Solar System
esiegel | May 8, 2012"There's nothing that cleanses your soul like getting the hell kicked out of you."
-Woody Hayes
There's no doubt that we lucked out when it came to the formation of our Solar System.
Image credit: Michael Pidwirny, retrieved from cosmosportal.org.
Our inner Solar System, where temperatures are ideal for liquid water and life-as-we-know-it, is full of rocky planets and devoid of any gas giants for many hundreds of millions of miles. But, as we know all too well from the last twenty years of finding exoplanets, this isn't the only way it could have turned out.
In fact, of the some 2,300…
esiegel | May 5, 2012"Without a wish, without a will,
I stood upon that silent hill
And stared into the sky until
My eyes were blind with stars and still
I stared into the sky." -Ralph Hodgson
The next month -- from May 5th to June 5th -- brings three of the most spectacular astronomy sights possible on Earth back-to-back-to-back for skywatchers of all types, without telescopes, binoculars, or any special equipment. Tonight, May 5th, marks what's come to be known as a Supermoon, or the largest, brightest full Moon of the year.
Image credit: Chris Kotsiopoulos at Earth Science Picture of the Day.
Not that you'll…
esiegel | May 1, 2012"A journey is a person in itself; no two are alike. And all plans, safeguards, policing, and coercion are fruitless. We find that after years of struggle that we do not take a trip; a trip takes us." -John Steinbeck
Here on Earth, we all get to enjoy the delight of being located in an extremely fortuitous place in our Solar System. Not just today, mind you, but billions of years ago, when the Solar System's planets were first forming!
Image credit: NASA / JPL-Caltech, retrieved from Jodrell Bank CfA.
Located close enough to our Sun, when the Earth first formed, like our neighbors Mercury,…
esiegel | April 22, 2012"Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity - in all this vastness - there is no hint that help will come from elsewhere to save us from ourselves. It is up to us." -Carl Sagan
Here on our planet, this is the one day that we take out of the year to stop and appreciate just how amazing the natural world really is, and how fortunate we are to have the Earth that we have. A wonderful but sad reminder of how fragile it is, and how quickly and easily we can affect it, comes through John Prine's great song,
Paradise.Here on our planet, there are countless…
esiegel | April 20, 2012"April is the cruellest month, breeding
Lilacs out of the dead land, mixing
Memory and desire, stirring
Dull roots with spring rain." -T. S. Eliot
Of course you all know the refrain, "April showers bring May flowers," but there's one April shower that brings fireballs instead: the Lyrids!
Image credit: John Chumack, retrieved from Bob King.
Like all meteor showers, the Lyrids come from a comet's dust trail that forms a great ellipse with respect to our Solar System. Once per year, the Earth, in its orbit around the Sun, passes through this dusty debris. When this happens, the Earth, moving…
esiegel | April 7, 2012"Well you run and you run to catch up with the Sun but it's sinking,
racing around to come up behind you again.
The Sun is the same in a relative way but you're older,
shorter of breath and one day closer to death." -Pink Floyd
For the last four-and-a-half billion years, the Earth has spun on its axis, orbiting its parent star: our Sun. Today, our home planet looks something like this.
Image credit: Reto Stöckli, Nazmi El Saleous, and Marit Jentoft-Nilsen, NASA GSFC.
Looking at our world, even from outer space, you see some very familiar features that we think of as essential parts of our…
esiegel | March 11, 2012"They call it a great wonder
That the Sun would not
though the sky was cloudless
Shine warm upon the men." -Sighvald, Icelandic poet
A couple of times a year, during the New Moon, the Sun, Moon, and Earth all line up in the same plane. As seen from Earth, the Sun's disc appears blocked, either in whole or in part, by the Moon. As The Beta Band would have told you, this creates an
Eclipse.Depending on how close the Moon and Sun are to the Earth, either the Moon's shadow will fall on the Earth, creating a total solar eclipse, or the shadow will end before it ever reaches Earth, in which case we…
esiegel | February 29, 2012"The Earth reminded us of a Christmas tree ornament hanging in the blackness of space. As we got farther and farther away it diminished in size. Finally it shrank to the size of a marble, the most beautiful marble you can imagine." -James Irwin
With everything that goes on in this world, from our daily lives to concerns around the globe, it's easy to forget just how vast the Universe is, and how small we all really are. You had so much fun playing with the Interactive Scale of the Universe tool a couple of weeks ago that I had to just give you a few things to ponder. We think of the Earth,…
esiegel | February 23, 2012"Day after day, day after day,
We stuck, nor breath nor motion;
As idle as a painted ship
Upon a painted ocean.
Water, water, every where,
And all the boards did shrink;
Water, water, every where,
Nor any drop to drink." -Samuel Taylor Coleridge, Rime of the Ancient Mariner
Despite the discovery of dozens of worlds -- planets and moons -- in our own Solar System, as well as hundreds (soon to spill into the thousands) of confirmed planets orbiting other stars, our Earth is still unique.
Image credit: The Suomi NPP Blue Marble, NASA / NOAA.
At least, it's unique as far as we know.
A smaller,…
esiegel | February 9, 2012"The phenomena of nature, especially those that fall under the inspection of the astronomer, are to be viewed, not only with the usual attention to facts as they occur, but with the eye of reason and experience." -William Herschel
We live in the most plentiful of scientific times, where the full extent of both our experience and understanding has expanded tremendously since the time of Herschel. You must remember that to Herschel, living in the 18th century, there were but six known planets (including Earth) in the Solar System: Mercury through Saturn.
