The new study, in rodents, shows that astronauts could suffer from a phenomenon called "space brain" during the long trip to Mars, as cosmic radiation bombards their bodies and damages their brain cells.

Researchers exposed the laboratory-bound rodents to a level of radiation similar to that expected on a six-month one-way trip to Mars. They found that the radiation caused significant long-term brain damage, including cognitive impairments and dementia, a result of brain inflammation and damage to the rodents' neurons. [10 Things You Didn't Know About the Brain]

The researchers said the new study revealed a far greater extent of brain damage than what was hinted at in their shorter, six-week study, conducted last year.

"This is not positive news for astronauts deployed on a two- to three-year round-trip to Mars," said Charles Limoli, a professor of radiation oncology at the University of California, Irvine School of Medicine, who led the study.

NASA told Live Science that the agency is funding such studies to better understand the risks posed to its astronauts, although the agency was not aware that Limoli's study was published and could not comment on the details. 

Radiation hazards

Astronauts in space face two kinds of radiation hazards. One is the solar radiation from the sun, including ultraviolet rays, X-rays, protons and electrons. The other is cosmic radiation, which emanates from all directions in deep space and comprises atomic particles far more energetic (and thus more damaging) than solar radiation.

Limoli's research was aimed at assessing the possiblehuman health problems that could be caused by cosmic radiation on a prolonged space journey. There are almost no studies so far that have looked at this, Limoli said. Humans have lived on the International Space Station (ISS) for months at a time. Russian cosmonaut Valeri Polyakov (born Valeri Ivanovich Korshunov but later changed his name) holds the record for the longest, continuous time in orbit — almost 438 days aboard the Mir space station.

However, because Mir (which is no longer in use) and the ISS are relatively close to Earth, Earth's magnetosphere — a natural magnetic field that deflects charged atomic particles from the sun and deeper space — mostly protects astronauts on board the orbiting labs from dangerous radiation exposure. Tests have shown that Polyakov and other astronauts have no serious brain damage as a result of their time in orbit. [5 Mars Myths and Misconceptions]

Astronauts who visited the moon ventured beyond this protective magnetosphere, but their entire round-trip lasted only about two weeks, so their radiation exposure was kept to a minimum. One previous study, done in 2013 in mice, suggested that radiation may hasten the development of Alzheimer's.

To simulate the cosmic radiation exposure humans would face during a long Mars trip, Limoli's group exposed rodents to charged particles at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory in Upton, New York.

The researchers found that although the bombardment of the radiation was painless, it caused significant brain damage in the rodents. Imaging revealed that the animals' brain cells had a sharp reduction in features of the cells called the dendrites and spines, which would disrupt the transmission ofsignals among neurons, they said.

Limoli told Live Science that loss of dendrites and spines were "like a tree losing its leaves and branches," compromising the health of the tree. These physical losses explained the deficiencies the rodents showed in behavioral tasks designed to test learning and memory, Limoli said. In humans, this loss could lead astronauts to make poor decisions that could affect the safety of the crew, he added.

The researchers also discovered that the radiation affected the part of the brain that normally suppresses prior unpleasant and stressful associations, as part of a process called "fear extinction." This loss of fear extinction could make the astronauts prone to anxiety, Limoli said. [Infographic: How Radiation Affects the Human Body]

Yet Limoli remains optimistic that NASA can still send astronauts safely to Mars. "This is not a deal breaker," he told Live Science. "This [cosmic radiation] is simply something we have to deal with."

A 30-month trip

NASA estimates that a 30-month trip to Mars — six months of travel each way, plus 18 months living on the Red Planet — would expose astronauts to a total of 1 sievert (Sv) of radiation. For comparison, Limoli said people who undergo certain kinds of radiation treatment for brain cancer may need to endure a dose at least 10 times higher than that through the course of that treatment. He said that these cancer patients, although they may be cured of cancer, have notable declines in their cognitive function.

