Tag Archives: Astronomy

New study: model of 700 quintillion terrestrial exoplanets suggests Earth is special

The Circumstellar Habitable Zone, where liquid water could potentially exist
The Circumstellar Habitable Zone, where liquid water could potentially exist

This is from Scientific American. (H/T William)

Excerpt:

More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle on its head.

Astronomer Erik Zackrisson from Uppsala University and his colleagues created a cosmic compendium of all the terrestrial exoplanets likely to exist throughout the observable universe, based on the rocky worlds astronomers have found so far. In a powerful computer simulation, they first created their own mini universe containing models of the earliest galaxies. Then they unleashed the laws of physics—as close as scientists understand them—that describe how galaxies grow, how stars evolve and how planets come to be. Finally, they fast-forwarded through 13.8 billion years of cosmic history. Their results, published to the preprint server arXiv (pdf) and submitted to The Astrophysical Journal, provide a tantalizing trove of probable exoplanet statistics that helps astronomers understand our place in the universe.

Discover magazine, which is all in for Darwinism and aliens everywhere, says this about the study:

Zackrisson found that Earth appears to have been dealt a fairly lucky hand. In a galaxy like the Milky Way, for example, most of the planets Zackrisson’s model generated looked very different than Earth — they were larger, older and very unlikely to support life.

[…]Zackrisson’s work suggests an alternative to the commonly held assumption that planets similar to Earth must exist, based on the sheer number of planets out there.

[…]One of the most fundamental requirements for a planet to sustain life is to orbit in the “habitable zone” of a star — the “Goldilocks” region where the temperature is just right and liquid water can exist. Astronomers have, to this point, discovered around 30 exoplanets in the habitable zones of stars. Simply extrapolating that figure based on the known number of stars suggests that there should be about 50 billion such planets in the Milky Way alone. Probability seems to dictate that Earth-twins are out there somewhere.

But according to Zackrisson, most planets in the universe shouldn’t look like Earth. His model indicates that Earth’s existence presents a mild statistical anomaly in the multiplicity of planets. Most of the worlds predicted by his model exist in galaxies larger than the Milky Way and orbit stars with different compositions — an important factor in determining a planet’s characteristics. His research indicates that, from a purely statistical standpoint, Earth perhaps shouldn’t exist.

Time for me to list out some of the things that are required for a galaxy, solar system and planet to support complex embodied life. Not just life as we know it, but life of any conceivable kind given these laws of physics.

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

It’s not easy to make a planet that supports life. For those who are interested in reaching out to God, he has left us an abundance of evidence for his existence – and his attention to detail.

Related posts

Atheist gets her PhD in astronomy and astrophysics and finds evidence for God

Christianity and the progress of science
Christianity and the progress of science

Christian apologist Terrell Clemmons tweeted this testimony by Sarah Salviander, a research scientist in astronomy and astrophysics at the prestigious University of Texas at Austin.

Dr. Salviander writes:

I was born in the U.S., but grew up in Canada. My parents were socialists and political activists who thought British Columbia would be a better place for us to live, since it had the only socialist government in North America at the time. My parents were also atheists, though they eschewed that label in favor of “agnostic.” They were kind, loving, and moral, but religion played no part in my life. Instead, my childhood revolved around education, particularly science. I remember how important it was to my parents that my brother and I did well in school.

I just want to point out that I hope that all you Christian parents are taking seriously the obligation to make your kids do well in school, because even if they start out as atheists when they are young, they can still find their way back to God through study, as Sarah did.

She had a bad start, that’s for sure:

I grew up in the 1970s and 1980s, a time when science fiction was enjoying a renaissance, thanks largely to the popularity of Star Wars. I remember how fascinated I was by the original Star Wars trilogy. It had almost nothing to do with science—it’s more properly characterized as space opera—but it got me thinking about space in a big way. I also loved the original Star Trek, which was more science fiction. The stoic and logical character of Mr. Spock was particularly appealing to me. Popular science was also experiencing a renaissance at that time, which had a lot to do with Carl Sagan’s television show, Cosmos, which I adored. The combination of these influences led to such an intense wonder about outer space and the universe, that by the time I was nine years old I knew I would be a space scientist someday.

