Phoenix Mars Lander Extended Mission. Sol 90+ & R.I.P Sol 157.

[3488]

Keep in mind, it's not that Mars is to cold, but its lack of atmosphere. Mars (correct me if I'm wrong) is in the habitable zone and could be earth like with the correct atmosphere. Same would hold true with Venus, I think, if it had less atmosphere.

Hi Tim,

That is true, Mars is indeed within the outer edge of the Habitable Zone for Earth like planets.

However, even allowing for that, if Mars was an Earthlike planet, it would still be pretty cold by terrestrial standards, though not so cold as to be uninhabitable.

Worth mentioning that Mars on average recieves only 44% of the solar radiation that Earth does. Enough to keep an Earthlike planet from being too cold for surface life & maintain liquid water oceans in the tropics, but from the mid latitudes polewards, the oceans would probably remain frozen, though an ice free region would probably follow the Sun during the Summer months.

True also with Venus, though Venus recieves almost double the solar radiation Earth does (note the short stubby solar arrays on Venus Express, as against the lengthy ones on Mars Express. Also compare MESSENGER with DAWN, the difference is even more striking).

Venus with an Earthlike atmosphere would remain within tolerable temperature limits for life, but compared to Earth, would still be pretty hot.

Andrew Brown.

[tampaDreamer]

So it's just coincidence that the planet on the inner edge of the habitable zone has too much atmosphere making it too hot, the planet on the outer edge has not enough atmosphere making it too cold, and the planet right in the middle of the habitable zone has just the right amount of atmosphere making it perfect?

I guess my next question would be 'why do they have those amounts of atmosphere?' I suppose if mars was larger its gravity would have held on to an atmosphere, or perhaps it'd be big enough to maintain a liquid core and magnetic field, also aiding in maintaining an atmosphere? For venus.. it's not size because it's similar to the earth, and it has less of a magnetic field for no reason i understand, so that's not causing the excessive atmosphere.

[bearack]

So it's just coincidence that the planet on the inner edge of the habitable zone has too much atmosphere making it too hot, the planet on the outer edge has not enough atmosphere making it too cold, and the planet right in the middle of the habitable zone has just the right amount of atmosphere making it perfect?

I guess my next question would be 'why do they have those amounts of atmosphere?' I suppose if mars was larger its gravity would have held on to an atmosphere, or perhaps it'd be big enough to maintain a liquid core and magnetic field, also aiding in maintaining an atmosphere? For venus.. it's not size because it's similar to the earth, and it has less of a magnetic field for no reason i understand, so that's not causing the excessive atmosphere.

Here is my understanding and Andrew and company can answer more scientifically and more accurately.

Mars core has cooled which made it's magnetic field dissipated to a point that it is non-existent. This has allowed for the solar winds to strip away Mar's atmosphere and there is no volcanic activity to help replenish it effectively.

Regarding Venus, Venus is an extremely volatile planet that renews it's surface every few hundred million years (someone will correct me on this). Venus is also lacking a magnetic field but has a mechanism called an induce magnetosphere (Venus's ionosphere) that helps protect the atmosphere from solar winds. It is speculated that Venus at one time in it's earlier life was Earth like and sustain liquid water. As this water evaporated into the thick atmosphere, the water vapor acted as a green house gas.

At least that is my two pence.

[3488]

Hi Tim,

You are pretty well spot on.

Mars's core has largely solidified, though there is some evidence from precise tracking of the Mars Pathfinder, MERs & Phoenix Mars Lander, suggests the core is not 100% solid, perhaps 90% of the way there.

This certainly has killed off any convection hense ceased generating a global magnetosphere & as you correctly say, the Solar Wind has been stripping the martian atmosphere away ever since. The MGS orbiter detected fossilized local fields, perhaps fossilized remains from the original global magnetosphere, when the core was still hot & molten & was in a convective state.

Venus is stranger in that it is much closer to being like the Earth in size, density & mass than Mars. Also Venus has a 'fresh' volcanic surface, fresh looking shields, fresh looking lava flows, etc.

However, Venus like Mars lacks a global magnetosphere, hense lack of convection. Gravity data from the Pioneer Venus Orbiter as well as from the more recent Magellan orbiter, suggests that Venus has only a single layered core as against the Earth's double layered core. Jupiter's moon Ganymede & now possibly Mercury also appear to have dual layered cores like the Earth & all three have internally driven magnetospheres, something Venus & Mars both lack.

Venus's Ionosphere does apper to induce a weak magnetosphere, certainly reducing the rate of stripping away by the solar wind, but it's worth mentioning that solar intensity at Venus is nearly twice that at Earth or nearly five times that at Mars. Venus does indeed have a huge tenuous tail, passing well beyond Earth's orbit.

Also unlike Mars, Venus appears to have active volcanism (though none as yet has been detected, but the youthulness of the volcanoes suggest recent activity), thus replenishing said atmosphere & keeping it dense.

Andrew Brown.

[tampaDreamer]

Thanks a bunch!

