Since I was a young child Mars held a special fascination for me. It was so close and yet so faraway. I have never doubted that it once had advanced life and still has remnants of that life now. I am a dedicated member of the Mars Society,Norcal Mars Society National Space Society, Planetary Society, And the SETI Institute. I am a supporter of Explore Mars, Inc. I'm a great admirer of Elon Musk and SpaceX. I have a strong feeling that Space X will send a human to Mars first.
To find life on Mars, we'll need new orbiters, more advanced rovers, and humans
There’s a good reason NASA hasn’t said they’ve found life on Mars—it’s beyond their current capabilities.
This is a false-color image of Gale crater, which the rover Curiosity is currently exploring. The colors indicate different compositions of the surface.
It’s a constant cycle. NASA puts out a press release saying new Mars news is forthcoming in a press conference. Then, the ultimate announcement is tantalizing—but far from the discovery of actual life on actual Mars.
This played out recently, with the announcement last month of the discovery of ancient organics found on the surface, and fluctuations of methane in the atmosphere on Mars. Methane is often produced through biological processes, so seasonal releases on Mars could be a sign that something is constantly replenishing an underground supply of that hydrocarbon.
But yet again–life wasn’t found on Mars. And NASA won’t be announcing the discovery of life on Mars anytime soon. It’s not disinterest on the agency’s part, instead it’s because of a simple fact: none of these missions had the capabilities to directly detect life, past or present.
CURIOSITY ROVER TAKES A SELF PORTRAIT
In October 2015 Curiosity used the camera at the end of its mechanical arm to take a self portrait inside Gale Crater
Life on Mars
It’s a bright, hot June day at the InterPlanetary Festival in Santa Fe. Los Alamos National Lab is out vaporizing rocks for passers-by. On the stage, Nina Lanza, a staff scientist at Los Alamos, is talking Mars.
“There is methane currently in the atmosphere on Mars,” she says, “and it’s not just there constantly, it’s little puffs that appear to be seasonal.” Methane on Earth, she says, comes from volcanoes and life. “Methane doesn’t last long, it lasts on the order of a hundred years … so when we see methane on Mars, we know that something is making it now.”
“Don’t say you heard it from me that there’s life on Mars, we’re still working that out, but it’s an important observation for us to track down because of its implications.” Lanza says.
Lanza is part of the team behind the ChemCam on the Curiosity rover, currently exploring the ancient lakebed of Gale Crater. There are two components to the system: a laser and a spectrometer. The laser vaporizes rock samples, while the spectrometer looks for tell-tale traces of certain elements in the vaporized remains.
“We can actually see the constituent atoms of the molecules, so we can see, is there carbon here, is there hydrogen, is there phosphorus? Is there nitrogen? We can see all these things,” she told Popular Science after her panel. She has a handy acronym for it: CHyN OPS (pronounced “chin ups”), or carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. Each of these elements have a hand in life on Earth, but ChemCam can’t see how each of these individual elements interact to form molecules. So it can see hydrogen and see carbon, but can’t tell if the two are paired together or not.
That also means that ChemCam can only look for the most basic ingredients of life. It can’t confirm whether life exists or existed on Mars, even though the environment surrounding Curiosity would have been perfect for life at one point in time.
“Gale Crater is an environment that was absolutely habitable, we just don’t know if it was inhabited,” Lanza says. It’s unlikely—though not impossible—that there’s anything today, but there might have been in the distant past.
An artist's concept of what the Mars 2020 rover would look like.
NASA/JPL-Caltech
Luckily, NASA’s capabilities on the planet are about to expand. The Mars 2020 rover will get an all-new, souped-up version of the ChemCam called SuperCam. While ChemCam can pick up elements, SuperCam will pick up the key traces of molecules in its ultimate landing site. This means that it will be able to identify more complex organics rather than individual elements. Using the Laser Induced Breakdown Spectroscopy (LIBS), it will be able to get cursory information about rocks it hasn’t even vaporized yet.
Oh, and it will have a microphone.
“Not only are we going to listen to the Martians,” Lanza jokes, ”but you can actually get information about the target by the sounds the LIBS shockwaves makes."
“When you shoot the laser, it actually does make a version ‘pew pew.’ It makes a snapping sound, and that sound changes based on what the material is and if you’re penetrating through a rock coating. that’s actually going to allow us to interpret our data even better,” She says.