Astronauts could be protected from cosmic radiation in two ways, a NASA press officer told Live Science. One would be to a passive method of installing thick metal shields or layers with water, either around the entire spacecraft or around sleeping chambers to block the radiation. Cosmic radiation is very penetrating, however, and shields that would be thick enough to block the rays would add considerable weight (and thus, expense) to the Mars mission.

Another way is an active method of installing an electromagnetic field to deflect the radiation, analogous to the magnetosphere itself. Limoli said his group and others are working on another strategy, medicines that could repair the damage caused by radiation, or protect or even restore neurons.  

It will certainly be a memorable trip to Mars, and NASA hopes the astronauts will stay healthy enough to remember it.

Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.

No fees are required for the citizenship applications and new citizens will not be expected to contribute to the cost of the first satellite, to be called Asgardia, which the program team plans to launch in late 2017. Ashurbeyli would not provide any details about the satellite or what its function will be, but said it was "100 percent funded."

Ashurbeyli said Asgardia's first satellite would be launched from one of the spacefaring nations, but the launching state (the country that will pay for the launch) would be a country with an emerging economy that is not a signatory to the Outer Space Treaty. The project team views partnering with a developing country as a way to get countries involved that have not previously had access to space.

The Outer Space Treaty (OST) is an international agreement made during the Cold War in 1967, and assumes all activity in space will be led by a nation-state. Ashurbeiylj said he views the OST as restrictive, with its state actors-led approach. Ashurbeyli wants private individuals and companies to be able to act in space without direct government involvement. The OST also says that no nation-state can own territory in outer space and signatories are obliged to follow this. Partnering with a non-signatory nation would avoid such legal complications with regard to exploiting space resources, he said. Non-OST signatory African countries ─ Ethiopia and Kenya, in particular ─ are seen as potential candidates for the satellite's launching state.

The Asgardia project team also has plans for satellites that would protect the Earth from asteroids and space debris. Asgardia project team member, Joseph Pelton, who is the director emeritus of the Space & Advanced Communications Research Institute at George Washington University, told Space.com after the news conference that the defense of the Earth would require different spacecraft.

For asteroid defense, Pelton envisages a flotilla of spacecraft that would be launched to meet the huge space rock years before it reached Earth and would fire lasers at the object’s surface. The laser fire would vaporize parts of the surface and the resulting jets of vapor would create enough force to slowly push the asteroid in another direction, avoiding Earth. Pelton expects Asgardia to work with Earth-based nation states to fund such a defense system.

For a defense against coronal mass ejections (powerful bursts of charged particles from the sun that can damage satellites or power grids), Pelton told Space.com: "I am working with Jim Green who is head of planetary sciences at NASA and we think it might be possible to deploy a system at L1, a million and a half kilometers [930,000 miles] out, that would have one to two Tesla magnetic fields that would be like an artificial Van Allen belt." Tesla is the unit of measurement for the strength of a magnetic field (not only the name of a car company), and the L1 orbit lies between the Earth and the moon. The Van Allen belts are a collection of charged particles, gathered in place by Earth’s magnetic field, which deflect harmful particles from the sun.

Pelton went on to describe a Bigelow Aerospace inflatable space stationpositioned at L1, that uses solar power to create the magnetic force field to mitigate the impact of the coronal mass ejections. For these defense projects and other space technology developments, Ashurbeyli said he foresees crowdfunding as one potential source of investment capital.

Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

 In a separate statement, Conselice said that the results are "very surprising as we know that, over the 13.7 billion years of cosmic evolution since the Big Bang, galaxies have been growing through star formation and mergers with other galaxies. Finding more galaxies in the past implies that significant evolution must have occurred to reduce their number through extensive merging of systems."

The results of the study are detailed in The Astrophysical Journal.

