As Comet C/2013 A1 Siding Spring inches closer to the Red Planet, NASA’s taking steps to protect its fleet of orbiting Mars spacecraft. On October 19, the comet’s icy nucleus will miss the planet by just 82,000 miles (132,000 km). That’s 17 times closer than the closest recorded Earth-approaching comet, Lexell’s Comet in 1770.
No one’s worried about the tiny nucleus doing any damage. It’ll zip right by. Rather it’s dust particles embedded in vaporizing ice that concern NASA planners. Dust spreads into a broad tail that could potentially brush Mars’ upper atmosphere and strike an orbiter. A single particle of debris half a millimeter across may not seem like your mortal enemy, but when it’s traveling at 35 miles (56 km) per second relative to the spacecraft, one hit could spell trouble.
“Three expert teams have modeled this comet for NASA and provided forecasts for its flyby of Mars,” explained Rich Zurek, chief scientist for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The hazard is not an impact of the comet nucleus, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles — or it might not.”
The agency’s taking a prudent approach. NASA currently operates the Mars Reconnaissance Orbiter (MRO) and Mars Odyssey spacecraft with a third orbiter, MAVEN, currently on its way to the planet and expected to settle into orbit a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of Mars when the comet is most likely to pass by.
Already, mission planners tweaked MRO’s orbit on July 2 to move it toward a safe position with a second maneuver to follow on August 27. A similar adjustment is planned for Mars Odyssey on August 5 and October 9 for the Mars Atmosphere and Volatile Evolution (MAVEN) probe. The time of greatest risk to the spacecraft is brief – about 20 minutes – when the widest part of the comet’s tail passes closest to the planet.
One question I’m always asked is whether the Mars rovers are in any danger of dust-producing meteors in the comet’s wake. While the planet might get peppered with a meteor shower, its atmosphere is thick enough to incinerate cometary dust particles before they reach the surface, not unlike what happens during a typical meteor shower here on Earth. Rover cameras may be used to photograph the comet before the flyby and to capture meteors during the comet’s closest approach.
Despite concerns about dust, NASA knows a good opportunity when it sees one. In the days before and after the flyby, all three orbiters will conduct studies on the comet.
According to a recent NASA press release, instruments on MRO and Odyssey will examine the nucleus, coma and tail and possible effects on the Martian atmosphere:
“Odyssey will study thermal and spectral properties of the comet’s coma and tail. MRO will monitor Mars’ atmosphere for possible temperature increases and cloud formation, as well as changes in electron density at high altitudes and MAVEN will study gases coming off the comet’s nucleus as it’s warmed by the sun. The team anticipates this event will yield detailed views of the comet’s nucleus and potentially reveal its rotation rate and surface features.”
This is Comet Siding Spring’s first trip to the inner solar system. Expect exciting news as we peer up close at pristine ices and dust that have been locked in deep freeze since the time the planets formed.
For more information on the event, check out this NASA website devoted to the comet.
NASA has now released a breathtaking high resolution image of the rover Curiosity captured from Mars orbit coincidentally coinciding with her crossing the targeted landing ellipse just days after she marked ‘1 Martian Year’ on the Red Planet in search of the chemical ingredients necessary to support alien microbial life forms.
The orbital image was taken on June 27 (Sol 672) by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO) and clearly shows the rover and wheel tracks at the end of the drive that Sol, or Martian day.
You can simultaneously experience the Martian eye view of Curiosity from above and below by checking out our Sol 672 ground level photo mosaic – below. It’s assembled from raw images taken by the mast mounted navigation camera (Navcam) showing the rovers wheel tracks and distant rim of the Gale Crater landing site.
The six wheeled robot drove about 269 feet (82 meters) on June 27 traversing to the boundary of her targeted landing ellipse in safe terrain – approximately 4 miles wide and 12 miles long (7 kilometers by 20 kilometers) – for the first time since touchdown on Mars nearly two years ago on August 5, 2012 inside Gale Crater.
Curiosity celebrated another Martian milestone anniversary on June 24 (Sol 669) – 1 Martian Year on Mars!
A Martian year is equivalent to 687 Earth days, or nearly two Earth years.
