Comparing the climates of the terrestrial planets Mars, Earth and Venus is a complex task
CREDIT: NASA

A Comparative Climatology Symposium held at NASA Headquarters on May 7 focused on new approaches to climate research by highlighting the similarities and contrasts between the environments of the rocky worlds Venus, Earth, Mars and Saturn’s smoggy moon Titan. 

The symposium also included discussions about exoplanets, the sun and past, present and future space missions.

John Grunsfeld, Associate Administrator for NASA’s Science Mission Directorate, said that the upcoming James Webb Space Telescope will be able to make important observations of the atmospheres of exoplanets. [Photos: The James Webb Space Telescope]

He said JWST won’t be able to locate the exoplanets, only study them, but the recently selected TESS mission could act as a  planet scout for JWST targets. It is estimated that TESS will discover around 300 “super-Earth” alien planets, many of them in the habitable zone.

But the number one challenge, Grunsfeld noted, is figuring out the climate of our own planet.

Understanding climate change

Jim Green, NASA’s Planetary Science Division Director, said that one goal is to examine a variety of planetary bodies as a system, to see if there are trends or similarities. He also pointed out that from a planetary scientist’s perspective, climate change on our planet is not a new thing.

“Earth’s climate has done nothing but change,” Green said. 

Green said that three Earth-observing satellites will be launched this year, and they will help us better understand how the climate is currently changing and the implications that has for our planet’s environment.

David Grinspoon, holder of the first Baruch S. Blumberg NASA/Library of Congress chair in Astrobiology, talked about Mars’ “ferocious and interesting” meteorology, and how Martian global dust storms may help unravel what happened on our planet during the K-T extinction 65 million years ago, when an asteroid hitting the Yucatan Peninsula is thought to have eradicated 75 percent of animals and plants on Earth, including the dinosaurs. [Wipeout: History's Most Mysterious Extinctions]

The ‘Venus mafia’

As for Venus, Grinspoon said scientists believe current-day volcanism on Venus is thought to be necessary to sustain the planet’s thick clouds. He added that the active surface has eradicated most ancient rocks, preventing us from easily understanding Venus’ early history.

Grinspoon also discussed the unique climate of Titan, noting that the methane cycle on this moon of Saturn is “like Earth’s hydrological cycle on steroids.”

Studying the climates of Mars, Venus, Titan and even exoplanets could help us refine our climate models of the Earth. However, Grinspoon said that “clouds are the biggest uncertainty in understanding the past of Venus and predicting the future of Earth.”

Tying climatology to astrobiology, Grinspoon said that our expectations of the other planets, in the absence of data, were that they’d be much more Earth-like than they actually are. We still haven’t found a planet quite like our own, although astronomers are zeroing in on exoplanets that should have habitable conditions.

But, Grinspoon said, “it may be that conditions for life’s origin aren’t rare, but the hard part is the persistence of habitable conditions.”

Venus was a popular topic during the symposium. Roald Sagdeev, University of Maryland professor and former director of the Space Research Institute of the USSR Academy of Sciences, said during an overview of the Russian missions to Venus that “from the point of view of habitability, Venus is like having a dead body to study, which is of course very useful for learning anatomy.”

David Crisp, Senior Research Scientist at the Jet Propulsion Laboratory/California Institute of Technology, said that sending weather balloons to Venus taught us a lot about atmospheric physics. And Roger Bonnet, Executive Director of the International Space Science Institute, said there was no chance for a big “flagship” mission to Venus, since the viewpoint among many amounts to “Who cares about clouds and wind on Venus, when we have so much of that on Earth? We want to see little green men!”

One participant noted the presence of “the Venus mafia” at the symposium, inferring that the focus on Earth’s “twin planet” had muscled out discussion of other places of interest. 

Habitable exoplanets

But in addition to studies of Venus and other terrestrial worlds, there was a talk about our sun and its influence on space weather, and general discussions about refining climate models, defining habitable zones, and the importance of basic research.

The participants seemed to agree that, most importantly, planetary climate studies needed to be interdisciplinary, with scientists from different fields communicating and collaborating.

