The celestial maps of Su Song, Chinese polymath of the Song dynasty, the oldest known star charts in existence, dating from 1092 AD.
Sun, you’ve got something on your face… No, right there…
In the summer of 1612, Galileo made a series of historic sunspot observations. Every day, he would sketch the magnetic blemishes present on the solar disk, diligently replicating their position and shape with ink and paper. Here’s a sequence of those sketches in flip-book form, a sort of parchment-era animated GIF. If Galileo had kept up his observations for 26.24 days, he may have seen some of those spots return after a complete trip around the rapidly rotating sun.
Sunspots appear dark against the comparatively hot solar surface (~5,500 ˚C), but they are still a scorchingly intense 3,000-4,000 ˚C. Isolated from the sun, they would be brighter than the moon!
Using his sketches, Galileo was able to prove that sunspots were actual features on the sun and not tiny, undiscovered planets or moons that were passing in between Earth and the sun. That idea seems hilariously quaint today, but in the early days of the telescope, people were planet-crazy, and more than a few religious scholars of the day viewed the sun as a “perfect” body which simply could not possess spots, no siree.
Galileo made these early telescopic observations by doing what any scientist or doctor or parent will tell you that you should absolutely never do: Staring directly at the sun (although he confined his observations to sunrise and sunset in order to not completely fry his retinas).
Although Galileo’s published sunspot work was the most important of its day, on account of the “that’s no moon” smackdown it delivered to the Jesuit scientific community, G-dub was not the first to observe the solar speckles. Englishman Thomas Harriot inked the first-known telescopic drawing of sunspots in 1610. Harriot also beat Galileo to drawing the moon, but his work remained unknown until the 18th century. Galileo was already a science celebrity in his day, a sort of Italian Neil deGrasse Tyson, and his fame meant that his works were more widely known than those of his contemporaries, even if he was repeatedly beaten to the scientific punch. Ever heard of Johannes Fabricius? Didn’t think so. He was 24 when he also beat Galileo to sunspots.
None of these men were the first to make scientific observations of sunspots, though. English monk John Worcester observed “black spheres against the sun” in 1128 (below), which coincides with a particularly intense aurora recorded by Korean astronomers just days later and halfway around the world. And Chinese astronomers recorded a “black spot within the sun” just 104 days later, in 1129. Of course, Chinese astronomers had been recording sunspots since at least 364 BCE, so no biggie.
(Top image: Galileo’s 1612 sunspot observations, Bottom image: John of Worcester’s sunspot observations)
The Far Future of the Universe
It’s natural to wonder what the future has in store for us. While we may not be able to predict what will happen to us tomorrow, science has made some pretty strong predictions about what will happen to the universe in the eons to come.
From the rearrangement of the constellations and meteorite impacts to the evaporation of our oceans and the stars themselves going out, there’s a lot of stuff to (not) look forward to.
Sure, the universe might not have a happy ending, but that just makes today more special, doesn’t it? Plus, BLACK HOLES.
Watch the latest It’s Okay To Be Smart (below) and I’ll tell you all about it!
Another New Earth… Or Not.
You may have heard the news last week that astronomers discovered the best candidate to date for an Earth-like planet. Kepler-186f is a rocky planet that is, like other so-called “second Earths”, the right distance away from its parent star to have liquid water on its surface and maybe have the right conditions for maybe having life if that’s the kind of thing that maybe exists somewhere else… maybe.
As Adam Mann writes for WIRED, there’s a lot we don’t know about this exoplanet, and a lot that makes it not very Earth-like. Like the fact that its star is way different from ours. And that we haven’t imaged it directly. Matt Francis adds his two cents at The Daily Beast, noting that a planet that close to its parent star is tidally locked, with the same side facing, and being baked by, its parent star all the time. Sounds like it’s more of an Earth-cousin at best.