NASA isn’t alone in its pursuit of biology beyond our planet. ESA and Roscosmos, the Russian space agency, have also teamed up on the ExoMars mission. Half of it has already arrived at Mars, though the Schiaparelli lander failed. The other half is set for a July 2020 launch. This rover will actually dig down into the Martian surface, scoop up samples, and test them for evidence of advanced organics—stopping just short of confirming past life, but taking bigger steps than ever before.
Mars 2020 will scoop up Martian surface samples, but it will store those onboard for future retrieval. NASA’s future past on Mars past the 2020 rover is unclear, but NASA has a target of putting humans on Mars by the 2030s. Once human boots are on the ground, confirmation of past or present life could come much more swiftly—as Lanza says, “I’m still a better geologist than Curiosity.” Humans could operate a microscope or a lab and complete more advanced experiments than the rovers—which are currently limited in scope by their a six-to-24-light-minute communications delay with Earth.
There is, of course, another component to Mars missions, though, beyond rovers, landers, and theoretical human explorers. That’s the orbiter.
While Curiosity may have dug into evidence of an ancient lake on the surface, much of the heavy lifting of finding water on Mars (over and over and over) has been up to a fleet of a few orbiters. A rover may be only able to explore a tiny fraction of Mars in their lifetime, but orbiters can give a comprehensive global view every day. Right now, there are a few Mars orbiters, but two of them do the most visual recon work: NASA’s Mars Reconnaissance Orbiter (MRO) and ESA’s Mars Express.
“With something like MRO, we can’t see anything smaller than the rovers on the surface really with the resolution of the cameras we have,” Tanya Harrison, the director of research at Arizona State University’s NewSpace Initiative says in a Twitter DM. “So if there were alien cars or alien buildings on the surface of Mars, we definitely would’ve seen them by now.”
Both Mars Express and MRO are more than 15 years old. A new orbiter with better capabilities could be able to make out more details about the methane plumes, and maybe even see them directly. The HiRISE instrument—MRO’s eye in the sky—isn’t sensitive enough to pinpoint the methane’s origin. For that, there would have to be a lot more methane getting released into the Martian atmosphere.
“MRO isn't equipped to detect methane, but Mars Express has an instrument that was able to detect it spectroscopically,” Harrison says. “To see it visually, it the methane would have to be venting out at a level akin to fumaroles here on Earth—think like the plumes you see at the geysers or hot springs in Yellowstone or Iceland.”
One idea for a mission treats Mars exploration like a game of catch. A lander or rover would scoop up samples and launch them to orbit on a tiny rocket. The orbiter will then retrieve and store those canisters of Mars for an eventual return to Earth. This theoretical orbiter could provide an interesting opportunity to confirm life on Mars as never before with direct sampling.
“Using [an electron microscope] you can actually see structures that look like microbes, but we don’t have that on Mars,” Lanza says. “We have microimagers, but they’re not as high resolution. We can say there’s mineralogy, there’s chemistry, there’s organic molecules, you can build a very good circumstantial story and I think it’s reasonable. But for an extraordinary claim you require extraordinary evidence.”
NASA Will Attempt Its Eighth Mars Landing in One Week
Touching down on the surface of the Red Planet is one of the most difficult engineering challenges ever attempted, and InSight is about to give it a go
Once NASA's InSight lander touches down on the surface of Mars, it will use a seismometer to measure "Marsquakes," and a self-hammering heat probe will burrow five meters below the surface to study the internal heat of the planet.(NASA/JPL-Caltech)
InSight is barreling in for a landing on Mars. The spacecraft will make its approach and landing next week via a tried and true method, but even though NASA has pulled this stunt before, dozens of things need to go exactly right during entry, descent, and landing (EDL) for InSight to arrive safely on the surface of the Red Planet.
At 2:47 p.m. EST on November 26, the InSight lander will hit the top of the Martian atmosphere, about 125 kilometers (70 miles) above the surface, traveling at 5.5 kilometers per second (12,000 mph). The craft’s ablative silica heat shield will rise to a temperature of more than 1,500 degrees Celsius—hot enough to melt steel. About three and a half minutes after atmospheric entry, the spacecraft will still be hurtling toward the ground at supersonic speeds. A parachute will deploy to decelerate as much as possible, the heat shield will jettison, and the spacecraft will start looking for the ground with a radar. About six minutes after hitting the atmosphere, the lander will separate from its back shell—still traveling about 180 mph—and fire its retro rockets to bring it the rest of the way home, touching down roughly a minute later.
