Courtesy NASAWe like to think of our home planet – Earth – as a pretty unique place. It's the only planet in our solar system capable of sustaining life. We look through telescopes and to see exotic looking planets of various sizes and shapes. But we're the one and only Earth, right?
A new census of planets in the Milky Way galaxy shakes up that thinking. New data collected by NASA's Kepler spacecraft pegs one in six stars in the Milky Way of having planets that are the same size as Earth. That one-sixth fraction translates into an estimate of about 17 billion planets that are the same approximate size as our home.
So we're not as exclusive as might like to think. But the exclusivity meters edges back toward us when you factor in the Goldilocks zone – a distance from the host star that's not too hot nor too cold to sustain life. So far, extended research on the new-found planets has identified only four Earth-sized planets that could possibly reside in a Goldilocks zone. The Kepler project has identified a total of 2,740 potential new planets with more research ongoing.
Astronomers have found a new planet, and it's the closet planet to our solar system. But don't get your hopes on going to visit there. It would take 40,000 years to get there and once you arrive, you'll find the planet is mostly lava. And it's much closer to its star than Mercury is to our sun. Its quick orbits on that short track take just 3.2 Earth days to make a year.
Courtesy NASA/JPL-Caltech/T. PyleNASA announced this week the discovery of two Earth-sized planets orbiting a star 1000 light-years away in the constellation Lyra. The star system, called Kepler 20, is orbited by five planets. The two planets of interest, named Kepler-20e and Kepler-20f, are the first exoplanets their size to be discovered around another star resembling our own.
Francois Fressin, the lead author of the study which appears in the journal Nature, said the Kepler mission's main goal is to discover Earth-sized planets located in the habitable zone of other star systems. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them,” Fressin said.
Kepler 20e is slightly smaller than Venus, while Kepler-20f is slightly larger than Earth. The exoplanets' host star is smaller than the Sun and a bit cooler in temperature, however, the orbits of Kepler-20e and 20f are closer to their star than Mercury is to our sun, which makes them far too hot to support liquid water and too inhospitable to support life.
But the discovery is a big step in the three-and-a-half year Kepler mission, which uses ground-based telescopes and space telescopes to search out possible planet candidates.
In this recent Ted Talk, historian David Christian of the Australian Academy of the Humanities lays out a Big History of the universe from the Big Bang to the internet, complete with many thresholds and all sorts of complexity.
Courtesy lttizJoining my list of most-pleasing words (ala Donny Darko's "cellar door"), which includes such old favorites as "jasper geode" and "top banana," is the phrase "Martian ocean." And, as it happens, a Martian ocean may have once been a real thing.
Based on the analysis of dozens of the red planet's geographical features, a team of scientists from the University of Colorado at Boulder believe that an ocean may have covered about one-third of Mars' surface, about 3.5 billion years ago. Most of the river delta-like features on Mars, they claim, likely marked the boundaries of the ancient ocean. And although the ocean would have been only about one-tenth the volume of Earth's oceans, the amount of sediment in the deltas suggests that there was once a significant amount of precipitation on Mars, carrying silt through the many river valleys to the ocean.
If the theory is true, Mars would have had a water cycle very similar to Earth's, with "precipitation, runoff, cloud formation, and ice and groundwater accumulation."
And, most importantly, a Martian ocean. Martian ocean. Maaartiiaaan ooocceeaaan. Martian ocean.
I enjoy working with our team to develop on-line interactive education activities. We are in the final testing of whose goal is to teach about the balance of global water, land coverage, atmosphere and cloudiness required to create a "liveable planet". If you want to play with it and give us feedback - here is the link:
The goal is to make a habitable planet by adding enough water, atmosphere and clouds to reach a global average temperature of about 15°C (59°F). You can mix and match, add or remove.
* Drag (and drop) an item from the right side to the left to add that element
* Drag (and drop) from the left are back to the right to remove that element
* HINT You must put at least 3 clouds by the planet!!
There is a timer to see how fast you can make the planet livable.
Popular Mechanics summarizes how our knowledge of planets in the Solar System has changed over the last 30 years of space exploration.
Every space probe ever launched, all on one map of the Solar System.
So we've been stuck in the deep freeze in Minnesota for a while. I'm ready to go to HD80606b. You haven't heard of it? It's a newly discovered planet that has hot weather. Extremely hot weather that can climb by 1,200 degrees in just hours. Read more about it here. Now where did I put my sunscreen?
If you were sad to see Pluto stripped of its planetary status, you can be glad that the poor mass of rock and ice has been given a break. The international body that officially defines the names of stellar objects has decided to call all objects like Pluto, plutoids. So if Pluto isn't a planet, what is it? It's a plutoid...so is Eris.