At right, a new gully appears in pictures of the same region of Terra Sirenum on Mars. The picture at left was taken in November 2010, and the right in May 2013. Credit: NASA/JPL-Caltech/Univ. of Arizona
Check out the groove! In the blink of a geological lifetime, a new gully has appeared on the planet Mars. These images from NASA’s Mars Reconnaissance Orbiter show a new channel in the southern hemisphere region of Terra Siernum that appeared between November 2010 and May 2013.
While there’s a lot of chatter about water on Mars, this particular feature is likely not due to that liquid, the agency added.
“Gully or ravine landforms are common on Mars, particularly in the southern highlands. This pair of images shows that material flowing down from an alcove at the head of a gully broke out of an older route and eroded a new channel,” NASA stated.
It’s unclear in what season the activity occurred because the observations took place more than a Martian year apart, NASA added. These ravines tend to happen in the southern highlands and other mid-latitude regions on Mars.
“Before-and-after HiRISE pairs of similar activity at other sites demonstrate that this type of activity generally occurs in winter, at temperatures so cold that carbon dioxide, rather than water, is likely to play the key role,” the agency said.
Last week, the agency also announced that MRO recovered from an unplanned computer swap that put the spacecraft into safe mode. Incidents of this nature have happened four times before, the agency noted.
Palikir Crater as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. Visible are warm-season flows called "recurring slope linea" that could have been created by salty liquid water. Credit: NASA/JPL-Caltech/UA/JHU-APL
One hotspot of debate are flows called “recurring slope lineae”, which are features that appear in warmer temperatures. These would seem to imply some kind of briny water flowing. A team recently checked out 13 of these sites. While they didn’t find any water or salt evidence in the spectra, they did find more iron-bearing minerals on “RSL slopes” compared to those that aren’t. So what’s going on?
“We still don’t have a smoking gun for existence of water in RSL, although we’re not sure how this process would take place without water,” stated Lujendra Ojha, a graduate student at the Georgia Institute of Technology in Atlanta who led two reports on these features. Pictures were taken using NASA’s Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE), which is led by the University of Arizona.
Palikir Crater as seen by the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera. Visible are warm-season flows called “recurring slope linea” that could have been created by salty liquid water. Credit: NASA/JPL-Caltech/UA/JHU-APL
It’s possible that the grains are being sorted by size (more plainly speaking, taking the fine dust away and leaving the larger grains behind), which could happen either with water or without it. Or, water might be present but not in a way that is obvious immediately if the area got darker because of moisture, or the minerals became oxidized. Water could be “missing” from these observations because they took place in the afternoon (meaning they could miss morning dew), or because the dark flows are smaller than the sample size in the picture.
While researchers still aren’t sure, the team says they still believe it’s salty water of some sort that is flowing despite very cold temperatures on Mars.
“The flow of water, even briny water, anywhere on Mars today would be a major discovery, impacting our understanding of present climate change on Mars and possibly indicating potential habitats for life near the surface on modern Mars,” said Richard Zurek, MRO project scientist who is at NASA’s Jet Propulsion Laboratory in California.
A related paper also found that RSL sites are rare on Mars, appearing in only 13 of 200 sites surveyed with similar slopes, latitudes and other features. You can read the accepted versions of the reports as they appear in Geophysical Research Letters and Icarus.
"Defrosting of dunes with large gullies", one of the images released in February 2014 from the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Credit: NASA/JPL/University of Arizona
As NASA’s missions at the Red Planet age, it’s so important not to take any of the pictures beamed back to Earth for granted.
The latest release of raw images from the University of Arizona’s High Resolution Imaging Science Experiment (aboard the Mars Reconnaissance Orbiter, launched in 2005) is as close as most of us will get to seeing the Red Planet, and each picture captures a planet in action.
Snow, dust and wind are combining to make the incredible images you will see below. These shots, by the way, are close-ups colorized at the source; to see the full raw image, click on each picture you see below.
