Solar System
esiegel | November 19, 2014“Every dreamer knows that it is entirely possible to be homesick for a place you’ve never been to, perhaps more homesick than for familiar ground.” -Judith Thurman
You'd think that landing on a comet for the first time, with all ten instruments functioning, and collecting more than two full Earth-days worth of data would be more than enough to sate the scientifically curious among us.
Image credit: ESA/Rosetta/Philae/CIVA.
But the sad reality is that despite the tremendous successes of Philae, we'll always be left to wonder what might have been if it had functioned optimally, and given us…
esiegel | November 12, 2014“I must trust that the little bit of love that I sow now will bear many fruits, here in this world and the life to come.” -Henri Nouwen
So, maybe you've been living under a rock, but whether you have or haven't, the news is still amazing: we've just landed on our first not-a-rock in space, but rather the remnants of an icy world from our Solar System's early moments of formation.
Image credit: ESA / CNES / Philae, via https://twitter.com/ObservingSpace/status/532596055783661568/photo/1.
That's right, for the first time ever, we've landed a manmade probe on a comet, and are now prepared to…
esiegel | November 6, 2014“It is not when truth is dirty, but when it is shallow, that the lover of knowledge is reluctant to step into its waters.” -Friedrich Nietzsche
Out beyond Neptune, the last of our Solar System's gas giants, the icy graveyard of failed planetesimals lurks: the Kuiper Belt. Among these mixes of ice, snow, dust and rock are a number of worlds -- possibly a few hundred -- massive enough to pull themselves into hydrostatic equilibrium.
Image credit: Wikimedia Commons user Lexicon; modified from the NASA original.
The most famous among them are Pluto, the first one ever discovered, and Eris, of…
esiegel | October 30, 2014“You cannot be lonely if you like the person you’re alone with.” -Wayne Dyer
We like to think of our Solar System as typical: a central star with a number of planets -- some gas giants and some rocky worlds -- in orbit around it. Yes, there's some variety, with binary or trinary star systems and huge variance in the masses of the central star being common ones, but from a planetary point of view, our Solar System is a rarity.
Image credit: NASA / JPL-Caltech.
Because even though there are hundreds of billions of stars in our galaxy for planets to orbit, there are most likely around a…
esiegel | September 26, 2014“I sometimes catch myself looking up at the Moon, remembering the changes of fortune in our long voyage, thinking of the thousands of people who worked to bring the three of us home. I look up at the moon and wonder, when will we be going back, and who will that be?” -Tom Hanks
Imagine, hopefully, the not-too-distant future, when humanity launches the first manned mission to another planet in our Solar System: probably Mars. You're on your way, and then -- all of a sudden -- you realize that something is wrong.
Image credit: Frank G., via https://shufti.wordpress.com/2011/11/26/aaa-around-…
esiegel | September 25, 2014“It surprises me how disinterested we are today about things like physics, space, the universe and philosophy of our existence, our purpose, our final destination. It’s a crazy world out there. Be curious.” -Stephen Hawking
The story of where everything came from in the Universe -- of how we came from empty, expanding space to our rich and complex Universe-of-today -- is without a doubt the most remarkable story ever told: the story the Universe has to tell us about itself!
Image credit: Kfir Simon / Demetrius Gore, via http://www.pbase.com/tango33/image/140317019/original..
Although there…
esiegel | September 23, 2014When you think of astrology today, you probably think of someone who makes false promises and proclaims either platitudes or fabrications as though they were preordained truths. But for many millennia dating to just a few centuries ago, astrology was anything but. In fact, by many metrics, it was the very beginning of what has grown into the enterprise of science.
House of Wisdome. Maqamat of al-Hariri Illustration by Yahyá al-Wasiti, 1237 (Wikimedia commons)
Our initial thoughts on the idea that what happens in the heavens affects what happens on Earth may have been flawed, but as it…
esiegel | September 9, 2014In 1992, scientists discovered the first planets orbiting a star other than our Sun. The pulsar PSR B1257+12 was discovered to have its own planetary system, and since then, exoplanet discoveries have exploded!
Artist’s conception of worlds around PSR 1257+12, the first system (discovered 1992) with verified extrasolar planets. Illustration credit: NASA/JPL-Caltech/R. Hurt (SSC).
But did you know that long before that, back in the 1940s, 1950s and 1960s, a scientist studying Barnard's Star -- the second-closest star system to the Sun -- claimed to have discovered the first exoplanets in…
esiegel | September 8, 2014“O, swear not by the moon, the inconstant moon,
That monthly changes in her circled orb,
Lest that thy love prove likewise variable.” -Romeo & Juliet, Act 2, Scene 2
Tonight holds a full Moon in store for skywatchers everywhere. Not just any old full Moon, mind you, but a Supermoon, the last one of the year.
Image credit: John Gaughan / Pete Lardizabal / WJLA, via http://www.wjla.com/pictures/2012/10/daily-eye-wonder-november-2012/sup….
What makes a Supermoon so super? As it turns out, not a whole lot. But as far as the physics, astronomy and science of why-and-how the Moon appears to…
esiegel | August 21, 2014“We came all this way to explore the Moon, and the most important thing is that we discovered the Earth.” -Bill Anders, Apollo 8 astronaut
When you think about the most amazing sights available to humanity here on Earth, you probably don't think about leaving Earth in order to capture them. But sometimes, doing exactly that can give you an otherworldly perspective that adds a beauty that you'd never be able to experience otherwise.
