The working definition of a galaxy is a huge collection of stars whose motions we do not understand. It was therefore a surprise when a galaxy was recently discovered whose motions we do understand. This new type of galaxy is called an Ultra Diffuse Galaxy (UDG).
Astronomers usually ascertain the mass of a galaxy by observing the speeds of the stars and star clusters that orbit it. There is a straightforward formula which relates the speed of the stars with the mass of the galaxy.
The Sun and the Earth, for example, move at a speed of 475,000 miles per hour about the center of the Milky Way. From this fact we work out that the mass of the Galaxy is about 300 billion times the mass of the Sun. But what is this mass anyway?
Well, embarrassingly we cannot even see the majority of the mass in the Milky Way. Put another way, there is some form of material, called dark matter, which dictates how the Sun and another 300 billion stars will move yet which we cannot identify. Now we can see why the working definition of a galaxy is a collection of stars whose motions we do not understand.
An interesting new chapter arises with the discovery of the UDG. Like a house built out of glass so that you can see all its contents, this galaxy also leaves no mysteries about what is inside of it. By studying the speeds of old groups of stars called globular clusters we measure a mass that is exactly what we expect if we just sum up the mass of its huge collection stars.
To add to this developing story, globular clusters are usually associated with massive, dark-matter dominated galaxies. We are driven to ask a different question: why do we understand the motion of the stars of an UDG? Where did its dark matter go, or are there some galaxies for which the dark matter was never there?
In the weeks to come, I will offer brief reflections on two projects to bring science into the seminary classroom. Seminary, for those who do not know, is the name given to the school that future priests attend. The name "seminary" means "a seedbed." Therefore, a seminary is not only a school of academics, but it is an environment of formation in which the soil of our hearts is tilled to receive the seeds of faith.
As I have written about in the past, one of the deficiencies I experienced in my seminary education was instruction on questions of faith and science. Whether it be writing for The Catholic Astronomer, participating in wonderful experiences like the Faith and Astronomy Workshop, or being a guest on Slooh, God has allowed me to embark on a unique "independent study" that has borne a great deal of fruit to help address this deficiency.
Below are two videos, one from the AAAS and the other from Exploring Science in Seminaries. The first video is a brief exploration of what the desired pastoral outcomes were for the conference on Exploring Science in Seminaries. The second is a video on one of the more powerful connections between faith and science - Awe and Wonder. Enjoy these videos and may they help all of us, clergy and non-clergy, better understand the relationship between faith and science.
“Scientifically untenable and theologically heretical.” That is how a committee of consultants for the Roman Inquisition assessed the heliocentric theory four hundred years ago today, on February 24, 1616—or, that is how the historian Maurice Finocchiaro paraphrases their assessment. Well, there is an interesting story about exactly what it was the consultants said.
Read various secondary sources and you will find differing translations of the consultants’ report, which was in Latin. For example, Finocchiaro translates the part of the report in which the consultants assess the heliocentric proposition that the sun is the immobile center of the world as
All said that this proposition is foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture, according to the literal meaning of the words and according to the common interpretation and understanding of the Holy Fathers and the doctors of theology.
But another highly regarded historian, Albert van Helden, translates this as
All declared the said proposition to be foolish and absurd in philosophy and formally heretical, because it expressly contradicts the doctrine of the Holy Scripture in many passages, both in their literal meaning and according to the general interpretation of the Fathers and the Doctors of the Church.
The big difference here is the punctuation. “Foolish and absurd in philosophy, and formally heretical since it explicitly contradicts” means one thing, and “foolish and absurd in philosophy and formally heretical, since it explicitly contradicts” means something else. This could be something out of Eats, Shoots & Leaves. To borrow Finocchiaro’s words, the second phrasing “conveys the impression that biblical contradiction is being given as a reason for ascribing both philosophical-scientific falsehood and theological heresy.” Finocchiaro points this out while discussing how in the original document there is in fact a semicolon following “philosophy,” not just a comma.
Read various secondary sources that give the original Latin and, guess what? They differ on the punctuation of the Latin! Some agree with Finocchiaro regarding the semicolon. Others do not.