“Avalanche monitoring at steep chasma boreale headscarp”, one of the images released in February 2014 from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment. Credit: NASA/JPL/University of Arizona“Avalanche monitoring at steep north polar scarp”, one of the images released in February 2014 from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment. Credit: NASA/JPL/University of Arizona“Dunes with serious slope streaks dubbed tleilax”, one of the images released in February 2014 from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment. (“Tleilax” is a reference to Dune, a science-fiction book series most famous for the eponymous first one concerning a desert planet.) Credit: NASA/JPL/University of Arizona“Cerberus region intracrater dune and ripple changes”, one of the images released in February 2014 from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment. Credit: NASA/JPL/University of Arizona
A series of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter show how the appearance of dark markings on Martian slope changes with the seasons. Image credit: NASA/JPL-Caltech/Univ. of Arizona.
Get ready, because here are some more findings about possible water on Mars. This picture above from the Mars Reconnaissance Orbiter is a series showing changing dark lines on an equatorial hillside — which could be an indication of salty water, scientists said.
As MRO circled the planet and peered at the lines with its High Resolution Imaging Science Experiment (HiRISE) camera, it tracked these changes at five locations in Valles Marineris, the biggest canyon our solar system has to offer. The lines were on slopes that faced the north and the south, and most intriguingly, they activated when the sun hit their respective sides.
“The equatorial surface region of Mars has been regarded as dry, free of liquid or frozen water, but we may need to rethink that,” stated Alfred McEwen of the University of Arizona in Tucson.
“The explanation that fits best is salty water is flowing down the slopes when the temperature rises,” added McEwen, who is HiRISE principal investigator. “We still don’t have any definite identification of water at these sites, but there’s nothing that rules it out, either.”
A 2010 image of ice excavated on Mars after a recent meteorite impact. Image from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera. Credit: NASA/JPL-Caltech/Univ. of Arizona
Scientists first spotted these types of features two years ago in the mid-latitudes of Mars, but in that case these were small features (usually less than 16 feet or five meters wide). The slopes observed here range as wide as 4,000 feet (1,200 meters).
Salt can keep water flowing even in temperatures where more pure water gets frozen, and also reduce the evaporation rate. NASA also noted it used data from two other MRO instruments (Compact Reconnaissance Imaging Spectrometer for Mars and the Context Camera) and the Mars Oddysey’s Thermal Emission Imaging System.
That’s not all, however. Scientists also reported 15 fresh craters that excavated ice that used to be hidden underneath the soil of Mars.
A radar on NASA’s Mars Reconnaissance Orbiter has detected widespread deposits of glacial ice in the mid-latitudes of Mars.NASA/JPL-Caltech/ASI/University of Rome/Southwest Research Institute
“The more we find, the more we can fill in a global map of where ice is buried,” stated Colin Dundas of the United States Geological Survey in Flagstaff, Ariz.
“We’ve now seen icy craters down to 39 degrees north, more than halfway from the pole to the equator. They tell us that either the average climate over several thousand years is wetter than present or that water vapor in the current atmosphere is concentrated near the surface. Ice could have formed under wetter conditions, with remnants from that time persisting today, but slowly disappearing.”
Results were presented at the American Geophysical Union’s fall meeting this week.
A crater imaged by the Mars Reconnaissance Orbiter's HiRISE (High Resolution Imaging Science Experiment). Credit: NASA/JPL/University of Arizona
Stop what you’re doing, grab the nearest 3-D glasses (red/blue type) you have available and then pretend you’re hovering above Mars for a while. These are some of the latest images from the Mars Reconnaissance Orbiter, which has been cruising above the planet since 2006.
“Candidate Future Landing Site at Valley North of Jezero Crater”, imaged by the Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment). Credit: NASA/JPL/University of Arizona“Fossae Source of Outflows,” a picture taken by Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment). Credit: NASA/JPL/University of Arizona“Floor of East Candor Chasma,” a picture taken by the Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment). Credit: NASA/JPL/University of Arizona“Knobs with bright layers in Noctis Labyrinthus”, a picture taken by the Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment). Credit: NASA/JPL/University of Arizona
Loose soil, dust and rock stains an icy cliffside on Mars (NASA/JPL/University of Arizona)
Mars may be geologically inactive but that doesn’t mean there’s nothing happening there — seasonal changes on the Red Planet can have some very dramatic effects on the landscape, as this recent image from the HiRISE camera shows!
