Chinese Space Rendezvous

There is good evidence that two Chinese satellites recently maneuvered in space and met, possibly even physically, gently touched. The ability to rendezvous spacecraft is central to any program with ambitions. The most famous example of that is the U. S. Gemini project. The biggest goals of Gemini were learning how to get astronauts out of and back into their ships in space, and developing experience in the rendezvous and docking of spacecraft. Both skills were essential to carrying out the lunar missions of Apollo.

That China has demonstrated the ability to rendezvous two unmanned craft shows the progress being made by the Chinese space program. Being able to rendezvous unmanned craft suggests manned craft could, too-- a skill essential for operating a space station. The capability to bring satellites together, some would point out, is another demonstration of anti-satellite potential. That, however, goes to political motivation, not technical achievement.

The Eerie Silence

In this fiftieth anniversary year of SETI, physicist Paul Davies has published a book called The Eerie Silence which examines the premise of SETI and proposes a broader search for alien life generally and evidence of intelligence in the cosmos specifically. The book is full of fascinating ideas, from scouring Earth for life forms based on something besides DNA-- a "second genesis," as Davies calls it, that he says would cinch the case for life being abundant throughout the universe-- to speculation that if we ever find intelligent life, it will likely be machine intelligence, or cyborg, or something humans cannot yet imagine.

Davies is also currently chair of a taskgroup charged with working out possible procedures and strategies that might be employed if SETI, in fact, succeeds. His views on what might happen to human civilization and humanity's view of itself in that new circumstance are also interesting.

Since SETI has only been pursued for fifty Earth years so far, and for much of that time only fitfully and focused on strategies that made sense to humans but may or may not resonate with aliens, the silence to this point might not be particularly eerie, especially considering a few incidents that may yet lead to success. Still, it's a fascinating, worthwhile book.

Curious Commercial

A commercial currently running on television notes "a bunch of guys" once got together to build rockets. Well, that bunch was NASA and its contractors, and the guys didn't build the rockets on a lark, but in pursuit of U. S. Government policy. The point of the commercial is to sell cars, so expecting too much from it is a mistake, but expecting some more respect for one of the seminal achievements of humanity might not be asking too much.

NASA's Big Announcement

Well, the speculation wasn't exactly right.

Before the NASA press conference Thursday, as reported in this blog, some speculation had been that the planet-hunting Kepler spacecraft had discovered an Earth-like world that could possibly support life. In fact, NASA announced Kepler had discovered a star system that contained at least two Saturn-sized planets, and possibly another planet only slightly larger than Earth. Both big exoplanets travel in orbits that would be inside Mercury's orbit around the Sun, and the smaller world, if it's confirmed, is closer yet, taking about 1.6 Earth days to make one complete revolution. There is, therefore, no real question of life as we know it on any of those worlds.

Still, NASA and the astronomical community are pleased. The discoveries confirm the sensitivity of Kepler's instruments and the ability of the adopted strategy to find planets around other stars-- even worlds roughly the size of Earth.

Another Alien Star System?

NASA has scheduled a news conference for later today to announce new results from the Kepler space probe. Kepler is maintaining an unblinking gaze on a specific part of the Milky Way, looking for planets orbiting other stars by noting dips in a star's brightness that could be caused by a planet moving between the star and Kepler. Speculation is that NASA will announce it has found an Earth-like planet, and possibly one that orbits in its star's habitable zone-- possibly as part of a system of planets.

The habitable zone of a star refers to the space around it in which a planet could orbit and never get too hot or too cold to support life as we know it. Roughly, it's the distance from the star at which water could exist in liquid form on the surface of an Earth-like world.

If that is in fact the news, it would be a huge discovery-- one of the most significant yet in the Space Age. Coming on the heels of the announcement by astronomers using Earth-based telescopes that they have found a star system with at least five, and possibly seven planets, such an announcement could mark the opening of a new era of our understanding of the universe and our place within it.

Testing The Dragon

SpaceX has completed a series of tests of the parachute deployment and splashdown systems in its Dragon capsule. In the final test, a helicopter lifted Dragon to altitude off the California coast and releaseed it. The drop test seemed to be a success.

Dragon is to begin carrying cargo to ISS under contract to NASA after the shuttle is retired. It will also bring garbage back from ISS. Later, SpaceX has plans to turn Dragon into a human-rated spacecraft that would ferry up to seven astronauts between Earth and low Earth orbit. NASA is looking for just such a commercial American craft to compete with Russia's Soyuz in the early post-shuttle era. SpaceX also plans to add a rocket package to Dragon at some point that would allow it to come down on land as well as into water.

Dragon's first spaceflight, atop its Falcon 9 launcher, is scheduled for next year.

Alien Star System

Astronomers have found a planetary system circling a Sun-like star 127 light-years away. The system has five firmly established planets, plus two more likely ones. All five of the firm planets have masses similar to Neptune, but they orbit their star close in, closer than Mars' orbit around the Sun. With five masses of that size orbiting so comparatively close to each other, the long term stability of that arrangement might be open to question.

The most interesting worlds in the system, however, might be the two not completely nailed down yet. One seems to have the mass of Saturn and orbits the star at a distance roughly comparable to Saturn's distance from the Sun. The second likely seems to be only a bit more massive than Earth-- which would make it the smallest exoplanet yet discovered-- but it orbits its star twice in about three of our days. No Earth-like life there.

All these worlds were discovered by noting "wobbles" in the star caused by the gravity of planets tugging it this way and that. The prrocess is laborious and time-consuming, but it works.