Michael Meyer, lead scientist for the Mars Exploration Program at NASA Headquarters, also pointed out that we should never become complacent in our scientific understanding. For instance, he said that while climate models have not been able to make early Mars warm enough to sustain liquid water on its surface, the same can be true for models of the young Earth. 

And when it comes to understanding where a planet needs to reside in its solar system to be habitable — the so-called Goldilocks Zone where the temperature is just right for water to be liquid rather than ice or gas — he commented that “the approach [to the habitable zone] is very Goldilocks in that it’s almost a fairy tale.”   

Finally, Meyer noted, just when we thought we understood how planets are made, we discovered hot Jupiters and other unusual exoplanets that “turned all of our planet formation models on their head.” 

“And that’s a good thing,” he added.

The featured speakers at NASA’s Comparative Climatology Symposium, titled “New Approaches to Climate Research,” were John Grunsfeld, Jim Green, David Grinspoon, Lori Glaze, Mark Bullock, Roald Sagdeev, Jack Kaye, Lennart Bengtsson, David Crisp, Roger Bonnet, Mark Marley, and Madhulika Guhathakurta.

This story was provided by Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program.

Article source: http://www.space.com/21234-alien-planets-earth-climate-future.html

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(NBC NEWS) — A one-way trip to Mars sounds like something you’d wish on your worst enemy – so why would more than 78,000 people from around the world pay up to $75 for a chance to die on another planet?

“I can say I have an ulterior motive,” said David Brin, who has written more than a dozen science-fiction novels – including “The Postman,” which was turned into a Kevin Costner movie in 1997. “I’d get a lot of writing done, and it might be memorable.”

As a master of hard science fiction, the 62-year-old Brin knows better than most applicants what the first Red Planet settlers would face if they’re sent off in 2022, as the Dutch-based Mars One venture has proposed.

The settlers would have to be sealed up in habitats, protected from harsh radiation, supplied with machine-made air and water, and nourished by whatever food can be grown on a cold, barren planet. They’d have to keep their sanity, millions of miles away from their families and Mission Control. Worst of all, they’d have to face the fact that there’s no guarantee of ever going back.
Survey

Will this scheme actually work? “I give it a low probability of happening,” Brin said, “and I don’t consider it to be the most responsible thing I’ve ever seen.”

Nevertheless, the venture has an attraction for Brin and tens of thousands of others, The ages of those listed in Mars One’s database range from 18 to 71. All those applicants are facing a long road even before the first four-person crew gets off the planet. Mars One is accepting applicants through Aug. 31. The field of applicants would first be whittled down by panels of experts. Then they’d undergo trial by reality TV, followed by years of training.

“This may sound crazy, but it kind of reminds me of ‘The Hunger Games,’” said Kayli McArthur, an 18-year-old student who’s one of the youngest Mars One applicants. “It’s cool that it would be televised, but that’s not my whole thing.”

On the other end of the age spectrum, 71-year-old psychiatrist Sanford Pomerantz is a little surprised that it’s taking this long to get something like Mars One off the ground. “I thought by now we would have colonized Mars,” said Pomerantz, who’s currently the oldest applicant on Mars One’s list.

So what’s the appeal of Mars One? It’s too early for Brin, McArthur and Pomerantz to give a lot of thought to their adventure on Mars, let alone their death on Mars. Instead, they’re focusing on the adventure here on Earth. Here’s what’s behind their thinking: 

David Brin: ‘My main purpose is the conversation’
Brin sees Mars One as just one of a number of ventures aimed at expanding humanity’s frontier, ranging from Virgin Galactic’s suborbital space tours to Golden Spike’s moon missions. “It’s emblematic of the new era that we’re about to enter at long last – what I call the barnstorming era,” he said.

Like the daring airplane fliers of the 1920s, these 21st-century space barnstormers are willing to take bigger risks in hopes of providing bigger thrills – and eventually, earning bigger payoffs. The Mars One project is “a great way to get the discussion going,” Brin said.

