Seeking Other Worlds: Kepler Space Telescope Launches
A new telescope that will be able to detect earth-like planets around other stars successfully launched Friday night from Kennedy Space Center in Cape Canaveral, Florida at 10:49 p.m. Eastern time.
The Kepler Space Telescope is the first human tool that will be able to find planets capable of supporting life as we know it.
Its trip into orbit went exactly as planned, with the @NASA twitter feed declaring it, “A perfect launch!”
NASA Headquarters sent out a release at 1:00 am in which Kepler’s project manager drew attention not just to the launch, but the telescope’s ultimate mission.
“It was a stunning launch,” said Kepler Project Manager James Fanson of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Our team is thrilled to be a part of something so meaningful to the human race — Kepler will help us understand if our Earth is unique or if others like it are out there.”
“She lives! Let’s go find planets!” tweeted S. Pete Worden, head of NASA Ames, which co-managed the project.
Let us indeed!
Kepler’s wonderfully suited for her mission:
Using a sophisticated photometer, Kepler will detect the shadows of planets as they travel across the faces of their home stars in their distant orbits. It may reveal and characterize hundreds of planetary systems, some of which could be like our own, complete with a “twin” of Earth. During its four-year mission in Earth-trailing orbit, the specially designed photometer will focus on and record data from a single swath of stars in our galaxy where stellar systems with habitable planets are likely to exist. The spacecraft will store the data and transmit to Earth about once a week.
To the right there, you can see the photometer. This is an exquisite piece of equipment with a super-exciting mission, and it’s good to see she made it into orbit.
And here’s the completed beastie. Hard to believe that something that looks like mylar wrapping paper stuck in a magazine rack is one of the most sophisticated planet-hunters ever created, eh? But she is:
The Kepler instrument is a specially designed 0.95-meter diameter telescope called a photometer or light meter. It has a very large field of view for an astronomical telescope — 105 square degrees, which is comparable to the area of your hand held at arm’s length. It needs that large a field in order to observe the necessary large number of stars. It stares at the same star field for the entire mission and continuously and simultaneously monitors the brightnesses of more than 100,000 stars for the life of the mission—3.5 years.
The diameter of the telescope needs to be large enough to reduce the noise from photon counting statistics, so that it can measure the small change in brightness of an Earth-like transit. The design of the entire system is such that the combine differential photometric precision over a 6.5 hour integration is less than 20 ppm (one-sigma) for a 12th magnitude solar-like star including an assumed stellar variability of 10 ppm. This is a conservative, worse-case assumption of a grazing transit. A central transit of the Earth crossing the Sun lasts 13 hours. And about 75% of the stars older than 1 Gyr are less variable then the Sun on the time scale of a transit.
The photometer must be spacebased to obtain the photometric precision needed to reliably see an Earth-like transit and to avoid interruptions caused by day-night cycles, seasonal cycles and atmospheric perturbations, such as, extinction associated with ground-based observing.
In the meantime, have a gander at what you’ll be seeing through her eyes: