Tag: astronomy

Episode 109 of Stories from Space is Live!

Episode 109 of Stories from Space is Live!

In this latest episode, I discuss the Standard Model of Cosmology, how scientists arrived at it, and how recent discoveries are causing some to question whether or not it is correct. To break it down, it is known as the Lambda Cold Dark Matter (ΛCDM) model, which basically combines the following theories.

  • The Big Bang: The theory that the Universe expanded from an initial state in which all matter was in hot, dense state (c’mon, you know the tune!) Evidence for this theory includes the Cosmic Microwave Background (CMB), the abundance of light elements (hydrogen, helium, etc.), the large-scale structure of the Universe, and cosmic expansion (see below).
  • Special Relativity: Einstein’s famous theory (E=mc2) that asserts that matter and energy are equivalent and how space and time are part of a four-dimensional framework in which the speed of light is constant and cannot be exceeded.
  • General Relativity: The extended generalized version of Einstein’s famous theory, which asserts that mass alters the curvature of spacetime.
  • Dark Matter: The theory that the majority of matter in the Universe is made up of a mysterious mass that doesn’t interact with normal matter in visible light.
  • Cosmological Constant: Also known as the Hubble-Lemaitre Constant (colloquially referred to as “Dark Energy”), wherein 68% of the cosmos is made up of energy that counteracts the force of gravity.

Over the past 120 years, these theories have come together to create the ΛCDM model of the Universe. For decades, scientists have been hoping to get a look at the very early Universe (less than 1 billion years after the Big Bang) to test this theory. When Webb finally provided the first observations of this period in cosmic history, what astronomers saw challenged many of the assumptions inherent in this model. Check out the episode below to learn more…

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Episode 90 of Stories from Space is now Live!

Episode 90 of Stories from Space is now Live!

This week’s episode asks the question, “Are Red Dwarf Star Systems Habitable?” Red dwarf stars, also known as M-type stars, are pretty controversial. For starters, they are the most common type of star in the Universe, accounting for 75% of stars in our galaxy alone. In addition, red dwarfs seem particularly good at producing rocky planets that orbit within their habitable zones (HZs). In fact, of the 31 potentially habitable exoplanets located within a 50-light-year radius of our Solar System, 29 are located within red dwarf star systems.

However, there are also downsides. For starters, red dwarf suns are variable and prone to flare-ups. While the most powerful are emitted from the poles and are unlikely to affect orbiting exoplanets, the fact that these exoplanets are tidally locked with their stars (where one side constantly faces toward the star) means they would still be bombarded by radiation. But then again, there’s research suggesting this radiation could be essential for life to develop. Like I said, it’s a controversial issue, and we simply don’t know… yet!

Follow the links below to learn more:

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Episode 76 of SfS – Where is Everybody? The Waterworlds Hypothesis – is now Live!

Episode 76 of SfS – Where is Everybody? The Waterworlds Hypothesis – is now Live!

In this week’s episode, I returned to the ongoing segment about Fermi’s Paradox (“Where is Everybody?”), which focuses on another proposed resolution known as the Waterworlds Hypothesis. Basically, this theory takes the traditional “follow the water” and asks the question: could rocky exoplanets orbiting distant stars have too much water to be habitable? This theory is based on the current exoplanet census, which indicates that there are many rocky planets several times the size and mass of Earth but with lower densities.

This suggests that volatile elements (such as water) make up a significant fraction of these planets’ mass. If true, this would indicate that these rocky worlds are completely covered in deep oceans. If they don’t possess a dense atmosphere, they would likely consist of an icy outer shell, an interior ocean, and a rocky and metallic core. This is similar to what we see in our own Solar System, where many satellites orbiting the gas giants are thought to have interior oceans beneath their icy crusts.

Like Jupiter’s moon Ganymede, the depths and pressure conditions in these oceans would lead to the formation of an ice layer between the ocean and the rocky, metallic core. If true, this would mean that the very things that could support the emergence of life – hydrothermal activity at the core-mantle boundary – would be missing. Based on the fossil record, this is how scientists believe life emerged on Earth (around deep-sea vents) and what is believed to be happening inside Jupiter’s moon Europa.

However, this does not mean that all Waterworlds can’t support life. In fact, there’s also research that indicates that planets lacking continents and plate tectonics could still support life, perhaps in the form of “space whales“! Still, using Earth as a template, the lack of continents and land masses could mean that evolution would be restricted, and tool-using species may not emerge. So it begs the question: If rocky planets with too much water are the norm, and Earth is an outlier, could this be why we haven’t heard from any extraterrestrial civilizations yet?

Check out the links below to learn more!

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Episode 75 of SfS – “The Grand Tour: The Legacy of the Voyager Probes” – is Now Live!

