COMET CREATED CHAOS IN MARS’ MAGNETIC FIELD

by Evan Gough

Comet Siding Spring (C/2007 Q3) as imaged in the infrared by the WISE space telescope. The image was taken January 10, 2010 when the comet was 2.5AU from the Sun. Credit: NASA/JPL-Caltech/UCLA

In the Autumn of 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft arrived at Mars and entered into orbit. MAVEN wasn’t the only visitor to arrive at Mars at that time though, as comet Siding Spring (C/2013 A1) also showed up at Mars. Most of MAVEN’s instruments were shut down to protect sensitive electronics from Siding Spring’s magnetic field. But the magnetometer aboard the spacecraft was left on, which gave MAVEN a great view of the interaction between the planet and the comet.

Unlike Earth, which has a powerful magnetosphere created by its rotating metal core, Mars’ magnetosphere is created by plasma in its upper atmosphere, and is not very powerful. (Mars may have had a rotating metal core in the past, and a stronger magnetosphere because of it, but that’s beside the point.) Comet Siding Spring is small, with its nucleus being only about one half a kilometer. But its magnetosphere is situated in its coma, the long ‘tail’ of the comet that stretches out for a million kilometers.

When Siding Spring approached Mars, it came to within 140,000 km (87,000 miles) of the planet. But the comet’s coma nearly touched the surface of the planet, and during that hours-long encounter, the magnetic field from the comet created havoc with Mars’ magnetic field. And MAVEN’s magnetometer captured the event.

MAVEN was in position to capture the close encounter between Mars and comet Siding Spring. Image: NASA/Goddard.

Jared Espley is a member of the MAVEN team at Goddard Space Flight Center. He said of the Mars/Siding Spring event, “We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”

“The main action took place during the comet’s closest approach,” said Espley, “but the planet’s magnetosphere began to feel some effects as soon as it entered the outer edge of the comet’s coma.”

Espley and his colleagues describe the event as a tide that washed over the Martian magnetosphere. Comet Siding Spring’s tail has a magnetosphere due to its interactions with the solar wind. As the comet is heated by the sun, plasma is generated, which interacts in turn with the solar wind, creating a magnetosphere. And like a tide, the effects were subtle at first, and the event played out over several hours as the comet passed by the planet.

Siding Spring’s magnetic tide had only a subtle effect on Mars at first. Normally, Mars’ magnetosphere is situated evenly around the planet, but as the comet got closer, some parts of the planet’s magnetosphere began to realign themselves. Eventually the effect was so powerful that the field was thrown into chaos, like a flag flapping every which way in a powerful wind. It took Mars a while to recover from this encounter as the field took several hours to recover.

MAVEN’s task is to gain a better understanding of the interactions between the Sun’s solar wind and Mars. So being able to witness the effect that Siding Spring had on Mars is an added bonus. Bruce Jakosky, from the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, is one of MAVEN’s principal investigators. “By looking at how the magnetospheres of the comet and of Mars interact with each other,” said Jakosky, “we’re getting a better understanding of the detailed processes that control each one.”

Astronomers say they’ve found the biggest structure in the universe and they named it the BOSS

The BOSS is big. Really big. Yuuuuuge.

So big that when a star is born on one side of the BOSS, it takes a billion years for the light to reach the other side.

So big that comparing the BOSS to the next biggest thing like it is like comparing Andre the Giant to your 3-year-old nephew.

What is the BOSS? It’s a wall. A Great Wall. It makes other walls — you know which ones — look like, well, nothing, because the BOSS Great Wall is an immense complex comprising more than 800 galaxies and weighing 10,000 times as much as the Milky Way and other walls are just a measly pile of rocks on an insignificant planet in a remote part of space.

 

Anyway, scientists working for the Baryon Oscillation Spectroscopic Survey— the international galaxy-mapping effort from which the BOSS gets its truly spectacular acronym — say that the newly discovered cosmic feature is the largest structure in the universe. Or at least, as much of the universe as they’ve mapped so far.

