Nineteenth century astronomers had it right, 20th century got it wrong and it drastically delayed the search for exoplanets
While space based telescopes such as Hubble and Kepler have become really, really damn good at finding exoplanets now that we know what we’re looking for, there was a point in the early 20th century when scientists thought our planet-rich solar system was a total fluke, and it was likely there weren’t many other planets at all in the solar system. Problem is, this overturned 19th century ideas of planetary formation that were right all along, and would have begun the search for exoplanets much earlier. Nineteenth century astronomers believed solar systems formed in gaseous nebulae, but in the 20th century, the idea became popular that our solar system was a freak, and that all the stuff from the other bodies in it was due to another star passing too close to the sun, causing the sun to eject out all kinds of junk that became the planets and moons, and that such an event was probably extremely unlikely to happen in any other cases, if at all.
Trying to figure out exactly what the Big Bang was, what caused it, and what might have come before it, is one of the greatest and most fundamental questions in understanding our universe. One new theory, that may sound crazy, but is mathematically sound and possibly testable, is that what we perceive as a “big bang” was the collapse of a four dimensional star into a black hole, and that our three dimensional universe is merely that four dimensional star being smashed into three dimensions, exactly like how in our universe, three dimensional objects become two dimensional when they reach the event horizon of a black hole.
Astronomers have detected an ancient stellar remnant that’s 10 times fainter than the dimmest white dwarf ever discovered. Fortuitously orbited by a pulsar, this cold and collapsed star consists of crystallized carbon — essentially making it an Earth-sized diamond in space. Indeed, this white dwarf would have never been discovered if it hadn’t been for the pulsar that spins around it.
Be prepared for a whole hell of a lot of scrolling. This map is pretty awesome in the sense that it really puts perspective on just how much distance there is between us and basically everything in just our small corner of the Milky Way.
Scientists think they’ve found evidence of Theia, the planet that collided with Earth to create our moon
Among the most likely theories about the formation of the Earth’s moon is that a small-ish Mars sized planet, one of many in the early solar system, crashed into Earth at an angle, and the resulting catastrophic destruction created a disk of dust, rock and other debris around the Earth, which then quickly coalesced into the gray ball we now see in the night sky. This theory had been supported by lunar rock chemistry, but now scientists have gone even further, using lunar samples taken from the Apollo missions and examined them under electron microscopes, and the theory still holds up.
Titled Archaeology, Anthropology and Interstellar Communication and edited by SETI Director of Interstellar Message Composition Douglas Vakoch, the document draws on “issues at the core of contemporary archaeology and anthropology” to prepare us “for contact with an extraterrestrial civilization, should that day ever come.”
You’ve no doubt heard the mathematics of the Drake Equation about how there are an estimated 10^24 stars in the universe, or 10,000 stars for every grain of sand on Earth, and an estimated 10 quintillion possible Sun-like stars, hosting 100 billion billion Earth-like planets, which means somewhere out there, even with a conservative estimate, there should be nearly 100,000 intelligent civilizations in our galaxy alone. And yet, we haven’t heard from, contacted or even seen any evidence whatsoever of a single one. Anywhere. So what’s up? Shouldn’t there be at least one out there somewhere among those quadrillion possible planets? Maybe not.
Take life on Earth— in four billion years, there have been perhaps trillions and trillions of different species, going all the way back to the earliest prokaryote life forms in the primordial ooze, and of those zillion species, only a tiny branch of apes, producing only a few intelligent, abstract thinking, tool building, environment altering species of which we are the last. So even the odds on a planet with the biological diversity existing for long enough without getting totally wiped out to produce the kinds of creatures to even ask this question, are so insanely low, that it doesn’t offer a lot of hope that even among those 10^24 stars that the exact conditions would have existed long enough to produce another intelligent species on another planet for us to communicate with.