Episode 75 of SfS – “The Grand Tour: The Legacy of the Voyager Probes” – is Now Live!

This week’s episode was dedicated to the Voyager 1 and 2 probes, and it was a long time in the making! Launching in 1977, these two probes explored the outer Solar System and accomplished many firsts. This included obtaining the first evidence that Jupiter’s moon, Europa, could have an interior ocean. They also examined Saturn’s rings and got the first close-up look at Saturn’s moon, Titan, and its dense hydrocarbon atmosphere, which led to speculation that liquid methane lakes might exist on its surface.

The Voyager Golden Record. Credit: NASA

While Voyager 2 became the first mission to visit Uranus and Neptune, a feat which has not yet been repeated, Voyager 1 conducted the Pale Blue Dot campaign, obtaining the best-known image of Earth. And, of course, they both carry the Voyager Golden Records, which contain sounds and images of Earth and simple diagrams indicating the location of Earth and the Solar System. These records could be the first interstellar message sent by humanity to another civilization or a time capsule for future generations of humans.

The two probes are now in interstellar space, where they continue to operate and return data on the interstellar medium. Regardless of how much time has passed, the Voyager probes will forever remain iconic and their accomplishments legendary. Check out the episode below:

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Episode 72 of SfS – The Gift of Gravitational Lensing (with Dr. Slava Turyshev) – is now Live!

Episode 72 of SfS – The Gift of Gravitational Lensing (with Dr. Slava Turyshev) – is now Live!

This week, my guest was Russian-American physicist Dr. Slava Turyshev, a Senior Research Scientist, Technologist, and Project Manager at NASA’s Jet Propulsion Laboratory. Dr. Turyshev has spent years studying the phenomenon known as gravitational lenses, a consequence of General Relativity, where massive objects amplify and alter the path of light from more distant objects. Astronomers have used this phenomenon to study objects that would otherwise be very difficult to see, including some of the farthest galaxies in the Universe.

In recent years, Turyshev has published numerous studies advocating for a space telescope that would travel to the focal region of our Sun’s Gravitational Lens (SGL). Once there, it could conduct the most detailed astronomical studies ever, which includes taking extremely high-resolution images of exoplanets. In fact, astronomers predict that an SGL telescope could take pictures of exoplanets that would have the same resolution as images of Earth taken from high orbit (see below).

Toth H. & Turyshev, S.G.

Not only that, but Turyshev predicts that gravitational lenses could also be used for communications from one star system to another. These ideas could lead to an “interstellar internet,” which could be how advanced civilizations keep in touch in our galaxy. Perhaps this is why we haven’t found evidence of any extraterrestrial civilizations: they are routing all their calls through a gravitational lens network, and we aren’t hooked up to it yet!

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Episode 70 of SfS – The Crisis in Cosmology: What is the Hubble Tension? – is now live!

Episode 70 of SfS – The Crisis in Cosmology: What is the Hubble Tension? – is now live!

This week’s episode deals with a rather pressing matter for astronomers and cosmologists. Shortly after Einstein revealed his Theory of General Relativity in 1916, scientists began pondering how it predicted that the Universe was either expanding or contracting. The debate was settled when Georges Lemaitre and Edwin Hubble confirmed that it was expanding (in 1927 and 1929, respectively). In honor of their accomplishments, the rate at which the cosmos is expanding was named the “Hubble-Lemaitre Constant” (or more commonly, the “Hubble Constant”).

As the field of astronomy expanded and telescopes improved, scientists were able to make distance measurements for objects located farther and farther away. However, these observations were restricted to objects within 4 billion light-years due to the way Earth’s atmosphere distorts light. Depending on the distances involved, astronomers relied on different methods, which came to be known as the “Cosmic Distance Ladder.” In addition to determining the age and size of the Universe, these measurements allowed astronomers to refine their estimates of the Constant.

The Hubble Space Telescope revolutionized astronomy by gradually pushing the boundaries of the “observable Universe” to less than 1 billion years after the Big Bang (13 billion light years!) That’s when scientists noticed some discrepancies. Not only did they learn that the rate of expansion had accelerated over time, but distance measurements to objects located 13 billion light-years away (the earliest galaxies) yielded different values than local measurements. This came to be known as the “Hubble Tension” or the “Crisis in Cosmology.”

While it was hoped that the James Webb Space Telescope would resolve this crisis, its observations have only confirmed that Hubble was right on the money! The crisis endures, and scientists are seeking answers. Is Einstein’s Theory of General Relativity, which is foundational to our cosmological models, wrong? Or are there additional physics/forces at work that we haven’t yet accounted for? Once we know that, we’ll know how just about everything in the Universe works!

Check out the episode below.

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Episode 64 of SfS – “The Europa Clipper Mission: A Conversation with Dr. Steve Vance” – is now Live!

