New Mars Photographs - The Not So Red Planet

www.techinsider.io...

Here are some great new shots of Mars that I haven't seen posted here yet. I was surprised at the colour contrast of the various sediments and unique geological features that can be found on Mars.

Looks to me that there is a lot of frozen water almost everywhere on Mars and that at one point in its past it was fairly volcanically active. There are so many interesting landscapes depicted here that I feel like the rovers are in the most boring place possible but I guess many of these areas would be pretty hard for the rover to acess with terrain that it would likely get stuck in.

a reply to: Athetos

That's intriguing, though it looks like the color in the images has been manipulated for better separation of details.

soulwaxer

ETA:
From the article:
"But scientists use such a range of photographing techniques that the planet can end up a rainbow of colors."

soulwaxer

a reply to: Athetos

Lots of those pictures are labeled erosion of this and that. Dunes surely look windswept. Whats the fastest wind speed on Mars in that near vacuum?

How big are the sand grains that get blown into those fantastical desert dune scape?

Yea I kinda assumed there was some filters applied. The purple dune image kinda gave it away.



a reply to: soulwaxer

originally posted by: intrptr
a reply to: Athetos

Lots of those pictures are labeled erosion of this and that. Dunes surely look windswept. Whats the fastest wind speed on Mars in that near vacuum?

How big are the sand grains that get blown into those fantastical desert dune scape?

You'd be surprised. According to a Q&A on NASA's site:

The maximum wind speeds recorded by the Viking Landers in the 1970's were about 30 meters per second (60 miles an hour) with an average of 10 m/s (20 mph). Just as on Earth, at certain latitudes, the winds tend to blow in certain directions.

Mars Facts

I'm too bored to look up more recent calculations, though. ETA: Actually it's not a Q&A, just a list of facts. Meh.

a reply to: enlightenedservant

Thanks for the link. I could have done my own digging, but wanted some site that others already reviewed.

Atmospheric density on earth and mars, respectively:

1.2256, 0.0155

There is much less gas available at Mars for the wing to generate lift and for the propeller to produce thrust.

So I don't understand how those dunes get so big, unless we're talking about millions of years of elapsed time. The wind velocity has little effect if theres little pressure behind it.

How come they always show the pictures of craters, mountains and volcanoes? Do none of the planets or moons that NASA takes photos of have plains? I mean by the way the pictures look you wouldn't want to go unless you really liked seismic activity.

a reply to: intrptr

In the solar system, dunes are found on Earth, Mars, Venus, Titan, and perhaps even Pluto. Planetary scientists study them from orbit to infer wind directions—like a “free wind sock,” says Jani Radebaugh, who studies Titan’s dunes at Brigham Young University in Provo, Utah. They can also use them to infer wind speed. From theoretical models and wind tunnel tests using crushed walnut shells to mimic sand blowing in Mars’s weak gravity, researchers have estimated that wind speeds need to reach about 15 to 20 meters a second for martian dunes to form.

www.sciencemag.org...

a reply to: JDeLattre89
Craters, mountains, and volcanoes tell you more about the geological history of a region than plains do.

a reply to: Phage

Thank you, I forgot to account for lo gravity.

Ancient landscapes there. That part always amazes me. We have old trees here that go back thousands, a grand canyon and undersea Hawaiian volcano chain that go back tens if not hundreds of millions. The surface of mars is been there for ...billions?

a reply to: soulwaxer

Those colours are not real, as the photos are taken through a red filter, a filter that catches blue and green light and an infrared filter. Then they use the image from the red channel as red, the image from the blue+green channel as green and create the image for the blue channel with a mix of the red and blue+green channel.

They also have what they call IRB images, made with the infrared used for red, the red for green and the blue+green blue.

For those interested, here are some of India's images:

www.issdc.gov.in...

originally posted by: JDeLattre89
How come they always show the pictures of craters, mountains and volcanoes? Do none of the planets or moons that NASA takes photos of have plains? I mean by the way the pictures look you wouldn't want to go unless you really liked seismic activity.

Erm, have you seen the New Horizons' photos of Pluto? In particular, a certain heart-shaped plain?



There are pently of photos of plains on Mars too.

Thing is, without a thick atmosphere like ours protecting the surface from cosmic impacts, other bodies in the Solar System are bound to be pockmarked with craters.

originally posted by: intrptr
a reply to: enlightenedservant

Thanks for the link. I could have done my own digging, but wanted some site that others already reviewed.

Atmospheric density on earth and mars, respectively:

1.2256, 0.0155

There is much less gas available at Mars for the wing to generate lift and for the propeller to produce thrust.

So I don't understand how those dunes get so big, unless we're talking about millions of years of elapsed time. The wind velocity has little effect if theres little pressure behind it.

Well, it can't be millions of years when one of the images has "seasonal dunes" in the title.

a reply to: 3n19m470

You're right, as dunes are active features. A fixed feature resulting from a dune would be a consolidated dune.

originally posted by: intrptr
a reply to: enlightenedservant
So I don't understand how those dunes get so big, unless we're talking about millions of years of elapsed time. The wind velocity has little effect if theres little pressure behind it.

Winds on Mars are strong enough to transport sand grains across the surface, and that's how those dunes form. Martian winds are particularly strong around the polar regions during the seasons when the frozen CO2 warms up and sublimates. MRO photos show that on some dunes there, sand has actually been travelling up the slope!

Those winds are also responsible for filling up craters with dust and sand, meaning that around the polar regions, you'll find a lot less craters than elswhere on Mars:



Wind-induced (aka "aeolian") processes on Mars is a major part of studies done using the orbiters and rovers: www.uahirise.org...

a reply to: wildespace

Winds on Mars are strong enough to transport sand grains across the surface, and that's how those dunes form.

Thank you. As Phage pointed out up the slope, the thin atmosphere combined with the lesser gravity is what makes this possible.

According to the Mars-One webpage 'What are the risks of dust and sand on Mars?', that even though the wind speeds of the dust storms can be quite high - hurricane force, due to the far thinner atmosphere (1% of Earth), it would feel like a slight breeze.

stackexchange

So there, (insert fart sound)
Goes on to say the grains are fine, but sharper and more abrasive. Some of the dune like features aren't drifts of piled up grains but are eroded away by the currents of wind born sand, like a sand bank gets formed into dune patterns in a stream or river bed.

originally posted by: intrptr
a reply to: wildespace
Some of the dune like features aren't drifts of piled up grains but are eroded away by the currents of wind born sand, like a sand bank gets formed into dune patterns in a stream or river bed.

They could be, but this huge dune recently explored by Curiosity _had_ to be formed by sand piling up on top of itself due to wind:

I have seen Mars through my own telescope its a bombed out red husk like the moon enjoy what the NASA animators present you to justify sending another Tonka toy to the Egyptian desert whilst they spend hundreds of billions on God only knows what

a reply to: khnum

Amazing how much insight and understanding about Mars you gained from looking at it through a telescope.

Did you know that Curiosity rover is an international mission, with some of its instruments designed by, and operated by guys in Germany, Finland, Spain, and other European countries?

Sorry to hear that the humanity's efforts to study and learn about its cosmic home in the Solar Systems seem to offend you so much.