September 22 – Falling All Over The Place

Today’s factismal: Today is the first day of Fall, the twenty-second day of fall, and the fifty-third day of fall.

Well, Summer is over at last. Then again, according to some folks Summer has been done for quite some time. How can that be? It all has to do with people and our need to categorize things. The problem is that different groups of people can look at the same thing and break it apart in different ways. For example, today marks the first day of Fall for the astronomers. (Unless you are in the Southern Hemisphere, in which case, it is the first day of Spring.) For a meteorologist, today is the twenty-second day of Fall. And for folks who studied the classics, it is the middle of Fall!

It all started back in the days of the early Roman kings (about 2,700 years ago) when the calendar ran from late spring to early winter and then went silent for a couple of months. The Romans held various fertility and harvest festivals to celebrate the seasons, but the actual date when those were held slipped around a bit thanks to those missing two months. It wasn’t until Julius Caesar fixed the calendar that we started seeing folks who could say with any authority (a legion of armed men is authority, right?) that Summer was officially over and Fall had begun.

Visitors to the National Cherry Blossom Festival (My camera)

We no longer use the blooming of trees to determine the seasons – or do we? (My camera)

The interesting thing is that, while the various Roman provinces didn’t like the Romans very much (after all, what had Rome done for them other than the aqueducts, sanitation, roads, education, and the wine?), they loved the calendar because it made it easier for them to observe their religious rites and mark their seasons. And one of the most influential (at least in Europe) set of seasons was the one that modern pagans call “the Wheel of the Year”, which divided the year into four seasons (Spring, Summer, Winter, and Fall) and arranged them so that the middle of each season happened on an astronomically significant date. The middle of Winter would show up on December 20 (the Winter Solstice), the middle of Spring would occur on March 20 (the Vernal Equinox), the middle of Summer would be on June 20 (the Summer Solstice), and the middle of Fall would roll in on September 21 (the Autumnal Equinox). This method of timing the seasons lasted for more than 1,900 years; you can see its influence in things such as Shakespeare’s “Midsummer’s Night’s Dream” which takes place on the Summer solstice. And while the dates have slipped a bit due to the Earth’s wobble in its orbit, the basic idea remains and is celebrated in many countries.

But as we moved into the 20th century, we decided that those dates didn’t work well for us (mainly because there is nothing special to mark February first as the start of Spring). So we came up with a new system. Actually, we came up with two new systems. Around 1950, the meteorologists decided that the seasons would start on the first day of a specific month, so that each season was roughly the same length of time. Spring ran March, April, and May, Summer took up June, July, and August, Fall was September, October, and November, and Winter was December, January, and February. (These seasons are generally referred to as “meteorological spring” etc.)

M42 (Orion Nebula) Over Virginia (My camera)

The stars don’t set our calendar either – or do they? (My camera)

At about the same time, the astronomers decided that they weren’t going to let no stinking pagans decide when the seasons started based on obsolete astrological superstitions; instead, they’d start the seasons based on the stars. So the astronomers decreed that Spring would begin on the Vernal Equinox, Summer would come in on the Summer Solstice, Fall would commence on the Autumnal Equinox, and Winter would hold sway beginning on the Winter Solstice. That this effectively shifted the seasons by half a wavelength was irrelevant; it just made more sense to the astronomers.(These seasons are generally referred to as “astronomical spring” etc.)

The three seasonal calendars in use today

The three seasonal calendars in use today

So, as a result, we now have three different dates to start each season. Of course, Mama Nature is famous for not reading calendars (as anyone who has been caught in a May snowstorm can attest); she starts her seasons when she wants and marks it by changes in the plants and animals. And it turns out that there are a lot of scientists who are more interested in reading her calendar than man’s. If you would like to help them do so by recording when the leaves change color or the butterflies leave or the buds blossom in your area, then why not write a few pages in Nature’s Notebook?
https://www.usanpn.org/natures_notebook

June 22 – Go To Heliocentric

Today’s factismal: Galileo was convicted of heresy 383 years ago today.

Today marks the 383rd anniversary of Galileo’s conviction for heresy. Why should you care? Because Galileo’s trial and subsequent exoneration (a mere 359 years later) show what happens when you let civil authority decide what is and isn’t true.

Galileo's sketch of the Moon

Galileo’s sketch of the Moon

His story starts out well. In 1610, Galileo had published The Starry Messenger (Sidereus Nuncius), a book based on observations of the heavens that he had made using the telescope that he had created. In addition to pointing out the planets orbiting Jupiter (today we call them the Galilean moons: Io, Europa, Callisto, and Europa), he made several statements supporting Copernicus’ heliocentric theory. At the time, the idea that the Earth orbited the Sun was considered to be heresy (Giordano Bruno had been burned at the stake in 1600 for espousing that view). Galileo’s views combined with his sometimes acerbic manner led Caccini and other priests to denounce him to the Inquisition. In 1616, the Inquisition ordered Galileo to stop teaching, promoting, defending, or even discussing heliocentrism and threatened him with torture if he failed to obey. Being no dummy, Galileo agreed.

But, being a scientist, he kept looking for evidence, and, being a bright guy, he kept finding it. He also amassed a few powerful friends, including a passing acquaintanceship with Urban VIII who became Pope in 1623. Those friends encouraged Galileo in his studies and encouraged him to return to the subject of what orbited what. In 1632, Galileo finally organized his thoughts and his evidence into a new book called A Dialogue On Two World Systems. To put it mildly, the book was a hit. Not only did it succinctly rebut the Church’s position, but it did it in an entertaining manner through an extended conversation between Sagredo (“thinker” in colloquial Italian), Salviati (“smart guy”) and Simplicio (“dummy”). As you might guess, Salviati had the right idea (heliocentrism) and all of the best lines. But what you might not guess is that Simplicio, who supported the Church’s position, did so using Urban’s own arguments.

Galileo faces the Inquisition (Painting by Cristiano Banti)

Galileo faces the Inquisition
(Painting by Cristiano Banti)

What followed was predictable. The pope was enraged by being called “dummy” and ordered Galileo brought before the Inquisition again. This time, they didn’t let him off with a slap on the wrist. They showed him the instruments of torture (excuse me – “gentle correction of heresy”) and threatened his life if he didn’t recant. Galileo promptly did so, and was sentenced to life under house arrest with every letter, book, and grocery list he wrote being subject to inspection and approval by the Inquisition. And there things remained for 359 years.

In the meantime, other scientists found yet more evidence that Copernicus was right and the Church was wrong. By 1835, there was enough evidence that Galileo’s book was removed from the Index Librorum Prohibitorum (“List of Forbidden Books”). In 1939, Pope Pius XII praised Galileo’s courage. And in 1979, the Roman Catholic Church began a new investigation into Galileo’s claims. Finally, on October 31, 1992, they announced what the rest of the world had known for centuries: Galileo wasn’t a heretic – he was right.

March 29 – Where the Home Fire Burns

Today’s factismal: Heinrich Olbers discovered Vesta , the eleventh planet in the Solar System, 209 years ago today.

If there is one thing that is sure to set planetologists and astronomers fighting, it is the question of how to define a planet. Astronomers claim that they get to define what a planet is because they are in the sky; planetologists claim that right because planets are what they study. But no matter how you define a planet, both sides will agree that the definition has changed several times.

For example, when Galileo discovered the four largest moons of Jupiter he called them planets. (Well, first he called them stars before realizing his mistake.)  And astronomers agreed with him until similar planets were found orbiting Saturn and the number of planets around Jupiter reached embarrassing levels – how could a mere planet have more planets than the Sun did? So astronomers decreed that any planet orbiting another planet was actually just a moon.  When Uranus was discovered in 1781, it fit neatly into the system as a new planet. When Titania and Oberon were seen circling Uranus and Enceladus and Mimas were seen orbiting Saturn, those were moons. Problem solved.

But then came Ceres. Astronomers had been searching for a “missing” planet between Mars and Jupiter based on the assumption that planetary orbits followed a spacing pattern that they called the Titus-Bode law. Like Kepler’s laws of orbital mechanics, Titus-Bode was an empirical rule based on observation and not theory. Unlike Kepler’s laws, Titus-Bode wouldn’t work out, though we wouldn’t discover that for more than a century. In the meantime, astronomers used it to tell them where to look for new planets. And, for a while, it seemed to deliver.

In 1801, Guiseppe Piazzi discovered a planet exactly where Titus-Bode predicted and named it Ceres. Less than a year later, Heinrich Olbers discovered another planet in the same area and named it Pallas. Then Karl Harding found Juno in 1804 and Olbers spotted Vesta in 1807. All in all, there were four planets where astronomers had expected to see but one and there were a total of eleven planets in the Solar System. But the new planets were tiny little things, just barely visible in the best telescopes of the day. Because they were so small, they could hardly be discerned from the stars behind them, and so Herschel proposed calling them “asteroids” or “star shaped”.

Despite the new nomenclature, astronomers still considered the asteroids to be planets. And that’s how they were spoken of in the press and in scientific papers for nearly forty years. They were given astronomical symbols to make it easier for astronomers to look them up in their texts and the origin of these planets was hotly debated. One popular suggestion was that they were the remains of a single, larger planet that had somehow broken apart. And other asteroids were eagerly sought to help fill in the gaps. But, despite many efforts, no new planets were found for nearly four decades.

The Universe, as matters stood in 1853. The four planets of Ceres, Pallas, Juno, and Vesta all fit into a gap that had been predicted by Titus and Bode.

But when they did start finding new asteroids, the floodgates opened. By 1860, 62 minor planets had been discovered. By 1890, that number had risen to 300. And in 1891, Max Wolf perfected a means of identifying asteroids using photographic plates that allowed them to be discovered almost automatically; indeed, a variant of that method is now in use and has identified more than 700,000 different asteroids!

Asteroids closer than Mars (Image courtesy JPL)

Asteroids closer than Mars (Image courtesy JPL)

Now here’s the crazy part: even though we’ve found more than 700,000 asteroids there are probably at least another 700,000 out there. And the ones still in hiding are too small or too lumpy or too weird to be found by an automatic program. What they need to find the remaining asteroids is someone who knows how to play hide-and-seek with a lump of rock a million  miles away. They need a human.

And that’s where you come in. Asteroid Zoo needs people to look at images and mark where they think an asteroid is hiding. With enough folks like you, we can find out where the remaining “vermin of the skies” (as the astronomers call them) are so we can know things how the Solar System formed, where the hazardous asteroids are, and if any of them are worth visiting. To learn more, zip on over to:
https://www.asteroidzoo.org/

March 20 – Spring Forward

Today’s factismal: Today is the first day of Spring, the twentieth day of Spring, and the forty-ninth day of Spring.

Right now, you are probably scratching your head, wondering if I’ve lost my mind. How can one season start three different times? The answer lies, as it so often does, in the ineluctable propensity of mankind to name things. Back in the days of the early Roman kings (about 2,700 years ago), the calendar ran from late spring to early winter and then went silent for a couple of months. The Romans held various fertility and harvest festivals to celebrate the seasons, but the actual date when those were held slipped around a bit thanks to those missing two months. It wasn’t until Julius Caesar fixed the calendar that we started seeing folks who could say with any authority (a legion of armed men is authority, right?) that Spring was officially over and Summer had begun.

Visitors to the National Cherry Blossom Festival (My camera)

We no longer use the blooming of trees to determine the seasons – or do we? (My camera)

The interesting thing is that, while the various Roman provinces didn’t like the Romans very much (after all, what had Rome done for them other than the aqueducts, sanitation, roads, education, and the wine?), they loved the calendar because it made it easier for them to observe their religious rites and mark their seasons. And one of the most influential (at least in Europe) set of seasons was the one that modern pagans call “the Wheel of the Year”, which divided the year into four seasons (Spring, Summer, Winter, and Fall) and arranged them so that the middle of each season happened on an astronomically significant date. The middle of Winter would show up on December 21 (the Winter Solstice), the middle of Spring would occur on March 20 (the Vernal Equinox), the middle of Summer would be on June 21 (the Summer Solstice), and the middle of Fall would roll in on September 21 (the Autumnal Equinox). This method of timing the seasons lasted for more than 1,900 years; you can see its influence in things such as Shakespeare’s “Midsummer’s Night’s Dream” which takes place on the Summer solstice.

But as we moved into the 20th century, we decided that those dates didn’t work well for us (mainly because there is nothing special to mark February first as the start of Spring). So we came up with a new system. Actually, we came up with two new systems. Around 1950, the meteorologists decided that the seasons would start on the first day of a specific month, so that each season was roughly the same length of time. Spring ran March, April, and May, Summer took up June, July, and August, Fall was September, October, and November, and Winter was December, January, and February. (These seasons are generally referred to as “meteorological spring” etc.)

M42 (Orion Nebula) Over Virginia (My camera)

The stars don’t set our calendar either – or do they?  (My camera)

At about the same time, the astronomers decided that they weren’t going to let no stinking pagans decide when the seasons started based on obsolete astrological superstitions; instead, they’d start the seasons based on the stars. So the astronomers decreed that Spring would begin on the Vernal Equinox, Summer would come in on the Summer Solstice, Fall would commence on the Autumnal Equinox, and Winter would hold sway beginning on the Winter Solstice. That this effectively shifted the seasons by half a wavelength was irrelevant; it just made more sense to the astronomers.(These seasons are generally referred to as “astronomical spring” etc.)

The three seasonal calendars in use today

The three seasonal calendars in use today

So, as a result, we now have three different dates to start each season. Of course, Mama Nature is famous for not reading calendars (as anyone who has been caught in a May snowstorm can attest); she starts her seasons when she wants and marks it by changes in the plants and animals. And it turns out that there are a lot of scientists who are more interested in reading her calendar than man’s. If you would like to help them do so by recording when the leaves change color or the butterflies leave or the buds blossom in your area, then why not write a few pages in Nature’s Notebook?
https://www.usanpn.org/natures_notebook

February 19 – Birth Of A Notion

Today’s Factismal: Nicolas Copernicus, the father of modern astronomy, was born 543 years ago.

If you look at the sky, it is very easy to see why some people thought that the universe revolves around the Earth. Every day, the Sun appears in the East and slowly climbs through the sky until it finally disappears in the West. The Moon and distant stars do the same; up in the East, dance across the heavens and back into bed in the West. Only the “wanderers”, or planets as they came to be known, defied that pattern.

The Solar System as the Greeks saw it

The Solar System as the Greeks saw it

Though some early scientists, such as Philolaus and Aristarchus had proposed that the Earth actually revolved around the Sun, most disagreed. After all, it just made more sense for the Sun and Moon to revolve around the Earth – as long as you ignored those pesky planets. You could have each celestial object be embedded in a transparent sphere centered on the Earth; tomes were written on the exact spacing of the spheres and what musical note each would play. (And you thought that the music of the spheres was just a phrase.) And, if you put each of the wandering planets on a sphere embedded in the principle sphere, you could even almost explain their motion.

The Solar System according to the Romans; this view held for nearly 1,500 years

The Solar System according to the Romans; this view held for nearly 1,500 years

But there is a lot of difference between “almost” and “accurately”. And it was that difference that led Copernicus to derive a system that put the Sun (“Helios” in Greek) at the center of the universe, replacing the Earth (“Geo” in Greek). When Copernicus used his heliocentric (“Sun-centered”) model, he was able to predict where the planets would be much more accurately than the geocentric (“Earth-centered”) model did. Unfortunately, the geocentric model had been accepted for centuries and was considered the equivalent of Holy Writ; anyone disputing it was in for a very bad time indeed. Being a prudent man who did not enjoy the prospect of being visited by the Inquisition, Copernicus waited until he was on his death bed before allowing his ideas to be published.

The Solar System as Copernicus saw it (and Galileo proved)

The Solar System as Copernicus saw it (and Galileo proved)

This clever move allowed his works to be spread further than they would have been if he had faced the Inquisition; it also helped that he had phrased his arguments in such deeply technical language that people who weren’t astronomers had a hard time understanding what his conclusions were. Despite this, Copernicus’ book did eventually make its way onto the official list of banned books. But before that happened, it had lit a fire in the astronomical community. It was read by Tycho Brahe and Galileo, among others, and inspired them to look deeply into the heavens seeking evidence that would either confirm or refute the idea.

Copernicus sees the heavens as they are (Image courtesy Steward Observatory)

Copernicus sees the heavens as they are (Image courtesy Steward Observatory)

Eventually, Galileo would find that confirmation in the phases of Venus and the moons of Jupiter, while Brahe would amass so much data that it would allow Kepler to derive his laws of planetary motion and give Newton the base he needed to show how gravity explained the motions. Today, the search for a better model of the universe goes on, and scientists continue to amass data to help them in their quest. If you’d like to join them, then take a look at the Global Telescope network:
http://gtn.sonoma.edu/

December 31 – And So It Begins

Today’s factismal: The New Year will be filled with amazing science news!

This past year was amazing but next year will be even better. It will be filled with new discoveries and old favorites, new opportunities and old reliables, new improvements and old projects. Here are just a few of the things we can expect to see (numbers and dates are approximate):

Astronomy
January 4: Quarantids Meteor Shower
February 8: Centaurids Meteor Shower
March 9: Total solar eclipse
March 14: Normids Meteor Shower
March 23: Penumbral lunar eclipse
May 5: Aquariids Meteor Shower
May 8: Lyrids Meteor Shower
June 27: Bootids Meteor Shower
July 28: Austrinids Meteor Shower
July 30: Aquariids Meteor Shower
July 30: Capricornids Meteor Shower
August 12: Perseids Meteor Shower
August 31: Aurigids Meteor Shower
September 1: Annular solar eclipse
September 9: Perseids Meteor Shower
September 16: Penumbral lunar eclipse
September 27 Sextanids Meteor Shower
October 10: Taurids Meteor Shower
October 11: Aurigids Meteor Shower
November 28: Orionids Meteor Shower
December 2: Pheonicids Meteor Shower
December 7: Puppid-Velids Meteor Shower
December 22: Ursids Meteor Shower

High Energy Physics
New results from the Large Hadron Collider
New observations of Cosmic Background Microwave radiation

Biology
100 New species discovered
10 species go extinct

Geology
1,500,000 earthquakes
50 volcanic eruptions

Space
July: Juno probe arrives at Jupiter
October: ExoMars probe arrives at Mars

And the best thing about all of these things is that most of them offer you an opportunity to join in on the fun. Just stay tuned and I’ll post new citizen science activities throughout the year.

See you soon!

October 16 – The Gold Bug

Today’s factismal: There is more gold on one asteroid (433 Eros) than has ever been mined on Earth.

Ask any third grader what killed the dinosaurs and odds are she’ll tell you that an asteroid did it. (That’s not quite correct but it is close enough for now.) And if the third grader is especially clever, she may even know the name of the asteroid: Chicxulub (“Chick-sue-loob” or “the well of the great horns”). Like all major impact structures, the name comes from the closest town and not from the actual asteroid; those are usually given names like  433 Eros or 1992 QB1 or 1999 FN53. But what your third grader may not know is that Chicxulub was hardly the only asteroid to every hit the Earth.

Every day, nearly 170 meteorites hit the Earth; that adds up to 42,000 meteorites each year! (For the purposes of this article, we’ll treat asteroids and meteorites and comets as being roughly equivalent simply because they are, planetologically speaking.) Most of these are small pieces of rock and ice about the size of a grain of rice that burn up in the outer atmosphere leaving nothing behind but a little dust and a pretty lightshow. But about 2,800 of those meteorites each year are large enough to actually make it deeper into the atmosphere.

A meteorite as seen from above the atmosphere (Image courtesy NASA/Ron Garan)

A meteorite as seen from above the atmosphere
(Image courtesy NASA/Ron Garan)

Every year, about 500 meteorites survive their fiery plunge through the atmosphere and make it to the ground. Most of those are small and do little damage, but every once in a while we get something a little larger that causes trouble. In 2013, a meteor that was 60 ft across and weighed more than the Eiffel tower fell above Chelyabinsk, Russia. When it exploded in the sky, it created a shockwave that shattered glass for miles around, injuring more than 1,500 people who had gone to the window to see what the pretty bright light was. When it was all over and done, the Chelyabinsk meteor left behind $33 million in damages, more than 1,500 pounds of fragments, and a 20 ft wide hole known as an “astrobleme” (star wound) in the trade or a “meteor crater” to news reporters.

And that isn’t the worst that could happen. Based on what we know right now, scientists expect to see an impact creating a Chelyabinsk style crater roughly every 250 years, an Odessa style 500 ft crater every 540 years, a Wolfe Creeksized half-mile across crater every 13,000 years, a (Barringer) Meteor Crater mile-wide crater every 21,000 years, a Pingualuit two mile across impact every 50,000 years, and a Chicxulub 110 mile across crater every 100,000,000 years. As you might guess from that big gap at the end, there is still a lot that we don’t know for sure about impact craters.

The Pingualuit impact crater (Image courtesy NASA)

The Pingualuit impact crater (Image courtesy NASA)

But we can learn. And surprisingly on of the best places to learn about impact craters is from the things that make them – asteroids! That’s because unlike the Earth, which has wind and water and plate tectonics to erase old impact craters, the asteroids just have impacts to erase other impacts. So by examining impact craters on asteroids, we can learn more about how they happen on Earth which can help us keep another Chicxulub from knocking on our planet one day. If you’d like to learn more about imact craters on asteroids, why not zoom over to Vesta Mappers at Cosmo Quest? They’ll show you how to identify impact craters on the latest images of Vesta and then let you loose on the newest data we’ve got!
https://cosmoquest.org/?application=vesta_mappers