If everything goes right—while engineers monitor control screens during the “seven minutes of terror,” unable to steer the distant craft in real time—InSight will come to rest in Elysium Planitia on the Monday after Thanksgiving and prepare to begin studying the seismology and internal heat of Mars. NASA can take comfort in the fact that such landings have succeeded in the past, but when you are attempting to land a craft millions of miles away, it’s impossible to prepare for every eventuality.
The statistics are dramatic, but the story they tell is a little dated. There was a spectacular run of failures in the latter part of the 20th century—Mars 96, Mars Observer, Mars Climate Orbiter and Mars Polar Lander’s losses still sting. But while Russia has never achieved a complete success at Mars, NASA, the European Space Agency (ESA) and the Indian Space Research Organisation (ISRO) have all pretty much nailed orbital insertions at Mars since Y2K. China, India and Japan have their second Mars-bound missions in the works, and the United Arab Emirates is planning their first, not to mention the ambitions of several private entities.
Mars orbit insertions have become relatively routine in the 21st century, but Mars landings are still some of the most difficult deep-space missions ever attempted. ESA’s two successful orbiters both included tiny landers that were never heard from after touchdown, though ExoMars’ Schiaparelli lander returned data nearly all the way to the surface.
Three things make a Mars landing much more difficult than a moon landing—or an Earth landing, for that matter. First, unlike the moon, Mars is too far away for any ground-bound human to be in the loop during a landing attempt. The time it takes for a signal to travel from Mars to Earth and back is never less than nine minutes and is usually much longer, so by the time we can hear and respond to a signal that our spacecraft has hit the top of the atmosphere, the end result, one way or another, has already occurred.
The second problem is Mars’ atmosphere. There is both too much and too little. On Earth, when astronauts and sample capsules return from space, we can protect spacecraft behind heat shields and use the friction of atmospheric entry to slow the hypersonic craft to subsonic speeds. Once the flamey part is over, we can simply pop out a parachute to further reduce the velocity and drift to a gentle (or, at least, survivable) touchdown on land or water.
Mars’ atmosphere is thick enough to generate a fiery entry, requiring a heat shield, but it’s too thin for a parachute alone to slow an entering spacecraft to a safe landing speed. When Curiosity hit the top of Mars’ atmosphere in 2012, it was traveling at 5.8 kilometers per second (13,000 mph). When the heat shield had done all it could do, the spacecraft was still hurtling toward the ground at 400 meters per second (895 mph). Curiosity’s parachute could, and did, slow it down, but only to 80 meters per second (179 mph). Hitting the ground at that speed is not survivable, even for a robot.
On an airless world like the moon, heat shields are not required and parachutes do you no good. But fear not, we’ve had the technology for lunar landings since the 1960s: take some rockets and point them downward, canceling out the craft’s velocity.
The atmosphere makes things a little trickier on Mars, though. With moving air as an additional factor, unpredictable winds can add an equally unpredictable horizontal velocity to a descending spacecraft. For this reason, landing regions on Mars are required to have low regional slopes. High horizontal winds plus high slopes could put a lander much farther from, or closer to, the ground than it expects—and either situation could spell disaster.
Illustration of NASA's InSight lander about to land on the surface of Mars. (NASA/JPL-Caltech)
So a Mars lander needs three technologies to reach the surface: a heat shield, a supersonically deployable parachute and retrorockets. The Viking missions to Mars in the mid-1970s prepared by test-launching parachutes on suborbital rockets to verify that they could inflate without shredding at faster-than-sound speeds. All successful Mars landings since then (all of them NASA’s) have relied on parachutes with Viking legacy. Recently, NASA has worked on a new effort to develop deceleration technologies able to land spacecraft heavier than the Viking probes—an effort that was not, initially, successful, resulting in catastrophically shredded parachutes. (More recent tests have worked better.)
Keeping all of this in mind, what do we know about what went wrong for recently failed Mars landers? For two of them—Mars Polar Lander and Beagle 2—we can only speculate. The spacecraft had no ability to transmit real-time telemetry data as they descended. The Mars Polar Lander failure taught NASA an important lesson: If we are to learn anything from our failures, we have to collect as much data as we can up to the point of failure. Ever since the Mars Polar Lander crashed into the surface at the end of 1999, every Mars lander except ESA’s Beagle 2 has transmitted data to an orbiter that recorded raw radio signals for future analysis in the event of failure.
These days, there are many orbiters at Mars, so we can do even better than that. There’s always one orbiter listening to and recording every last bit of radio signal from a lander, just in case of disaster. And there’s usually a secondary orbiter that doesn’t just listen to the signal, but decodes it and relays the information to Earth as fast as the slow travel of light will allow. This “bent-pipe” data transmission has given us the adrenaline-laced, real-time picture of Mars landing attempts.