The full extent of the 1000-meter-long dusty landslide (NASA/JPL/University of Arizona)
When increasing light from the springtime Sun warms up the sides of sheer cliffs made from countless layers of water and carbon dioxide ice near Mars’ north pole, some of that CO2 ice sublimes, sending cascades of loose soil and dust down to the terraced base below. This uncovered material stains the frost-covered polar surface dark, outlining the paths of avalanches for HiRISE to easily spot from orbit. (See the original HiRISE image here.)
The rust-colored avalanche shown above has fallen hundreds of meters from the middle of a layered ice deposit, spreading nearly a kilometer across the frozen ridges at the base of the cliff. The view was acquired on Sept. 13, 2013.
Check out a video explaining this view and the processes that created it below, narrated by Phil Plait (aka the Bad Astronomer).
Mars’ seasonal polar caps are composed primarily of carbon dioxide frost. This frost sublimates (changes from solid directly to gas) in the spring, boosting the pressure of Mars’ thin atmosphere. In the fall the carbon dioxide condenses, causing the polar caps to reach as far as ~55 degrees latitude by late winter. By learning about current processes on a local level we can learn more about how to interpret the geological record of climate changes on Mars. (Source)
HiRISE image of comet ISON from Mars orbit (NASA/JPL/University of Arizona)
It’s not much to look at, but there it is: the incoming comet ISON (aka C/2012 S1) as seen by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter. An enlarged version of one of four just-released images, this represents a 256-by-256-pixel patch of sky imaged by HiRISE on Sunday, September 29. ISON is the fuzzy blob at center, 8.5 million miles (13.8 million km) away.
See all four images below:
HiRISE images of ISON on Sept. 29, 2013 (NASA/JPL/University of Arizona)
HiRISE researchers Alan Delamere and Alfred McEwen explained in a news release:
Based on preliminary analysis of the data, the comet appears to be at the low end of the range of brightness predictions for the observation. As a result, the image isn’t visually pleasing but low coma activity is best for constraining the size of the nucleus. This image has a scale of approximately 8 miles (13.3 km) per pixel, larger than the comet, but the size of the nucleus can be estimated based on the typical brightness of other comet nuclei. The comet, like Mars, is currently 241 million kilometers from the Sun. As the comet gets closer to the sun, its brightness will increase to Earth-based observers and the comet may also become intrinsically brighter as the stronger sunlight volatilizes the comet’s ices.
More images of ISON from HiRISE are expected as the comet came even closer to Mars, approaching within 6.7 million miles (10.8 million km), but the illumination from those angles may not be as good.
NOTE: These are preliminary single (non-stacked) images, and still contain noise and background stars – hence the fuzziness. Plus HiRISE was not really designed for sky imaging! (Thanks to HiRISE team member Kristin Block for the info.)
So even though it’s at the “low end” of brightness predictions in these HiRISE images, ISON certainly hasn’t “fizzled” like some reports claimed earlier this year (although just how bright it will get in our skies remains to be seen.)
Comet ISON will make its closest pass of the Sun (perihelion) on November 28, 2013, coming within 724,000 miles (1.16 million km) before heading back out into the Solar System… if it survives the encounter, that is. Read more about how to view ISON here and here.
Worried about ISON’s first (and possibly last) visit to the inner Solar System? Don’t be. Recent rumors of comet-caused catastrophe are greatly exaggerated… read more on David Dickinson’s article Debunking Comet ISON Conspiracy Theories (No, ISON is Not Nibiru).
HiRISE image of lobate landforms called "brain terrain" that wrap around a small hill on Mars
It doesn’t take much thought to understand why this landscape on Mars is called “brain terrain” — the swirling lobes of ice, part of a large glacial deposit in Mars’ northern hemisphere, uncannily resemble the texture of a brain — or at the very least a brain coral!
What causes this strange landscape? Find out below:
It’s suggested that brain terrain is the result of the thermal stress and contraction, followed by sublimation, of these large ice deposits, laid down during a mid-latitude glaciation period ten to 100 million years ago. (Read more in this 2009 paper by Brown University’s Joseph Levy et al.)
This image was obtained by the HiRISE camera aboard the Mars Reconnaissance orbiter on August 23, 2013. See the original RGB color scan here.