In science, we get data to answer a question. A while back I decided to get my own data. As part of some research I was working on, I wanted to see the original document, to determine if the semicolon was really there. But a published image of it seemed to be impossible to find. So I e-mailed the Vatican Secret Archives, where the original lives, and they sent me a digital copy for a small fee. And here it is:*
This statement was a pretty big event in the history of science, and so perhaps you expected, as did I, this document to look formal, clear, and imposing, as would befit an Important Proclamation. Instead it looks very ordinary, the script is not so clear, and the writer uses a lot of abbreviation. It looks less like an Important Proclamation than like hastily scrawled meeting notes. But Finocchiaro was right. There is a semi-colon after “philosophy.”
Thus the consultants’ assessment was this: heliocentrism is scientifically untenable; and, since it contradicts the literal sense of scripture, it is theologically heretical (I am borrowing Finocchiaro’s words again).
So why would it be so hard to figure out just what was said on February 24, 1616? Because the Inquisition issued no formal condemnation. The consultants’ report got filed away. Then seventeen years later the report was referred to in the Inquisition’s 1633 judgment against Galileo. That judgment was written in Italian. Then Giovanni Battista Riccioli included a Latin translation of the judgment in his 1651 Almagestum Novum. Riccioli’s translation is punctuated in a manner that does convey the impression that biblical contradiction is being given as a reason for ascribing both philosophical-scientific falsehood and theological heresy.
Riccioli’s version of the consultants’ statement reads “The sun to be in the center of the World, and fixed in place, is an absurd proposition, both false in Philosophy, and formally heretical; because it is expressly contrary to Sacred Scripture.”
Riccioli’s translation was widely referenced for two centuries, but it was a Latin translation of an Italian paraphrase of a Latin original. Translating it into English, for example, added a fourth layer of translation. The original statement itself was not published until the mid-19th century. But according to Finocchiaro Riccioli’s version was still influential even after that. I speculate that after a whole two centuries of Riccioli’s version being the standard, the tendency was to interpret the new information in light of the old.
And so, four hundred years after the Inquisition’s consultants made their assessment, you have to look carefully if you want to know exactly what it was that they said.
*For high-resolution color images of the original document, tables illustrating the various versions of the statement provided by secondary sources, and lots of references, see “The Inquisition's Semicolon: Punctuation, Translation, and Science in the 1616 Condemnation of the Copernican System”—arXiv:1402.6168.
We believe in things we cannot see – God, say, or Black Holes – because we observe their effects on the things that we can see. Still, there is a little bit of Doubting Thomas in all of us. It would certainly be nice to have a direct image of what a black hole actually looks like!
Diagram of the locations of the various telescopes who are networked to make the Event Horizon Telescope. Credit: ESO/O. Furtak - https://www.eso.org/public/images/ann17015a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=57580702
The Event Horizon Telescope (EHT) is designed to do just that. It isn’t one instrument, but a collection of radio telescopes spread around world, observing the same object at the same time. Using a technique called Very Long Baseline Interferometry (VLBI), which compares the very tiny differences between different telescopes’ signals, a high resolution picture emerges. The farther apart the telescopes are, the better the image’s resolution; the EHT telescopes span the width of Earth itself.
After nearly 25 years assembling the team of telescopes and refining the technique, this month the EHT began its first concerted observations of the black hole at the center of our galaxy. We can’t see the black hole itself, of course; light can’t escape from its massive gravity. But a black hole’s size and shape can be measured by the shadow it casts against the radiation emitted when material falls into the hole.
Brother Guy and Heino Falcke in December 2016 at Radoud University
Chair of the science council for the EHT is Heino Falke, an astronomer at Radboud University (where I spoke in December, 2016, at his invitation). I first met Heino in 1993 when we were students together at the Vatican Observatory’s Summer School (VOSS). This week I sent him an email to ask about the EHT.
“I first developed the idea in 1993, while I was at the VOSS,” he wrote me. His thesis advisor, Peter Biermann, was a VOSS lecturer; they eventually worked out how one could use VLBI to detect the shadow of a black hole. Subsequent visits to Arizona, including using the Sub Millimeter Telescope (next door to the Vatican’s telescope on Mt. Graham), ultimately led him to the EHT project.
