Outgoing US President Barack Obama has revived calls to send humans to Mars by the 2030s - but even if astronauts get there, would they remember much of it?

Scientists at the University of California have investigated a weird phenomenon called "space brain", which, though it sounds like a line from a David Bowie song, could affect missions to the red planet.

They found that exposure to highly energetic, charged particles - much like those found in the galactic cosmic rays that will bombard astronauts during extended space flights - causes significant long-term brain damage in test rodents, resulting in cognitive impairments and dementia.

"This is not positive news for astronauts deployed on a two-to-three-year round trip to Mars," said study author Professor Charles Limoli.

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"The space environment poses unique hazards to astronauts."

Exposure to these particles could lead to a range of potential central nervous system complications that might occur during and persist long after actual space travel - such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making.

"Many of these adverse consequences to cognition may continue and progress throughout life."

Preventive treatments however offer hope, and Limoli's group is working on new pharmacological strategies to combat the impacts of space brain.

What the "Death Star" could mean for Earth

Researchers have demonstrated for the first time how an asteroid or comet could have caused the mega crater on Martian moon Phobos. Credit: Lawrence Livermore National Laboratory
Researchers have demonstrated for the first time how an asteroid or comet could have caused the mega crater on Martian moon Phobos. Credit: Lawrence Livermore National Laboratory

In other strange Mars-related news, researchers have used a 3D simulation to explain the quirk that gave the planet's biggest moon its oft-cited resemblance to the Death Star from

Star Wars

.

The dominant feature on the surface of Phobos is Stickney crater, a mega crater measuring nine kilometres across that spans nearly half of the Martian moon.

Over the decades, understanding the formation of such a massive crater has proven elusive for researchers, but, for the first time, physicists have demonstrated how an asteroid or comet impact could have created it without destroying Phobos completely.

The study, led by the Lawrence Livermore National Laboratory in the US, showed there was a range of possible solutions for the size and speed of what struck it, including an object spanning 250m across and travelling at a speed close to six kilometres per second, or 21,600km/h.

"Something as big and fast as what caused the Stickney crater would have a devastating effect on Earth," lead researcher Megan Bruck Syal said.

"If Nasa sees a potentially hazardous asteroid coming our way, it will be essential to make sure we're able to deflect it."

We'd only have one shot at it, she said, and the consequences couldn't be higher.

"We do this type of benchmarking research to make sure our codes are right when they will be needed most."

Fact: dinosaurs didn't sing

Scientists have proven that dinosaurs weren't capable of singing like their direct descendants, birds. Photo: Metha Limrosthip/123RF stock image.
Scientists have proven that dinosaurs weren't capable of singing like their direct descendants, birds. Photo: Metha Limrosthip/123RF stock image.

Perhaps with the exception of kids' favourite Barney, we can now be reasonably sure dinosaurs couldn't sing.

It's just been reported that the oldest known vocal organ of a bird has been found in an Antarctic fossil of a relative of ducks and geese that lived more than 66 million years ago during the age of dinosaurs.

The discovery of the Mesozoic-era vocal organ, called a "syrinx", and its apparent absence in non-avian dinosaur fossils of the same age, indicate that the organ may be have originated late in the evolution of birds, which are considered to be direct descendants of dinosaurs.

This suggests other dinosaurs may not have been able to make noises similar to the bird calls we hear today.

"This finding helps explain why no such organ has been preserved in a non bird dinosaur or crocodile relative," said study author Julia Clarke, a palaeontologist at The University of Texas at Austin.

"This is another important step to figuring out what dinosaurs sounded like as well as giving us insight into the evolution of birds."

This study follows recent research that found some dinosaurs would likely have made closed-mouth vocalisations akin to ostrich booms that don't require a syrinx.

This selfless spider is dying to have kids

A female dark fishing spider (left) and its male counterpart, which sacrifices itself as a food source immediately after mating. Credit: Karina I. Helm
A female dark fishing spider (left) and its male counterpart, which sacrifices itself as a food source immediately after mating. Credit: Karina I. Helm

Scientists have just revealed one of the noblest acts of the animal world: a spider that sacrifices himself to help his offspring.

Three years ago, a bizarre study found that the male dark fishing spider begins to curl up and die immediately after mating with a female, which then devours him.

Now researchers from the University of Nebraska-Lincoln and Gonzaga University have published new work showing that the male's sacrifice appears to increase the number, size and survival odds of his future spiderlings.

Females that cannibalised their mates produced nearly twice as many spiderlings as females that were denied their post-sex dessert, the study reported.

The spiderlings also grew nearly 20 per cent larger, and survived about 50 per cent longer, than those whose mothers did not eat their mates.

"It's only when a female eats the male that we see these benefits - so there's something unique, something special, about the males," study co-author Steven Schwartz said.

"There might be a nutrient, or maybe a cocktail of nutrients, that is somehow concentrated in the males' bodies.

"We don't know what that is, but there is something going on there."

What scientists think about Twitter

Scientists are yet to widely take up Tweeting - but those who do find it useful, a new study shows. Photo: rvlsoft/123RF stock image
Scientists are yet to widely take up Tweeting - but those who do find it useful, a new study shows. Photo: rvlsoft/123RF stock image

Donald Trump has mastered the art - but can scientists also make Twitter work for them?

A new study has surveyed scientists for the first time on their attitudes towards social media and how they're using it to get their research out of the lab and into the public.

The paper, co-authored by Kimberley Collins and Dr Jenny Rock of Otago University, and David Shiffman of the University of Miami, surveyed 587 scientists to show widespread take-up was lacking - but those using it found plenty of advantages.

"Most scientists saw the benefit in using Twitter - they said it was a good way to access a large and diverse audience," Collins said.

"They also appreciate the ease of communicating in snippets, how little time it takes, and how accessible it is."

The study also found that scientists mostly use Twitter to communicate with colleagues and share peer-reviewed literature within the scholarly community.

"Many scientists said they use Twitter to communicate specifically with other scientists.

"Some used it as a forum to share their research directly with the public and media, but most saw it as a tool to share research within their field and to stay updated with science outreach and communication."