Astronomy
esiegel | September 12, 2017"Being a scientist and staring immensity and eternity in the face every day is as grand and inspiring as it gets." -Carolyn Porco
Launched back in October of 1997, Cassini will take its final plunge into the ringed world it’s been orbiting for over a decade on Friday, September 15th. Before it does, however, it’s worth a look back at the tremendous science that’s come about from the first dedicated mission to venture out to Saturn, including a series of surprises that we had no idea we’d find when we were planning and preparing this mission.
A diagram of the Cassini spacecraft, including the…
esiegel | September 7, 2017"The older you get, the more you realize that the way you look is a reflection of how you treat yourself." -Hope Davis
Age may be just a number, but in cosmic terms, there are some rules it’s pretty important to obey. It should be impossible to have a complex creature that’s older than the planets; a rocky planet that predates the stars; or a star that’s older than the Universe itself. With a figure of 13.8 billion years, we’ve arrived at an incredibly accurate estimate for the age of the Universe since the Big Bang from a slew of different sources, and so nothing should be older than that.…
esiegel | September 5, 2017"The sun is a miasma Of incandescent plasma The sun's not simply made out of gas No, no, no The sun is a quagmire It's not made of fire Forget what you've been told in the past" -They Might Be Giants
Ask anyone where the Sun (or any star) gets its energy from, and most people will correctly answer “nuclear fusion.” But if you ask what’s getting fused, most people -- including most scientists -- will tell you that the Sun fuses hydrogen into helium, and that’s what powers it. It’s true that the Sun uses hydrogen as its initial fuel, and that helium-4 is indeed the end product, but the…
esiegel | September 4, 2017"Just the fact that you so desperately attempt to dismantle our theory proves that we are on the right track. Otherwise you would not feel so threatened by our theories!" -Giogrio Tsoukalos (in a letter to Jason Colavito)
Whenever we detect a signal that we can't immediately explain, it's a very human trait to ascribe our greatest hopes (or fears) to it. In the case of a peculiar radio signal originating from deep space, that means the wildest speculations will involve intelligent aliens. But as much as many of us would hope that such a thing would be true, the physical properties of these…
esiegel | September 2, 2017"Comrades, this man has a nice smile, but he's got iron teeth." -Andrei A. Gromyko
When you have a star, perhaps its most defining characteristic is that it fuses lighter elements into heavier ones, releasing energy. While all stars fuse hydrogen into helium, the more massive ones will undergo helium fusion, with the most massive also fusing carbon, oxygen, and eventually silicon, producing iron in the end. By time you get to iron, the most stable element of all, you would lose energy if you fused anything further, so iron’s the end-of-the-road, with a supernova as the next inevitable step.…
esiegel | August 31, 2017"It’s becoming clear that in a sense the cosmos provides the only laboratory where sufficiently extreme conditions are ever achieved to test new ideas on particle physics. The energies in the Big Bang were far higher than we can ever achieve on Earth. So by looking at evidence for the Big Bang, and by studying things like neutron stars, we are in effect learning something about fundamental physics." -Martin Rees
Two years ago, advanced LIGO turned on, and in that brief time, it’s already revealed a number of gravitational wave events. All of them, to no one’s surprise, have been merging black…
esiegel | August 29, 2017"Curious that we spend more time congratulating people who have succeeded than encouraging people who have not." -Neil deGrasse Tyson
Last week, millions of people across the United States got to experience the awe and wonder of a total solar eclipse, many for the very first time. But in a puzzling event, astrophysicist and one of the world’s most famous science communicators, Neil deGrasse Tyson, decided to use his fame to put down a great many people who were excited about this rare cosmic event. And sadly, when someone explained to him why they would (correctly) say that eclipses are rare…
esiegel | August 28, 2017"The origin and evolution of life are connected in the most intimate way with the origin and evolution of the stars." -Carl Sagan
When it comes to dying stars, supernovae get all the press. They may be the largest and most massive stars to die, but hundreds of times more common are the planetary nebulae of the Universe, formed by dying Sun-like stars. These astronomical wonders blow off their outer layers -- not just hydrogen but also heavier elements -- to return them to the interstellar medium.
In this contrast-enhanced view, the structure of the evaporating gas globules at the interior…
esiegel | August 24, 2017“Man has gone out to explore other worlds and other civilizations without having explored his own labyrinth of dark passages and secret chambers, and without finding what lies behind doorways that he himself has sealed.” -Stanisław Lem
One of the questions that’s fascinated humanity since we first began looking up at the night sky is whether or not we’re alone in the Universe. Although we now know of other stars, other planets, and potentially inhabited worlds, we have yet to make contact with another intelligent species. Despite our curiosity, a great many people live in fear that if we did…
esiegel | August 23, 2017"Presently thought to be the most powerful explosions in nature... their sources have only recently been localized by observations of associated afterglows in X-rays, visible light, and radio waves, delayed in that order." -Richard Matzner, on the dictionary entry for Gamma Ray Burst
It seems like an eternity ago, but it’s been under two years since LIGO first began the science run that would first detect merging black holes. Their latest scientific data run is scheduled to end in just two days, and thus far, they’ve announced a total of three black hole-black hole merger discoveries, along…
esiegel | August 22, 2017"All that is now
All that is gone
All that's to come
and everything under the sun is in tune
but the sun is eclipsed by the moon." -Pink Floyd
No matter how well-prepared you were for your first total solar eclipse, no amount of reading or photograph-searching could do the experience justice. There were so many things to feel, see, and be overwhelmed by that you literally needed to be there to relate to. Yet it was remarkable how many things there were that surprised scientists and skywatchers alike.