Sub-millimeter radio waves are just right to resolve the shape of the black hole’s shadow. There is plenty of radiation emitted in these wavelengths from the “Event Horizon,” the last point where light can escape the black hole’s gravity. The black hole’s shadow should be visible against the scattering of these radio waves. And Earth is just big enough that comparing signals from opposite hemispheres can resolve the magnified shadow. (It helps that the shadow is magnified by the black hole’s gravity itself.) Heino pointed out, “those three effects are completely unrelated. So, that is truly fine tuning of the universe… Thank God!”
The goal of the experiment is to test if the shadow’s size and shape matches what General Relativity predicts: between 45 (if it is rotating rapidly) and 52 (non-rotating) micro-arc-seconds (about the size a DVD on the Moon would look to us on Earth). The shape of the shadow should tell us how fast it is spinning.
A parallel project hopes to measure pulsars in the Galactic Center. “That would help us to get even better combined constraints of the nature of space-time, like the quadrupole moment, which in General Relativity is uniquely determined by mass and spin,” Heino explained. Black holes don’t show these higher order details; as Heino puts it, “black holes are the simplest objects in the universe.” So far, only one observable pulsar has been found, but he remains hopeful.
Want to know more? “Ah, ja, also Ray Jayawardhana wrote this nice article in The Atlantic recently about the EHT and my work,” Heino told me. “We were at the same VOSS, of course.”
Guy Consolmagno SJ is the director of the Vatican Observatory.
Detection of Star Icarus (formally, MACS J1149 Lensed Star 1). Credit: NASA, ESA, and P. Kelly (University of Minnesota)
Using the Hubble Space Telescope and gravitational lensing, astronomers have set a new distance record for the farthest individual star ever seen: 9 billion light years! One of those astronomers includes Dr. Brenda Frye from the University of Arizona Department of Astronomy, and blogger for the Catholic Astronomer! Tucson News Now
What is Gravitational Lensing?
Massive objects in space have gravitational fields associated with them(1); the more massive the object, the stronger its gravitational field. Galaxies are massive objects with large gravitational fields - galaxy clusters even more so. Strong gravitational fields can bend light - much like the lens of a refracting telescope.
Bending light around a massive object from a distant source. The orange arrows show the apparent position of the background source. The white arrows show the path of the light from the true position of the source. Credit: Public Domain
If a distant galaxy is lined up just right with a galaxy cluster and the Earth, light from the distant galaxy will be bent and magnified by the gravity of the galaxy cluster. Astronomers have found numerous examples of this type of gravitational lensing - many examples appearing as smears or odd elliptical shapes.
An Einstein Ring. Credit: ESA/Hubble & NASA
Cosmic Snake. Credit: ESA/NASA
For the first time, astronomers have identified a magnified individual star in a distant galaxy. The star is named "MACS J1149+2223 Lensed Star 1" nicknamed Icarus- a blue supergiant about 9 billion light years distant. Previously, the most distant individual stars astronomers could identify were millions of light years away - this discovery has pushed that limit well past several billions of light years.
"This technique with its high magnification factors of 1000 or more may offer a viable route to detect not just distant stars, but also distant galaxies, or even the first galaxies. We will hope to develop this new technique in time for the launch of JWST in May, 2020." - Dr. Brenda Frye
The James Webb Space Telescope, now scheduled to launch in May of 2020, could potentially find many more examples of distant gravitationally lensed stars.
Artist's concept of the James Webb Space Telescope. Image credit: Northrop Grumman
(1): "In general relativity, the presence of matter (energy density) can curve spacetime, and the path of a light ray will be deflected as a result. This process is called gravitational lensing and in many cases can be described in analogy to the deflection of light by (e.g. glass) lenses in optics. Many useful results for cosmology have come out of using this property of matter and light." From: http://w.astro.berkeley.edu/~jcohn/lens.html
The southern predawn sky has been interesting to watch over the last several weeks; each morning, everything in the southern sky has moved slightly towards the west - except Mars. Mars continues its retrograde motion - causing it to move west but at a much slower pace. The distance between Mars and Saturn will continue to grow well into the summer.
A thin crescent Moon joins Venus is low in the western sky near sunset for the next couple days.
Venus and the Moon in the western sky shortly after sunset, Apr. 17, 2018. Credit: Stellarium / Bob Trembley.