Email Hanneke Weitering at hweitering@space.com or follow her@hannekescience. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

 In a separate statement, Conselice said that the results are "very surprising as we know that, over the 13.7 billion years of cosmic evolution since the Big Bang, galaxies have been growing through star formation and mergers with other galaxies. Finding more galaxies in the past implies that significant evolution must have occurred to reduce their number through extensive merging of systems."

The results of the study are detailed in The Astrophysical Journal.

Email Hanneke Weitering at hweitering@space.com or follow her@hannekescience. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

A single impact

Morgan Schaller, an assistant professor of earth and environmental sciences at Rensselaer Polytechnic Institute in Troy, New York, was looking for biological fossils from a period in Earth's history known as the Paleocene-Eocene boundary (or the Paleocene-Eocene Thermal Maximum), which took place about 55 million years ago. While searching for small, white shells, he happened to spot one of the black glass spheroids, also known as microtektites or microkrystites, according to a statement from Rensselaer.

"It was an accident," Schaller, who co-authored the new study, told Space.com. 

That original core sample came from a site in New Jersey. Schaller and his colleagues looked at two other core samples — another in New Jersey, and a second sample taken from the floor of the Atlantic Ocean, more than 620 miles (1,000 km) away. A fourth sample was later taken from another site in New Jersey to confirm that the other samples had not been contaminated or potentially altered by underground drilling; the microtektites were found there as well, according to the paper. [When Space Attacks: The 6 Craziest Meteor Impacts]

During the Paleocene-Eocene boundary, Earth experienced a period of intense global warming. While some evidence has suggested that volcanic activity may have been responsible for the global heating, the new paper explains that the newly discovered microtektites could not have been formed by volcanic activity. For one, the microtektites contain high-temperature glass. A terrestrial volcano cannot produce temperatures and conditions required to produce high-temperature glass, Schaller told Space.com, but meteorite impacts can. 

In addition, the scientists found "shocked quartz" in the microtektites. Quartz has a very organized molecular structure, and a "shocked" grain shows signs of intense physical pressure that has altered what is normally an orderly molecular arrangement. Those quartz grains were not liquefied by the impact, the researchers said, but were mixed with the liquid material and can be found essentially petrified in the microtektites. Shocked quartz does not form from volcanic activity, Schaller said.

Those characteristics indicate that there was a meteorite strike, but they also show that all of the microtektites found in the four different sites formed from the same event, Schaller said. All four locations contain microtektites with high-temperature glass and with shocked quartz, and they also have the same chemistry,  he said, suggesting that the material they formed from originated in the same place.

"Wherever the projectile hits, the material it hits has a unique chemistry to begin with," Schaller said. That material could be a dense rock found in the Appalachian Mountains or carbonate platforms at the bottom of the ocean. "All that stuff's going to be [vaporized or melted] and flung up in [the] air, and have very little time to mix with one another. So you're going to find a range of chemistries [in the microtektites] that are all kind of consistent with different mixes of the material that was hit."

The impact crater

Even though the microtektites share chemistries, that doesn't necessarily reveal where they originated. Schaller said the best way to find the impact site will likely be by looking for microtektites from this same impact in more locations. In theory, the microtektites would be more abundant and larger the closer they are to the impact site.

"Right now, all we can say is that it's either small and close by, or big and far away," Schaller said. But he added that this approach doesn't always reveal an impact site — ejecta, or material flung from volcanoes, have been found "all over the globe" from what's known as the Australasian Impact, but scientists have not been able to find the impact crater.

To find more microtektites from the newly discovered impact, the team will have to study layers of Earth from areas that were underwater when the impact took place, Schaller said, because the microtektites are quickly destroyed when they're on the surface of the Earth and exposed to weather. 

"I think I'd compare their preservation potential to a scoop of ice cream," he said. "But they do get preserved in ocean sediment."

(The three New Jersey sites where the team took samples would have been under water 56 million years ago). 

