Emotional tributes as Mars Opportunity Rover pronounced dead
By Stephen Jones, Press Association
Emotions were running high on social media as the universe waved goodbye to Nasa's Opportunity rover after 15 years on the surface of Mars.
Former US president Barack Obama led tributes to the vehicle, which was only built to operate for three months but ended up surviving far, far longer.
He wrote: "Don't be sad it's over, be proud it taught us so much. Congrats to all the men and women of @NASAon a @MarsRovers mission that beat all expectations, inspired a new generation of Americans, and demands we keep investing in science that pushes the boundaries of human knowledge."
Opportunity and its long-dead twin, Spirit, found evidence that ancient Mars had water flowing on its surface and may have been capable of sustaining life.
Flight controllers tried on several occasions to contact Opportunity and sent one final series of recovery commands on Tuesday night, accompanied by one last wake-up song, Billie Holiday's I'll Be Seeing You. However, there was only silence in response.
That meant Opportunity's final message was made in June 2018, to the effect of "my battery is low and it's getting dark".
For many, it was simply too much to take.
Writer Jocelyn Rish tweeted: "I never imagined I'd be sitting at my computer crying over a last message from a robot on Mars, but here I sit wiping away tears. Job well done, #Oppy."
Former Star Trek actor George Takei said: "A sad, sad development for #Opportunity and for @NASA. Perhaps one day we shall find you again, friend, when humans finally set foot on Mars."
Others felt compelled to offer a message in terms the rover itself would understand.
Twitter user @dutchess_becky wrote: "Dear Opportunity, 01000111 01101111 01100100 01110011 01110000 01100101 01100101 01100100 00100000 01001111 01110000 01110000 01111001, from A Martian Fan."
Converted from binary to English text, the message reads: "Godspeed Oppy."
Similar sentiments were shared among space professionals themselves.
Dr Tanya Harrison, director of research at ASU NewSpace, said she spent the evening at Nasa's jet propulsion laboratory as the final commands were sent.
She tweeted: "There was silence. There were tears. There were hugs. There were memories and laughs shared. #ThankYouOppy #GoodnightOppy"
One Nasa scientist who worked as an engineer on the Opportunity project since 2007 revealed she had a tattoo made up in tribute to it.
"This tattoo means more to me than just Oppy. Of course, the biggest significance is this is Oppy's final measurement. I studied tau (atmospheric optical depth) as a student researcher. Don't worry, I consulted my advisor on the value before committing to the ink," said Keri Bean on Twitter.
One of the more eloquent tributes on Twitter came from poet Dylan Thomas, via graphic designer Dan Mason.
"Do not go gentle into that good night, Old age should burn and rave at close of day; Rage, rage against the dying of the light," he tweeted.
"Projected mission lifespan: 90 days. Achieved lifespan: 15 years. You had a good innings, #Oppy."
NASA bids farewell to record-setting Mars Rover
By Jamie Harris, Press Association Science Technology Reporter
A Mars rover that was designed to carry out research for 90 days but went on to operate for almost 15 years has officially been declared dead by US space agency Nasa.
Engineers last received communication from the history-setting Opportunity rover on June 10 last year, before it was caught up in a severe dust storm on the Red Planet.
A final attempt to make contact with Opportunity was made on Tuesday to no avail, Nasa said, following more than 1,000 commands to restore communications.
"We have made every reasonable engineering effort to try to recover Opportunity and have determined that the likelihood of receiving a signal is far too low to continue recovery efforts," said John Callas, manager of the Mars Exploration Rover project at Nasa's Jet Propulsion Laboratory.
Opportunity - affectionately known as Oppy - arrived on Mars on January 24 2004, seven months after it was launched from Cape Canaveral Air Force Station in Florida, on a mission to uncover evidence of life.
The solar-powered rover was only expected to travel 1,000 metres on Mars, but amassed 28 miles and set a one-day driving record on March 20 2005, when it managed 220 meters.
During its time on the Martian surface, Opportunity sent more than 217,000 images back to Earth, and uncovered the surfaces of 52 rocks with fresh mineral surfaces for analysis.
It also found a mineral known as hematite that forms in water, as well as other indications that could help answer the question of life on Mars.
"From the get-go, Opportunity delivered on our search for evidence regarding water," said Steve Squyres, principal investigator of the rovers's science payload.
"And when you combine the discoveries of Opportunity and Spirit, they showed us that ancient Mars was a very different place from Mars today, which is a cold, dry, desolate world. But if you look to its ancient past, you find compelling evidence for liquid water below the surface and liquid water at the surface."
The six-wheeled vehicle outlived its twin rover Spirit, which managed almost five miles on the planet before ceasing in May 2011.
Attempts to explore the Red Planet continue with newer missions, including Nasa's InSight lander which touched down on November 26.
The European Space Agency's ExoMars rover, recently named after British scientist Rosalind Franklin, is expected to launch in July 2020 on its own mission to find signs that life could have once existed on Mars.
"It is because of trailblazing missions such as Opportunity that there will come a day when our brave astronauts walk on the surface of Mars," said Jim Bridenstine, Nasa administrator.
"And when that day arrives, some portion of that first footprint will be owned by the men and women of Opportunity, and a little rover that defied the odds and did so much in the name of exploration."