Posted on by Elizabeth Howell

Here’s One Idea Of How To Search For Life Beyond Earth

Early on, Mars had giant active volcanoes, which would have released significant methane. Because of methane’s high greenhouse potential, even a thin atmosphere might have supported liquid water. Credit: NASA

Using a phone to search for signs of life? Yeah, we can get behind that. One group of researchers has a system that they’ve been testing out in analog environments with the aim of (eventually, one day, they hope) it being applied, say, to other planets — such as Mars.

Here’s  how it works:

“Initially the human astrobiologist takes images of his/her surroundings using a mobile phone camera. These images are sent via Bluetooth to a laptop, which processes the images to detect novel colors and textures, and communicates back to the astrobiologist the degree of similarity to previous images stored in the database,” read a press release on the technology.

View of Mars' surface near the north pole from the Phoenix lander. Credit: NASA/JPL-Calech/University of Arizona
View of Mars’ surface near the north pole from the Phoenix lander. Credit: NASA/JPL-Calech/University of Arizona

The aim is to eventually have robots, if necessary, do the same thing on Mars or in other locations. Field tests have been done in Martian analog environments, with intriguing results.

“In our most recent tests at a former coal mine in West Virginia, the similarity-matching by the computer agreed with the judgement of our human geologists 91% of the time,” stated Patrick McGuire, who works in Freie Universität’s planetary sciences and remote sensing department in Germany.

“The novelty detection also worked well, although there were some issues in differentiating between features that are similar in color but different in texture, like yellow lichen and sulfur-stained coalbeds. However, for a first test of the technique, it looks very promising.”

You can check out more details in this paper on Arxiv, a site that publishes articles before they are peer-reviewed. The information has also been accepted for publication in the International Journal of Astrobiology.

Source: European Planetary Science Congress

Posted on by Elizabeth Howell

When We Look For Life Beyond Earth, Let’s Consider Dying Planets: Study

Upper Geyser Basin region in Yellowstone National Park in Wyoming. A new study supposes the Earth will look like this after the sun heats up in a few billion years' time. Credit: Jack O’Malley-James

Bacteria. They’re so resilient that they can survive just about anywhere on Earth, even in spots of extreme hot or cold. As the sun warms up in the next few billion years, it’s likely that bacteria will be the only living creatures left on the planet, according to new research.

The study not only has implications for human survival — hopefully, our descendants will have left by then — but also our search for life on other planets. By predicting the signature these bacteria leave behind on the atmosphere, we can better hone our search for new planets, the study states.

Earth’s history shows that a species, just like an individual, can expect a lifetime that only lasts for so long. Sometimes a catastrophic event will wipe out a species, like what likely happened to the dinosaurs around 65 million years ago when a huge asteroid hit the Earth. Other times, it’s a slow process that is infinitesimal in an individual’s lifetime, but will eventually lead to changes that are unfriendly for life.

Thermophilic (heat-loving) bacteria may be among the last living creatures on Earth, the study suggests. Credit: Mark Amend / NOAA Photo Library
Thermophilic (heat-loving) bacteria may be among the last living creatures on Earth, the study suggests. Credit: Mark Amend / NOAA Photo Library

A computer model by Ph.D. astrobiologist Jack O’Malley James, who is at the University of St Andrews, suggests the first changes will take place in only a billion years. He will present his research at the ongoing Royal Astronomical Society national meeting at St. Andrews, Scotland, which is taking place this week.

“Increased evaporation rates and chemical reactions with rainwater will draw more and more carbon dioxide from the Earth’s atmosphere,” the Royal Astronomical Society stated. “The falling levels of CO2 [carbon dioxide] will lead to the disappearance of plants and animals and our home planet will become a world of microbes.”

Earth will then run out of oxygen and begin to dry out as temperatures rise and the oceans evaporate. Around two billion years in the future, there will be no oceans left.

The Sun in H-Alpha with close-up on a rushing prominence on 02-07-2013. Credit and copyright: John Chumack.
The sun, which allows Earth to be life-friendly right now, will warm up the planet and kill off most live forms in the next few billion years. Credit and copyright: John Chumack.

“The far-future Earth will be very hostile to life by this point,” O’Malley James stated. “All living things require liquid water, so any remaining life will be restricted to pockets of liquid water, perhaps at cooler, higher altitudes or in caves or underground.”

Life would disappear almost altogether in about 2.8 billion years.

Thankfully, humans plenty of time to figure out how to get around this problem. In the meantime, we can use the knowledge when seeking life beyond Earth.

Searches these days often focus on finding life like our own, which would leave “fingerprints” behind like oxygen and ozone.

“Life in the Earth’s far future will be very different to this, which means, to detect life like this on other planets we need to search for a whole new set of clues,” O’Malley James stated. “By the point at which all life disappears from the planet [surface], we’re left with a nitrogen:carbon-dioxide atmosphere, with methane being the only sign of active life”.

More information on this research is contained in an April 2013 article in the International Journal of Astrobiology.

Source: Royal Astronomical Society