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An artist rendition of Kepler-444 planetary system, which hosts five planets, all smaller than Earth. Credit: Tiago Campante,  University of Birmingham, UK.

An artist rendition of Kepler-444 planetary system, which hosts five planets, all smaller than Earth. Credit: Tiago Campante, University of Birmingham, UK.

Using data from the Kepler space telescope, an international group of astronomers has discovered the oldest known planetary system in the galaxy – an 11 billion-year-old system of five rocky planets that are all smaller than Earth. The team says this discovery suggests that Earth-size planets have formed throughout most of the Universe’s 13.8-billion-year history, increasing the possibility for the existence of ancient life – and potentially advanced intelligent life — in our galaxy.

“The fact that rocky planets were already forming in the galaxy 11 billion years ago suggests that habitable Earth-like planets have probably been around for a very long time, much longer than the age of our Solar System,” said Dr. Travis Metcalfe, Senior Research Scientist Space Science Institute, who was part of the team that used the unique method of asteroseismology to determine the age of the star.
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Is The Moon A Planet?

Composite picture of  a dark red Moon during a total lunar eclipse. Credit: NASA/ Johannes Schedler (Panther Observatory)

Composite picture of a dark red Moon during a total lunar eclipse. Credit: NASA/ Johannes Schedler (Panther Observatory)

What makes a planet a planet? The Moon is so big compared to the Earth — roughly one-quarter our planet’s size — that occasionally you will hear our system being referred to as a “double planet”. Is this correct?

And we all remember how quickly the definition of a planet changed in 2006 when more worlds similar to Pluto were discovered. So can the Moon stay the Moon, or is the definition subject to change?

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Are Asteroids the Future of Planetary Science?

The asteroid Vesta as seen by the Dawn spacecraft. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

The asteroid Vesta as seen by the Dawn spacecraft. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

I don’t think I ever learned one of those little rhymes – My Very Educated Mother Just Served Us Nine Pizzas – to memorize the order of the planets, but if I had, it would’ve painted for me a minimalist picture of the solar system. (Side question: what is my Very Educated Mother serving now that we only have Dwarf Pizzas?) After all, much of the most exciting work in planetary science today happens not at the planets, but around them.

Ask an astronomer where in the solar system she’d like to visit next and you’re just as likely to hear Europa, Enceladus, Titan, or Triton as you are Venus, Mars, or Neptune. Our solar system hosts eight planets but nearly 200 known moons. And moons, it turns out, are just the start. We’ve detected more than a million asteroids; surely that’s just a fraction of what’s lurking beyond our limits of observation. Let’s not even think about the billions, perhaps even trillions, of Kuiper belt and Oort cloud objects – we could be here all day! So, while the planets may dominate the solar system gravitationally, they are pitiful numerically. [click to continue…]

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Illustration by artist Ron Miller of the gigantic ring system around J1407b. (© Ron Miller)

Illustration by artist Ron Miller of the gigantic ring system around J1407b. (© Ron Miller. Used with permission.)

Astronomers watching the repeated and drawn-out dimming of a relatively nearby Sun-like star have interpreted their observations to indicate an eclipse by a gigantic exoplanet’s complex ring system, similar to Saturn’s except much, much bigger. What’s more, apparent gaps and varying densities of the rings imply the presence of at least one large exomoon, and perhaps even more in the process of formation!

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This animation, created from individual radar images, clearly show the rough outline of 2004 BL86 and its newly-discovered moon. Credit: NASA/JPL-Caltech

This animation, created from 20 individual radar images, clearly show the rough outline of 2004 BL86 and its newly-discovered moon. Click for larger animation. Credit: NASA/JPL-Caltech

Wonderful news! Asteroid 2004 BL86, which passed closest to Earth today at a distance of 750,000 miles (1.2 million km), has a companion moon. Scientists working with NASA’s 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, California, have released the first radar images of the asteroid which show the tiny object in orbit about the main body. [click to continue…]

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