Search for Life Archives

July 11, 2022July 11, 2022 by Evan Gough

A Swarm of Swimming Robots to Search for Life Under the Ice on Europa

An artist’s interpretation of liquid water on the surface of the Europa pooling beneath chaos terrain. Credit: : NASA/JPL-Caltech

When Galileo pointed his telescope at Jupiter 400 years ago, he saw three blobs of light around the giant planet, which he at first thought were fixed stars. He kept looking, and eventually, he spotted a fourth blob and noticed the blobs were moving. Galileo’s discovery of objects orbiting something other than Earth—which we call the Galilean moons in his honour—struck a blow to the Ptolemaic (geocentric) worldview of the time.

Galileo couldn’t have foreseen the age of space exploration that we’re living in now. Fast forward 400 years, and here we are. We know the Earth doesn’t occupy any central point. We’ve discovered thousands of other planets, and many of them will have their own moons. Galileo would be amazed at this.

What would he think about robotic missions to explore one of the blobs of light he spotted?

February 23, 2022February 23, 2022 by Evan Gough

Does the Entire Planet Have a Mind of its Own?

In a self-described "thought experiment," University of Rochester astrophysicist Adam Frank and colleagues David Grinspoon at the Planetary Science Institute and Sara Walker at Arizona State University use scientific theory and broader questions about how life alters a planet, to posit four stages to describe Earth's past and possible future. Image Credit: (University of Rochester illustration / Michael Osadciw)

What is humanity? Do our minds set us apart from the rest of nature and from the rest of Earth? Or does Earth have a collective mind of its own, and we’re simply part of that mind? On the literal face of it, that last question might sound ridiculous.

But a new thought experiment explores it more deeply, and while there’s no firm conclusion about humanity and a planetary mind, just thinking about it invites minds to reconsider their relationship with nature.

Overcoming our challenges requires a better understanding of ourselves and nature, and the same is true for any other civilizations that make it past the Great Filter.

February 14, 2022February 14, 2022 by Evan Gough

Astronomers Scan the Center of the Milky Way for Any Sign of Intelligent Civilizations. Nothing but Silence.

This is an image of the center of the Milky Way. The bright white area right of center is home of the supermassive black hole Sagittarius A star. Image Credit: By NASA/JPL-Caltech/ESA/CXC/STScI - http://photojournal.jpl.nasa.gov/catalog/PIA12348See also http://www.spacetelescope.org/images/opo0928a/ and http://hubblesite.org/newscenter/archive/releases/2009/28/image/a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=24958921

Are there civilizations somewhere else in the Universe? Somewhere else in the Milky Way? That’s one of our overarching questions, and an answer in the affirmative would be profound.

Humanity’s pursued the Search for Extraterrestrial Intelligence (SETI) in one form or another since shortly after the advent of radio waves in the early 20th century. Efforts have waxed and waned over the decades, but the search has never been completely abandoned.

The search detected transient hints in the form of unexplained radio waves in the past, but nothing that comprises reliable evidence. Now a new search for technosignatures in the Milky Way’s center has turned up nothing.

January 17, 2022January 17, 2022 by Evan Gough

Remember When Life was Found in a Martian Meteorite? Turns out, it was Just Geology

The Alan Hills meteorite is a part of history to Mars aficionados. It came from Mars and meteorite hunters discovered in Antarctica in 1984. Scientists think it’s one of the oldest chunks of rock to come from Mars and make it to Earth.

The meteorite made headlines in 1996 when a team of researchers said they found evidence of life in it.

Did they?

November 22, 2021November 22, 2021 by Evan Gough

Is That a Fossil on Mars? Non-Biological Deposits can Mimic Organic Structures

NASA's Perseverance rover, which is searching signs of ancient life on Mars (credit: NASA/JPL-Caltech/MSSS)

There’s nothing easy about searching for evidence of life on Mars. Not only do we somehow have to land a rover there, which is extraordinarily difficult. But the rover needs the right instruments, and it has to search in the right location. Right now, the Perseverance lander has checked those boxes as it pursues its mission in Jezero Crater.

But there’s another problem: there are structures that look like fossils but aren’t. Many natural chemical processes produce structures that mimic biological ones. How can we tell them apart? How can we prepare for these false positives?