In a study published in the newest issue of the journal Astronomy and Astrophysics, the scientists describe the BOSS Great Wall (BGW) as an enormous collection of galaxies more than one billion light-years across.

“It was so much bigger than anything else in this volume,” Heidi Lietzen of the Canary Islands Institute of Astrophysics, a lead author on the study, told the New Scientist.

“Walls” like the BGW are part of the underlying structure of the universe. Most of space is a vast empty void, and all the stuff that astronomers look for — stars, planets, the galaxies they constitute — is threaded through that nothingness. Pulled together by gravity, galaxies coalesce into clusters, which in turn form larger structures called superclusters, as explained by PBS. Those are then corralled into “walls” — the coronary arteries of this giant system of matter, and the biggest things in space.

Researchers for the Sloan Digital Sky Survey (the BOSS survey is one of its projects) have been trying to map that web in order to better understand the universe’s history, size and speed of expansion. Using a dedicated telescope located in the remote desert scrubland of Sunspot, N.M., they scan huge swaths of the sky for distant galaxies, brilliant quasars and other celestial objects.

In the process, they’ve found some pretty enormous things. Like the “Sloan Great Wall,” which Lietzen and her co-authors say is the closest system of superclusters comparable to the BGW.

But even that is dwarfed by the Sloan survey’s newest find. The BOSS Great Wall has ten times the volume of the Sloan wall and is almost 70 percent larger in diameter. It comprises four superclusters containing 830 galaxies, and it looms in space some 5 billion light-years away from Earth. (For what it’s worth, the biggest thing in our neck of the woods, the Laniakea supercluster that includes our own Milky Way galaxy, is less than half the size of the BGW.)

“I don’t entirely understand why they are connecting all of these features together to call them a single structure,” Allison Coil, an astrophysicist at the University of California at San Diego, told the New Scientist. “There are clearly kinks and bends in this structure that don’t exist, for example, in the Sloan Great Wall.”

But size isn’t really the point, Smithsonian Magazine noted. The discovery of the BOSS Great Wall is just one part of a larger survey that will — astronomers hope — reveal not just what the universe looks like, but how it’s evolved and how it continues to change.

Which is a very nice sentiment. But the BOSS Great Wall is still biggest. And you know what that makes it.

A winner.

Sarah Kaplan is a reporter for Morning Mix.

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A radical new study has pin pointed the most compelling locations where we could soon discover intelligent aliens

Jessica Orwig,Business Insider

With Mars in Mind, Lockheed Martin Designs Human Habitat to Orbit Moon

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Lockheed Martin’s concept of a habitat that could be used during future exploration missions near the moon

Lockheed Martin’s concept of a habitat that could be used during future exploration missions near the moon. (Image: Lockheed Martin)

As the idea of a human mission to Mars leaps from the pages of science fictionliterature (or off the silver screen) and into reality, NASA is taking a serious look at how astronauts will live, work and survive during the long journey to the red planet.

The federal space agency and its manufacturing partner Lockheed Martin have recently crossed a major milestone in preparation to land the first humans on Marsby completing the pressure module or “backbone” of the vehicle that will take them there—the Orion Crew Module. This spacecraft will launch atop the Space Launch System—the most powerful rocket ever built—and sustain a crew for 21 days as they travel into deep space.

It takes a lot longer than three weeks to get to our neighboring planet so where will astronauts live and work during the rest of the trek through the solar system?Lockheed Martin is in the early stages of providing an answer.

As part of NASA’s NextStep habitat study that is currently underway, Lockheed is one of the four companies conceptualizing an Exploration Augmentation Module or “outpost” that will mate with Orion and sustain a crew for up to 60 days during the first deep space missions leading up to Mars. These outings will see humans travel beyond low-Earth orbit for the first time since 1972 and head toward a destination in cislunar space—a distant orbit around the Moon.

