Universe Today

October 5, 2021October 17, 2021 by Matt Williams

Beyond “Fermi’s Paradox” XVII: What is the “SETI-Paradox” Hypothesis?

The Arecibo Radio Telescope in Puerto Rico was the site of NASA's High Resolution Microwave Survey, a search for extraterrestrial radio messages. Credit: Unites States National Science Foundation

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that we haven’t heard from any aliens is because no one is transmitting!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?”

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, including the possibility that everyone is listening, but no one is broadcasting – otherwise known as the “SETI-Paradox.”

October 5, 2021October 5, 2021 by David Dickinson

Arid Meteor Outburst in the Works This Week?

The new Arid meteor shower may be making itself known in early October 2021.

It’s not every day that we witness an outburst from a new meteor shower gracing the skies of the Earth. But that’s just what may be in store this week for fortunate observers deep in the southern hemisphere, with the advent of the Arid meteors.

October 5, 2021October 5, 2021 by Andy Tomaswick

There’s Enough Sunlight Getting Through Venus’ Clouds to Support High-Altitude Life

Carl Sagan once famously, and sarcastically, observed that, since we couldn’t see what was going on on the surface of Venus, there must be dinosaurs living there. Once humans started landing probes on the planet’s surface, any illusion of a lush tropical world was quickly dispelled. Venus was a hellscape of extraordinary temperatures and pressures that would make it utterly inhospitable to anything resembling Earth life.

But more recently, astrobiologists have again turned their attention to the Morning Star. But this time, instead of looking at the surface, they looked in the clouds. And now, a new study from researchers at California Polytechnic, Pomona, has calculated that there is likely a layer in the atmosphere where photosynthesis can occur. Meaning there is a zone in Venus’ cloud layer where life could have evolved.

October 5, 2021October 5, 2021 by Nancy Atkinson

NASA Spacecraft Takes a Picture of Jupiter … From the Moon

Jupiter seen from the Moon, as imaged by the Lunar Reconnaissance Orbiter Camera on 20 August 2021. Two of Jupiter's moons, Io and Europa, can just barely be seen here to the right of Jupiter. Scene has been enlarged by a factor of four. Credit: NASA/GSFC/Arizona State University.

You know the feeling …. seeing Jupiter through your own telescope. If it gives you the chills — like it does for me — then you’ll know how the team for the Lunar Reconnaissance Orbiter felt when they turned their spacecraft around – yes, the orbiter that’s been faithfully circling and looking down at the Moon since 2008 – and saw the giant planet Jupiter with their camera. If you zoom in on the picture, you can even see Jupiter’s Galilean moons.

October 4, 2021October 4, 2021 by Matt Williams

A Technique to Find Oceans on Other Worlds

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

You could say that the study of extrasolar planets is in a phase of transition of late. To date, 4,525 exoplanets have been confirmed in 3,357 systems, with another 7,761 candidates awaiting confirmation. As a result, exoplanet studies have been moving away from the discovery process and towards characterization, where follow-up observations of exoplanets are conducted to learn more about their atmospheres and environments.

In the process, exoplanet researchers hope to see if any of these planets possess the necessary ingredients for life as we know it. Recently, a pair of researchers from Northern Arizona University, with support from the NASA Astrobiology Institute’s Virtual Planetary Laboratory (VPL), developed a technique for finding oceans on exoplanets. The ability to find water on other planets, a key ingredient in life on Earth, will go a long way towards finding extraterrestrial life.

October 4, 2021October 4, 2021 by Andy Tomaswick

It’ll Soon be Possible to Make Satellite Phone Calls With Your Regular Phone

Not all who wander are lost – but sometimes their cell phone reception is. That might change soon if a plan to project basic cell phone coverage to all parts of the globe comes to fruition. Lynk has already proven it can use a typical smartphone to bound a standard SMS text message off a low-earth-orbiting satellite, and they don’t plan to stop there.