Image credit: Daniel Dendy.
While each…
esiegel | February 3, 2012"More days to come / New places to go
I've got to leave / It's time for a show
Here I am / Rock you like a hurricane!" -The Scorpions
It isn't just Earth, of course, where these great cyclonic storms occur, whipping across the planet and wreaking havoc as they rage above the surface. Most famous, perhaps, is Jupiter, whose great red spot has existed for as long as we've been able to see at the necessary resolution.
But one doesn't often think of Saturn when it comes to devastating storms.
Image credit: Earth-based telescope, retrieved from SolarSystemQuick.com.
Saturn, quite famously, is a…
esiegel | January 24, 2012"Events are the ephemera of history; they pass across its stage like fireflies, hardly glimpsed before they settle back into darkness and as often as not into oblivion. Every event, however brief, has to be sure a contribution to make, lights up some dark corner or even some wide vista of history... illumined by the intermittent flare of the event." -Fernand Braudel
The spectacular event of the day, however, isn't something that started on Earth. Rather, 93 million miles away, it was our Sun, early yesterday morning (about 38 hours ago as I write this), that had a brief... shall we say...…
esiegel | December 30, 2011The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. -Carl Sagan
If the story of our entire Universe's history, from the last stages of inflation and the Big Bang up to the present day, were to be compressed into one calendar year, what would it look like?
As 2011 comes to an end, here's my final present of the year to you.
(As always, click for a more readable, higher-resolution version.)
Happy new year to all; may you all enjoy our shared story and journey while you celebrate. See you in 2012!
esiegel | December 20, 2011"Continue to surprise those who would put you in a neat demographic. Be insistently curious." -Gordon Gee
Twenty years ago, our Solar System was the only one we knew of that we were certain had planets orbiting around a main-sequence star.
Image credit: retrieved from Universe-Review.ca.
Perhaps surprisingly, it wasn't until 1995 that the first Extra-Solar Planet (exoplanet) -- or planet orbiting a star outside of our Solar System -- was discovered. And when it was, it was nothing like the planets in our Solar System. In fact, most of the earliest exoplanets discovered were not only more…
esiegel | December 9, 2011"Life is not a miracle. It is a natural phenomenon, and can be expected to appear whenever there is a planet whose conditions duplicate those of the Earth."
-Harold Urey
One of the most exciting investigations going on right now in space is NASA's Kepler Mission, which is on the hunt for planets beyond our Solar System!
Image credit: Dana Berry / NASA / Kepler Mission.
From high above the Earth's atmosphere in outer space, Kepler points at a small region of our sky, sensitive to a remarkable 150,000 stars within our galaxy!
Image credit: NASA / Kepler, retrieved from the Astronomical…
esiegel | December 1, 2011"Years of science fiction have produced a mindset that it is human destiny to expand from Earth, to the Moon, to Mars, to the stars." -Barney Oliver
Just five days ago, the newest rover sent to Mars, Curiosity, was successfully launched aboard an Atlas V rocket.
Image credit: NASA / Bill White, retrieved from gizmag.com.
But if you're anything like me, you can't just sit around and wait until its arrival in August of next year! After all my favorite rover is still rolling around on Mars after eight years, and has just uncovered something no other craft on Mars has seen before.
Image credit…
esiegel | November 21, 2011"Nations, like stars, are entitled to eclipse. All is well, provided the light returns and the eclipse does not become endless night. Dawn and resurrection are synonymous. The reappearance of the light is the same as the survival of the soul." -Victor Hugo
Everyone knows the Earth revolves around the Sun, which takes a year, and the Moon revolves around the Earth, which takes just under a month. So why, then, don't we have 12 solar eclipses and 12 lunar eclipses a year?
If you didn't know any better, you'd expect that each time the Moon passes between the Earth and Sun, its shadow would fall…
esiegel | November 16, 2011"She eyes me like a pisces when I am weak
I've been locked inside your Heart Shaped box for weeks
I've been drawn into your magnet tar pit trap
I wish I could eat your cancer when you turn black" -Nirvana, Heart-Shaped Box
By looking at the right combinations of wavelengths of light, one can literally find almost anything in the depths of space.
Image credit: Daniel Marquardt, of nebula IC 1805.
But back on Earth, we have some surprising natural features that have been captured from above with nothing more than a camera.
Image credit: NASA / STS-129 / Space Shuttle Atlantis, retrieved from…
esiegel | November 14, 2011"We don't understand how a single star forms, yet we want to understand how 10 billion stars form." -Carlos Frenck
When we look out into the distant Universe, we're also looking back into the Universe's past. The farther away an object is, the longer it's taken its light to travel from it to our eyes. And each time we observe something farther away than anything we've seen before, we're looking farther back into the past -- closer to the Big Bang -- than ever before.
Image credit: NASA, ESA and A. Felid (STScI).
The earliest thing we've ever been able to see -- of course -- is the Cosmic…
esiegel | October 3, 2011"To me it made no sense to pull one of even a few objects out of the swarm and call them something other than part of the swarm." -Mike Brown, A.K.A. PlutoKiller
In our Solar System, the four rocky planets dominate the inner portion, while the four gas giants dominate the outer Solar System. But out beyond Neptune, thousands of icy, rocky worlds -- including Pluto, the former ninth planet -- make up a vast, wide ring known as the Kuiper Belt.
Image credit: NASA.
What began as a curious collection of a few icy worlds has since revealed itself to us as an incredibly busy place, where -- since…