Canada was already post-Christian by the 1970s, so I grew up with no religion. In retrospect, it’s amazing that for the first 25 years of my life, I met only three people who identified as Christian. My view of Christianity was negative from an early age, and by the time I was in my twenties, I was actively hostile toward Christianity. Looking back, I realized a lot of this was the unconscious absorption of the general hostility toward Christianity that is common in places like Canada and Europe; my hostility certainly wasn’t based on actually knowing anything about Christianity. I had come to believe that Christianity made people weak and foolish; I thought it was philosophically trivial. I was ignorant not only of the Bible, but also of the deep philosophy of Christianity and the scientific discoveries that shed new light on the origins of the universe and life on Earth.

She documents a phase of following Ayn Rand and embracing “Objectivism”, but eventually she rejects it for failing to answer the big questions of life.

More:

I began to focus all of my energy on my studies, and became very dedicated to my physics and math courses. I joined campus clubs, started to make friends, and, for the first time in my life, I was meeting Christians. They weren’t like Objectivists—they were joyous and content. And, they were smart, too. I was astonished to find that my physics professors, whom I admired, were Christian. Their personal example began to have an influence on me, and I found myself growing less hostile to Christianity.

This is why I think it is so important for Christian parents to raise their children to get advanced degrees… either to become professors themselves, or to finance others (e.g. – our own children) to do advanced degrees. It is so important for university students to see Christian professors on campus. And failing that, it’s important that we bring Christian speakers in to debate non-Christian speakers on the important issues. This will not happen unless we recognize how important it is, and then make a plan to achieve it.

More:

I had joined a group in the Center for Astrophysics and Space Sciences (CASS) that was researching evidence for the big bang. The cosmic background radiation—the leftover radiation from the big bang—provides the strongest evidence for the theory, but cosmologists need other, independent lines of evidence to confirm it. My group was studying deuterium abundances in the early universe. Deuterium is an isotope of hydrogen, and its abundance in the early universe is sensitive to the amount of ordinary mass contained in the entire universe. Believe it or not, this one measurement tells us whether the big bang model is correct.

If anyone is interested in how this works, I’ll describe it, but for now I’ll spare you the gruesome details. Suffice it to say that an amazing convergence of physical properties is necessary in order to study deuterium abundances in the early universe, and yet this convergence is exactly what we get. I remember being astounded by this, blown away, completely and utterly awed. It seemed incredible to me that there was a way to find the answer to this question we had about the universe. In fact, it seems that every question we have about the universe is answerable. There’s no reason it has to be this way, and it made me think of Einstein’s observation that the most incomprehensible thing about the world is that it’s comprehensible. I started to sense an underlying order to the universe. Without knowing it, I was awakening to what Psalm 19 tells us so clearly, “The heavens declare the glory of God; the skies proclaim the work of his hands.”

That summer, I’d picked up a copy of The Count of Monte Cristo by Alexandre Dumas and was reading it in my off hours. Previous to this, I’d only known it as an exciting story of revenge, since that’s what the countless movie and TV adaptations always focused on. But it’s more than just a revenge story, it’s a philosophically deep examination of forgiveness and God’s role in giving justice. I was surprised by this, and was starting to realize that the concept of God and religion was not as philosophically trivial as I had thought.

All of this culminated one day, as I was walking across that beautiful La Jolla campus. I stopped in my tracks when it hit me—I believed in God! I was so happy; it was like a weight had been lifted from my heart. I realized that most of the pain I’d experienced in my life was of my own making, but that God had used it to make me wiser and more compassionate. It was a great relief to discover that there was a reason for suffering, and that it was because God was loving and just. God could not be perfectly just unless I—just like everyone else—was made to suffer for the bad things I’d done.

The Count of Monte Cristo is one of my favorite, favorite books as well, and had the same impact on me as it did on her.

OK, that’s enough for this post. Go read the rest, and please share it. This woman is an expert Christian apologist and her life will have an influence. Are you going to be like her? Will you mentor others to be like her? Will you marry someone like her? Will you raise children who are like her (which is my plan)? We really need everyone to pull their weight now, because everywhere you look, the truth of Christianity is under attack.

