APOD: Curiosity: Wheels on Mars (2013 Jun 03)

[APOD Robot]

Curiosity: Wheels on Mars

Explanation: Could life ever have existed on Mars? To help find out, humanity landed the Curiosity rover on Mars last August. To make sure the car-sized explorer survived the interplanetary trip and dramatic landing intact, the above image and others was taken peering at, under, and around Curiosity. Pictured above in this unusual vista are three of Curiosity's six wheels, each measuring about half a meter across. In recent months, Curiosity has been exploring the surroundings of an area dubbed Yellowknife Bay. Analyses of data taken by Curiosity's cameras and onboard laboratories has provided strong new evidence that Mars could once have supported life. In the distance is part of the slope to the central peak inside Gale Crater that Curiosity is scheduled to attempt to climb -- Mt. Sharp.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

[alter-ego]

That's right. These wheels have "JPL" written all over them, don't they.
I like the APOD view - a monster "rover" kind of look.

Click to view full size image

[Boomer12k]

Thought it was a Monster Truck at first.....Keep on Truckin' Curiosity!!!

Can't wait for it to start climbing the Mountain....I think I can....I think I can...I think I can....

:---[===] *

[supamario]

Put some tracks on it and you have the sandcrawler from Star Wars. Looks like the same planet too

[neufer]

Put some tracks on it and you have the sandcrawler from Star Wars. Looks like the same planet too

[b][color=#0000FF]From a small pod above the vehicle's back, a spotter kept lookout for enemy forces. Though there was a large view of the area, he was an easy target for hostile troops. This observation mast could be retracted when not in use.[/color][/b]

---

<<The Heavy Assault Vehicle/wheeled (HAVw) A6 Juggernaut, also known as the Turbo Tank, was an upgraded version of the A5 Juggernaut heavy assault vehicle. The A6 Juggernaut model was larger than its predecessor. It measured 30.4 meters in height and 49.4 meters in length. Its interior space was greatly increased to allow for up to three hundred troopers and equipment, a complement of close support craft such as speeder bikes and light airspeeders, or a mix of both. A combination of twelve crew members were required to pilot and control the massive vehicle, although with an automation package, that requirement could be reduced to just two pilots.

With thick, thermally superconducting armor (capable of absorbing enemy fire and dispersing heat over a wide area) and a heavier load, the A6 Juggernaut could only achieve 160 kilometers per hour, and the turning issues of the A5 model were magnified with the A6. The slowness required for negotiating turns encouraged the A6's use on open terrain rather than urban battlefields.

Weapons systems were also upgraded to include a heavy laser cannon turret, a rapid repeating laser cannon, two medium antipersonnel laser cannons, two twin antipersonnel blaster cannons, and two turreted projectile launchers, loadable with variable-yield concussion grenades for close support or missiles added for anti-armor firepower. Missile range was 30km. Against an unshielded target, a Juggernaut could deliver the heat of a nuclear bomb into a small area.

The A6 model saw its heaviest use in service of the Galactic Republic during the Clone Wars. Due to a flawed direct-delivery system maintained by Kuat Drive Yards during the conflict, some A6 Juggernauts also fell into the hands of the CIS. HAVw A6 Juggernauts were used fairly extensively in the Battle of Kashyyyk alongside AT-APs, where they went up against enemy NR-N99 tank droids and DSD1 dwarf spider droids.

After the Clone Wars, the Imperial Army developed sleeker and more versatile combat vehicles. The various Juggernaut models were gradually phased out, and during the Galactic Civil War, they primarily served on battlefronts in the Outer Rim. Some fell into the hands of the Rebel Alliance. It appears that the Heavy Assault Vehicle Transport B5 Juggernaut served as its successor, even though its purpose was different. A6s were deployed in the Battle of Hoth. By 13 ABY, they were one of a number of Clone Wars-era Galactic Republic vehicles being used by the Restored Empire faction of the Imperial Remnant.>>

[rstevenson]

I'm wondering about some image artifacts in this one. Obviously the image is made up of several sub-images, and each sub-image is tilted. I can only imagine the contortions the camera arm was forced into to get down there to take the shots.

Within the sub-images there are thin white streaks, many of which end (or start, I suppose) at a white spot. I've pulled out four of them here, with an arrow to show where each spot is. I increased the contrast and brightness to show them more clearly. Each streak runs continuously from the white spot at its end to the far side of its sub-image.

spots.jpg (30.68 KiB) Viewed 6909 times

Does anyone have any idea what the streaks and white spots represent? (If it was good ol' film, it'd be obvious - scratches. So what's the digital equivalent of a scratch?)

Rob

[Chris Peterson]

I'm wondering about some image artifacts in this one. Obviously the image is made up of several sub-images, and each sub-image is tilted. I can only imagine the contortions the camera arm was forced into to get down there to take the shots.

Within the sub-images there are thin white streaks, many of which end (or start, I suppose) at a white spot. I've pulled out four of them here, with an arrow to show where each spot is. I increased the contrast and brightness to show them more clearly. Each streak runs continuously from the white spot at its end to the far side of its sub-image.