The association of the impact with the onset of the Paleocene-Eocene boundary is "nothing short of remarkable," Schaller said in a statement from Rensselaer. He told Space.com that because the microtektites can be radiometrically dated, they offer a new milestone in the Earth's history that could help scientists date layers of Earth in the future. The goal of studying this particular period in Earth's history, he said, is to understand what happens to the planet when global temperatures rise. 

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

According to the simulations, the system can stay stable for more than 10,000 orbits lasting 11 years each, with one stipulation, said lead author Steven Rieder, a postdoctoral fellow at the RIKEN Advanced Institute for Computational Science in Japan.

"The system is only stable when the rings rotate opposite to how the planet orbits the star," Rieder said in a statement. "It might be far-fetched, massive rings that rotate in opposite direction," he added, "but we now have calculated that a 'normal' ring system cannot survive." More usually, a planet's rings circle in the same direction as the planet is traveling, and the planet orbits in the same direction as the star turns.

It's also possible that the stellar eclipses were created by a free-floating object passing between Earth and the star, but this would be true only if that object's velocity as measured in the observations was not correct, Rieder said. He added that this would be a strange explanation, as the measurements the team obtained are "very accurate."

The researchers said they next plan to examine how the ring structure was created, and how it evolves. A paper based on the research will appear shortly in the journal Astronomy and Astrophysics.

Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We're also on Facebook and Google+. Original article on Space.com.

Other experts say Obama's stated timeline is not bold enough.

"We are far closer today to sending humans to Mars than we were to sending men to the moon in 1961, and we were there eight years later," said Robert Zubrin, president of nonprofit organization The Mars Society and the author of "The Case for Mars: The Plan to Settle the Red Planet," (Free Press, 2011). The next president should announce an ambitious goal to get to Mars by the end of the second term, or by 2024, Zubrin said. Otherwise, the momentum for the mission could be lost, and space exploration could be delayed further, he added. [SpaceX to Mars: Awe-Inspiring Video Shows Vision for Red Planet Exploration]

Either way, before astronauts start packing their spacesuits and intergalactic playlists, scientists have to sort out a few problems.

Step 1: Build American technology to get astronauts to space

Currently, the United States relies on a Russian Soyuz spacecraft to get astronauts to the International Space Station. That is set to change, as private spaceflight companies have taken on the challenge of building a system to launch humans and cargo spaceward: Elon Musk's SpaceX is working on the Dragon robotic launch vehicles, while Boeing is building its CST-100, Logsdon said. Musk has also said that SpaceX's robotic launch vehicle could head off to Mars as soon as 2018. (A launch vehicle is a rocket-powered vehicle designed to send spacecraft or satellites into space.)

Step 2: Build bigger spacecraft

A Mars voyage requires a spacecraft that can carry multiple people, along with all the supplies for a three-year round-trip, including potential cargo items, said Bret Drake, an engineering specialist with Los Angeles-based Aerospace Corp., a nonprofit organization that researches launch vehicles, satellite systems, ground control systems and space technology for the federal government.

"To sustain a crew all the way to Mars means being able to launch rather heavy payloads, because you have to have the fuel and supplies for the round-trip," added Logsdon. "And there's no 7-Eleven on Mars where you can stock up to come home," he told Live Science.

One alternative is to create a giant spacecraft; another is to develop multiple smaller modules that can be launched separately into orbit and then assembled in space, Logsdon said. (Some of these modules could hold people while others could hold supplies, for instance).

Either way, the basic technology is there, Zubrin said. "It has to be larger than any we've built before," he said. Even so, "there isn't new science here."

Currently, Lockheed Martin is developing a four-person spacecraft called the Orion, which will sit atop the heavy-lift launch system, called the Space Launch System (SLS), that NASA is developing to take people into deep space. Orion already completed one successful test flight on Dec. 5, 2014, and is set to take a trip around the moon in 2018. 

Step 3: Build bigger rockets

Launching a bigger spacecraft into deep space requires bigger rockets on any launch vehicles used. NASA plans to conduct a second test of what will be the world's largest rocket, which will be part of the SLS, sometime in 2021, according to NASA. SpaceX is also developing the Falcon Heavy rocket, which is designed to launch heavier payloads, including people, into space.