There is no special filter necessary to bring out the pink coronal loops near the very edge…
esiegel | August 21, 2017"A candidate is not going to suddenly change once they get into office. Just the opposite, in fact. Because the minute that individual takes that oath, they are under the hottest, harshest light there is. And there is no way to hide who they really are." -Michelle Obama
The most massive stars in the Universe are true behemoths, rising to hundreds of times the mass of our Sun and burning at temperatures upwards of 30,000 K at their surface. But there are stars out there that are even hotter, despite only being 10% or less as massive: Wolf-Rayet stars. The key to their cosmic success? Blowing…
esiegel | August 18, 2017"We live in a moment of history where change is so speeded up that we begin to see the present only when it is already disappearing." -R. D. Laing
This coming Monday, tens of millions of people will gather to watch the total solar eclipse that will go coast-to-coast across the continental United States. Total solar eclipses like this happen, on average, about once every 18 months, due to the frequency of alignment as well as the Moon’s apparent angular size. At present, about 40% of all solar eclipses are total eclipses, with annular eclipses making up 50% and hybrid eclipses the other 10%.…
esiegel | August 17, 2017“We [are] a species endowed with hope and perseverance, at least a little intelligence, substantial generosity and a palpable zest to make contact with the cosmos.” -Carl Sagan
When the Voyager and Pioneer spacecraft were launched, they contained a message emblazoned on them: a map of 14 pulsars, showing the location of Earth relative to them. This was a brilliant idea: showcase bright, unique identifiers, complete with their observed periods and distances from our world, and people would be able to find Earth. If we wanted to be found, it was the best idea 1977 had to offer.
A colorized…
esiegel | August 16, 2017"Even though the reason for taking the photographs was science, the result shows the enormous beauty of nature." -Miloslav Druckmuller, eclipse photographer
During those moments of totality, the Sun is eclipsed by a new Moon, with the latter’s shadow falling onto Earth. From within that shadow, the Sun’s disk is blocked entirely, revealing a slew of fainter objects: stars, planets, and the Sun’s corona, all of which cannot normally be seen during the day. Yet one object even brighter than all the stars -- the new Moon -- will remain invisible throughout the eclipse.
The Sun's atmosphere is…
esiegel | August 14, 2017"An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide." -Alexei A. Sharov & Richard Gordon
We talk about the origin of life on Earth with bated breath, wondering all the time how things occurred to make our planet unique. But within that big question lies an assumption that may not be true: that life on Earth originated on Earth itself. It’s entirely possible, based on what we’ve seen out there in the…
esiegel | August 14, 2017"Yes, I am well aware that nature -- or what we call nature: that totality of objects and processes that surrounds us and that alternately creates us and devours us -- is neither our accomplice nor our confidant." -Octavio Paz
For most of us heading to the path of totality, we're in for an incredible experience. If we get clear skies, it will take roughly an hour for the Moon to pass in front of the Sun's disk completely, and after that we'll get just over two minutes of totality: an experience like no other. Yet if you're not careful -- or if you get too excited about one particular thing…
esiegel | August 11, 2017“Honestly, if you’re given the choice between Armageddon or tea, you don’t say ‘what kind of tea?” -Neil Gaiman
Enjoying the Perseid meteor shower this year, as perhaps you do every August? As you look up, the great cosmic show might have a lot more to offer than mere streaks of light, due to cometary debris brightly burning up in the Earth’s atmosphere. This year, Jupiter has slightly disturbed the debris stream, resulting in an increase in the number of meteors-per-hour, as the stream passes quite centrally through Earth’s location.
The comet that gives rise to the Perseid meteor shower,…
esiegel | August 9, 2017"Our first priority was making sure we weren’t fooling ourselves." -Keith Riles, LIGO team member
When LIGO announced their first discovery of a black hole-black hole merger, it came as a surprise to almost everyone. The shocking part wasn’t that LIGO had seen merging black holes, but that they were discovered to be so massive. At right around ~30 solar masses each, these were black holes that were much larger than expected, forcing astronomers to confront the fact that they didn’t have a good, comprehensive model for how many black holes -- and what mass they should be -- were in the…
esiegel | August 8, 2017"To be on my very first spacewalk, to be outside, and to have contamination in my suit to the point that I couldn't see in either eye - that, I think, would cause some people to lose control." -Chris Hadfield
Sure, you probably laughed about it when you first heard that NASA had a Planetary Protection Officer, as though Earth actually needed protection from non-existent alien invasions. Perhaps, you thought, this might have been relevant back in the 1960s, before we realized how barren the Moon was, or how woefully insufficient the Solar System is for harboring some type of doomsday,…