The Moon Apr. 17-23, 2018 2018. Visualizations by Ernie Wright
The Moon is a waxing crescent visible in the western sky at dusk.The Moon will be at first quarter on April 23rd, making it a great observing target this weekend.
The Sun has been spot-free for 2 days. There is a coronal hole at the Sun's south pole, and a large oddly-shaped coronal hole along the equator. There is also a lot of coronal loop activity just north of the equatorial hole. SpaceWeather.com says: "G1-class geomagnetic storms and polar auroras are possible when the solar wind arrives on April 19-20. Sky watchers between 50o and 60o N latitude should also be alert for STEVE, an aurora-like phenomenon which tends to appear in that latitude range during springtime geomagnetic storms."
The solar wind speed is 294 km/sec, with a density of 3.0 protons/cm3.
The Sun's chromosphere had a large persistent prominence over the last couple days - see the 4:00 o'clock region in the video below.
Upcoming Earth-asteroid encounters:
Note the asteroid highlighted in red at the top of the list below - this one was a surprise to everyone! Asteroid 2018 GE3 flew by the Earth at half the distance to the Moon, only a day after it was discovered! Space.com has an article stating that the asteroid was 3.6 times the size of 1908 Tunguska impactor!
The Lyrids Meteor shower runs from April 16-25, peaking April 21-22. Best viewing time is after midnight. Meteors will appear to originate from the area shown in the image below.
Lyrids Meteor Shower Radiant. Credit: Stellarium
On Apr 16, 2018, the NASA All Sky Fireball Network reported 6 fireballs. That number will likely increase with the onset of the Lyrids meteor shower.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth.
The Solar System
This is the position of the planets in the solar system:
Position of the planets in the inner solar system, Apr. 17, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the solar system, Apr. 17, 2018 - alternate view. Credit: NASA Eyes on the Solar System / Bob Trembley.
I was playing with NASA's Eyes on the Solar System while writing this post, and turned on constellations for the first time. It's pretty cool to be able to point to the constellation Sagittarius and say that the New Horizons probe is there.
Position of the New Horizons spacecraft in Sagittarius, with constellations shown. Credit: NASA Eyes on the Solar System / Bob Trembley.
Continuing to play, I ended up at Neptune's tiny moon Nereid. Nereid has a highly elliptical orbit, and takes 360 (Earth) days to complete one orbit of Neptune. I wondered how Neptune would look from Nereid at farthest and closest approaches:
Nereid’s Orbit around Neptune. Credit: NASA Eyes on the Solar System / Bob Trembley.
Nereid at apoapsis – Aug. 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Nereid at periapsis – Feb. 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
A result was announced last week that the supermassive black hole at the center of our Galaxy has company in the form of 10,000 much smaller stellar mass black holes.
We think that supermassive black holes are situated in the centers of most galaxies. The one in Milky Way has a mass of about 3-4 million times the mass of the Sun. This "invisible" astronomical body assimilates any object that hits its surface or "event horizon," with the result being to grow its size. This is similar to how a fan of hamburgers and french fries "assimilates" that tasty fare in the form of a big tummy.
It is thought that there are a great many examples of the much smaller stellar mass black hole varieties, which are the ones formed by the explosions of massive stars. Or, at least it is thought that there _were_ many examples of this stellar black hole variety. That is before these unsuspecting small black holes got swallowed up by the supermassive black hole a long, long time ago.
In other words, stellar mass black holes near to the Galactic center should be rare. Instead, astronomers are finding 10,000 of them!
We do not know how long all those stellar mass black holes have been loitering around the Galactic center in such large numbers, or even if the result will hold up to the scrutiny of additional checks.
If true, then this will help us to understand the assimilation rates of black holes which produce waves in spacetime as predicted by Einstein. This result appeared in a National Public Radio announcement last week.
A woman receives ashes on Ash Wednesday at St. Francis of Assisi Church in New York March 5. Ash Wednesday marks the start of the penitential season of Lent, a time of reflection, prayer, fasting and charity before Easter. (CNS photo/Gregory A. Shemitz) (March 5, 2014)
The Lenten and Easter Seasons are of great significance in the Christian life. The call into the spiritual desert to embrace the practices of fasting, penance, and almsgiving are meant to transform the human heart to be more conformed to the love of Jesus Christ. When this purification has concluded, we are to embrace a celebratory disposition of heart as we remember Christ's resurrection and the empty tomb.
