists observed that the region of the emissions corresponded to an area where the strongest magnetic field is localized.
Much better data has been received from Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter.
In February 2001 clickworkers started processing new images from Mars Global Surveyor, surveying small craters never before cataloged.
An image below from Mars Global Surveyor shows this.
Using data from Mars Global Surveyor, Mars Odyssey and the Mars Reconnaissance Orbiter, scientists have found widespread deposits of chloride minerals.
More recent data from Mars Global Surveyor and the Mars Odyssey spacecraft have shown no specific evidence that explosive eruptions ever occurred at Alba Mons.