Archive

Posts Tagged ‘exomoon’

Faraway Moon Or Faint Star? Possible Exomoon Found


Titan, Europa, Io and Phobos are just a few members of our solar system’s pantheon of moons. Are there are other moons out there, orbiting planets beyond our sun?

NASA-funded researchers have spotted the first signs of an “exomoon,” and though they say it’s impossible to confirm its presence, the finding is a tantalizing first step toward locating others. The discovery was made by watching a chance encounter of objects in our galaxy, which can be witnessed only once.

“We won’t have a chance to observe the exomoon candidate again,” said David Bennett of the University of Notre Dame, Ind., lead author of a new paper on the findings appearing in the Astrophysical Journal. “But we can expect more unexpected finds like this.”

The international study is led by the joint Japan-New Zealand-American Microlensing Observations in Astrophysics (MOA) and the Probing Lensing Anomalies NETwork (PLANET) programs, using telescopes in New Zealand and Tasmania. Their technique, called gravitational microlensing, takes advantage of chance alignments between stars. When a foreground star passes between us and a more distant star, the closer star can act like a magnifying glass to focus and brighten the light of the more distant one. These brightening events usually last about a month.

Link To Full Story

Magnetic Shielding Of Exomoons: To Be Or Not To Be

September 10, 2013 Leave a comment

A new study on magnetic fields around extrasolar giant planets sheds first light on the magnetic environment of extrasolar moons. The work, authored by René Heller of the Department of Physics and Astronomy at McMaster University (Canada) and Jorge I. Zuluaga of the FACom group in the Institute of Physics of the University of Antioquia (Colombia) is the first to explore the complex magnetic environment of exomoons and its impact on the habitability of these peculiar bodies.

Regrettably the results are not completely encouraging. Even the most massive moons that can be expected from a formation point of view will be small compared to Earth. Thus, the only possibility these moons can be magnetically protected from the stellar and cosmic high-energy radiation is that they are encoated by their giant planet’s magnetosphere. Yet, in orbits close to the planet, these moons can be subject to enormous tidal heating, potentially making them uninhabitable. These results represent just the beginning of an interesting research branch, which introduces a new key factor for the habitability of those “Pandora”-like environments.

Probably the first image that comes to our minds when thinking of an inhabitated extrasolar moon shows the beautiful landscapes of Pandora, the hypothetical moon of James Cameron’s movie Avatar. But the environments of extrasolar moons seem to be less favored than the idealized version shown on the big screen. Even if located around planets in the stellar “Habitable Zone”, where the amount of incoming light allows for the existence liquid water and hence life, exomoons are subject to a number of other perturbing effects making things harsher for life than previously thought.

Full Story: http://urania.udea.edu.co/sitios/facom/press.php?_inicomp=3&_numcomp=1&#