A map of Mars, showing the locations of all seven of NASA's successful landings along with InSight's landing site in the flat region of Elysium Planitia. (NASA)
When InSight lands, it will fall to the Mars Reconnaissance Orbiter to record telemetry for future dissection if the attempt fails. To get real-time data of the landing, however, InSight has brought along two little spacefaring companions: the MarCO CubeSats, each only about three feet long. The Mars Cube One spacecraft are the first-ever interplanetary CubeSats. If the craft succeed, the world will get its real-time reports on InSight’s landing, and the little space robots will pave the way for future, tinier, cheaper trips to Mars.
But for now, all eyes are on InSight. NASA has successfully landed on Mars seven times, and before the month is out, the space agency is going to try to make it eight.
Close up view of Oxia Planum, which has been selected as the preferred landing site for the ExoMars rover
When the ExoMars 2020 mission touches down on the Red Planet, it will most likely be at Oxia Planum. The ExoMars Landing Site Selection Working Group has announced that this flat area near the Martian equator was recommended for the ESA-Roscosmos rover and surface science platform because it provides the best chances for finding signs of life, balanced against the need for a safe landing zone.
Oxia Planum is the lead contender of two primary landing sites under consideration by the Working Group. The other area is Mawrth Vallis, and both are located only a few hundred kilometers apart in the same region located north of the equator and have an elevation of about 3,000 m (1.8 mi) below the Martian equivalent of "sea level."
According to ESA, the site dates back to the time when liquid water could exist on the surface of the Mars – about four billion years ago. It boasts one of the richest known clay deposits on the planet and there are numerous channels running from the southern highlands to the northern lowlands, exposing older and interesting geological deposits.
This is particularly important because the primary goals of the unmanned ExoMars mission is to make the first search for direct signs of life on Mars since the NASA Viking lander missions of the 1970s. This means that during its recent two-day meeting at the National Space Centre in Leicester, England, the Working Group had to find the sweet spot between scientific, engineering, and technical requirements, and is the latest in five years of detailed examination of up to eight candidates.
The Group had to find a site with a low enough elevation to provide enough atmosphere for the parachutes during descent, a choice of landing zones free of obstacles for landing and deployment, and a number of scientifically interesting areas within driving distance without too much in the way of steep slopes or loose debris.
ESA says Oxia Planum meets these requirements with its clay deposits, wet ancient history, and recently exposed deposits that includes ones that have been sealed by later volcanic activity, protecting them from only the most recent erosion and space radiation.
"With ExoMars we are on a quest to find biosignatures," says ESA's ExoMars 2020 project scientist Jorge Vago. "While both sites offer valuable scientific opportunities to explore ancient water-rich environments that could have been colonized by microorganisms, Oxia Planum received the majority of votes. An impressive amount of work has gone into characterizing the proposed sites, demonstrating that they meet the scientific requirements for the goals of the ExoMars mission. Mawrth Vallis is a scientifically unique site, but Oxia Planum offers an additional safety margin for entry, descent and landing, and for traversing the terrain to reach the scientifically interesting sites that have been identified from orbit."
ExoMars 2020 is slated to launch between July 25 and 13 August 2020 atop a Proton-M rocket from Baikonur, Kazakhstan for a landing on Mars on March 19, 2021. In the meantime, the latest landing site selection will undergo internal review by ESA and Roscosmos and an official confirmation in mid-2019.
Mars probably won’t be habitable anytime soon, but scientists still remain hopeful about the planet’s life-carrying potential.
Recently, a study in Nature Geoscience suggested that pockets of salty water with enough dissolved oxygen to support life may rest under Mars’ surface, Smithsonian Magazine reported.
Researchers used computer models to determine the possible existence of these brine puddles and their ability to support microorganisms.
In the best-case scenario, the models suggested the puddles could have enough oxygen to support complex organisms like sponges. Even in the worst-case scenario, bacteria could thrive.
“There are so many abiotic ways of creating small but sufficient amounts of oxygen which then, at the colder temperatures, can be absorbed effectively and could actually maybe trigger evolution in a different way than we got on the Earth,” lead author Vlada Stamenković told Space.com
Judging by landscape features and manganese oxide that must have formed on the surface in wet, oxygen-rich conditions, scientists hypothesize that oceans covered Earth’s neighbor billions of years ago.
The team cannot yet prove the existence of the briny puddles, or if they hold any life, but the researchers plan to further test their results.
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