Central to these seasons is a rather unique understanding of time. We began Lent on Ash Wednesday, marked with the ash from burned palm branches as a reminder of our call to repentance (Repent, and return to the Gospel) and to embrace humility (Remember that you are dust and to dust you shall return). This starting point marks the beginning of a forty day journey, give or take a couple days based on when Easter falls, to focus intently on the themes of penance and purification.
The period of forty days and forty years are significant in the Bible. Whether it be the forty days of penance called for by Jonah to the city of Nineveh, the forty years that the Children of Israel wandered in the desert seeking the Promised Land, or the forty days that Jesus spent in the desert, the reference to this number implies an intentional time that is essential for preparing the soul for mission. It is a time of detachment from those things that bring death and attachment to those things that bring life.
Last weekend, we finished a rather intentional time of celebration we call the Octave of Easter. For those of you who are musicians, you know that an octave constitutes the eight notes of a musical scale. Therefore, the Octave of Easter is an eight day period in which each celebration of Mass is seen as having the same importance as Easter Sunday. In other words, it is an "Easter that never ends."
Astronomers love high places. This view of the Vatican Museums' open courtyard was taken from the Tower of the Winds, where the Vatican Observatory had its first offices in 1891.
As I have reflected on in the past, times like the forty days of Lent and the eight days of the Octave of Easter constitute an understanding of time we call Kairos or intentional time that has a kind of timeless quality. Chronos is more of the day to day passing of time in the mundane sense. What I always find of interest is how this commingling of Kairos and Chronos points us to a fluid sense of time in contrast to the precise sense of time that is the obsession of modern society.
A while back, I had the privilege of being interviewed by Bob Berman, author for Astronomy Magazine and astronomer with Slooh.com. In the interview, Bob was speaking with me about time and how the best science of the day is pointing to time as more of an illusion. When I shared this insight with one of my college student at the University of Wisconsin - Stout, he simply affirmed, "Oh, yes Father. Time is most likely the measure of decay." Maybe Bob should have interviewed my student! In any event, this reflection on time begs the question: Do we understand time as well as we think we do?
In Augustine's Confessions, the great Saint and Church Doctor also speaks of time as a type of illusion in which the true sense of time is the observation of change. Now, when Augustine speaks of this change, he is not speaking of decay in the scientific sense. Rather, he is speaking more of change as it occurs in our moral and spiritual lives. Augustine's understand of time implies a type of "evolution" into the person that God created us to be or observing how we "devolve" into a life of sin and separation from God. It is this tension of change met with the reality of our decay that affirms, to quote the band Five For Fighting, at best, we only have 100 years to live. This truth creates an urgency to change our hearts to be who God made us to be while the natural part of who we are slowly moves toward its natural end.
Lent and Easter, then, place us in an odd tension between the sense of time that is marked by our physical limitations and the sense of time that is spiritual, evolving into something that is more than simply a decaying world. This tension is embedded deep within every human heart, making all people wonder, whether they are religious or not, "What am I supposed to do with my life?"
For example, when I am called to give the Anointing of the Sick before someone dies, I never hear people say "I regret living my life in service of God and my neighbor." However, I do hear heartbreaking reflections on how people focused to much upon unimportant things and not enough on important things - namely faith, hope, and love. In these moments, it reminds me of the brevity of my life, realizing that my journey is, hopefully, approaching its halfway point at 44, begging me to pray with the question, "What does God have in store for me in the second half of my faith journey?"
How do you approach time? Do you have Kairos moments of timeless joy? Do you fear that Chronos has overtaken your life, robbing you of meaning and purpose? Pray with these questions and, as we all live in the tension between becoming and decaying, may we discover a life of meaning, maximizing the potential that God has placed within all of us, so that our time may be pleasing to God and contribute to building up the Kingdom of God in our midst.
The Lyrids meteor shower is a medium strength shower that typically produces good rates for three nights centered on the maximum. These meteors usually lack persistent trails, but have been known to produce fireballs. This shower is best seen from the northern hemisphere, where the radiant is high in the dawn sky. This shower can be seen from the southern hemisphere, but at a lower rate.
