October 2012

Swansong Earth: Refuges for Life

October 31, 2012

As we begin to identify planets in the habitable zone of their stars, the larger issue becomes what fraction of stars have such planets. This is eta-Earth (ηEarth), the percentage of Sun-like stars with Earth-like planets in the habitable zone, a figure we can gradually home in on as statistical surveys like Kepler continue to [...]

Read the full article →

Asteroid Deflection: The Paintball Solution

October 30, 2012

Planetary Resources has us thinking about mining the asteroids to extract useful materials, but learning more about these objects will benefit us in all kinds of ways. Not only do asteroids offer up clues about the early Solar System, but getting to understand their composition and structure will be a key element in any future [...]

Read the full article →

Opening Minds to the Stars

October 29, 2012

When it comes to experiencing the night sky, there are times when mathematics fades away and poetry comes to the fore. Witness these lines from John Milton’s Paradise Lost: A broad and ample road, whose dust is gold, And pavement stars, as stars to thee appear Seen in the galaxy, that milky way Which nightly [...]

Read the full article →

SETI: Rummaging in the Data

October 26, 2012

Astronomy is moving at a clip that sees more data accumulated than can possibly be examined at the time they’re collected. We’re creating vast storehouses of information that can be approached from various angles of study. Now ponder how we might use these data for purposes beyond what they were collected for. In a new [...]

Read the full article →

Wanderers Between the Galaxies

October 25, 2012

The idea of planets outside their normal settings is unsettling. It implies that beyond the stars all around us there may be worlds without suns, dark planets presumably pushed there by gravitational instabilities in their home systems. We’ve looked at such ‘nomad’ worlds before, noting that ice overlaying a frozen ocean might trap enough geothermal [...]

Read the full article →

On Missions and Nearby Stars

October 24, 2012

Sara Seager’s thoughts on who might join a crew bound for Alpha Centauri have had resonance, as witness Dennis Overbye’s story Discovery Rekindles Wish for a Journey to the Stars in the New York Times. Overbye, a touchstone in science journalism, has probably been pondering the issue because of Seager’s response to his question about [...]

Read the full article →

Deck Hands for a Four Decade Journey

October 23, 2012

If you were offered a chance to make an interstellar journey, would you take it? How about a garden-variety trip to low-Earth orbit? I’m often asked questions like this when I make presentations to the public, and I have no hesitation in saying no. Though I’m no longer doing any flight instructing, I used to [...]

Read the full article →

Centauri B: Targets and Possibilities

October 19, 2012

Voyager 1, now 17 light hours from Earth, continues to be my touchstone when asked about getting to Alpha Centauri — and in the last few days, I’ve been asked that question a lot. At 17.1 kilometers per second, Voyager 1 would need 74,000 years to reach the blistering orb we now believe to be [...]

Read the full article →

Reflections on Centauri B b

October 18, 2012

When planet-hunter Greg Laughlin (UC-Santa Cruz) took his turn at the recent press conference announcing the Alpha Centauri B findings, he used the occasion to make a unique visual comparison. One image showed the planet Saturn over the limb of the Moon, as shown immediately below in a 1997 photo from Krzysztof Z. Stanek. Think [...]

Read the full article →

Alpha Centauri and the New Astronomy

October 16, 2012

For much longer than the nine years Centauri Dreams has been in existence, I’ve been waiting for the announcement of a planetary discovery around Centauri B. And I’m delighted to turn the first announcement on this site over to Lee Billings, one of the most gifted science writers of our time (and author of a [...]

Read the full article →

← Previous Entries