Astrobiology Archives

July 26, 2022July 26, 2022 by Matt Williams

Before we Develop Self-Replicating Machines to Explore the Universe, we Should Figure out how to Turn Them off Again

An early NASA concept of an interstellar space probe. Credit: NASA/Johns Hopkins University Applied Physics Laboratory

In 1948/49, famed computer scientist, engineer, and physicist John von Neumann introduced the world to his revolutionary idea for a species of self-replicating robots (aka. “Universal Assemblers”). In time, researchers involved in the Search for Extraterrestrial Intelligence (SETI) adopted this idea, stating that self-replicating probes would be an effective way to explore the cosmos and that an advanced species may be doing this already. Among SETI researchers, “Von Neumann probes” (as they’ve come to be known) are considered a viable indication of technologically advanced species (technosignature).

Given the rate of progress with robotics, it’s likely just a matter of time before humanity can deploy Von Neumann probes, and the range of applications is endless. But what about the safety implications? In a recent study by Carleton University Professor Alex Ellery explores the potential harm that Von Neumann Probes could have. In particular, Ellery considers the prospect of runaway population growth (aka. the “grey goo problem”) and how a series of biologically-inspired controls that impose a cap on their replication cycles would prevent that.

July 23, 2022July 24, 2022 by Laurence Tognetti

Solar System Tours: Plumes of Enceladus

“We’re coming up on the plumes!” The co-pilot announced over the intercom.

The other six passengers and I took our positions along the viewing cupola at the belly of the “Tour Bus”, and each grabbed on to the hand and foot restraints to keep ourselves in place in the weightlessness. We were traveling about 400 km (250 miles) above the south pole of Enceladus looking down at the highly reflective surface that was so bright it took about a minute for our eyes to adjust. We all remained silent, and my heart was pounding in anticipation. The Tour Bus silently coasted for a few more minutes as we took in the breathtaking view of Saturn’s sixth-largest moon.

July 12, 2022July 12, 2022 by Laurence Tognetti

Perseverance is Searching for the Perfect Landing Spot for the Upcoming Sample Return Mission

NASA’s car-sized Perseverance (Percy) Mars rover has been had at work carrying out its science campaign in Jezero Crater on the Red Planet, but it’s equally been busy scouting for sites for NASA’s planned Mars Sample Return (MSR) mission, which is a joint mission with the European Space Agency. One of the many tasks for Percy has been to collect sample tubes that MSR will eventually return to Earth for further analysis, having collected its ninth sample on July 6. This most recent sample is especially intriguing as it’s the first taken from the Jezero’s delta itself, which is believed to be one of the most ideal locations to search for past life on the Red Planet.

July 9, 2022July 12, 2022 by Laurence Tognetti

Snooping on Alien Messages Passing Through the Solar System

Researchers at Penn State University have studied a new technique that could use a star’s ability to focus and magnify communications which could be passing through our own solar system, and has been accepted for publication in The Astronomical Journal and was part of a graduate course at Penn State covering the Search for Extraterrestrial Intelligence (SETI. The study describes our Sun as potentially acting as a kind of node as part of an interstellar communication network involving probes or relays near our Sun, acting like cellular telephone towers in space.

July 5, 2022July 5, 2022 by Laurence Tognetti

Mars Rovers Will Need to Dig Deeper If They Want to Find Evidence of Life

The search for life—even ancient life—on Mars is trickier than we thought. In a recent study published in the journal Astrobiology, researchers have determined that NASA’s Mars Perseverance (Percy) Rover will have to dig two meters (6.6 feet) beneath the Martian surface in order to find traces of ancient life. This is because the surface of Mars is constantly bombarded with extreme levels of solar radiation that scientists hypothesize would quickly degrade small molecules such as amino acids. The reason for this extreme level of radiation is due to the absence of a magnetic field, which scientists believe was stripped away billions of years ago when the planet’s liquid outer core ceased to produce the dynamo that created the field.