October 4, 2021October 4, 2021 by Nancy Atkinson

Here’s Perseverance, Seen From Space

The white speck in the middle of this image is the Perseverance rover, as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/University of Arizona

The Mars Perseverance rover is on the move! The HiRISE camera on the Mars Reconnaissance Orbiter spotted the rover from above, the first view since shortly after the rover landed in February 2021. Perseverance appears as the white speck in the center of the image above, in the the “South Séítah” area of Mars’ Jezero Crater.

The HiRISE team said the rover is about 700 meters (2,300 feet) from its original landing site.

October 3, 2021October 3, 2021 by Matt Williams

Astronomers Look at Super-Earths That had Their Atmospheres Stripped Away by Their Stars

Figure 1: Artist’s conceptual image showing the sizes of the planets observed in this study. The radius of TOI-1634 is 1.5 times larger than Earth’s radius and TOI-1685 is 1.8 times larger. The planets would appear red, due to the light from the red dwarf stars they orbit. (Credit: Astrobiology Center, NINS)

As the planets of our Solar System demonstrate, understanding the solar dynamics of a system is a crucial aspect of determining habitability. Because of its protective magnetic field, Earth has maintained a fluffy atmosphere for billions of years, ensuring a stable climate for life to evolve. In contrast, other rocky planets that orbit our Sun are either airless, have super-dense (Venus), or have very thin atmospheres (Mars) due to their interactions with the Sun.

In recent years, astronomers have been on the lookout for this same process when studying extrasolar planets. For instance, an international team of astronomers led by the National Astronomical Observatory of Japan (NAOJ) recently conducted follow-up observations of two Super-Earths that orbit very closely to their respective stars. These planets, which have no thick primordial atmospheres, represent a chance to investigate the evolution of atmospheres on hot rocky planets.

October 3, 2021October 3, 2021 by Scott Alan Johnston

When Did Photosynthesis Begin?

Sometime around 2.4 billion years ago, a nascent planet Earth underwent one of the most dramatic changes in its history. Known as the Great Oxidation Event, this period saw Earth’s atmosphere suddenly bloom with (previously scarce) molecular oxygen. The rapid alteration of the atmosphere’s composition was nothing short of a cataclysm for some early lifeforms (at the time, mostly simple celled prokaryotes). Anaerobic species – those that dwell in oxygen-free environments – experienced a near extinction-level event. But the Great Oxidation was also an opportunity for other forms of life to thrive. Oxygen in the atmosphere tempered the planetary greenhouse effect, turning methane into the less potent carbon dioxide, and ushering in a series of ice ages known as the Huronian Glaciation. But oxygen is an energy-rich molecule, and it also bolstered diversity and activity on the planet, as a powerful new source of fuel for living organisms.

The cause of this dramatic event? The tiniest of creatures: little ocean-dwelling cyanobacteria (sometimes known as blue-green algae) that had developed a new super-power never before seen on planet Earth: photosynthesis. This unique ability – to gain energy from sunlight and release oxygen as a waste product – was a revolutionary step for so small a critter. It quite literally changed the world.

October 3, 2021October 3, 2021 by Matt Williams

Communication With Mars is About to Become Impossible (for two Weeks)

Every two years, Mars enters what is known as a “Solar Conjunction,” where its orbit takes it behind the Sun relative to Earth. During these periods, the hot plasma regularly expelled by the Sun’s corona can cause interference with radio signals transmitted between Earth and Mars. To avoid signal corruption and the unexpected behaviors that could result, NASA and other space agencies declare a moratorium on communications for two weeks.

What this means is that between Oct. 2nd and Oct. 16th, all of NASA’s Mars missions will experiencing what is known as a “commanding moratorium.” This will consist of NASA sending a series of simple commands to its missions in orbit, which will then be dispatched to landers and rovers on the surface. These simple tasks will keep all of the robotic Martian explorers busy until regular communications can be established.