The Moon will be a waxing crescent, nearing first quarter. The Moon will set around 2:00 AM, so it should not hinder meteor observing from 3:00-5:00 AM.
Here are a couple images of the orbit of the meteor shower's parent body: comet C/1861 G1 (Thatcher). Note how the comet's aphelion is way out past Neptune at 55.68 AU, and the perihelion is very near Earth's orbit at 0.92 AU. It takes this comet 415 years to complete one orbit the Sun.
Orbit of Comet C/1861 G1 (Thatcher) – zoomed-out. Credit: JPL Small Body Browser. Visualizations by Kevin Gill.
Orbit of Comet C/1861 G1 (Thatcher) – inner system. Credit: JPL Small Body Browser. Visualizations by Kevin Gill.
Here is an interactive visualization of the meteoroid stream from comet C/1861 G1 (Thatcher).
Planets circle the sun—you probably learned this in grade school. Johannes Kepler was the person who came up with the modern description for the motions of planets: planets move in elliptical orbits; planets closer to the sun move faster than those further from the sun; and even the individual planets move faster when closer to the sun in their orbits. You might have learned this in college, if you took astronomy for a science class.
Prior to Kepler, people had always theorized that celestial bodies moved with circular motions, either simple or compound (a circle on a circle). In fact, from the time of Aristotle, several centuries before Christ, all the way to the time of Copernicus, more than fifteen centuries after Christ, circles were “The Thing”. Circles endured across time—nearly twenty centuries. Circles endured across cultures—the ancient Greek culture of Aristotle, the Greco-Roman-Egyptian culture of Ptolemy, the Islamic culture of Al-Tusi, the European Christian culture of Copernicus and Tycho Brahe. Kepler made a big break with very established astronomical thought. My students in my college astronomy classes wanted to know why he made that break.
The orbits of Mercury, whose orbit is noticeably elliptical, and of Venus, whose orbit is nearly a perfect circle.
How does a professor explain Kepler here? Well, what is pretty normal is to point out that Kepler was Tycho Brahe’s assistant; Brahe had the best data available on the positions of the planets seen from Earth; Kepler used that data to come up with the elliptical orbit idea. The textbook used in the college astronomy class that I took as a student, Kaufmann’s Universe, said—
Kepler turned from circles to ovals. For years he tried in vain to fit ovals to the orbits of planets about the Sun. Then he began working with a slightly different curve called an ellipse.... To Kepler’s delight, the ellipse turned out to be the curve he had been searching for.
The text used in the history of science class that I took while in college, Mason’s A History of the Sciences, said—
Hence he abandoned the idea [of circles], and trying out other geometrical figures, he found in 1609 that the ellipse fitted perfectly, giving predictions of the required degree of accuracy.
Simple, right? When I wrote my own textbook for my astronomy class, I said more or less the same thing. But my students would have none of this. They were not satisfied with my explanation of Kepler and ellipses, and kept asking questions:
—What do you mean, he “fit” an ellipse?
—I don’t understand how you “fit” something. Can you explain exactly how he did that?
—Prof. Graney, if everyone had been thinking “circles” for two thousand years, what made Kepler think “ellipses”? Why would he ever even think of ellipses when no one else ever had?
I could not answer these questions. I did not know how. I had just accepted that Kepler did it. Eventually I got tired of giving weak answers that did not persuade the students. So, I did some research (finding answers to the endless questions of my students is what led me to do research on the history of astronomy).
Owen Gingerich, an astronomer and historian of science at Harvard, had written a lot on Kepler. I knew Owen and had heard him speak. So I read some of his articles on Kepler and the ellipse.* I also checked Kepler’s original work to confirm for myself what Owen was saying. And, based on that research, I added this to my textbook when I created a new edition:
But what led Kepler to think of elliptical orbits with the sun at one focus? He actually had tried a variety of oval orbits that would have worked quite well, but he was not satisfied with just picking any shape that worked. But when he noticed that elliptical orbits worked well if the sun was at one focus, he latched on to that idea. For Aristotle, the Prime Mover was the cause of the motions of heavenly bodies. Kepler supposed that the sun was the cause of the motions of the planets. Focus is the Latin word for “hearth”, as in a fireplace hearth. For Kepler the sun was the hearth or focus of the universe. Kepler, a deeply religious man who once wrote “I wanted to become a theologian; for a long time I was restless: Now, however, observe how through my effort God is being celebrated through astronomy” and who included statements of praise to God in his books, also saw the sun as a symbol of God. He argued that while Aristotle's geocentric theory divided the universe into two parts, the heavens (made of the Fifth Element) and the Earth (made of the other four), in the heliocentric theory “there are three regions, symbols of the three persons of the Holy Trinity”, noting “the beautiful correspondence of the immobile sun, fixed stars, and intermediate space [where the planets are] with God the Father, the Son, and the Holy Spirit”.
