July 4, 1997: Sojourner Arrives on the Red Planet

From NASA History

July 1, 2020

July 4, 1997: Sojourner Arrives on the Red Planet

Hitching a ride on the Mars Pathfinder mission, the Sojourner rover arrived at the Red Planet on July 4, 1997. The mission was designed to demonstrate a low-cost method for delivering a set of science instruments to Mars, and served as the foundation for the Mars rovers of today.

Pathfinder landed the rover using an air bag landing system and innovative petal design, which have been used since in various incarnations to land other rovers on the Red Planet. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, snapping photographs and taking chemical, atmospheric and other measurements.

The lander, formally named the Carl Sagan Memorial Station following its successful touchdown, and the rover, named after civil rights pioneer Sojourner Truth, both outlived their design lives — the lander by nearly three times, and the rover by 12 times. Mars Pathfinder returned 2.3 billion bits of information, including more than 16,500 images from the lander and 550 images from the rover, as well as more than 15 chemical analyses of rocks and soil and extensive data on winds and other weather factors.

This panoramic view of Pathfinder’s Ares Vallis landing site shows Sojourner rover is the distance. The Mars Pathfinder mission completed the last successful data transmission cycle at 6:23 a.m. EDT on Sept. 27, 1997.

Image Credit: NASA/JPL

Last Updated: July 2, 2020

Editor: Yvette Smith

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Stefan Xhunga
July 4, 2020 2:37 am

This is a veri interesting post of NASA about planets

Ron Long
July 4, 2020 2:44 am

Wow! What a great photo to go with a great accomplishment, and on the 4th of July. As a geologist I am struck by the fragment nature of the large rocks visible in the photo, no water erosion signs at all. Maybe impact ejecta debris? Like from a meteorite impact crater? It’s nice to have an atmosphere sufficiently dense to burn up most meteorites. Is that a volcanic cone in the background right? Good luck to whoever traveler first walks on Mars! Stay sane and safe.

Geoff Sherrington(@sherro1)
Reply to  Ron Long
July 4, 2020 4:23 pm

Agreed. There are signs everywhere of processes inviting explanations. Some linear features like roads between the rocks, sediment on high rocks indicating wind, how fast depends partly on gravity ( about 38% of Earth), smaller rocks with short linear tracks, seemingly uneven distribution of rock sizes (many big, many small, not so many Goldilocks). Just a few impressions after a 5 minute look at the image.
Geoff S.

Lewis P Buckingham
July 4, 2020 2:58 am

What an inhospitable place.
After Covid 19 best do it all with remote sensing and robotic chemical analysis and geological hammering.
We seem to have the technology.
If people really want to experience it, there is an opening for Disney to build a theme park, with virtual reality and alien life form sideshows.

Jamie Moodie
July 4, 2020 3:08 am

Where can I see all the photos of the exploration?

Reply to  Jamie Moodie
July 4, 2020 3:40 am

Here you go. Got it with the search “NASA Sojourner/Pathfinder images”

Bryan A
Reply to  Jamie Moodie
July 4, 2020 1:47 pm

And here is a link to the Mission Website

Jamie Moodie
Reply to  Bryan A
July 4, 2020 2:16 pm

Thanks Bryan

Regards Jamie

Bryan A
Reply to  Jamie Moodie
July 4, 2020 4:45 pm

You’re welcome, one of my faves since it opened

July 4, 2020 3:37 am

OT, but as good a place to put it as any and I thought some might like to know. The crazy types are planning on protesting and burning an American flag at Gettysburg today.


Other than the day Lee surrendered the Army of Northern Virginia, July 4th, 1863 was the day more than any other that the fate of the Confederacy was determined.

On that day:
1. Lee and his Army of Northern Virginia retreated from Gettysburg having been defeated by Mead and his Army of the Potomac. Never again would a Confederate Army invade the North except as a defensive diversion.