The bright spot in the center of this HiRISE image may be the 11-meter-wide parachute from Mars 3's descent stage (NASA/JPL-Caltech/Univ. of Arizona)
On May 28, 1971, the Soviet Union launched the Mars 3 mission which, like its previously-launched and ill-fated sibling Mars 2, consisted of an orbiter and lander destined for the Red Planet. Just over six months later on December 2, 1971, Mars 3 arrived at Mars — five days after Mars 2 crashed. The Mars 3 descent module separated from the orbiter and several hours later entered the Martian atmosphere, descending to the surface via a series of parachutes and retrorockets. (Sound familiar?) Once safely on the surface, the Mars 3 lander opened its four petal-shaped covers to release the 4.5-kg PROP-M rover contained inside… and after 20 seconds of transmission, fell silent. Due to unknown causes, the Mars 3 lander was never heard from or seen again.
Until now.
These images show what might be hardware from the Soviet Union’s 1971 Mars 3 lander (NASA/JPL-Caltech/Univ. of Arizona)
The set of images above shows what might be hardware from the 1971 Soviet Mars 3 lander, seen in a pair of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.
While following news about Mars and NASA’s Curiosity rover, Russian citizen enthusiasts found four features in a five-year-old image from Mars Reconnaissance Orbiter that resemble four pieces of hardware from the Mars 3 mission: the parachute, heat shield, terminal retrorocket and lander. A follow-up image by the orbiter from last month shows the same features.
“Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out.”
– Alfred McEwen, HiRISE Principal Investigator
The Mars 3 lander (NSSDC)
Vitali Egorov from St. Petersburg, Russia, heads the largest Russian Internet community about Curiosity. His subscribers did the preliminary search for Mars 3 via crowdsourcing. Egorov modeled what Mars 3 hardware pieces should look like in a HiRISE image, and the group carefully searched the many small features in this large image, finding what appear to be viable candidates in the southern part of the scene. Each candidate has a size and shape consistent with the expected hardware, and they are arranged on the surface as expected from the entry, descent and landing sequence.
“I wanted to attract people’s attention to the fact that Mars exploration today is available to practically anyone,” Egorov said. “At the same time we were able to connect with the history of our country, which we were reminded of after many years through the images from the Mars Reconnaissance Orbiter.”
The predicted Mars 3 landing site was at latitude 45 degrees south, longitude 202 degrees east, in Ptolemaeus Crater. HiRISE acquired a large image at this location in November 2007, and promising candidates for the hardware from Mars 3 were found on Dec. 31, 2012.
Candidate features of the Mars 3 retrorockets (top) and lander (bottom)
The candidate parachute is the most distinctive feature in the images (seen above at top.) It is an especially bright spot for this region, about 8.2 yards (7.5 meters) in diameter.
The parachute would have a diameter of 12 yards (11 meters) if fully spread out over the surface, so this is consistent.
“Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson. “Further analysis of the data and future images to better understand the three-dimensional shapes may help to confirm this interpretation.”
Enhanced-color HiRISE image of impact craters from MSL's ballast weights (NASA/JPL-Caltech)
During its “seven minutes of terror” landing on August 6, 2012, NASA’s Mars Science Laboratory dropped quite a few things down onto the Martian surface: pieces from the cruise stage, a heat shield, a parachute, the entry capsule’s backshell, a sky crane, one carefully-placed rover (obviously) and also eight tungsten masses — weights used for ballast and orientation during the descent process.
Two 75 kilogram (165 lb) blocks were released near the top of the atmosphere and six 25 kg (55 lb) weights a bit farther down, just before the deployment of the parachute. The image above, an enhanced-color image from the HiRISE camera aboard the Mars Reconnaissance Orbiter, shows the impact craters from four of these smaller tungsten masses in high resolution. This is part of a surface scan acquired on Jan. 29, 2013.
These four craters are part of a chain of six from all the 55 kg weights. See below for context:
CLICK TO PLAY – Before-and-after images of the 55 kg-mass landing sites (NASA/JPL/MSSS)
Captured by MRO’s Context Camera shortly after the rover landed, the animation above shows the impact site of all six 55 kg masses. These impacted the Martian surface about 12 km (7.5 miles) from the Curiosity rover’s landing site.
A mosaic has been assembled showing potential craters from the larger ballast blocks as well as other, smaller pieces of the cruise stage. Check it out below or download the full 50mb image here.
HiRISE images of MSL’s impact craters (NASA/JPL/University of Arizona)