The textbook continues, explaining that Kepler sort of replaced Aristotle's Prime Mover, which to Aristotle represented the action of God, with the sun. Aristotle thought things closer to the Prime Mover moved faster, while things further away moved slower (this leads to the idea in Dante’s Divine Comedy that hell, being the furthest place from God, was cold, frozen, and devoid of motion). Kepler has echoes of this, in that bodies like Mercury that are close to the sun move faster, while those that are far from the sun, like Saturn, move slower. And, each individual planet also moves faster when closer to the sun in its orbit.
In short, Kepler did not just “fit” the ellipse to the data. Kepler settled on his ideas in part because of how he viewed the universe in religious terms. My students had questions, and answering those questions brought Kepler’s faith into astronomy class. Students now do not seem bothered by Kepler and the ellipses any more. This explanation satisfies them.
Now that there is this information on Kepler’s faith in my textbook, some students think Kepler is really cool—he reflects their own faith-oriented approach to the world. Indeed, Kepler is a key figure for engaging students who care about science and about learning but who are scared of science on account of what they may have heard about science in church or at home. On the other hand, some students don’t like how Kepler’s religion mixed with his science—and they are challenged by the fact that Kepler was such a “breakthrough figure”. Still other students just ask what the Holy Trinity is. But regardless, I think students now connect better with Kepler and what he did. Johannes Kepler now has a little more “personality” in the class. He’s not just some guy who mysteriously “fit the data”. He’s the guy who followed a faith-formed hunch and broke with two thousand years of circles and finally got the “right answer” regarding planetary orbits.
*Specifically, the following Gingerich works: “The Great Martian Catastrophe and how Kepler fixed it”, Physics Today, Volume 64 (2011), pg. 50; “Kepler's Trinitatian Cosmology”, Theology and Science, Volume 9 (2011), pg. 45; “Kepler as a Copernican”, Katalog zur Kepler-Austellung in Linz (1971), pg. 109 (the source of the three Kepler quotations seen here); “The Origins of Kepler's Third Law” in Vistas in Astronomy volume 18, edited by A. Beer and P. Beer (Pergamon Press: Oxford, 1975), pg. 595.
By Jessica Stoller-Conrad
Mars is Earth’s neighbor in the solar system. NASA’s robotic explorers have visited our neighbor quite a few times. By orbiting, landing and roving on the Red Planet, we’ve learned so much about Martian canyons, volcanoes, rocks and soil. However, we still don’t know exactly what Mars is like on the inside. This information could give scientists some really important clues about how Mars and the rest of our solar system formed.
This spring, NASA is launching a new mission to study the inside of Mars. It’s called Mars InSight. InSight—short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport—is a lander. When InSight lands on Mars later this year, it won’t drive around on the surface of Mars like a rover does. Instead, InSight will land, place instruments on the ground nearby and begin collecting information.
Just like a doctor uses instruments to understand what’s going on inside your body, InSight will use three science instruments to figure out what’s going on inside Mars.
One of these instruments is called a seismometer. On Earth, scientists use seismometers to study the vibrations that happen during earthquakes. InSight’s seismometer will measure the vibrations of earthquakes on Mars—known as marsquakes. We know that on Earth, different materials vibrate in different ways. By studying the vibrations from marsquakes, scientists hope to figure out what materials are found inside Mars.
NASA's InSight Lander, Credit: NASA/JPL-Caltech
InSight will also carry a heat probe that will take the temperature on Mars. The heat probe will dig almost 16 feet below Mars’ surface. After it burrows into the ground, the heat probe will measure the heat coming from the interior of Mars. These measurements can also help us understand where Mars’ heat comes from in the first place. This information will help scientists figure out how Mars formed and if it’s made from the same stuff as Earth and the Moon.