Targeted for the mid 2020s, these exploration missions will see NASA attempt to redirect an asteroid into lunar orbit and eventually study that captured asteroid by rendezvousing with it. A habitat will provide a temporary home for astronauts during these endeavors and will enable them to forge the skills and push the innovations of long-duration spaceflight required to ensure a safe trip for a Mars-bound crew.

Currently, the International Space Station serves as the only scientific laboratory and permanent human outpost in low-Earth orbit. A habitat orbiting the Moon would operate very differently. “The cislunar outpost is actually what we call crew-tended. Crew will not be there year-round like they are on the ISS,” Lockheed Martin’s space exploration architect Josh Hopkins told the Observer. “They will visit for a mission-a-year and that mission could be 30-60 days long.”

One of the major hurdles for a manned mission to Mars is human exposure to space radiation, and this issue will be tackled in cislunar space. The habitat’s initial 60-day limit was established by Lockheed’s team to ensure a safe stay for the crew given this element of radiation. Solar storms and the continuous exposure to cosmic rays are difficult to shield from, but it does become more manageable by limiting the amount of time astronauts spend in deep space. “As we build more knowledge of the biomedical effects and how to protect astronauts, we can start gradually doing longer and longer missions,” explained Hopkins.

As for the random bursts of radiation from a solar storm that could occur, the crew would be able to use the advanced built-in capabilities of Orion, which can act as a storm shelter. In the crew module, the closer an astronaut is to the heat shield, the more protection they have. In order to leverage this capability, they must remove supplies from “locker” spaces behind their seats and actually climb inside.

Protecting humans from radiation on Earth requires shielding from heavy elements like lead but with low-dosage space radiation, lighter materials can do the job. For this reason, Lockheed’s designers are mindful about the placement of consumables and waste products inside the habitat due to these items being a potential source of protection. “What we want are light elements. So things like water, food and plastics tend to be fairly good shielding,” said Hopkins. “We can adjust the locations and positioning of these things we’re going to have in a way that maximizes the amount of protection they give us.”

Along with acting as an emergency radiation storm shelter for the crew, Orion can also provide power, temperature control, and can even recycle air—features than enable a habitat to be low-maintenance and cost-effective.

The crew vehicle can use its propulsion system to provide maneuvering capability for the outpost, but Lockheed’s concept will include on-board, independent propulsion. “You don’t want to return to a habitat that’s tumbling because it wasn’t able to maintain its position in orbit,” said William Pratt, Lockheed’s NextSTEP study manager. “There will be a propulsion stage attached to the habitat and the capability to provide a small amount of power you’ll need when Orion is not there.”

The Orion spacecraft contains advanced capabilities that are unique to long duration deep space missions, enabling a cis-lunar outpost that is less complex and more affordable.

The Orion spacecraft contains advanced capabilities that are unique to long duration deep space missions, enabling a cis-lunar outpost that is less complex and more affordable.(Image: Lockheed Martin)

A human habitat or any spacecraft far from Earth will require some degree of autonomy, and this is a specialty for Lockheed Martin’s engineers. Unmanned probes like the MAVEN and the Juno spacecraft that will arrive at Jupiter this summer were both manufactured by Lockheed with autonomous capability. “We feel that’s something we can really bring to a cislunar habitat,” Pratt said. “Our thinking is more about autonomy and giving the crew more autonomy to handle things as they come up at the outpost.”

The primary reason for spacecraft autonomy is communication—or lack thereof. On the long journey to Mars, which could see astronauts spend at least two years aboard a habitat, delays in communication with Earth-based mission control will certainly occur. This could pose a problem when troubleshooting vehicle sub-systems that include life support and oxygen supply.

A major concerned for Lockheed is the long passage of time between the crew’s training and the moment a serious issue does come up during a mission—which could be a few years later. “They may not remember the training. Having the right kind of on-board documentation and flight computer to be able to provide the astronauts the information they need when they need it, is important,” Pratt said. “Not just having the alarm go off but having the alarm go off and the PDF file of the manual come up at the same time. That’s really useful in helping the crew understand how to operate their own vehicle.”

