A Jupiter-like gas giant planet orbits a young star in an artist’s conception. Credit: T. Pyle (SSC), NASA/JPL-Caltech
Of the billions of stars in our Milky Way galaxy, 15 percent may host “twins” of our solar system, a new study says.
While that might not sound like much, the find suggests that several hundred million star systems look a lot like the one we call home, the study authors say.
The research is based on surveys of stars with gas giant planets—similar to Jupiter and Saturn—that orbit far from their stars.
As in our solar system, vast distances stretch between these stars and their gas giants. This creates ample room for rocky planets to thrive in the stars’ habitable zones, the regions where liquid water can exist.
And that boosts the likelihood that other Earths, and maybe even other forms of life, abound in the Milky Way.
“For the first ten years of planet hunting, we were feeling a bit worried—other systems looked so different from our own solar system,” noted Debra Fischer, an astronomer at San Francisco State University who was not involved in the research.
“[These] results are reassuring us that there are solar systems akin to our own. This is real data that strengthens the hypothesis that there are many habitable worlds like our Earth.”
Read the rest…
Taken by astronaut William Anders from the Apollo 8 spacecraft, this December 1968 photo of Earth rising over the lunar surface would become one of the most famous images of the 20th century. Credit: NASA
NASA heads into 2010 with the bittersweet assignment of retiring the space shuttle after nearly three decades. But that’s not all the agency has planned: There are also launches of three new satellites aimed at better understanding the Earth’s climate and oceans, and the sun.
Two of the probes will examine Earth — specifically the concentration of salt in the world’s oceans and the presence of aerosol particles, such as soot, in the atmosphere. A third mission will study the sun and its effect on space weather including solar flares that can disrupt communication on Earth.
All three come at a critical time for NASA. Data from the two Earth probes will likely influence global-warming research, and the trio of launches could serve as bright spots in a year otherwise dominated by debate over the future of the agency’s manned space program.
“They are extraordinary timely,” said Michael Freilich, head of NASA’s Earth-science division, of the two Earth probes. “It is a quest for understanding of the Earth system and [to improve] our ability to predict how our wonderful environment and our planet is going to change in the future.”
Combined, the three missions will cost more than $1.5 billion.
Get the full details here…
Most astronomers today believe that one of the most plausible reasons we have yet to detect intelligent life in the universe is due to the deadly effects of local supernova explosions that wipe out all life in a given region of a galaxy.
While there is, on average, only one supernova per galaxy per century, there is something on the order of 100 billion galaxies in the observable Universe. Taking 10 billion years for the age of the Universe (it’s actually 13.7 billion, but stars didn’t form for the first few hundred million), Dr. Richard Mushotzky of the NASA Goddard Space Flight Center, derived a figure of 1 billion supernovae per year, or 30 supernovae per second in the observable Universe!
Certain rare stars -real killers -type 11 stars, are core-collapse hypernova that generate deadly gamma ray bursts (GRBs). These long burst objects release 1000 times the non-neutrino energy release of an ordinary “core-collapse” supernova. Concrete proof of the core-collapse GRB model came in 2003.
Read the rest here…
Even more from NASA here: A Hypernova: The Super-charged Supernova and its link to Gamma-Ray Bursts
NASA’s new asteroid-hunting spacecraft will roll out to the pad at Vandenberg Air Force Base, Calif., Friday in preparation for launch next month.
The spacecraft is due to launch Dec. 9 aboard a United Launch Alliance Delta 2 rocket.
Known as the Wide-field Infrared Survey Explorer (WISE), the spacecraft will spend the next 10 months circling the Earth over the poles, scanning the complete sky at infrared wavelengths to uncover hidden cosmic objects, including cool stars, dark asteroids and luminous galaxies.
“You can kind of think of it as the Google Map of the universe,” said Amy Mainzer, NASA’s deputy project scientist for WISE, explaining that the instrument will take repeated exposures of the same swath of sky, creating overlapping images as the telescope progresses through its sky scan. The stars and galaxies will appear fixed on the sky in each exposure, but asteroids will move over short amounts of time.
“WISE is going to be finding about 100,000 new asteroids in the main asteroid belt,” Mainzer said during a Nov. 17 news conference at NASA headquarters here. “And we expect it’s going to find several hundred new asteroids that get close to Earth orbits. These are asteroids and comets whose orbits take them close to Earth’s orbit.”
Read the rest of the article at www.space.com