Scientists know that the very center of Mars, called the core, is made of iron. But what else is in there? InSight has an instrument called the Rotation and Interior Structure Experiment, or RISE, that will hopefully help us to find out.
Although the InSight lander stays in one spot on Mars, Mars wobbles around as it orbits the Sun. RISE will keep track of InSight’s location so that scientists will have a way to measure these wobbles. This information will help determine what materials are in Mars’ core and whether the core is liquid or solid.
InSight will collect tons of information about what Mars is like under the surface. One day, these new details from InSight will help us understand more about how planets like Mars—and our home, Earth—came to be.
Artist rendition of the formation of rocky bodies in the solar system - how they form and differentiate and evolve into terrestrial planets. Image credit: NASA/JPL-Caltech
This article is provided by NASA Space Place. With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov to explore space and Earth science!
NASA InSight arriving at Mars, Nov. 26, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley
This article was annotated by Bob Trembley: several hyperlinks and 2 additional images were added.
Sometimes I write columns and then decide not to submit them to The Tablet. This was my alternate column for April 2016; this is the first time it's been published. Comments?
The Vatican Observatory exists to show the world how the Church supports astronomy, and so a large part of my work is traveling the world to talk about our work. Two recent  stops have been particular eye-openers to me.
This is how I remember seeing Provo, with snow-capped mountains and a glorious sky out every window. Gorgeous. This image is from a web site called "Five Things To Know About Living in Provo". They don't mention coffee.
Brigham Young University in Provo, Utah, just outside Salt Lake City, is the premier center of learning for the Mormon Church. For reasons that still puzzle me, I was invited to be the first non-Mormon scientist to give their annual Summerhays Lecture on Science and Religion.
They went remarkably out of their way to make me feel at home. Indeed, the university guest house even caters to its gentile guests by having a coffee machine — the only coffee allowed on campus. (Stimulants like caffeine are forbidden to Mormons, though they’ve decided that cola-based sodas are exempt.) A planetary scientist colleague of mine there, herself an active Mormon, invited me to her class and organized a seminar for me to talk about my research. I was even taken up to the famous Sundance Ski Resort for an afternoon of snowshoeing. (They’d offered to show me the historical and religious sites of Salt Lake City. I pointed out that, as I live in Rome, hiking their glorious mountains would be more of a treat.)
Meanwhile, a retired chemistry professor (a Catholic married to a Mormon), was my local guide to the oddities of Mormon theology. I had devised a talk that I thought would be non-controversial, examining how we “people of The Book” — Christians, Jews, and Muslims — are free to study nature with science because we reject nature gods: our God is supernatural. But the more I learned of Mormon beliefs, the less clear it was such an assumption about how they view God actually fits their unusual theology.
A month later, I was at a small school set in the rolling hills of my home state of Michigan, a liberal arts university where a third of the students are active Catholics. Hillsdale College is famous for proudly refusing to accept any government money. The sticking point, according to a document that they included in their welcome packet, is how the Government (specifically naming “the Obama Administration”) demands to know the racial makeup of their student population. This is insulting to a college like Hillsdale, which since its founding before the American Civil War has proudly proclaimed that it accepts students of any race or creed. Indeed, Hillsdale sent a record number of graduates to fight for the Union in that war; those veterans are commemorated in a prominent statue on campus. More recent statues honor Winston Churchill, Ronald Reagan, and Margaret Thatcher.
Indeed, it is hard to imagine that any black student ever encounters prejudice at Hillsdale; in my two days there, I never saw a single black student — or teacher. (I am told they have a few scholarship students from Africa.) When I asked if they had any Jewish faculty, I was told, “he’s retired.” At least they did serve coffee.
I feel churlish commenting about these places. In both schools, the hospitality was genuine and the students were wonderful. Both schools have active astronomers doing first-class work. But in both places, I felt uncomfortably out of place. I realize now that it’s probably how my non-Catholic friends must feel when they visit me at the Vatican Observatory.
The glorious thing, however, is that even though our politics or theology may be very different, we are all nonetheless united by our love of astronomy.
We all live under the same stars. The heavens proclaim the glory of God to everyone.