Even though Lockheed Martin’s early habitat concept will service exploration missions near the Moon, the company is always thinking about the manned mission to Mars, which will require a far more advanced successor to their current designs. Engineers will need to go through a few iterations of the concept after the health effects of long-duration human spaceflight are known and as new technology is developed. This is the basis that NASA created NextSTEP on.

The federal space agency is looking for a modular habitat that can grow, evolve and be added to. “New modules are built upon the lessons of the previous modules,” Hopkins said.

 



NASA’s wild new plan to hunt for life on Mars would test SpaceX in ways never done before

Jessica Orwig

spacexSpaceX Photos on Flickr

There are 99 Mars rocks on Earth, but they’re not the kind that scientists need in order to resolve the all-too-intriguing  mystery of whether there is — or once was — life on Mars.

So far, all efforts to answer this question have painted a picture of an ancient Mars once covered in water with a thicker atmosphere and warmer temperatures — a world similar to Earth. But no signs of past or present life have been found, yet.

That’s why a team of scientists at NASA’s Ames Research Center in California have come up with a wild notion to do what has never been done before: transport rocks currently on Mars to Earth.

NASA has been seriously considering a sample-return mission like this for a while, ranking it as the highest-priority big-budget mission for the future in the U.S. National Research Center’s 2013 decadal survey. The return mission that NASA envisioned in 2013 would cost $6 billion, but the team at NASA’s Ames Research Center thinks they might have found a cheaper way.

Enter the “Red Dragon” mission, which would see NASA team up with Elon Musk’s company SpaceX, once again, for an epic mission of engineering firsts, including the first time anyone will have launched a vehicle off the surface of Mars.

spaceXSpaceX Photos

The project would launch a modified version of SpaceX’s current Dragon spacecraft to the Red Planet by as early as 2022, hence the project name “Red Dragon.”

The project is “technically feasible with the use of these emerging commercial technologies, coupled with technologies that already exist,” NASA senior systems aerospace engineer Andy Gonzales told NBC News.

Why we need to get Mars rocks back to Earth

Right now, the only Mars rocks available to scientist are not really rocks at all. They’re meteorites that were flung into space by a powerful impact and later plummeted to Earth at blazing speeds of more than 160,000 miles per hour.

However, this sort of rough, bumpy ride might have destroyed any valuable evidence within the rocks that could point to past life on Mars. And while NASA’s Curiosity rover is currently drilling into the Martian surface in search for signs of ancient alien life, it has come up empty-handed.

To determine, once and for all, whether Mars once harbored a thriving ecosystem on its watery and warm former self, scientists need to get their hands on Martian rocks that are sitting on the surface right now.

mars waterESO/M. KornmesserIllustration of what Mars might have looked like covered in water billions of years ago.

“Red Dragon” would follow NASA’s Mars 2020 mission, scheduled to launch a rover similar to Curiosity to Mars in 2020 — if the project is fully funded.

The Dragon spacecraft would then retrieve the samples taken by the Mars 2020 rover, store them in a Mars Ascent Vehicle (MAV), which would then launch the samples back to Earth, as described in the graphic below:

red dragon mission conceptNASA Ames Research Center/Red Dragon Internal Study Team

Gonzales and his team have not approached SpaceX yet to see if Elon Musk and his company would actually be interested in such a mission. First, the team needs to get NASA to approve the concept and fund the mission, which was first proposed last year.

Despite no funding in site, Gonzales is still actively pushing for the project, which he discussed last week during a NASA Future In-Space Operations working group. Gonzales told NBC News that his team has not estimated the total cost of “Red Dragon” but they suspect it will cost less than NASA’s $6 billion mission envisioned in the U.S. National Research Center’s 2013 decadal survey.