October 12, 2021October 12, 2021 by Evan Gough

Greenland’s Ice Sheet is Similar in Many Ways to the Solar System’s Icy Worlds and Can Teach Us How to Search for Life

Floating ice at the calving front of Greenland's Kangerdlugssuaq glacier, photographed in 2011 during Operation IceBridge (Credit: NASA/Michael Studinger)

Many regions on Earth are temperate, nutrient-rich, stable environments where life seems to thrive effortlessly. But not all of Earth. Some parts, like Greenland’s ice sheet, are inhospitable.

In our nascent search for life elsewhere in the Solar System, it stands to reason that we’ll be looking at worlds that are marginal and inhospitable. Icy worlds like Jupiter’s moon Europa and Saturn’s moon Enceladus are our most likely targets. These frozen worlds have warm oceans under layers of ice.

What can Greenland’s cryo-ecosystems tell us about searching for life on icy bodies like Europa and Enceladus?

October 1, 2021October 1, 2021 by Evan Gough

Rogue Planets Could be Habitable

An artist's illustration of a rogue planet, dark and mysterious. Image Credit: NASA

The search for potentially habitable planets is focused on exoplanets—planets orbiting other stars—for good reason. The only planet we know of with life is Earth and sunlight fuels life here. But some estimates say there are many more rogue planets roaming through space, not bound to or warmed by any star.

Could some of them support life?

January 5, 2021January 5, 2021 by Evan Gough

The Interior of Enceladus Looks Really Great for Supporting Life

Scientists recently determined that a certain strain of Earth bacteria could thrive under conditions found on Enceladus. Credit: NASA/JPL/Space Science Institute

When NASA’s Voyager spacecraft visited Saturn’s moon Enceladus, they found a body with young, reflective, icy surface features. Some parts of the surface were older and marked with craters, but the rest had clearly been resurfaced. It was clear evidence that Enceladus was geologically active. The moon is also close to Saturn’s E-ring, and scientists think Enceladus might be the source of the material in that ring, further indicating geological activity.

Since then, we’ve learned a lot more about the frigid moon. It almost certainly has a warm and salty subsurface ocean below its icy exterior, making it a prime target in the search for life. The Cassini spacecraft detected molecular hydrogen—a potential food source for microbes—in plumes coming from Enceladus’ subsurface ocean, and that energized the conversation around the moon’s potential to host life.

Now a new paper uses modelling to understand Enceladus’ chemistry better. The team of researchers behind it says that the subsurface ocean may contain a variety of chemicals that could support a diverse community of microbes.

October 27, 2020October 27, 2020 by Evan Gough

This is What Perseverance’s Landing Site Looked Like Billions of Years Ago. See Why it’s Such a Compelling Target?

This illustration shows Jezero Crater — the landing site of the Mars 2020 Perseverance rover — as it may have looked billions of years go on Mars, when it was a lake. An inlet and outlet are also visible on either side of the lake. Image Credit: NASA/JPL-Caltech

Today is a milestone in NASA’s Perseverance mission to Mars. At 1:40 pm Pacific time today, the rover will have traveled 235.4 million km (146.3 million miles). That means the spacecraft is halfway to Mars and its rendezvous with Jezero Crater. The spacecraft isn’t traveling in a straight line, and the planets are moving, so it’s not equidistant to both planets.

“Although we’re halfway into the distance we need to travel to Mars, the rover is not halfway between the two worlds,” Kangas explained. “In straight-line distance, Earth is 26.6 million miles [42.7 million kilometers] behind Perseverance and Mars is 17.9 million miles [28.8 million kilometers] in front.”

But today’s still a good time to take another look at Jezero Crater, and why NASA chose it as the mission’s target.

October 6, 2020October 6, 2020 by Evan Gough

Here’s a Clever Idea, Looking for the Shadows of Trees On Exoplanets to Detect Multicellular Life

Exoplanet Kepler 62f would need an atmosphere rich in carbon dioxide for water to be in liquid form. Artist's Illustration: NASA Ames/JPL-Caltech/T. Pyle

That’s the kind of headline that can leave us scratching our heads. How can you see tree shadows on other worlds, when those planets are tens or hundreds of light years—or even further—away. As it turns out, there might be a way to do it.

One team of researchers thinks that the idea could potentially be used to answer one of humanity’s long-standing questions: Are we alone?