June 15, 2022June 15, 2022 by Matt Williams

There Could Be Four Hostile Civilizations in the Milky Way

This artists’s cartoon view gives an impression of how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using the microlensing technique concluded that planets around stars are the rule rather than the exception. The average number of planets per star is greater than one.

In 1977, the Big Ear Radio Telescope at Ohio State University picked up a strong narrowband signal from space. The signal was a continuous radio wave that was very strong in intensity and frequency and had many expected characteristics of an extraterrestrial transmission. This event would come to be known as the Wow! Signal, and it remains the strongest candidate for a message sent by an extraterrestrial civilization. Unfortunately, all attempts to pinpoint the source of the signal (or detect it again) have failed.

This led many astronomers and theorists to speculate as to the origin of the signal and what type of civilization may have sent it. In a recent series of papers, amateur astronomer and science communicator Alberto Caballero offered some fresh insights into the Wow! Signal and extraterrestrial intelligence in our cosmic neighborhood. In the first paper, he surveyed nearby Sun-like stars to identify a possible source for the signal. In the second, he estimates the prevalence of hostile extraterrestrial civilizations in the Milky Way Galaxy and the likelihood that they’ll invade us.

June 15, 2022June 15, 2022 by Laurence Tognetti

High Altitude Life Can’t Explain the Trace Gases in Venus’ Atmosphere

The planet Venus is one of the most inexplainable and mysterious planetary objects in our solar system as its surface is beyond inhospitable for us fragile humans with temperatures at a searing 475 degrees Celsius (900 degrees Fahrenheit) and surface pressures more than 90 times that of Earth. However, its atmosphere is quite a different story as its temperature varies considerably ranging from -143 degrees Celsius (-226 degrees Fahrenheit) at night to 37 degrees Celsius (98 degrees Fahrenheit) in the daytime, and varies based on altitude, as well.

May 12, 2022May 12, 2022 by Laurence Tognetti

What’s the Right Depth to Search for Life on Icy Worlds?

Are we alone? Is there life beyond Earth? These are the questions that plague the very essence of science, and in particular, planetary science. Unfortunately, robotic exploration of exoplanetary systems currently remains out of reach due to the literal astronomical distances to get there. For context, our nearest star, Proxima Centauri, is 4.25 light years away, or a mind-blowing 40,208,000,000,000 km (25,000,000,000,000 miles) from Earth. Finding an intelligent civilization might be out of reach for now but searching for any forms of life beyond Earth is very much possible within the confines of our own solar system.

April 21, 2022April 21, 2022 by Laurence Tognetti

Perseverance Begins the Next Phase of its Mission, Studying an Ancient River Bed on Mars

On February 18, 2021, NASA’s Perseverance (Percy) Rover successfully landed in the dried-up lakebed known as Jezero Crater on Mars, beaming back images and video of its descent and landing to millions of space fans living on the planet that built and launched this incredible robotic explorer. With this landing came enormous excitement for a new era of robotic exploration of the Red Planet as we slowly continue to unlock the secrets of Mars and its ancient past, to include (hopefully) finding evidence of past life.

March 3, 2022March 3, 2022 by Matt Williams

How to Search for Life as we Don’t Know it

Artist's concept of Earth-like exoplanets, which (according to new research) need to strike the careful balance between water and landmass. Credit: NASA

The fields of extrasolar planet studies and astrobiology have come a long way in recent years. To date, astronomers have confirmed the existence of 4,935 exoplanets in 3,706 star systems, with another 8,709 candidates awaiting confirmation. With so many planets to study, next-generation instruments, and improved data analysis, the focus is transitioning from discovery to characterization. With the James Webb Space Telescope now deployed, these fields are about to advance much farther!

In particular, scientists anticipate that the characterization of planetary atmospheres may lead to the discovery of “biosignatures” – signs we associate with life and biological processes. The challenge will be how to recognize signatures that don’t conform to “life as we know it.” In a recent study, researchers from the School of Earth and Space Exploration (SESE) at Arizona State University (ASU) investigate possible tools for searching for life “as we don’t know it.”