The SUZ sized rover is driving as swiftly as possible to the base of Mount Sharp which dominates the center of Gale Crater and reaches 3.4 miles (5.5 km) into the Martian sky – taller than Mount Rainier.
During Year 1 on Mars, Earth’s emissary has already accomplished her primary objective of discovering a habitable zone on the Red Planet that contains the minerals necessary to support microbial life in the ancient past when Mars was far wetter and warmer billions of years ago.
To date, Curiosity’s odometer totals over 5.1 miles (8.4 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 165,000 images.
Curiosity still has about another 2.4 miles (3.9 kilometers) to go to reach the entry way at a gap in the treacherous sand dunes at the foothills of Mount Sharp sometime later this year.
Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.
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.
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.
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.
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!
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)
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 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).
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.
Curiosity accomplished historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182), shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169) – back dropped with Mount Sharp – where the robot is currently working. Curiosity will bore a 2nd drill hole soon following the resumption of contact with the end of the solar conjunction period. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo
See drill hole and conjunction videos below[/caption]
After taking a well deserved and unavoidable break during April’s solar conjunction with Mars that blocked two way communication with Earth, NASA’s powerful Martian fleet of orbiters and rovers have reestablished contact and are alive and well and ready to Rock ‘n Roll ‘n Drill.
“Both orbiters and both rovers are in good health after conjunction,” said NASA JPL spokesman Guy Webster exclusively to Universe Today.
Curiosity’s Chief Scientist John Grotzinger confirmed to me today (May 1) that further drilling around the site of the initial John Klein outcrop bore hole is a top near term priority.
The goal is to search for the chemical ingredients of life.
“We’ll drill a second sample,” Grotzinger told Universe Today exclusively. Grotzinger, of the California Institute of Technology in Pasadena, Calif., leads NASA’s Curiosity Mars Science Laboratory mission.
“We’ll move a small bit, either with the arm or the wheels, and then drill another hole to confirm what we found in the John Klein hole.”
Earth, Mars and the Sun have been lined up in nearly a straight line for the past several weeks, which effectively blocked virtually all contact with NASA’s four pronged investigative Armada at the Red Planet.
NASA’s Red Planet fleet consists of the Curiosity (MSL) and Opportunity (MER) surface rovers as well as the long lived Mars Odyssey (MO) and Mars Reconnaissance Orbiter (MRO) robotic orbiters circling overhead. ESA’s Mars Express orbiter is also exploring the Red Planet.
“All have been in communications,” Webster told me today, May 1.
The NASA spacecraft are functioning normally and beginning to transmit the science data collected and stored in on board memory during the conjunction period when a commanding moratorium was in effect.
“Lots of data that had been stored on MRO during conjunction has been downlinked,” Webster confirmed to Universe Today.
And NASA is already transmitting and issuing new marching orders to the Martian Armada to resume their investigations into unveiling the mysteries of the Red Planet and determine whether life ever existed eons ago or today.
“New commanding, post-conjunction has been sent to both orbiters and Opportunity.”
“And the sequence is being developed today for sending to Curiosity tonight (May 1), as scheduled more than a month ago,” Webster explained.
“We’ll spend the next few sols transitioning over to new flight software that gives the rover additional capabilities,” said Grotzinger.
“After that we’ll spend some time testing out the science instruments on the B-side rover compute element – that we booted to before conjunction.”
Curiosity is at work inside the Yellowknife Bay basin just south of the Martian equator. Opportunity is exploring the rim of Endeavour crater at the Cape York rim segment.
Mars Solar Conjunction is a normal celestial event that occurs naturally about every 26 months. The science and engineering teams take painstaking preparatory efforts to insure no harm comes to the spacecraft during the conjunction period when they have no chance to assess or intervene in case problems arise.
So it’s great news and a huge relief to the large science and operations teams handling NASA’s Martian assets to learn that all is well.
Since the sun can disrupt and garble communications, mission controllers suspended transmissions and commands so as not to inadvertently create serious problems that could damage the fleet in a worst case scenario.
So what’s on tap for Curiosity and Opportunity in the near term ?
“For the first few days for Curiosity we will be installing a software upgrade.”
“For both rovers, the science teams will be making decisions about how much more to do at current locations before moving on,” Webster told me.