[3488]

Thanks a bunch!

You are very welcome tampadreamer. You came up with an intelligent & interesting post with some highly intelligent comments, so it was worth Bearack (Tim) & myself to attempt to answer properly & thoroughly.

This is a most fascinating area of planetary science & something we are learning more about all of the time.

Andrew Brown.

[MeteorWayne]

I'm going to unstick this thread. If anyone disagrees with that action, please post your comments here.

[3488]

Phoenix Mars Lander science teams are analyzing the data from the Phoenix mission, one year on from the successful landing.

There WILL be several attempts in the Autumn to awaken Phoenix, assuming LAZARUS does not initiate.

Northern Spring Equinox will be on: Tuesday 27th October 2009.

Phoenix however may still be encased in Dry Ice so early in the season.

Update here.

The final colour image from Phoenix. Sol 151 early morning @ 05:11 HRS LMST with frost.


Frosty scene Sol 131 early morning. Beginning of the end for Phoenix as temperatures were dropping.


Andrew Brown.

[centsworth_II]

Northern Spring Equinox will be on: Tuesday 27th October 2009....
Phoenix however may still be encased in Dry Ice so early in the season.

Hopefully, we should have good pictures of the site by then and be able to SEE if Phoenix is encased.

[3488]

Northern Spring Equinox will be on: Tuesday 27th October 2009....
Phoenix however may still be encased in Dry Ice so early in the season.

Hopefully, we should have good pictures of the site by then and be able to SEE if Phoenix is encased.

Hi centsworth,

Of course it is only conjecture that Phoenix Mars Lander is encased in CO2 ice.

Phoenix Mars Lander is just past the midway point between the previous sunset on Sunday 5th April 2009 & the next one on: Tuesday 7th July 2009 as it was the northern Winter Solstice on: Friday 22nd May 2009.

Then at noon, the Sun approached to 4 degrees below the horizon at Midsol (Noon on Mars), so the area experienced a bright twilight, but the sun remained below the horizon.

Each Sol now, the Sun will be nudging slightly higher & closer to Phoenix's southern horizon at Midsol, but does not actually rise till 7th July, when the Sun appears for 14 minutes bewtween sunrise & sunset. Each sol afterwards, the days lengthen considerably.

Hopefully from July perhaps, more likely August, the MRO will be able to image the landing site from orbit using the HiRISE camera, to ascertain that Phoenix is indeed encased in CO2 ice & perhaps over the following months if encased monitor the Phoenix Mars Lander emerge from the ice.

Then we should have a clearer idea as to whether or not it is worth trying to raise Phoenix. MRO HiRISE is able to determine if the solar arrays are still attached, not torn off, if Phoenix has been dragged, whilst encased, etc.

If Phoenix DOES awaken due to the LAZARUS routine or is roused by Mission Controllers, I hope we get some images ASAP, to see if ice is still covering the landscape, if Phoenix has been dragged undamaged, if smaller stones have been dragged, etc.

It is going to be very interesting for sure.

Andrew Brown.

[stupidlaminatedrock]

I honestly believe we will all be in for a big suprise in October. Although i am thinking its capability is limited extremely. I mean it wont be digging for sure.


My background, I am Quality Assurance Senior in the aerospace field for Lockheed in Tampa florida. No we did not build the pheonix here, but we do have similiar projects you will hear about in the future if NASA opts to fully fund them.. We test our equipment in enviromental chambers. Set In much worse and more harsh conditions than any martian winter . Twice as bad and sometimes for months at a time. Sometimes with temperatures swinging from -200C to +200F. And our equipment fares well. It does just fine. Its very well built thats for sure. The quality process has always been the same. Pheonix will make it I promise.

The solar panels are a concern but even if 1/3 of them are operational. You will still have a functional lander. Solder Joints wont break at those temperatures, they treated and sheltered them from the elements with a variety of known techniques used on deep space probes (much colder in space). Cables will be fine. The camera lens is made of plexi-glass.


just wait.

[3488]

Wow, that's a fascinating insight stupidlaminatedrock.

I really hope that you are correct. It is encouraging to read from someone who knows what they are talking about, giving such an upbeat forecast as to Phoenix Mars Lander waking up.

If so I really hope that the LAZARUS kicks in as early as possible after Phoenix is exhiumed to the point that the arrays can generate power.

Sure the digging days are over, but the SSI (Stereo Surface Imager) & the Meteorological Station still offer enormous promise of new science, such as the emerging landscape of Scandia Colles as the ice sublimates, fogs, clouds, strange martian twilights, changing weather, the possibility of small stones being moved whilst under the ice, the condition of Phoenix herself, etc.

I still think it's a long shot that Phoenix will awaken in November, when the Martian Northern Spring is advancing (Martian Northern Spring Equinox is on: Tuesday 27th October 2009, though Phoenix is still expected to be encased in ice at this point).

I really hope that the MRO HiRISE in the not too distant future will image the Phoenix site. It is getting light there every sol now.

