PREVIOUS Nasa explorations to the red planet include Mars Phoenix, which launched in August 2007.
The probe was part of the continuing pursuit of water on Mars.
Phoenix landed farther north than any previous mission, at a latitude equivalent to that of northern Alaska.
During the course of its three-month mission, Phoenix dug into an ice-rich layer near the surface.
Mars Global Surveyor, was launched in November 1996.
It was the first successful mission to the red planet in two decades.
The mission completed a study of the entire Martian surface, atmosphere and interior.
Nasa's Viking 1 & 2 was launched in August 1975.
The Viking project found a place in history when it became the first U.S. mission to land a spacecraft safely on the surface of Mars and return images of the surface.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
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Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here