Positive arguments for Christian theism

The connection between our moon, plate tectonics and habitability

Christianity and the progress of science
Christianity and the progress of science

I found an interview with Peter Ward (atheist) and Donald Brownlee (agnostic) discussing astrobiology in Forbes magazine. They were asked about how important plate tectonics are for a planet to be able to support complex life.

Excerpt:

Astrobiologists often cite the sheer numbers of stars and galaxies as evidence that complex life elsewhere must surely have evolved somewhere. But is probability enough?

Without a moon, we don’t have any idea of how commonly a planet could have the long-term stability needed for complex life. Until we “get” that, going to the sheer numbers argument is useless. Without that moon-forming collision, we wouldn’t have plate tectonics. Without plate tectonics, we might have microbes but we’d never get to animals.

What about the rarity of earth’s crustal dichotomy of oceans and continents?

If you can’t make granite, you’re not going to have continents. But granite formation is a consequence of our moon-forming collision. That scrambled the entire density of our crust. Mars doesn’t have granite; all it’s got is this volcanic basalt. To build granite you need a planetary subduction [or plate tectonic] process.

In triggering complex life, how important were plate tectonics’ role in the continual recycling of earth’s atmosphere?

It’s this recycling that allows for a very rich planetary atmosphere with an extended life. Photosynthesis gets you oxygen, but how do you get enough photosynthesis to get oxygen at 10 to 20 percent? You’ve got to have a shoreline next to a rich sea with rocks eroding into it in order to provide the nitrogen and phosphates for [plant] photosynthesis.

This article from Astrobiology explains more about the importance of plate tectonics.

Excerpt:

Plate tectonics is the process of continents on the Earth drifting and colliding, rock grinding and scraping, mountain ranges being formed, and earthquakes tearing land apart. It makes our world dynamic and ever-changing. But should it factor into our search for life elsewhere in the universe?

Tilman Spohn believes so. As director of the German Space Research Centre Institute of Planetary Research, and chairman of ESA’s scientific advisory committee, he studies worlds beyond our Earth. When looking into the relationship between habitability and plate tectonics, some fascinating possibilities emerged.

It is thought that the best places to search for life in the Universe are on planets situated in “habitable zones” around other stars. These are orbital paths where the temperature is suitable for liquid water; not so close to the star that it boils away, and not so far that it freezes. Spohn believes that this view may be outdated. He elaborates, “you could have habitats outside those, for instance in the oceans beneath ice covers on the Galilean satellites, like Europa. But not every icy satellite would be habitable. Take Ganymede, where the ocean is trapped between two layers of ice. You are missing a fresh supply of nutrition and energy.”

So planets and moons that lie beyond habitable zones could host life, so long as the habitat, such as an ocean, is not isolated. It needs access to the key ingredients of life, including hydrogen, oxygen, nitrogen, phosphorous and sulphur. These elements support the basic chemistry of life as we know it, and the material, Spohn argues, must be regularly replenished. Nature’s method of achieving this on the Earth appears to be plate tectonics.

Spohn found that the further he delved into the issue, the more important plate tectonics seemed to be for life. For example, it is believed that life developed by moving from the ocean to the kind of strong and stable rock formations that are the result of tectonic action. Plate tectonics is also involved in the generation of a magnetic field by convection of Earth’s partially molten core. This magnetic field protects life on Earth by deflecting the solar wind. Not only would an unimpeded solar wind erode our planet’s atmosphere, but it also carries highly energetic particles that could damage DNA.

Another factor is the recycling of carbon, which is needed to stabilize the temperature here on Earth. Spohn explains, “plate tectonics is known to recycle carbon that is washed out of the atmosphere and digested by bacteria in the soil into the interior of the planet from where it can be outcast through volcanic activity. Now, if you have a planet without plate tectonics, you may have parts of this cycle, but it is broken because you do not have the recycling link.”

It has also been speculated that the lack of tectonic action on Venus contributed to its runaway greenhouse effect, which resulted in the immense temperatures it has today.

Most planets don’t have a moon as massive as ours is, and the collision that formed the moon is very fine-tuned for life. This is just one of the many factors that needs to be present in order to have a planet that supports complex, carbon-based life.

If you want to learn more about this data, I recommend watching “The Privileged Planet” DVD, and someone posted it on YouTube:

If you haven’t seen it, and have 90 minutes, this is time well-spent.

