NASA announced three small planets orbiting the red dwarf star KOI-961. The above image (credit: NASA/JPL-Caltech) compares sizes and distances with Jupiter and the four satellites Galileo discovered. (You can see Jupiter high in the night sky these days, and a good pair of binoculars will show the moons. Not so with LOI-961–from the Earth that star is pretty darn dim, invisible to human eyes, even with an earthbound telescope.)
The depiction of the new planets above is not an actual image from Kepler–it’s an artist’s interpretation of scientific data. It’s close to what you might see from about ten million miles away. Those planets 02, 01, and 03, by the way, will be toasty-warm that close to a red dwarf. Like the glowing metal in your toaster, come to think of it.
This is a nice breakthrough for the Kepler Mission, which is designed to detect very slight dimming as planets pass in front of faraway stars with respect to the Earth. This detection method works well in space, above the Earth’s atmosphere and the interference from air. (That interference causes the twinkle in those little stars.)
From the press office:
Astronomers using data from NASA’s Kepler mission have discovered the three smallest planets yet detected orbiting a star beyond our sun. The planets orbit a single star, called KOI-961, and are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars.
The three smallest planets? Sorry, no. Another instance of the astronomy community’s bias against the first planets to be confirmed outside our solar system.
PSR B1257+12A was found and confirmed in 1994, and is only twice the mass of the moon. It is also the smallest planet known, and likely not bigger than any of the Jupiter moons imaged above. I don’t think scientists, especially biologists, get excited about pulsar planets. Quite frankly, I wouldn’t want to visit one. I’d rather attend a TLM. But astronomers, even the fine scientists working on the Kepler mission, should give credit where due. Their new planets here are between the size of Earth and Mars–a fantastic achievement, to be sure. But they are still the 2nd, 3rd, and 4th smallest known planets beyond the solar system.
Link to the NASA release found on the Universe Today blog, which is an enjoyable daily read. Highly recommended.