It’s not right to call this planet a “New Earth” (and I can almost guarantee that the Face of Boe does not and will not ever live there), because there’s just too much that we don’t know about it. The same goes for other exoplanets: For every question they answer they force us to ask three more. But that’s science. What is cool about this latest discovery is that it shows us just how many types of stars, even weird ones like the M class red dwarf that 186f orbits, can harbor Earth-ish planets in their habitable zone.
The more we discover, the stronger the case that life exists somewhere, elsewhere. If you’d like to know more about our search for exoplanets and the life we hope they harbor, I did two videos on that for IOTBS. Watch ‘em below:
(Image via NASA)
We take iron for granted these days.
Before human cultures mastered the art and science of metallurgy, the ability to purify and alloy Earth’s various metals, especially iron, into useful stuff like swords, spoons, and steel, pure iron was rare stuff. Despite being common in the crust, Earth’s iron isn’t sitting there in huge nuggets like California gold. It is trapped in ores and require extensive science magic to extract.
Yet iron artifacts have been found that date back thousands of years before the beginning of the Iron Age. So where’d that metal come from?
Iron-rich meteorites have been falling to Earth since Earth was a thing. If early humans traced the streak in the night sky to its landing spot, they could collect the metal and carve it directly into tools or artifacts, given a little bit of inspiration and free time, which I hear there was a lot of before the internet.
I’ve collected a few meteorite-sourced goodies above. Not all date from pre-Iron Age, but they represent what could have been done. From top:
- Perhaps the most magical artifact on Earth, a meteorite-tipped harpoon made from narwhal tusk!!!
- The "Iron Man" sculpture, an 11th-century carving of a Buddhist deity from a single pice of space metal
- A dagger made from meteorite-source iron steel
- These are oldest iron artifacts ever found to date! These 5,000-year-old Egyptian beads were carved from meteoric iron and found in Gerzeh.
The word “iron” actually comes from the Anglo-Saxon word meaning “holy metal”, and many of these space-rock artifacts are ceremonial or meant for the era’s royalty or refer to deities. Before we knew that meteorites were just space debris, it’s no surprise that these rocks were sourced to a different sort of heaven.
I have a feeling that silk scarves printed with NASA satellite and Hubble images are a thing that some of you might need, in a “shut up and take my money” way.
Check ‘em out at Slow Factory.
Dust (the zodiacal light) pointing at dust (the Milky Way band)
One is the remnants of our solar system’s birth, and the other holds the seeds for solar systems dead and yet to come. Some more dusty goodness to go along with this week’s dusty episode of IOTBS on YouTube.
Photo by the superbly talented Cory Schmitz (Flickr, used with permission)
The Moon Goes Red Tonight
Are you in North, Central, or South America? Do you like staying up late and staring up at the sky? Yes? Then I have good news!
You can catch a total lunar eclipse Monday night, in all of its dusty-red glory, from just about anywhere in North America with a clear view of the night sky. The moon will enter the darkest part of Earth’s shadow (the “umbra”) at 1:58 AM ET, and remain there until 4:24 AM ET. At 3:06 ET, the moon will be completely darkened by the Earth’s shadow!
Except that the moon won’t be completely dark. During a lunar eclipse, the moon turns a dusty shade of red. Why is that? You can thank Earth’s atmosphere.
To understand the red color of a lunar eclipse, it’s best to see how Earth would look from the moon. Check out the image of Earth eclipsing the sun (it’s not a real photo, btw. It was created from several images taken by Apollo astronauts):
(via Astro Bob)
See that halo of light around Earth? Our diffuse shell of air and dust bends and reflects a portion of the eclipsed sun’s light around the planet and onto the obscured moon. And since only the longest wavelengths of light make it through our atmosphere without being scattered away by the air molecules (the same reason that sunsets are red), the moon is bathed in crimson! Here’s a video I made about that atmospheric color show:
Check out more eclipse goodness at Bad Astronomy. Top image via Wikipedia.
A technical glitch causes the Hubble Space Telescope, which ordinarily captures magnificently crisp scientific imagery of the cosmos, to lose balance and create this inadvertent piece of modern art.
It is suspected that in this case, Hubble had locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in this remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288.