Life may be possible in water on exomoons, even if the planet floats free of other stars…

Earth-sized exomoons orbiting gas giants could still be home to water — and perhaps life — even if their parent planet floats freely through space, a new study suggests. Image credit: The Cosmic Companion/Created in Universe Sandbox

It is hard to imagine life without water. In fact, liquid water is usually considered a prerequisite for the formation of life anywhere.

Water on Earth is kept warm by a careful balancing act between incoming solar radiation from the Sun, and heat reflected back to the surface by our atmosphere.

However, some planets (known as free-floating planets or FFPs) are thought to soar through the Cosmos without the benefit of a parent star. Small, rocky versions of these rogue planets are, almost…


New Ganymede photos from Juno provide the first up-close view of this giant moon in nearly a generation.

Two images of Ganymede from Juno, as well as the spacecraft.
Two images of Ganymede from Juno, as well as the spacecraft.
The Juno spacecraft returns closeup photos of Ganymede for the first time in 20 years. Image credit: NASA/JPL/JPL-Caltech/SwRI/MSSS

On June 7, 2021, at 1:35 pm EDT, the Juno spacecraft, soaring around the Jovian system, carried out a close encounter with the giant moon Ganymede.

Larger than the planet Mercury, Ganymede ranks as the largest moon in the Solar System. It is also the only moon in the Solar System known to have a magnetic field — a magnetosphere similar to a bubble of charged particles.

These Ganymede photos from Juno are just the third (fourth?) close look humans have carried…


Seeing 535 fast radio bursts around the Cosmos, the CHIME radio telescope sextuples the number of previously-known FRBs in only a year. But what are FRBs?

The CHIME radio telescope found 535 fast radio bursts in its first year of operation, scattered all over the sky, without ever moving a muscle. Image credit: CHIME

Each day, the CHIME radio telescope, composed from four cylindrical radio antennas, records signals from half the sky of Earth. The unique capabilities of this unusual telescope provides glimpses of the Cosmos unlike those available at other instruments.

In its first year of operation, this one-of-a-kind telescope at the Dominion Radio Astrophysical Observatory recorded 535 fast radio bursts previously unknown to astronomers.

“Called fast radio bursts (FRBs), these extraordinary events generate as much energy…


The Moon in June flirts with the planets of our Solar System, and puts on one sweet sight — Here’s how to watch it all happen!

The Moon seen in 2019 from the International Space Station, located 408 kilometers (254 miles) above the Pacific Ocean. Image credit: NASA

Our planetary companion is putting on quite a show for amateur astronomers all around the globe during the month of June! These events all happen slowly, and will be visible to people around the globe, providing us with a global show.

Over the course of June, the Moon will huddle up close to Venus, Mars, Jupiter, and Saturn! …


An ancient bottleneck in human population could be explained by an ancient volcano, and a whole lot of sulfur.

An ancient volcanic eruption — and ensuing cloud of sulfur dioxide — may have caused a bottleneck in human population seen today in the human genetic code. Image credit: Taro Taylor/Editing by The Cosmic Companion and Richard Bartz

Reading the human genetic code reveals a bottleneck in human population took place between 100,000 and 60,000 years ago, suggesting our fledgling species suffered a massive loss of life at that time, significantly reducing human populations.

A new international study builds on earlier work, suggesting this ancient catastrophe may have been the result of a massive volcanic eruption, tearing apart the protective ozone layer surrounding the Earth. …


A solar eclipse on June 10 will put on a show for Canada and Siberia, with lesser displays in Europe and the northeastern United States

An annular solar eclipse seen in China in 2010. Image credit: A013231

A solar eclipse on June 10 will grace parts of northern Canada and Siberia, where well-placed viewers will see the event as an annular solar eclipse. These events are marked by a bright ring surrounding the silhouetted Moon.

Skygazers in the northeastern United States, as well as large swathes of Asia, will also get a partial glimpse of the celestial display.

Prime Viewing for Santa. He’s Not Doing Anything Right Now, Anyway…

Skygazers in the northeastern United States (as well as parts of the Midwest and…


Viewing the lights of “downtown milky way” reveals a previously-unknown source of X-ray radiation near the center of our galaxy.

A composite image of the core of the Milky Way galaxy. Image credits: NASA/CXC/UMass/Q.D. Wang; Radio: NRF/SARAO/MeerKAT

Cloaked in an enveloping haze of gas and dust, the center of the Milky Way remains an elusive target for astronomers. Hidden near the center of our family of stars, a supermassive black hole sits, pulling gas and dust near the tenebrous void.

However, certain wavelengths of electromagnetic energy are able to penetrate this dusty curtain. Looking at “downtown Milky Way,” Chandra X-ray telescope, the n X-ray thread was seen shining near the center of the Milky Way. This structure…


The first microsecond of the Cosmos was filled with a weird quark-gluon plasma soup. Turns out, things may have been weirder than that.

Integration of the Inner Tracker inside ALICE at CERN. Image credit: Maximilien Brice/CERN

In the instant after the Big Bang, matter as we know it did not exist — the Cosmos was filled with a soup of subatomic particles. Astronomers and astrophysicists are now able to piece together large pieces of the history of the early Universe. But, significant questions remain concerning the processes by which energy transformed to a weird quark-gluon plasma, eventually forming stars and planets and galaxies.

Researchers from University of Copenhagen set out to better-understand the…


Snowflake yeast evolve quickly, providing a novel tool in the study one of the greatest events in the history of Earth

A look at what Earth may have looked like before the first leafy plants or animals evolved. Image credit: NASA

Traveling backward in time 2.5 billion years, an unlucky time traveler would find themselves choking in the oxygen-poor atmosphere of Earth. Before animals or leafy plants, our world was occupied largely by microscopic lifeforms which lived without oxygen, and for whom this gas was a deadly poison.

Around this time, however, cyanobacteria (once known as blue-green algae) first developed. Converting sunlight to energy, these miniscule beings exhaled oxygen into the atmosphere. For a while, this gas was largely caught…


Will the end of nations come from the colonization of space? It may happen sooner than you think.

Space is no place to ask anyone for their passport. Image credit: NASA/SAIC/Pat Rawlings

At 3:17 pm EDT on July 17, 1975, in orbit above the Atlantic ocean, a pair of docking hatches were unlatched aboard a pair of mated spacecraft, opening the door to a new age. The Apollo/Soyuz mission was the first mission where the adversaries at the center of the Cold War joined together in the exploration of space.

In his 1984 State of the Union address, then-President Ronald Reagan announced the United States would build an all-American space station Freedom. Following a…

James Maynard

Writing about space since I was 10, still not Carl Sagan. Weekly video show, podcast, comics, more: www.thecosmiccompanion.net

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