This Is How Amateur Astronomers Can Image What Professionals Cannot
“The Universe is full of astronomical wonders, but it’s up to humanity to observe and analyze them. The key factors determining what we can reveal are resolution, light-gathering power, and the wavelengths filters we choose. Professionals have larger, more powerful telescopes with superior instruments, but amateurs have the advantage of time.”
Have you ever looked at a spectacular image of a distant object in the sky and thought there was no way you could ever construct something like that? That it would simply be impossible to take such a large, high-quality image without the benefit of a professional telescope, observatory, or setup? Well, Ciel Austral, a team of five amateur astronomers, spent 10 months over 2018 and 2019 photographing the nearest large galaxy to our own: the Large Magellanic Cloud. They recorded a total of 1060 hours of observations over that time, stitching a total of 620 GB of data together into a single mosaic.
“The sky and ocean aren’t blue because of reflections at all; they’re both blue, but each of their own volition. If you took our oceans away entirely, a human on the surface would still see blue skies, and if you managed to take our skies away (but still somehow gave us liquid water on the surface), our planet would still appear blue.
For the skies, the blue sunlight scatters more easily, and comes to us indirectly from where sunlight strikes the atmosphere as a result. For the oceans, longer-wavelength visible light gets absorbed more easily, so the deeper they go, the darker bluer the remaining light appears. Blue atmospheres may be common for planets, as Uranus and Neptune both possess them, too, but we’re the only one we know of with a blue surface. Perhaps when we find another world with liquid water on its surface, we won’t be so alone in more ways than one!”
The sky is blue. The oceans are blue. Earth, as seen from space, is blue. But have you ever stopped to think about why? Many popular but incorrect explanations abound, such as the idea that sunlight is blue, that oxygen is blue, or that one reflects the other. Of course, none of these are correct! The sky really is blue, and it’s blue because of the physics that governs how light passes through the atmosphere. The ocean is really blue, too; it’s why our planet appears blue from space. But the physics of why the ocean is blue is completely independent of why the skies are blue!
Your Glorified Ignorance Wasn’t Cool Then, And Your Scientific Illiteracy Isn’t Cool Now
“You are not right about everything. Many of the opinions that you hold — and some of the facts that you believe to be true — will turn out to be falsely-held beliefs. Some of them, most likely, have already had their falsehood demonstrated beyond a reasonable scientific doubt. Unless you yourself are a huckster, trying to profit off of the willful deception of others, you must be open to changing your mind and deferring to the genuine experts who know more than you.
Glorified underachieving, proclaiming falsehoods as truths, and the derision of actual knowledge are banes on our society. The world is made objectively worse by every anti-science element present within it. Nobody likes to hear that sometimes, they’re the problem. But sometimes, it really is on each of us to do better. The next time you find yourself on the opposite side of an issue from the consensus of experts in a particular field, remember to be humble. Remember to listen and be open to learning. The future of our civilization may hang in the balance.”
Did you ever have an experience in school where you knew the answer, but didn’t raise your hand because it wasn’t cool to do so? Did you ever get a report card full of good grades, but were afraid to be proud of your achievement? Did you ever hear people proudly proclaiming falsehoods so outrageous that it seemed like people were flouting their ignorance, as though they were proud of it?
What Was It Like When The First Humans Arose On Earth?
“Approximately 300,000 years ago, the first Homo sapiens — anatomically modern humans — arose alongside our other hominid relatives. It is unknown whether we descended directly from Homo erectus, heidelbergensis, or antecessor, although neanderthals, which came slightly later at 240,000 years ago, most certainly came from Homo heidelbergensis. Modern speech is thought to have arisen almost as soon as Homo sapiens did.
It took 13.8 billion years of cosmic history for the first human beings to arise, and we did so relatively recently: just 300,000 years ago. 99.998% of the time that passed since the Big Bang had no human beings at all; our entire species has only existed for the most recent 0.002% of the Universe. Yet, in that short time, we’ve managed to figure out the entire cosmic story that led to our existence. Fortunately, the story won’t end with us, as it’s still being written.”
For those of you who haven’t been following, this is now part 30 of my series on “what was it like when…” where I’ve been chronicling our natural history, from before the Big Bang up through the present day. Next week’s will be the final installment of that series, as we’ll arrive at the present!
This Is Why Mars Is Red And Dead While Earth Is Blue And Alive
“Both Mars and Earth had early atmospheres that were heavy, massive, and extraordinarily rich in CO2. While Earth’s carbon dioxide got absorbed into the oceans and locked up into carbonate rocks, Mars was unable to do the same, as its oceans were too acidified. The presence of sulfur dioxide led to Martian oceans that were rich in sulfuric acid. This led to geology of Mars we’ve discovered with rovers and landers, and pointed to a different cause — the solar wind — as the culprit in the mystery of the missing Martian atmosphere.
Thanks to NASA’s MAVEN mission, we’ve confirmed that this story is, in fact, the way it happened. Some four billion years ago, the core of Mars became inactive, its magnetic field disappeared, and the solar wind stripped the atmosphere away. With our magnetic field intact, our planet will remain blue and alive for the foreseeable future. But for a smaller world like Mars, its time ran out long ago. At last, we finally know why.”
For most of the 20th century, we knew that Earth had a carbon dioxide-rich past for its atmosphere, but that those atmospheric molecules were deposited into the ocean and precipitated or fossilized out as carbonate rocks like limestone and dolomite. We assumed that Mars, which once had a thick atmosphere and a water-rich surface, lost its atmosphere the same way. But landers and rovers changed all of that, discovering very little in the way of carbonate rocks, meaning that there must have been a different process at play to strip the Martian atmosphere away.