With the Kepler mission scheduled for launch this spring, we should see increasing attention in the media on the detection of terrestrial-class exoplanets and speculations on possible life upon them. But it’s easy to forget that Kepler has other important goals, taking estimates, for example, on the disposition of planets in multiple star systems, and studying the stars that have planets in orbit around them. Kepler will also be looking at planetary distribution, including ‘hot Jupiters,’ and examining their size, density and reflectivity.
A Deep Space Challenge for Bloggers
All of which is a tall order for a three and a half-year mission, but we can expect a successful run to result in an extended mission as Kepler keeps its gaze fixed on a region in space allowing it to monitor the brightness of more than 100,000 stars. Have a look at OrbitalHub‘s treatment of Kepler in the current Carnival of Space, where DJ runs through the mission parameters and examines the equipment. Looking for transits, Kepler will monitor more than 100,000 stars for the duration of the mission, with the capability of detecting terrestrial planets in Earth-like orbits. We’ll learn a great deal about the orbit, mass and temperature of many new exoplanets and may well find rocky worlds inside the habitable zone.
I’m glad to see bloggers taking on the challenge of longer posts to explain the background of developing missions like Kepler. And I notice that Ethan Siegel does much the same thing with the dark energy question at his Starts with a Bang! site. Siegel has the knack of explaining complicated things in everyday terms, as in his illustration of intrinsic brightness told in terms of 100 watt light bulbs, and the relation of that discussion to calculating cosmic distances. We use type Ia supernovae, in which a white dwarf draws mass from a companion star in sufficient amount to cause an internal collapse and subsequent explosion, as helpful distance markers and, as Siegel points out, they’ve given us evidence for dark energy.
Problems in Interstellar Propulsion Studies
What else can we do to promote education in deep space matters? I often think about this in terms of where we are in the discipline of propulsion studies. The second half of the 20th Century saw two distinct threads of interstellar propulsion concepts. The first centered on approaches workable through known physics — lightsails, magsails, beamed particle and pellet propulsion, fusion and, to the extent that we might one day learn how to create sufficient quantities of the stuff, antimatter. The second thread looks at more exotic concepts including the bending of spacetime through wormholes and the possibility of exploiting interesting and little understood quantum effects.
Both these approaches have their adherents, but interstellar propulsion research has taken place in a largely disjointed fashion, with researchers usually under-funded (if funded at all), doing this work in their spare time as they toiled at their day jobs. The recent publication of the AIAA volume Frontiers of Propulsion Science (edited by Marc Millis and Eric Davis) consolidates much current work on breakthrough concepts, and the appearance of the Tau Zero Foundation will, we hope, begin to draw the two strands of research into closer contact, seeking funding for practitioners whose peer-reviewed work includes near-term concepts where the physics is well understood and the chief problem is on the engineering (and economic!) side.
An Interstellar Agenda for Today
Uncertain economic times are doubtless going to put the brakes on many useful mission concepts, but we should continue to develop interstellar studies as a discipline by deepening our commitment to public education over the Internet. Interstellar studies also needs two things crucial to healthy debate. One is a regular journal, beginning on an annual basis, to offer a venue for current research, adding to what outlets like the Journal of the British Interplanetary Society and Acta Astronautica already do part-time. The second is the re-emergence of a Robert Forward/Eugene Mallove-style bibliography to consolidate useful papers and links in a readily available resource.
As we work on all this, public outreach will remain crucial for developing the support any robust space program needs. And so, more power to bloggers like DJ and Ethan Siegel, who along with their many colleagues around the globe continue to explain complex issues with both clarity and an insistence on scientific rigor. Getting to the stars will be a multi-generational challenge that will require long-term commitment and a willingness to look beyond the demands of the present to see the broader goal. And who knows, maybe the economic meltdown will shake us out of our complacency enough to remember that we’re building a future not just for ourselves but for our grandchildren’s children.