2. Confederate Lt. General Pemberton unconditionally surrendered his besieged Army of the Mississippi to Grant and his Army of the Tennessee at Vicksburg. There by opening the Mississippi River to the Gulf and separating the states of Louisiana, Texas, and Arkansas from the rest of the Confederacy. (Yes, Island #10 still stood in the way but it was quickly neutralized.)

Proof that this it not about anything but destroying history.

Reply to  rah
July 4, 2020 4:20 am

All misbehaving protesters of any colour should be ‘blacklisted’

Bryan A
Reply to  Vuk
July 4, 2020 1:45 pm

Make that RedListed

Pat Frank
Reply to  Bryan A
July 5, 2020 10:00 am

It seems to me that anyone burning the flag is repudiating their citizenship.

Such people should receive a visit by polite INS officers and asked to recite the citizenship oath of allegiance to the Constitution.

If they do so, well and good.

If they refuse, they proceed through official renunciation of citizenship, are granted a visa, and given 12 months to tidy up their affairs and move to the alternative country of their choice.

Flag-burners get three chances. Times one and two get the polite INS visit and a recital of the oath.

Third flag-burning by the same individual (active or as a willing accessory), and citizenship is permanently revoked as was implicitly renounced by the flag-burner.

No one is suppressing speech. Anyone is free to renounce or refuse citizenship without criminal charge or penalty. But renunciation means embrace of alien status as regards the US, and with no legal grounds to remain absent a green card.

I see nothing unreasonable in such a law, or in an enabling executive order.

Anyone is welcome to show that view wrong. I’d welcome that, actually, because both renunciation and removal of citizenship are profoundly serious.

I’m not conversant with the law but the Immigration and Naturalization Act certainly gives the power of citizenship to the Executive branch Department of State, which has strict regulation over renunciation of citizenship.

Redress of grievances is a commonplace in the US. Burning or trampling on the flag is not an expression of grievance. It’s an expression of rejection. So, candidly, is kneeling during the national anthem; not so severe as flag-burning, but rejectionist none the same.

I’d enjoy seeing Colin Kaepernick faced with the necessity of taking the oath of allegiance. He’d suddenly face the prospect of making his poseury real. Did he take the oath, his subsequent grievance-mongering would come across as hypocritical.

Bruce Ploetz
Reply to  rah
July 4, 2020 5:50 am

The minds behind this mindless destruction actually don’t know much about history and couldn’t care less.

No point in trying to apply reason to the situation, rah. They just do whatever gets a reaction from a “reactionary”.

They insist on crazy issues like transgender bathrooms and abortion because they know that a reasoning, rational person tends to object. As soon as you say anything negative about the provocation, they can start spouting “J’Accuse”! like Robespierre and crank up the guillotines.

The average left-leaning follower has no idea about any of this and just goes along, fearing to be thought to be a troglodyte.

It is quite amazing how many contradictory thoughts have to fit into the double-think of the average leftwing mind-numb robot. No wonder they seem quite insane to an objective observer. The cognitive dissonance must be brutal.

Don’t forget, it was the 1939 collapse of the Molotov-Ribbentrop pact that inspired Orwell and many other left-leaning intellectuals of that era.

One day all the left-wing papers were praising Hitler, the next day they were condemning him. Which emphatic diatribe was true? Can’t be both. Maybe neither? Or maybe the truth doesn’t matter. It is all about how it makes you feel. If it makes the average ignorant consumer feel like taking up arms against the oppressor, then it worked.

After that they had to either follow the path of Obama’s mentor, Frank Marshall Davis, and turn on a dime at the whim of the Party or begin to question, like Orwell. Questioners and doubters are not welcomed in the messianic utopian world of the manipulative Left, leading to the awakening and departure of many.

So let them rage about words, symbols and irrelevancies, give them volume and stridency, never let their voices falter even when the subject changes from day to day. Some will follow, others will start to wonder “What’s Up With This?” and start to actually look at what is being said. And why. And who benefits.

The road back to reason may be long and fraught, but truth and sanity lies at the end.

Joe Crawford
Reply to  Bruce Ploetz
July 4, 2020 7:03 am

Bruce, I sure hope you’re right with that last statement.