Image credit: Cosmonaut Fyodor Yurchikhin and the Russian Space Agency Press Services.
But the best collections of photos that capture this weren't taken by an…
esiegel | August 7, 2014"I’m a shooting star. A meteor shower. But I’m not going to die out. I guess I’m more like a comet then. I’m just going to keep on coming back.” -C. JoyBell C.
Every year, meteor showers sizzle and fizzle, yet no matter what happens in the skies, there's always one meteor shower that's reliable for a good show: the Perseids. After sunset tonight (and for about the next week) in the skies, they'll delight skywatchers across the globe.
Image credit: created by me using Stellarium, available free at http://stellarium.org/.
Have you ever wondered where these (or any) meteors come from? If you'…
esiegel | July 29, 2014“In any field, find the strangest thing and then explore it.” -John Archibald Wheeler
It's been over a decade, nearly a hundred thousand turns of its wheels and an unprecedented journey that still continues. But finally, after all this time, the Mars Opportunity rover has arrived.
Image credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.
Not anyplace that isn't just like something it's seen hundreds of times before; this crater is run-of-the-mill if anything is. But after more than 10 years, Mars Opportunity has finally broken the distance record for a roving spacecraft of any type on a…
esiegel | July 24, 2014“Concentrate all your thoughts upon the work at hand. The sun’s rays do not burn until brought to a focus.” -Alexander Graham Bell
The Sun, contrary to what you might normally think about it, isn't a constant, uniform source of radiation. It has an active surface, replete with temperature variations, sunspots, and occasionally a large flare or mass ejection.
Image credit: NASA / GSFC / SDO.
But on very rare occasion, a flare like this makes it way through space and just happens to make its way towards Earth, where this hot, fast-moving ionized plasma collides with us. While the aurorae it…
esiegel | July 17, 2014“Geologists have a saying: rocks remember.” -Neil Armstrong
45 years ago, the Apollo 11 mission was on its way away from planet Earth and headed towards the Moon, where the first human beings would set foot on the surface just a few days later.
Image credit: NASA / Apollo 11, photo by Neil Armstrong.
Back in 2012, the very first man on the Moon, Neil Armstrong, left this world for good. But the impact he had, and what he left behind, are worth remembering, even for those of us who weren't yet alive to remember it firsthand.
Image credit: NASA. This is the official NASA / Apollo 11 mission…
esiegel | July 8, 2014“When you’re finally up at the moon looking back on earth, all those differences and nationalistic traits are pretty well going to blend, and you’re going to get a concept that maybe this really is one world and why the hell can’t we learn to live together like decent people.” -Frank Borman, Apollo 8
You've got to wonder about the Moon. I'm not talking about what it looks like or what it has to teach us about Earth, but why the far side of the Moon looks so different from the side that faces us?
Image credit: NASA / JPL - Caltech / LRO.
For the past 55 years, we've known that the far side…
esiegel | July 3, 2014“Some prophecies are self-fulfilling
But I’ve had to work for all of mine
Better times will come to me, God willing
Cause I can’t leave this world behind” -Josh Ritter
Sure, many of us have dreams of leaving this world at one time or another. How wonderful it would be to leap from one giant rock to the next, if only it were easier. But the sheer amount of energy it would take leaves it well out of reach for most of us.
Image credit: Daniel Dou of http://www.theendearingdesigner.com/anti-gravity-artwork-seems-to-be-fl….
But what if it were easier? What if we had a gravitational assist from…
esiegel | May 20, 2014“I would rather be ashes than dust! I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.” -Jack London
Here on Earth, we think of shooting stars and meteor showers as things that happen periodically; sometimes they're spectacular, sometimes they're rare. But in all cases, they're caused by comet debris, and they should flare up each time the Earth crosses the comet's path.
Image credit: Gerald Rhemann, of Comet Lemmon, from April 21, 2012.
But as it turns out, every meteor shower had a point in its past where it happened for the very…
esiegel | May 1, 2014“Most estimates of the mortality risk posed by asteroid impacts put it at about the same risk as flying in a commercial airliner. However, you have to remember that this is like the entire human race riding the plane — it is one of the few risks that really could wipe us all out.” -Nathan Myhrvold
Yes, it's easy to say that even though the risks of getting killed by an asteroid strike are low, the consequences of a major asteroid strike are simply too high for us to not address this threat.
Image credit: Don Davis.
But is that really true? This isn't pontificating; this is science! And in…
esiegel | April 22, 2014“It took less than an hour to make the atoms, a few hundred million years to make the stars and planets, but five billion years to make man!” -George Gamow
Whenever Earth Day comes around, I see a lot of different reactions from people. Some express their passion for the environment, others express disdain for the whole concept as a distraction. Some step up to act as responsible stewards of the world, while others fear nuclear accidents, asteroid strikes or climate change.
Image credit: NASA / Voyager 1. This (cropped) 1977 image is the first photo of the complete Earth and Moon in a single…
esiegel | April 9, 2014“And everything under the sun is in tune
But the sun is eclipsed by the moon.” -Pink Floyd
We normally think of eclipses as rare phenomena, something that happens only occasionally. While it's true than any particular location only experiences eclipses -- particularly solar eclipses -- infrequently, we actually experience these things around four times a year, typically, somewhere on Earth.
Image credit: Chaisson & McMillan, Astronomy Today.
If you've been paying attention, you might have heard that we're in store for a total lunar eclipse just next week here on Earth, and that it will…