News from Mars: Laser-Blasting and Soil Sampling

mars_lifeAs the exploration of Mars goes on, the small army of robotic rovers, satellites and orbiters continue to provide us with information, photographs and discoveries that remind us of how great a mystery the Red Planet truly is. For instance, in the past month, two major stories have been announced concerning the nature of Martian soil, its ancient history, and some of the more exciting moments in it’s exploration.

For example, Curiosity made news as its high resolution camera caught an image of sparks being generated as it zapped a Martian rock. In it’s lifetime, the rover has used its million watt Chemistry and Camera (ChemCam) laser to zap over 600 rock or soil targets as part of its mission. However, this was the first time that the rover team was able to get the arm-mounted Mars Hand Lens Imager (MAHLI) to capture the action as it occurred.

Curiosity-Laser-BeamThe ChemCam laser is used to determine the composition of Martian rocks and soils at a distance of up to 8 meters (25 feet). By hitting targets with several high-energy pulses, it is able to yield preliminary data for the scientists and engineers back at Earth to help them decide if a target warrants a closer investigation and, in rare cases, sampling and drilling activities.

ChemCam works through a process called laser-induced breakdown spectroscopy. The laser hits a target with pulses to generate sparks, whose spectra provide information about which chemical elements are in the target. Successive laser shots are fired in sequence to gradually blast away thin layers of material. Each shot exposes a slightly deeper layer for examination by the ChemCam spectrometer.

Mars_novarockAs Curiosity fired deeper into the target rock – named “Nova” – it showed an increasing concentration of aluminum as the sequential laser blasts penetrated through the uninteresting dust on the rock’s surface. Silicon and sodium were also detected. As Sylvestre Maurice, ChemCam’s Deputy Principal Investigator at the Research Institute in Astrophysics and Planetology, said in a statement:

This is so exciting! The ChemCam laser has fired more than 150,000 times on Mars, but this is the first time we see the plasma plume that is created… Each time the laser hits a target, the plasma light is caught and analyzed by ChemCam’s spectrometers. What the new images add is confirmation that the size and shape of the spark are what we anticipated under Martian conditions.

During it’s first year on Mars, Curiosity has already accomplished its primary objective of discovering a habitable zone on Mars that contains the minerals necessary to support microbial life billions of years ago when Mars was wetter and warmer. Currently, the rover is driving swiftly to the base of Mount Sharp at the center of Gale Crater, where it hopes to find more.

Mars_soilIn that same vein, according to new geological information obtained by Curiosty’s images and soil examinations, samples that were pulled out of a crater that is estimated to be some 3.7 billion years old contain more evidence that Mars was once much warmer and wetter. These findings were announced in a recent paper published in the online edition of Geology by University of Oregon geologist Gregory Retallack.

Unlike Earth, the Martian landscape is littered with loose rocks from impacts or layered by catastrophic floods. However, recent images from Curiosity from the Gale Crater reveal Earth-like soil profiles with cracked surfaces lined with sulfate, ellipsoidal hollows and concentrations of sulfate comparable with soils in Antarctica’s McMurdo Dry Valleys and Chile’s Atacama Desert.

mars-180-degrees-panorama_croppedRetallack, the paper’s lone author, studied mineral and chemical data published by researchers closely tied with the Curiosity mission. As a professor of geological sciences and co-director of paleontology research at the UO Museum of Natural and Cultural History, he internationally known as an expert on the recognition of paleosols – ancient fossilized soils contained in rocks.

As he explains in the paper:

The pictures were the first clue, but then all the data really nailed it. The key to this discovery has been the superb chemical and mineral analytical capability of the Curiosity Rover, which is an order of magnitude improvement over earlier generations of rovers. The new data show clear chemical weathering trends, and clay accumulation at the expense of the mineral olivine, as expected in soils on Earth. Phosphorus depletion within the profiles is especially tantalizing, because it attributed to microbial activity on Earth.

dryvalleysThe ancient soils do not prove that Mars once contained life, but they do add to growing evidence that an early, wetter and warmer Mars was more habitable than the planet has been in the past 3 billion years. Surface cracks in the deeply buried soils suggest typical soil clods. Vesicular hollows, or rounded holes, and sulfate concentrations, he said, are both features of desert soils on Earth.

Since Curiosity is currently on its way to Mount Sharp, future missions will be needed to fully explore these features. But as Retallack explained, the parallels with Earth are quite exciting:

None of these features is seen in younger surface soils of Mars. The exploration of Mars, like that of other planetary bodies, commonly turns up unexpected discoveries, but it is equally unexpected to discover such familiar ground.

The newly discovered soils indicate that more benign and habitable soil condition existed on Mars than previously expected. What’s more, their dating to 3.7 billion years ago places them within a transition period when the planet went from an early, benign water cycle to the acidic and arid Mars of today. This is especially important since major changes were taking place on Earth at around the same time.

Living-Mars.2Roughly 3.5 billion years ago, life on Earth is believed to have emerged and began diversifying. But some scientists have theorized that potential evidence that might indicate that life existed on Earth earlier may have been destroyed by tectonic activity, which did not occur on Mars. Basically, it may offer some credence to the theory that while flourished on Earth, it originated on Mars.

One person who supports this theory is Steven Benner of the Westheimer Institute of Science and Technology in Florida.  In the past, he has speculated that life is more likely to have originated on a soil planet like Mars than a water planet like Earth. In an email interview with Science Daily, Benner wrote that Retallack’s paper:

[S]hows not only soils that might be direct products of an early Martian life, but also the wet-dry cycles that many models require for the emergence of life.

