These two images show HD 157728, a nearby star 1.5 times larger than the sun. Its light has been mostly removed by Project 1640. The left image was made without the ultra-precise starlight control that Project 1640 is capable of, while the right image was made with the starlight control in place. (Images: Project 1640)

Astronomers have a powerful new tool to help them in their search for  planets outside of our solar system.

Project 1640 is a first-of-its-kind, high-contrast imaging program which combines high-tech instrumentation and software, giving scientists the ability to spot planets orbiting distant suns in star systems outside of our solar system.

Ever since the search for exoplanets began, astronomers have relied on various indirect methods to detect them because the blinding brightness of their stars makes it virtually impossible to observe the planets directly.

The Project 1640 instrument mounted at the focus of the 200-inch Hale telescope. (Photo: © AMNH/B. R. Oppenheimer)

Project 1640 uses a new technique which produces extremely precise dark holes around stars of interest. This allows scientists a look at areas surrounding the star which would normally be obscured by its intense light.

“We are blinded by this starlight,” says Ben Oppenheimer,  a principal investigator for Project 1640. “Once we can actually see these exoplanets, we can determine the colors they emit, the chemical compositions of their atmospheres, and even the physical characteristics of their surfaces. Ultimately, direct measurements, when conducted from space, can be used to better understand the origin of Earth and to look for signs of life in other worlds.”

Its creators say the system produces some of the highest-contrast images ever made, revealing objects that are one -to-10 million times fainter than the star at the center of the image.

The instrument, which started taking data last month, operates on the Hale Telescope at California’s Palomar Observatory. It’s been in development for more than six years through a collaborative effort among New York’s American Museum of Natural History, the California Institute of Technology (Caltech) and NASA’s Jet Propulsion Laboratory (JPL).

With Project 1640 up and running, researchers searching for extrasolar planets have begun a three-year survey to image hundreds of young stars outside of our solar system.

“The more we learn about them, the more we realize how vastly different planetary systems can be from our own,” says Gautam Vasisht,  a Jet Propulsion Laboratory astronomer. “All indications point to a tremendous diversity of planetary systems, far beyond what was imagined just 10 years ago. We are on the verge of an incredibly rich new field.”

S/2010 J 1 in motion Sept. 8, 2010. Animation is sped up by a factor of 2000. The actual time between each image in the animation is roughly 38 minutes. (Photo:Canada-France-Hawaii Telescope)

Astronomers have found that one of two recently-discovered moons of Jupiter is just two kilometers in diameter and may be the smallest of Jupiter’s 67 satellites.

Back in September 2010, scientists discovered two unknown distant satellites of Jupiter while conducting routine tracking observations of the planet’s previously identified moons.

To confirm that these were indeed new satellites of Jupiter, and not asteroids, the scientists re-observed them several more times during the autumn of 2010.

The International Astronomical Union’s Minor Planet Center designated the two new moons as S/2010 J 1 and S/2010 J 2.

S/2010 J 1 was discovered in September 2010 from images taken with the Palomar Observatory’s 200-inch Hale Telescope.  At its furthest, this moon is about 30,774,922 kilometers from Jupiter.

The second moon, S/2010 J 2, about 26,541,445 kilometers from the giant planet, was discovered the same month on images taken with the MegaCam mosaic CCD camera by the 3.6m Canada-France-Hawaii telescope (CFHT).  After checking observational data, astronomers also later found that the satellite was weakly visible, on Sept 7, 2010, at the Palomar Observatory.

It’s interesting to note that the moon that would come to be called S/2010 J 1, was first detected back in 2003, but was never classified as a satellite because it couldn’t be found in required follow-up observations.

The astronomers say the size of the two moons can be estimated on factors that are based on their brightness.  S/2010 J 1 is estimated to be around three kilometers in diameter. S/2010 J 1, the faintest and probably smallest Jovian moon, has been estimated to be about two kilometers in diameter.

Red diamonds show the 2010-11 observed locations of S/2010 J 1, while blue triangles show the locations of S/2010 J 2. The predicted positions of the satellites for the best fit orbits from JPL are plotted at 48-hour intervals, shown by the red and blue dots for S/2010 J 1 and S/2010 J 2, respectively (Courtesy: Mike Alexandersen)

S/2010 J 1 and S/2010 J 2 are designated as irregular satellites, or provisional moons, and are not given actual names by the International Astronomy Union (IAU) because their discoveries have not been confirmed.

Moons such as the S/2010 J 1 and S/2010 J 2 have been found to be clustered in families of other satellites with similar colors and orbits. Scientists believe these families may have formed as a result of ancient collisions with comets or asteroids with former larger moons.

S/2010 J 1 appears to belong to the Carme group, or family, while S/2010 J 2 appears to belong to the Ananke group.