Reply to  Bruce Ploetz
July 4, 2020 11:11 am

Well Bruce, I will continue to apply reason to a certain point. I can’t detail exactly what that point will be but I’ll know it when it comes and then this well armed former SF soldier will become what many I am sure would think is very unreasonable.

July 4, 2020 3:58 am

why are we still using solar pane with the risk of dust stoping the electrical output.

what is wrong with atomic generation. ?


Reply to  Michael
July 4, 2020 4:47 am

more info on General-Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG)
Isotopes thermoelectric units generates electricity from the heat of a decaying radioactive material using thermocouples.

July 4, 2020 4:08 am

Korolev ice crater on Mars

Reply to  Vuk
July 4, 2020 7:17 am

Happy 4th of July to all who celebrate today.

Ian Coleman
July 4, 2020 5:16 am

A genuine photo from Mars? Yeah. Okay. This better not be a fake, like that Apollo 11 nonsense.

Just kidding, boys. This really is amazing, and there is no way even an old grouch like me can disparage it.

Reply to  Ian Coleman
July 4, 2020 7:15 am

With all those boulders arranged in the near perfect circle, some have been worked on?!
More likely remnants of a neolithic ‘stonehenge. /sarc

Steve Keohane
Reply to  Vuk
July 4, 2020 4:15 pm

The were used to build the canals…

Interested Observer
July 4, 2020 10:00 am

Good article.

It is a testament to the idea that, for the foreseeable future, the exploration of our solar system is best done by robots. The rover out-lived its planned life-span by 12 times and sent back “550 images … as well as more than 15 chemical analyses of rocks and soil”. The lander “only” out-lived its planned life-span by 3 times but, it managed to send back “16,500 images… and extensive data on winds and other weather factors”. All that for just $265 million dollars total. Now that’s bang for your buck.

Compare that to the $450 million cost of an average space shuttle mission or the $400 million cost of a crewed Dragon launch. The total cost of Pathfinder wouldn’t even get a human crew into orbit, let alone all the way to Mars. I seem to remember somebody having the motto “Faster, Cheaper, Smarter” and it certainly applies to robotic exploration of the solar system.

Reply to  Interested Observer
July 4, 2020 10:55 am

Adjust for inflation? Point taken, but always more informative in real dollars.

Interested Observer
Reply to  brians356
July 5, 2020 9:45 am

$265 million (1997) = ~$433 million (2020)

The comparison actually becomes more pertinent when adjusted. For about the same amount of money as the Dragon launch to low-earth orbit, NASA got a mission to Mars that far exceeded its expected outcome. The mission was supposed to last just one week but, it ended after 83 days.

There is no way a manned mission could match that accomplishment. Far more likely would be cutting the mission short (or worse) due to some unforeseen danger.

July 5, 2020 8:45 pm

At one time travel from Europe to America was as much a challenge as travel from Earth to Mars is today.

“Ah, but a man’s reach should exceed his grasp, Or what’s a heaven for?”

Interested Observer
Reply to  ferdberple
July 5, 2020 11:50 pm

“At one time…”

Sure, it was during the stone age in the depths of the last glacial period.

By the time of Columbus and Magellan, not so much. They didn’t have to carry their own air supply or fuel for that matter. They only needed enough food and water to make it to the next port, though it was wise to have enough of a reserve to make it back just in case. Everywhere they went, people were already there with their own supplies of food and water, including the Americas. [Even the Vikings, who did it the hard way a few centuries earlier, didn’t have to take their own air.]

None of that is true for a trip to Mars. Anyone who goes will need enough air, fuel, food and water to make it there and back, plus have a healthy reserve just in case. In fact, humans will probably need to “take” their own gravity along with them, something that was never true for people going from Europe to America. And, not one single human will be on Mars to lend a hand if needed.

The real question is: why send people at all? To plant flags and look at rocks? On a planet we can’t live on (no air and 1/3 of Earth’s gravity)? And, at what cost? Would you be willing to sell everything you own to make it happen, the way people travelling to America did? Or, does it only appeal when somebody else is paying for it?

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