New study: survey of 700 quintillion terrestrial exoplanets suggests Earth is special

The Circumstellar Habitable Zone, where liquid water could potentially exist
The Circumstellar Habitable Zone, where liquid water could potentially exist

This is from Scientific American. (H/T William)

Excerpt:

More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle on its head.

Astronomer Erik Zackrisson from Uppsala University and his colleagues created a cosmic compendium of all the terrestrial exoplanets likely to exist throughout the observable universe, based on the rocky worlds astronomers have found so far. In a powerful computer simulation, they first created their own mini universe containing models of the earliest galaxies. Then they unleashed the laws of physics—as close as scientists understand them—that describe how galaxies grow, how stars evolve and how planets come to be. Finally, they fast-forwarded through 13.8 billion years of cosmic history. Their results, published to the preprint server arXiv (pdf) and submitted to The Astrophysical Journal, provide a tantalizing trove of probable exoplanet statistics that helps astronomers understand our place in the universe.

Discover magazine, which is all in for Darwinism and aliens everywhere, says this about the study:

Zackrisson found that Earth appears to have been dealt a fairly lucky hand. In a galaxy like the Milky Way, for example, most of the planets Zackrisson’s model generated looked very different than Earth — they were larger, older and very unlikely to support life.

[…]Zackrisson’s work suggests an alternative to the commonly held assumption that planets similar to Earth must exist, based on the sheer number of planets out there.

[…]One of the most fundamental requirements for a planet to sustain life is to orbit in the “habitable zone” of a star — the “Goldilocks” region where the temperature is just right and liquid water can exist. Astronomers have, to this point, discovered around 30 exoplanets in the habitable zones of stars. Simply extrapolating that figure based on the known number of stars suggests that there should be about 50 billion such planets in the Milky Way alone. Probability seems to dictate that Earth-twins are out there somewhere.

But according to Zackrisson, most planets in the universe shouldn’t look like Earth. His model indicates that Earth’s existence presents a mild statistical anomaly in the multiplicity of planets. Most of the worlds predicted by his model exist in galaxies larger than the Milky Way and orbit stars with different compositions — an important factor in determining a planet’s characteristics. His research indicates that, from a purely statistical standpoint, Earth perhaps shouldn’t exist.

Time for me to list out some of the things that are required for a galaxy, solar system and planet to support complex embodied life. Not just life as we know it, but life of any conceivable kind given these laws of physics.

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

It’s not easy to make a planet that supports life. For those who are interested in reaching out to God, he has left us an abundance of evidence for his existence – and his attention to detail.

Related posts

Atheist gets her PhD in astronomy and astrophysics and finds evidence for God

Christianity and the progress of science
Christianity and the progress of science

Christian apologist Terrell Clemmons tweeted this testimony by Sarah Salviander, a research scientist in astronomy and astrophysics at the prestigious University of Texas at Austin.

Dr. Salviander writes:

I was born in the U.S., but grew up in Canada. My parents were socialists and political activists who thought British Columbia would be a better place for us to live, since it had the only socialist government in North America at the time. My parents were also atheists, though they eschewed that label in favor of “agnostic.” They were kind, loving, and moral, but religion played no part in my life. Instead, my childhood revolved around education, particularly science. I remember how important it was to my parents that my brother and I did well in school.

I just want to point out that I hope that all you Christian parents are taking seriously the obligation to make your kids do well in school, because even if they start out as atheists when they are young, they can still find their way back to God through study, as Sarah did.

She had a bad start, that’s for sure:

I grew up in the 1970s and 1980s, a time when science fiction was enjoying a renaissance, thanks largely to the popularity of Star Wars. I remember how fascinated I was by the original Star Wars trilogy. It had almost nothing to do with science—it’s more properly characterized as space opera—but it got me thinking about space in a big way. I also loved the original Star Trek, which was more science fiction. The stoic and logical character of Mr. Spock was particularly appealing to me. Popular science was also experiencing a renaissance at that time, which had a lot to do with Carl Sagan’s television show, Cosmos, which I adored. The combination of these influences led to such an intense wonder about outer space and the universe, that by the time I was nine years old I knew I would be a space scientist someday.

