saturn
By Peter Gleick, Brett Walton, J. Carl Ganter
Water was a Top Risk on the 2015 Global Agenda
In early 2015, participants at the World Economic Forum, a who’s who of the political and business elite, ranked water crises as the top global risk. Water was also a key factor in the adoption by the United Nations General Assembly of the Sustainable Development Goals (SDGs), a blueprint for international development over the next 15 years. Ensuring safe drinking water and sanitation for all by 2030 is one of six water goals for the SDGs. In December at the UN climate change conference in Paris,…
On Life Lines, Dr. Dolittle examines the fascinating parallels between hummingbird and insect flight. He and/or she writes: "The researchers placed nontoxic paint on the wing of a ruby-throated hummingbird at 9 different spots then videotaped the animal flying at 1,000 frames per second with 4 cameras simultaneously." Despite being far removed from insects on the phylogenetic tree, hummingbirds "stir up air around their wings in a way similar to insects like mosquitoes and dragonflies." This is an example of convergent evolution, as natural selection engineers similar solutions for very…
"For most of the history of our species we were helpless to understand how nature works. We took every storm, drought, illness and comet personally. We created myths and spirits in an attempt to explain the patterns of nature." -Ann Druyan
Here on Earth, we are well aware of how devastating storms can be. From hurricanes to flash floods, an unpredictable change in weather can turn a serene setting into a catastrophe in no time at all. The clouds that fill the skies can often portend what type of weather is coming, and to me, the most impressive and fearsome of all is the rare and remarkable…
"Don't go around saying the world owes you a living. The world owes you nothing. It was here first." -Mark Twain
So, you've been around a while, seen all sorts of things, and learned an awful lot about the world, solar system and Universe that we live in. But how well do you know it, really?
Image credit: NASA / Lunar and Planetary Laboratory.
To scale and in order, these are the eight planets you know so well. There are the four rocky worlds of our inner solar system: Mercury, Venus, Earth, and Mars, and the four gas giants that dominate the outer solar system: Jupiter, Saturn, Uranus, and…
"Everyone is a moon, and has a dark side which he never shows to anybody." -Mark Twain
Back before the telescope was invented, Saturn was known as the Old Man of the Skies. The slowest-moving of the naked-eye planets, it's the only one that would reliably be in nearly the same location, year after year. You can find it all summer, after sunset, by following the "arc" of the handle of the big dipper all the way until you run into the brightest northern-hemisphere star, Arcturus, and then speeding on to the very bright Spica. Saturn is right next door.
Image credit: EarthSky.org.
But…
By Dr. Ignacio Mosqueira, an astrophysicist at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute, and Gail Jacobs
Ignacio Mosqueira works with Paul Estrada to piece together the way in which giant planets - such as Jupiter and Saturn -- and their moons and rings formed. Ignacio notes that making moons is similar to forming planets. Understanding moons may have something to tell us about the possible habitats for life, since large moons could, in principle, have both the liquid water and atmosphere necessary for the kind of diverse biology we see on planet Earth.…
By Dr. Paul EstradaPlanetary physicist at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute, and Gail Jacobs
If planets are a dime a dozen, moons are less than a penny each. There are at least 139 moons just within our own solar system. Most of these are the property of the gas giant planets beyond Mars. More than just a nice accompaniment to planets, moons may have habitats in which liquid water could ebb and flow - and possibly be a suitable home for life. Planetary physicist Dr. Paul Estrada investigates how moons around gas giants are formed -- an important…
By Dr. Mark R. Showalter
Planetary Astronomer at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute
In 1609, Galileo introduced to the world his new invention, the astronomical telescope. It opened up new opportunities to explore a territory that all prior generations had regarded as familiar--the night sky. In short order, he was making major discoveries. But the sky is very big and Galileo's telescope was very small. He had to choose his targets carefully.
In that context, Saturn was nothing special, the least of the known planets, just a bright point in a black…
by Nathalie A. Cabrol
I realize how immodest the title of this first blog may sound and it is certainly not my intention to convince anybody that I will answer this question in the limited space allowed here or even in a lifetime. My hope is, instead, to stir thoughts and invite an exchange of diverse perspectives to make this a thread that we can all pull from time to time. It is an immense subject debated in an abundant literature, but discussing it is certainly not the exclusive privilege of those called explorers. All beings, from the greatest minds to the simplest forms of life on this…