“You have to assume that it may not work, and that there will be a statue of you on Mars someday,” he said. “I’m aware of the tradeoffs, and I’m willing to explore it further, but largely my main purpose is the conversation. We’ve got to be talking about how we can be a more exploratory people – a more interesting people, if you like.”

Brin doesn’t doubt that Mars One will find plenty of qualified (and interesting) people willing to take the risk.

“People who cannot imagine any sane person making that choice simply aren’t envisioning the wide range of human diversity,” said Brin, who has three children in school. “Consider what I told my family. By the very earliest date that Mars One might launch, I expect to be a spry 75-year-old whose kids are already successfully launched, and who might spend a few years doing something truly remarkable.”

Even if it means dying on alien soil? Brin isn’t completely sure he’d go that far, but he’s willing to bet that others would.

“I think you’ll find tens of thousands of people who, under those circumstances, will at least ponder it seriously,” Brin said.

Kayli McArthur: ‘I’m trying to strive for something more’
McArthur, a freshman at the University of Arizona, is one of more than three dozen 18-year-olds on Mars One’s list of applicants. Ever since she applied, she’s been hearing that she has her whole life ahead of her, so why would she want to leave it all behind for Mars?

“Being young doesn’t make me want to do it any less because I have my whole life ahead of me,” she said. “It makes it more exciting. … I love all my friends, my guy friends, my family. It’s not that I’m trying to get away. It’s like I’m trying to strive for something more.”

She has long dreamed of going into outer space, and she figures that her future degree in materials science would come in handy for creating the first interplanetary settlement. “Going to Mars, there are so many opportunities for that,” she said.

So far, her family hasn’t stood in her way. “My family jokes, like, ‘Oh, Kayli, have your fun with it,’” she said. If the selection process gets more serious, she suspects she might face more resistance from her parents. But not from her grandfather.

“My grandpa is a retired three-star [general] in the Air Force,” she said. “We were talking about it. I get really worked up and excited, and he was talking about it, too, and being realistic about it. He said, ‘That would be so cool if you were able to do it.’ … I know my grandpa would totally support me.”

Sanford Pomerantz: ‘Grandpa is going to Mars!’
Pomerantz is old enough to remember when the idea of sending people into outer space seemed as far out as the idea of sending people on a one-way trip to Mars seems now. One of the books that made an impression on him in grade school was Robert Heinlein’s “Red Planet: A Colonial Boy on Mars,” which was published in 1949.

“I started as a physics major in the university, but then I got accepted into med school and changed directions,” he said. At the age of 71, he’s still a practicing psychiatrist in Topeka, Kan. But he’s also still holding onto that boyhood dream of spaceflight.

“The Mars thing is exciting, because I hope it’ll stimulate people to get interested in space. … And I hope it has the secondary effect of stimulating science education, especially in the U.S.,” he said.

Just as McArthur believes that Mars will need a materials scientist, Pomerantz believes the crew will need a psychiatrist. “Psychologically, it’s going to be an interesting challenge, but human beings are very adaptable,” he said. “It’ll be exciting to go to a whole new world. It’ll be a major step in human evolution.”

If Pomerantz ends up being selected for the first Mars crew, he’s likely to become not only the oldest human to head for the Red Planet, but the oldest human to go on any space mission. (The current record-holder is John Glenn, who flew on the shuttle Discovery when he was 77 years old.) For now at least, that prospect doesn’t faze Pomerantz’s three children and two grandchildren. “The grandchildren are excited,” he said. “It’s like, ‘Grandpa is going to Mars!’”

Pomerantz became a certified scuba diver just two years ago, and he still expects to be in good physical and mental shape for liftoff in 2022. “Remember, age is a state of mind,” he said. “Chronologlcally, I may be 71. … But psychologically and physically, I’m definitely in my 20s. I look in the mirror and say, ‘Who’s that old guy?’”

NBC News

Article source: http://www.firstcoastnews.com/news/article/314008/82/Why-sign-up-for-a-one-way-Mars-trip-Three-applicants-explain-the-appeal