Canada was already post-Christian by the 1970s, so I grew up with no religion. In retrospect, it’s amazing that for the first 25 years of my life, I met only three people who identified as Christian. My view of Christianity was negative from an early age, and by the time I was in my twenties, I was actively hostile toward Christianity. Looking back, I realized a lot of this was the unconscious absorption of the general hostility toward Christianity that is common in places like Canada and Europe; my hostility certainly wasn’t based on actually knowing anything about Christianity. I had come to believe that Christianity made people weak and foolish; I thought it was philosophically trivial. I was ignorant not only of the Bible, but also of the deep philosophy of Christianity and the scientific discoveries that shed new light on the origins of the universe and life on Earth.

She documents a phase of following Ayn Rand and embracing “Objectivism”, but eventually she rejects it for failing to answer the big questions of life.

More:

I began to focus all of my energy on my studies, and became very dedicated to my physics and math courses. I joined campus clubs, started to make friends, and, for the first time in my life, I was meeting Christians. They weren’t like Objectivists—they were joyous and content. And, they were smart, too. I was astonished to find that my physics professors, whom I admired, were Christian. Their personal example began to have an influence on me, and I found myself growing less hostile to Christianity.

This is why I think it is so important for Christian parents to raise their children to get advanced degrees… either to become professors themselves, or to finance others (e.g. – our own children) to do advanced degrees. It is so important for university students to see Christian professors on campus. And failing that, it’s important that we bring Christian speakers in to debate non-Christian speakers on the important issues. This will not happen unless we recognize how important it is, and then make a plan to achieve it.

More:

I had joined a group in the Center for Astrophysics and Space Sciences (CASS) that was researching evidence for the big bang. The cosmic background radiation—the leftover radiation from the big bang—provides the strongest evidence for the theory, but cosmologists need other, independent lines of evidence to confirm it. My group was studying deuterium abundances in the early universe. Deuterium is an isotope of hydrogen, and its abundance in the early universe is sensitive to the amount of ordinary mass contained in the entire universe. Believe it or not, this one measurement tells us whether the big bang model is correct.

If anyone is interested in how this works, I’ll describe it, but for now I’ll spare you the gruesome details. Suffice it to say that an amazing convergence of physical properties is necessary in order to study deuterium abundances in the early universe, and yet this convergence is exactly what we get. I remember being astounded by this, blown away, completely and utterly awed. It seemed incredible to me that there was a way to find the answer to this question we had about the universe. In fact, it seems that every question we have about the universe is answerable. There’s no reason it has to be this way, and it made me think of Einstein’s observation that the most incomprehensible thing about the world is that it’s comprehensible. I started to sense an underlying order to the universe. Without knowing it, I was awakening to what Psalm 19 tells us so clearly, “The heavens declare the glory of God; the skies proclaim the work of his hands.”

That summer, I’d picked up a copy of The Count of Monte Cristo by Alexandre Dumas and was reading it in my off hours. Previous to this, I’d only known it as an exciting story of revenge, since that’s what the countless movie and TV adaptations always focused on. But it’s more than just a revenge story, it’s a philosophically deep examination of forgiveness and God’s role in giving justice. I was surprised by this, and was starting to realize that the concept of God and religion was not as philosophically trivial as I had thought.

All of this culminated one day, as I was walking across that beautiful La Jolla campus. I stopped in my tracks when it hit me—I believed in God! I was so happy; it was like a weight had been lifted from my heart. I realized that most of the pain I’d experienced in my life was of my own making, but that God had used it to make me wiser and more compassionate. It was a great relief to discover that there was a reason for suffering, and that it was because God was loving and just. God could not be perfectly just unless I—just like everyone else—was made to suffer for the bad things I’d done.

The Count of Monte Cristo is one of my favorite, favorite books as well, and had the same impact on me as it did on her.

OK, that’s enough for this post. Go read the rest, and please share it. This woman is an expert Christian apologist and her life will have an influence. Are you going to be like her? Will you mentor others to be like her? Will you marry someone like her? Will you raise children who are like her (which is my plan)? We really need everyone to pull their weight now, because everywhere you look, the truth of Christianity is under attack.

Positive arguments for Christian theism