Step 4: Stick the landing

After people enter Mars' orbit, they need to land on the Red Planet. With past missions, friction, thermal effects and parachutes could provide the deceleration needed to land. But a parachute won't have enough stopping power for such heavy crafts.

However, scientists are making progress on that front.  

For instance, SpaceX has shown that high-speed crafts can decelerate using supersonic retropropulsion, which involves firing engines while landing, Drake said. "We now have a feasible technical solution for how to get large vehicles to the surface of Mars," Drake said.

Step 5: Figure out long-term habitation on a space station

Astronauts have logged many weeks and months on the International Space Station (ISS), demonstrating the feasibility of long-term habitation systems, such as those that provide safe water, process waste, and filter air in space. Similar systems could be used for a stay on Mars, experts say.

The difference, however, is that the ISS is in low Earth orbit, just a few hours' trip to the home planet. If anything breaks, Earth can still come to the rescue. That won't be possible on Mars, which is at least a six- to nine-month journey, even when the planets are at their closest point to each other.

"One key advancement for the life-support system is increasing the reliability of the systems," Drake said. "For Mars missions, there are no quick-abort modes back to Earth, nor ground-up resupply if systems fail. So the life-support systems need to be reliable, and maintainable by the crew, for long periods of time — many years," Drake said.

Step 6: Avoid deadly cosmic radiation

Astronauts going on a Mars mission will need protection from two forms of radiation: solar proton events (or solar flares) and galactic cosmic radiation.

The first "can be mitigated by proper vehicle design, along with a dedicated storm shelter, such as a water wall made from the life-support system water supply," Drake said. (This would involve literally lining the walls with the water used for drinking and showering.)

Shielding people from galactic cosmic radiation is trickier. In free space, cosmic radiation levels are extremely high. However, the Mars ScienceLaboratory, which landed on the Martian surface aboard the rover Curiosity, has measured cosmic radiation levels and showed that radiation exposure at the surface of the red planet is similar to levels seen aboard the ISS, Drake said. Because the ISS is located in low Earth orbit, it is below the two doughnut-shaped radiation belts called Earth's Van Allen belts, which block from Earth many of the charged particles spewed from the sun, as well as from cosmic rays, Logsdon said.

One strategy may be to make the trip through free space very quickly, minimizing the exposure to the area with the highest radiation, Drake said.

"It's safer to be on the surface of Mars than free space," Drake said.

Step 7: Get to the moon

Before making the three-year round-trip to Mars, many of these long-term space systems will be tested in cislunar orbit, according to NASA's timeline of the journey to Mars. Sometime between 2018 and 2030, NASA plans to send crewed missions on spacewalks in the region of space near the moon. Some of these missions could last a year, in preparation for the epic voyage to Mars.

The plans also include a trip to redirect and sample material from an asteroid.

This will provide an opportunity to test out all of the elements of the Mars mission, while not being too far from Earth in case something goes wrong, Logsdon said.

Step 8: Build housing on Mars

Once people have taken the effort to get to Mars, they won't just turn around. The outbound voyage would take six to nine months, but explorers can't return until Mars and Earth are in good alignment relative to the sun, which could take 14 months, Logsdon said. (The return trip will be much shorter if the Earth and Mars are on the same side of the sun, rather than on opposite sides.)

In a way, Mars pioneers would be similar to "the explorers of the 16th century that went on ships across the ocean and were gone from their home country for a long time," Logsdon said.

Given that, it makes sense to make some kind of permanent structure, Logsdon said.

"You need, on the Martian surface, some sort of habitat," Logdson said. "You're not going to live inside a spacesuit all the time. Though it seems far-fetched, the movie "The Martian" showed a relatively realistic depiction of a potential Mars living setup, he added.

Original article on Live Science.