This Week in Space

2015-10-15

The Looming Problem of Planetary Protection

The recent announcement by NASA confirming the presence of liquid water on Mars pulls planetary protection into the spotlight, and is causing some serious head-scratching in the scientific community. On the one hand, having existing liquid water on the Red Planet is a cause for wonder, excitement, and a strong desire to investigate it in a great deal more depth to look for the possibility of life. On the other hand, there is the dilemma of protecting a potential biosphere from contamination by Earthly bugs. As keen as the Curiosity mission team is to take advantage of the rover having a much closer look at recurring slope lineae (RSL), the rover itself is just not clean enough.

“There will be heated discussions in the next weeks and months about what Curiosity will be allowed to do and whether it can go anywhere near the RSLs,” said Andrew Coates of University College London’s Mullard space science laboratory. “Curiosity now has the chance, for example, to do some closer up, but still remote, measurements, using the ChemCam instrument with lasers, to look at composition. I understand there is increasing pressure from the science side to allow that, given this new discovery.”

It is a conundrum that is not new. If you send a spacecraft with the intention of finding life, how do you know if what you found was not brought there by the very thing you sent? This is known as ‘forward contamination’. There are, in fact, rules set in place by a worldwide organization called COSPAR(Committee on Space Research) that anything sent into space are assigned to one of five categories in increasing order of risk. Naturally, there are subcategories.

Image Credit: http://s.hswstatic.com

Curiosity is classed as Type IVb, whereas for it to take any samples from RSL, it would need to be Type IVc. Thus, an extra level of cleaning would be necessary. The rover can use instruments such as ChemCam to observe the flows remotely. Under COSPAR rules it cannot be allowed close enough to take direct samples. In fact, there was a mistake made when sending the rover to Mars when some drill bits were not sent through the final stage of cleaning. While the bits were still very clean, procedure was not strictly adhered to.

Some scientists are now arguing that the level of decontamination is not only a lengthy procedure, but also expensive and pointless as microbes from Earth will already have landed on Mars via asteroid strikes.

“We know there’s life on Mars already because we sent it there,” John Grunsfeld, the associate administrator of NASA’s Science Mission Directorate, said during a press conference last week.

In the paper, called The Overprotection of Mars, co-authors Alberto G. Fairén of the Department of Astronomy, Cornell University and Dirk Schulze-Makuch of the School of the Environment, Washington State University argue that the level of planetary protection needed to go to ‘sensitive areas’ would be prohibitively expensive to achieve.

“If Earth life cannot thrive on Mars, we don’t need any special cleaning protocol for our spacecraft; and if Earth life actually can survive on Mars, it most likely already does, after four billion years of meteoritic transport and four decades of spacecraft investigations not always following sterilization procedures,” Fairén says. “Planetary protection policies are at least partly responsible for the lack of life-hunting Mars missions since Viking, as they impose very stringent requirements for sterilization of the spacecraft which, in my opinion, are not necessary,” he adds.

You can do your best to clean your spacecraft, but you simply cannot eliminate it entirely. It is in fact possible that the high levels of radiation and UV light Curiosity has been exposed to, may have sterilized it enough. However, this point is debatable as, in the process of cleaning the spacecraft, the decontamination team may in fact have inadvertently allowed the few organisms tough enough to survive the cleaning process, the trip and Mars’ extreme environment to adapt and live on the planet.

Doubtlessly debate will continue to rage on, particularly with the upcoming Mars 2020 rover mission in mind. It will certainly be fascinating to see what additional revelations Curiosity may reveal to help scientists solve puzzles such as this.

I am quite sure you will want a little light relief by now! Bored of Mars? Too bad! TMC is far from done with the place.

Let’s Follow Mark Watney’s Journey!

Scientists from ‪German Aerospace Center, — who specialize in producing highly accurate topographical maps of ‪‎Mars‬ — reconstructed Watney’s route using stereo image data acquired by the High Resolution Stereo Camera on board European Space Agency’s ‪Mars Express‬ spacecraft. They then compiled this data into a video that shows the spectacular landscape that the protagonist would see ‘in the future’. Trust me, you will be glad you did! I had to clean dust bunnies off my jaw. It is that awesome.

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Curiosity Confirms Ancient Lakes on Mars

Data from the Curiosity rover has confirmed that sediments deposited there were assisted by water, which helped with the formation of  Mount Sharp itself. The rover’s findings support the notion of a warmer, wetter past for Mars.

“Observations from the rover suggest that a series of long-lived streams and lakes existed at some point between about 3.8 to 3.3 billion years ago, delivering sediment that slowly built up the lower layers of Mount Sharp,” said Ashwin Vasavada, Mars Science Laboratory project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and co-author of the new Science article to be published Friday, October 9.

“What we thought we knew about water on Mars is constantly being put to the test,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at NASA Headquarters in Washington. “It’s clear that the Mars of billions of years ago more closely resembled Earth than it does today. Our challenge is to figure out how this more clement Mars was even possible, and what happened to that wetter Mars.”

The story of water on Mars TMC has discussed before. It is an unfolding tale which is far more complicated than anyone previously imagined. The sediments found indicate long-lasting lakes although their source is still unknown.

“During the traverse of Gale, we have noticed patterns in the geology where we saw evidence of ancient fast-moving streams with coarser gravel, as well as places where streams appear to have emptied out into bodies of standing water,” Vasavada said. “The prediction was that we should start seeing water-deposited, fine-grained rocks closer to Mount Sharp. Now that we’ve arrived, we’re seeing finely laminated mudstones in abundance that look like lake deposits.”

“We have tended to think of Mars as being simple,” Grotzinger mused. “We once thought of the Earth as being simple too. But the more you look into it, questions come up because you’re beginning to fathom the real complexity of what we see on Mars. This is a good time to go back to reevaluate all our assumptions. Something is missing somewhere.”

There are so many mysteries the Red Planet will hopefully yield in time, such as why it went from being hospitable, to the dry arid place it is now. We will of course keep you updated.

Now for something competely different!

Cassini Flyby of Enceladus Sheduled for 14th October 2015

The craft is currently focused on looking for geological activity such as cryovolcanism, geysers and the moon’s ‘tiger stripes‘. The mission team is also very keen to see whether the moon’s northern regions have been active in the past, which is the aim of this flyby. There will be two more flybys later this month and in December.

“We’ve been following a trail of clues on Enceladus for 10 years now,” said Bonnie Buratti, a Cassini science team member and icy moons expert at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “The amount of activity on and beneath this moon’s surface has been a huge surprise to us. We’re still trying to figure out what its history has been, and how it came to be this way.”

“The global nature of Enceladus’ ocean and the inference that hydrothermal systems might exist at the ocean’s base strengthen the case that this small moon of Saturn may have environments similar to those at the bottom of our own ocean,” said Jonathan Lunine, an interdisciplinary scientist on the Cassini mission at Cornell University in Ithaca, New York. “It is therefore very tempting to imagine that life could exist in such a habitable realm, a billion miles from our home.”

The main event though will be on October 28 when the probe makes its closest approach. NASA has released a toolkit for interested folks. This close flyby is the one I am REALLY interested in as Cassini will dive through the moon’s icy plumes to see what may be there!

Be sure to tune in next week for more news from space!

This article originally appeared on TheMittani.com, written by Feiryred.

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