Does anyone have any idea what the streaks and white spots represent? (If it was good ol' film, it'd be obvious - scratches. So what's the digital equivalent of a scratch?)

They look like uncorrected hot pixels. Note that they are lined up with the physical columns of the detector (parallel to the subframe edges). A hot pixel is a defective pixel on a CCD that fills up very quickly- basically, it's always white. When it gets read out, it boosts the adjacent pixels in the same column, leaving a streak behind it in the readout direction. These sorts of artifacts are usually calibrated out using dark frames or bad pixel maps. This composite appears to be made from a pair of raw or only partially calibrated images. Note that the defects are fixed. If you overlay the two subframes, the streaks are in the same place on both of them.

[rstevenson]

Thanks Chris. I assumed some sort of defect, but hadn't seen (or noticed) this sort before. We're spoiled by seeing only well-processed for public consumption images most of the time.

Rob

[stephen63]

Thanks Chris. I assumed some sort of defect, but hadn't seen (or noticed) this sort before. We're spoiled by seeing only well-processed for public consumption images most of the time.

Rob

Rob, I looked up the chip used in this camera. It's a Kodak KAI-2020CM CCD. It was used quite often, and perhaps still is, by amateur astronomers for astro imaging. This is by no means a high end CCD (whatever the definition of that is)but for what it's used for, as explained by MSL, is certainly adequate. I downloaded a dark frame comparison to another chip and will post it.

The ST-2000 camera on the left uses the KAI-2020CM.

[Anthony Barreiro]

... In the distance is part of the slope to the central peak inside Gale Crater that Curiosity is scheduled to attempt to climb -- Mt. Sharp

"Mount Sharp" is an informal nickname used by the JPL team to honor the late geologist Robert Sharp. The official name of this mountain, according to the International Astronomical Union, is Aeolis Mons.

[geckzilla]

Copied from the Introductions thread.

Hi ! Dave Morgan here I am now 80, been amateur astronomer since age of 16 built several Newtonian/Dobs up to 16" over the years. Astronomy has come a long way since then. How does sand on surface of Mars stick to the rover wheels ( static electricity or moisture) Anyone?

[neufer]

Hi ! Dave Morgan here I am now 80, been amateur astronomer since age of 16 built several Newtonian/Dobs up to 16" over the years. Astronomy has come a long way since then. How does sand on surface of Mars stick to the rover wheels ( static electricity or moisture) Anyone?

• Definitely NOT moisture. Static electricity makes sense.

<<The Martian atmosphere will also pose considerable engineering problems for future astronauts. [A] real problem is static electricity. On Earth, walking across a carpet can produce enough charge to disable sensitive electronics. On Mars, there is no surface water, so there is no natural grounding mechanism. As a result, astronauts will develop huge differences in electrical charges relative to their equipment. This might produce an arc between the astronaut's space suit and equipment, meaning potential damage to sensitive instruments or the suit itself.>>

[rstevenson]

• Definitely NOT moisture. Static electricity makes sense.

This might help (This one's from Amazon. I'm sure you can find one locally -- but perhaps not on Mars.)...

31q8mAUJ-KL.jpg (9.8 KiB) Viewed 6726 times

Rob

[Anthony Barreiro]

Hi ! Dave Morgan here I am now 80, been amateur astronomer since age of 16 built several Newtonian/Dobs up to 16" over the years. Astronomy has come a long way since then. How does sand on surface of Mars stick to the rover wheels ( static electricity or moisture) Anyone?

• Definitely NOT moisture. Static electricity makes sense.

<<The Martian atmosphere will also pose considerable engineering problems for future astronauts. [A] real problem is static electricity. On Earth, walking across a carpet can produce enough charge to disable sensitive electronics. On Mars, there is no surface water, so there is no natural grounding mechanism. As a result, astronauts will develop huge differences in electrical charges relative to their equipment. This might produce an arc between the astronaut's space suit and equipment, meaning potential damage to sensitive instruments or the suit itself.>>

It would be wiser to use the conditional future tense rather than the simple future tense, i.e., "the Martian atmosphere would pose considerable engineering problems for future astronauts." Martian robots, yes; Martian astronauts, probably not.

[neufer]

<<The Martian atmosphere will also pose considerable engineering problems for future astronauts. [A] real problem is static electricity. On Earth, walking across a carpet can produce enough charge to disable sensitive electronics. On Mars, there is no surface water, so there is no natural grounding mechanism. As a result, astronauts will develop huge differences in electrical charges relative to their equipment. This might produce an arc between the astronaut's space suit and equipment, meaning potential damage to sensitive instruments or the suit itself.>>

It would be wiser to use the conditional future tense rather than the simple future tense, i.e., "the Martian atmosphere would pose considerable engineering problems for future astronauts." Martian robots, yes; Martian astronauts, probably not.

ZZZAPPP !