The Opportunity science team has said that the long lived robot has pretty much finished investigating the Cape York area at Endeavour crater where she made the fantastic discovery of phyllosilicates clay minerals that form in neutral water.
Signals from Opportunity received a few days ago on April 27 indicated that the robot had briefly entered a standby auto mode while collecting imagery of the sun.
NASA reported today that all operations with Opportunity was “back under ground control, executing a sequence of commands sent by the rover team”, had returned to normal and the robot exited the precautionary status.
“The Curiosity team has said they want to do at least one more drilling in Yellowknife Bay area,” according to Webster.
Curiosity has already accomplished her primary task and discovered a habitable zone that possesses the key ingredients needed for potential alien microbes to once have thrived in the distant past on the Red Planet when it was warmer and wetter.
The robot found widespread evidence for repeated episodes of flowing liquid water, hydrated mineral veins and phyllosilicates clay minerals on the floor of her Gale Crater landing site after analyzing the first powder ever drilled from a Martian rock.
Video Caption: Historic 1st bore hole drilled by NASA’s Curiosity Mars rover on Sol 182 of the mission (8 Feb 2013). Credit: NASA/JPL-Caltech/MSSS/Marco Di Lorenzo/Ken Kremer (http://www.kenkremer.com/)
During conjunction Curiosity collected weather, radiation and water measurements but no imagery.
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.
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
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.
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.”
Curiosity and Mount Sharp – Parting Shot ahead of Mars Solar Conjunction
Enjoy this parting view of Curiosity’s elevated robotic arm and drill staring at you; back dropped with her ultimate destination – Mount Sharp – in this panoramic vista of Yellowknife Bay basin snapped on March 23, Sol 223, by the rover’s navigation camera system. The raw images were stitched by Marco Di Lorenzo and Ken Kremer and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/KenKremer (kenkremer.com)
See video below explaining Mars Solar Conjunction[/caption]
Earth’s science invasion fleet at Mars is taking a break from speaking with their handlers back on Earth.
Why ? Because as happens every 26 months, the sun has gotten directly in the way of Mars and Earth.
Earth, Mars and the Sun are lined up in nearly a straight line. The geometry is normal and it’s called ‘Mars Solar Conjunction’.
Conjunction officially started on April 4 and lasts until around May 1.
From our perspective here on Earth, Mars will be passing behind the Sun.
Watch this brief NASA JPL video for an explanation of Mars Solar Conjunction.
Therefore the Terran fleet will be on its own for the next month since the sun will be blocking nearly all communications.
In fact since the sun can disrupt and garble communications, mission controllers will be pretty much suspending transmissions and commands so as not to inadvertently create serious problems that could damage the fleet in a worst case scenario.
Right now there are a trio of orbiters and a duo of rovers from NASA and ESA exploring Mars.
The spacecraft include the Curiosity (MSL) and Opportunity (MER) rovers from NASA. Also the Mars Express orbiter from ESA and the Mars Odyssey (MO) and Mars Reconnaissance Orbiter (MRO) from NASA.
Because several of these robotic assets have been at Mars for nearly 10 years and longer, the engineering teams have a lot of experience with handling them during the month long conjunction period.
“This is our sixth conjunction for Odyssey,” said Chris Potts of JPL, mission manager for NASA’s Mars Odyssey, which has been orbiting Mars since 2001. “We have plenty of useful experience dealing with them, though each conjunction is a little different.”
But there is something new this go round.
“The biggest difference for this 2013 conjunction is having Curiosity on Mars,” Potts said. Odyssey and the Mars Reconnaissance Orbiter relay almost all data coming from Curiosity and the Mars Exploration Rover Opportunity, as well as conducting the orbiters’ own science observations.
The rovers and orbiters can continue working and collecting science images and spectral data.
But that data will all be stored in the on board memory for a post-conjunction playback starting sometime in May.
Learn more about Curiosity’s groundbreaking discoveries and NASA missions at Ken’s upcoming lecture presentations:
April 20/21 : “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus Orion, SpaceX, Antares, the Space Shuttle and more! NEAF Astronomy Forum, Suffern, NY
April 28: “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus the Space Shuttle, SpaceX, Antares, Orion and more. Washington Crossing State Park, Titusville, NJ, 130 PM