The days are still pretty short though.

On Wednesday 12th August 2009. Sunrise at the Phoenix site is at: 13:57 UTC. MidSoL (Noon) @ 16:58 UTC with the Sun culminating at only 5 degrees 16' above the southern horizon & Sunset is at: 20:03 UTC.

So the Sun rises for 6 hours & 6 minutes today.

Below Redshift view of Sun at MidSol from Phoenix Mars Lander on: Wednesday 12th August 2009.


Andrew Brown.

[andrew_t1000]

I don't know about anyone else, but,
I am really annoyed they have not turned on the damn microphone!
And just to taunt me that little bit more, we get to see that little "wind teller" flapping around!
Grrr!
Even before Viking 1 and 2 landed, we knew there was an atmosphere of sorts there, I remember hoping that with all the instruments Viking had, JPL had included a microphone!
It makes so much sense to me, not only could we get some useful data, but it would make the whole idea of have landed on another world, whether it be Mars or Titan, more visceral, more real, more exciting.
Ok, I do a lot of experiments with sound, in the audible and ultrasonic ranges, not just ranging, but other stuff-

fooling around with an experimental non-contact stethoscope
sonic "vision" on my roverbot
sonic anemometry.

I would have liked to have seen a small steerable horn speaker/microphone experiment.
If you know the distance to an object you can extract a lot of information from a pulse of sound, things like -

Wind speed
Humidity
Temperature
Surface Profile

Simply sending out a regularly spaced series of pulses and watching the return echoes on an oscilloscope is great to watch, the amount of detail you can see is amazing.
It wouldn't take much bandwidth, a lot less than video or still images, especially if you compress the data.
And the thrill of hearing the Martian or Titianian wind or breeze would be wonderful, not to mention hearing an echo from a human made object on another world.

[3488]

Hi andrew_t1000.

The Phoenix Mars Lander microphone was designed for the final descent, when the thrusters were in action. Remeber that the Martian atmosphere at ground level on average is no denser than the Earth's atmosphere is at 30 KM / 19 miles above sea level.

How well does sound travel in such a thin atmosphere? Myself I reckon the microphone would have heard nothing post landing. In all honesty turning it on would have been a waste of time & power.

What wuld have been needed was to have been a giant earlobe type appendage to capture any soundwaves & focus them on the microphone. Problem is in that thin atmosphere, it would have to be very large & cumbersome.

On Titan it's very different. A 50% denser atmosphere conducts sound very well, as would that of Venus.

Andrew Brown.

[andrew_t1000]

The speed of sound on Mars is 244m/s.
When you do that classic experiment in high school, where you put an electric bell, under a bell jar and evacuate it, the sound is audible way bellow the 8 millibars of pressure that Mars has.
My reasoning for turning on the microphone is that if there is enough wind to move the "wind teller" around, it would be audible.
Ok, it might not sound that interesting to most people, but I for one would find it fascinating!
We have been sending out space probes since toe 60's, they have sent back some wonderful images, sensing and measurement have come a long way, in many wavelengths of EM radiation, magnetic field detection and visualisation.
But for most people it's the visible light images that hold us glued to our monitors, the added dimension of sound would get more people interested.
And let's face it, we need to get more of the general public interested!
Quite a few years ago a bloke from JPL came to Adelaide as part of the International Geophysical Year event, hosted here at Uni of SA.
He gave a talk on Voyagers encounter with Uranus and Neptune.
Nearly 4000 people came along! The lecture hall was packed, no standing room left, they ended up having to turn people away!
He was absolutely amazed and delighted!
At the start of his talk, he said straight up, "I wish we could get this level of interest in the space program back home in the USA."
I applaud the work that JPL do, but they really need to think of simple ways to get more people interested.
Listening to the wind whispering over the Martian landscape would do just that.

[MeteorWayne]

Phoenix has been spotted, encased in the Polar Dry Ice pack by HiRISE on MRO:

http://www.spaceflightnow.com/news/n0911/04phoenix/

MRO's High Resolution Imaging Science Experiment, or HiRISE, camera captured images on July 30 and Aug. 22 before the orbiter's science activities were halted by a safe mode in late August.

The pictures show Phoenix covered in carbon dioxide frost just before the predicted peak in ice coverage in September.

Spring began Oct. 26 and the frost should begin retreating over the next few months.

Scientists will attempt to contact Phoenix early next year as sunlight returns to the plains, but the odds of regaining communications with the frozen lander are slim.

http://marsprogram.jpl.nasa.gov/mro/new ... 1104a.html

Image:

http://hirise.lpl.arizona.edu/ESP_014393_2485

[3488]

Thank you very much Wayne.

Clearly shows that Phoenix was NOT encased in CO2 ice, as had been expected. It appears as if there is a lag effect here. There was more CO2 ice in the second shot, despite the Sun being highrer & the days getting longer each Sol.

I hope that MRO HiRISE will look again very soon. Very interesting indeed.

Andrew Brown.