So in addition to shedding light on the mysteries of Mars, Curiosity has also been pivotal in addressing some major questions which only increase the mystery of our own existence. Did life as we know it originate on Mars but flourish on Earth? Are there still some remnants of this microbial “Eden” being preserved deep within the soil and rocks? And could life exist there again some day?

All good questions that will no doubt keep robotic rovers, orbiters, landers, and even manned missions busy for many decades to come! In the meantime, check out the video from NASA’s Jet Propulsion Laboratory of Curiosity’s spark-generating laser blast being caught on tape:


Sources:
universetoday.com, sciencedaily.com

News from Space: Insight Lander and the LDSD

mars-insight-lander-labelledScientists have been staring at the surface of Mars for decades through high-powered telescopes. Only recently, and with the help of robotic missions, has anyone been able to look deeper. And with the success of the Spirit, Opportunity and Curiosity rovers, NASA is preparing to go deeper. The space agency just got official approval to begin construction of the InSight lander, which will be launched in spring 2016. While there, it’s going to explore the subsurface of Mars to see what’s down there.

Officially, the lander is known as the Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport, and back in May, NASA passed the crucial mission final design review. The next step is to line up manufacturers and equipment partners to build the probe and get it to Mars on time. As with many deep space launches, the timing is incredibly important – if not launched at the right point in Earth’s orbit, the trip to Mars would be far too long.

Phoenix_landingUnlike the Curiosity rover, which landed on the Red Planet by way of a fascinating rocket-powered sky crane, the InSight will be a stationary probe more akin to the Phoenix lander. That probe was deployed to search the surface for signs of microbial life on Mars by collecting and analyzing soil samples. InSight, however, will not rely on a tiny shovel like Phoenix (pictured above) – it will have a fully articulating robotic arm equipped with burrowing instruments.

Also unlike its rover predecessors, once InSight sets down near the Martian equator, it will stay there for its entire two year mission – and possibly longer if it can hack it. That’s a much longer official mission duration than the Phoenix lander was designed for, meaning it’s going to need to endure some harsh conditions. This, in conjunction with InSight’s solar power system, made the equatorial region a preferable landing zone.

mars-core_bigFor the sake of its mission, the InSight lander will use a sensitive subsurface instrument called the Seismic Experiment for Interior Structure (SEIS). This device will track ground motion transmitted through the interior of the planet caused by so-called “marsquakes” and distant meteor impacts. A separate heat flow analysis package will measure the heat radiating from the planet’s interior. From all of this, scientists hope to be able to shed some light on Mars early history and formation.

For instance, Earth’s larger size has kept its core hot and spinning for billions of years, which provides us with a protective magnetic field. By contrast, Mars cooled very quickly, so NASA scientists believe more data on the formation and early life of rocky planets will be preserved. The lander will also connect to NASA’s Deep Space Network antennas on Earth to precisely track the position of Mars over time. A slight wobbling could indicate the red planet still has a small molten core.

If all goes to plan, InSight should arrive on Mars just six months after its launch in Spring 2016. Hopefully it will not only teach us about Mars’ past, but our own as well.

LDSDAfter the daring new type of landing that was performed with the Curiosity rover, NASA went back to the drawing table to come up with something even better. Their solution: the “Low-Density Supersonic Decelerator”, a saucer-shaped vehicle consisting of an inflating buffer that goes around the ship’s heat shield. It is hopes that this will help future spacecrafts to put on the brakes as they enter Mar’s atmosphere so they can make a soft, controlled landing.

Back in January and again in April, NASA’s Jet Propulsion Laboratory tested the LDSD using a rocket sled. Earlier this month, the next phase was to take place, in the form of a high-altitude balloon that would take it to an altitude of over 36,600 meters (120,000 feet). Once there, the device was to be dropped from the balloon sideways until it reached a velocity of four times the speed of sound. Then the LDSD would inflate, and the teams on the ground would asses how it behaved.

LDSD_testUnfortunately, the test did not take place, as NASA lost its reserved time at the range in Hawaii where it was slated to go down. As Mark Adler, the Low Density Supersonic Decelerator (LDSD) project manager, explained:

There were six total opportunities to test the vehicle, and the delay of all six opportunities was caused by weather. We needed the mid-level winds between 15,000 and 60,000 feet [4,500 meters to 18,230 meters] to take the balloon away from the island. While there were a few days that were very close, none of the days had the proper wind conditions.

In short, bad weather foiled any potential opportunity to conduct the test before their time ran out. And while officials don’t know when they will get another chance to book time at the U.S. Navy’s Pacific Missile Range in Kauai, Hawaii, they’re hoping to start the testing near the end of June. NASA emphasized that the bad weather was quite unexpected, as the team had spent two years looking at wind conditions worldwide and determined Kauai was the best spot for testing their concept over the ocean.

If the technology works, NASA says it will be useful for landing heavier spacecraft on the Red Planet. This is one of the challenges the agency must surmount if it launches human missions to the planet, which would require more equipment and living supplies than any of the rover or lander missions mounted so far. And if everything checks out, the testing goes as scheduled and the funding is available, NASA plans to use an LDSD on a spacecraft as early as 2018.

And in the meantime, check out this concept video of the LDSD, courtesy of NASA’s Jet Propulsion Laboratory:


Sources:
universetoday.com, (2), extremetech.com