Episode 64 of SfS – “The Europa Clipper Mission: A Conversation with Dr. Steve Vance” – is now Live!

In this week’s episode, I had the good fortune to sit down with NASA scientist and astrobiologist Dr. Steve Vance so we could talk about NASA’s upcoming Europa Clipper mission. This mission, which was decades in the making, will launch this coming October, sending a spacecraft to Jupiter to explore its satellite Europa. Ever since the Voyager probes flew past Jupiter and its moons in 1979, scientists have speculated that there might be an ocean beneath this moon’s icy crust.

The mission will arrive around Jupiter by 2030, where it will begin making flybys of Europa and studying its surface with an advanced suite of instruments. Among its objectives are the characterization of Europa’s surface, investigating surface plume activity, and determining the existence and chemistry of its interior ocean. Another major objective is the search for potential biosignatures, indications that this interior ocean may harbor life!

We got into all of that and a number of other things – including Europa’s depiction in Arthur C. Clarke’s famed Space Odyssey series. As Vance told me during our chat, Clarke played a role in the mission planning, and (contrary to the monoliths told humanity in his stories) we do have permission to “attempt a landing there.”

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Episode 62 of Stories from Space – Living on Saturn’s Moons – is now Live!

Episode 62 of Stories from Space – Living on Saturn’s Moons – is now Live!

This week, as part of my continuing series, The Great Migration: Settling the Solar System, we took a look at Saturn and its system of moons. With the right technology, know-how, and the right kind of advancements, humanity could someday settle on Saturn’s largest satellites! Much like Jupiter’s icy moons, these satellites are icy bodies, many of which have interior oceans that could harbor life!

Another thing they have in common is their abundant resources, which include water, volatile elements, silicate minerals, metals, hydrogen, and helium-3. But whereas Jupiter has three satellites that could be settled (Europa, Ganymede, and Callisto), Saturn has six – Titan, Rhea, Tethys, Dione, Enceladus, and Mimas. And unlike Jupiter, Saturn has a mild radiation environment that makes harvesting hydrogen and helium-3 from its atmosphere easier and its larger satellites more habitable.

As famed aerospace engineer, science communicator, and space exploration advocate Robert Zubrin has said (many times), Saturn could become the “Persian Gulf of the Solar System,” providing the fuel for nuclear propulsion and fusion reactors across the Solar System. Take a listen to learn more!

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Sharing the gift of astronomy: The Asif Astronomy Club

Sharing the gift of astronomy: The Asif Astronomy Club

The field of astronomy has become increasingly accessible in recent years, thanks to the growth of online astronomical communities, citizen astronomers, and open-access databases. This growth has paralleled the creation of next-generation telescopes, instruments, and data-sharing methods allowing greater collaboration between observatories and the general public. 

Unfortunately, despite these positive developments, there are still millions of people around the world who do not have access to astronomy and would like to. This problem mirrors disparities that exist worldwide, where many communities experience lower education, health, and economic outcomes. These exist not only between nations but between urban and rural communities, where a lack of infrastructure can translate into a lack of access. 

To address this disparity, a growing number of organizations are looking to bring STEM education to traditionally underserved communities. This includes the Asif Astronomy Club, which has engaged with students in remote communities in Morocco’s Atlas Mountains since 2020.

Through its efforts, the club and its leader (El-Mehdi Essaidi) are spreading the culture of astronomy and its central message: “Space is for everyone.” They are also helping to inspire the next generation of scientists and change-makers to reach for the stars (literally and figuratively).

Continue reading “Sharing the gift of astronomy: The Asif Astronomy Club” →

Speaking Engagement: Nanaimo Astronomy Society, September 22nd

Speaking Engagement: Nanaimo Astronomy Society, September 22nd

An interesting development happened once I got back from Europe. Apparently, there are people on the island that are very interested in astronomy, people who were surprised to learn that I also lived here. They are the Nanaimo Astronomy Society, a group of amateur astronomers and stargazers located in the town of Nanaimo – which is in the central Vancouver Island area, about a two hours drive from where I live.

As they explained to me, they have been following my writing at Universe Today for awhile, but didn’t realize I lived locally. Once they realized that, they asked if I would be willing to speak at their upcoming meeting.  Needless to say I was flattered, especially when you consider that most of the UT team lives on Vancouver Island. I could only assume they didn’t know about the others. I mean, when you’re a chapter of the Beatles Fan Club, and the band lives in the same region, you don’t exactly invite Ringo to come talk, right?

Anyway, the topic will be “Colonizing Mars”, which will address all the current plans by federal space agencies, private corporations, and crowdfunded organizations to explore, settle and transform the Red Planet. Naturally, I want to throw in a bit about terraforming, since that’s kind of my thing these days!