Habitable Zones Are Not Forever
October 27, 2008
A new realization has broken on the astrobiological community: planetary habitable zones have no fences. Michael Sherber wrote for Astrobiology Magazine (see Space.com) that planets around low-mass stars tend to be pulled out of the habitable zone toward the star. They have just a billion years before migration can pull them in and cook them. […]
Earth from Space Is a Special Place
July 21, 2008
The Deep Impact spacecraft, 31 million miles away, captured images of the moon circling the Earth, reported Space.com (for the sequence of images, click here). “Making a video of Earth from so far away helps the search for other life-bearing planets in the universe by giving insights into how a distant, Earth-like alien world would […]
Beware of Starstuff
May 19, 2008
Stars can be dangerous. They spew out deadly particles, unless you are protected from them in a safety bubble – like Earth has. The Earth’s magnetic field and atmosphere only let in the life-giving part of sunlight. Studies of other stars, and our own moon, show that things could be far worse. Record flare: A […]
Planet Formation: Just Add Water?
March 19, 2008
The Spitzer Space Telescope found evidence of water in a dust disk around a star. Does this mean we understand how the earth, with all its water, formed? Using the Spitzer infrared instrumentation, John Carr (Naval Research Laboratory) and Joan Najita (National Optical Astronomy Observatory) found spectra of organic molecules and water in […]
Million-Degree Plasma Found in Orion
January 19, 2008
The Orion nebula, an object of beauty to stargazers (picture, Hubble view) is pervaded by plasma heated to two million degrees Kelvin, reported astronomers in Science.1 Two funnel-shaped regions of x-ray emitting plasma in the extended nebula were observed by astronomers using the X-Ray Multi-Mirror (XMM)-Newton satellite. “The energy requirement to heat the […]
Is Making Planets Child’s Play?
December 5, 2007
Are star children good at child's play? Like making mudballs, it should be easy to roll up dust into planets.
Hubble Explodes Star-Formation Assumption in Globular Clusters
May 3, 2007
The Hubble Telescope found three episodes of star formation in a globular cluster. While this announcement might make a layman yawn, what’s interesting are the expressions of grief and anguish coming from astronomers about what this does to their theories. For many years, astronomers had prided themselves on their understanding of globular clusters. These massive, […]
Are the Red Dwarfs Ready for SETI?
April 16, 2007
There are oodles of M-type red dwarf stars. Before now, most SETI researchers didn’t pay them much attention, because their habitable zones are narrow. Also, because the habitable zones are closer in, any planets in the lucky radius would most likely be tidally locked to the star, leaving one hemisphere in darkness and the other […]
Stardate: Destruction Estimate Was 0.1% Correct
January 23, 2007
According to a press release from JPL’s Spitzer Space Telescope team, the famous Eagle Nebula “Pillars of Creation” are eroding fast. A supernova that was possibly witnessed by humans 1,000 to 2,000 years ago is sending a blast wave at the structures. An earlier supernova that may have occurred 6,000 years ago has probably already […]
Strange Exploding Star Continues to Puzzle Astronomers
November 1, 2006
The Hubble took another image of the expanding shell of star V838 Monocerotis (see ESA and Hubblesite). Four years after the first dramatic sequence (see 05/29/2003), astronomers are still puzzled by this star, with the most dramatic light echo ever photographed. Leading hypothesis now is that two stars collided before the outburst. The image made […]
SETI Tries to Stretch the Habitable Zone
February 9, 2006
Can life exist outside the circumstellar habitable zone, that ring of life around a star where the temperature is comfy? “For more than 150 years,” Ker Than wrote for LiveScience, “…this zone has been defined as a narrow disk around a star where temperatures are moderate enough that water on the surface of a planet […]
Late Bloomer Galaxy Just Now Getting Into Star Formation?
December 15, 2004
According to a story in New Scientist, a “young” galaxy is just now starting its process of star formation. Most galaxies formed more than 10 billion years ago. Those born later tend to be fashioned from recycled gas rich in metals that were forged by previous generations of stars. But astronomers Trinh Thuan of the […]
Planet-Building a Mess, or Theories a Mess?
October 18, 2004
A news release from the Spitzer Space Telescope operated by JPL says, “Astronomers Discover Planet Building is Big Mess.” Data from the orbiting infrared observatory indicates that dust disks around stars appear to be dominated by collisions of large bodies. Surprisingly, the dust disks do not correlate with the stars’ ages. A study of 266 […]
A Completely Different Slant on Solar System Formation
July 20, 2002
51; “Did great balls of fire form the planets?” New Scientist asks. A new theory “challenges the notion that the solar system started out as a placid sea of dust motes which simply clumped together to form planets.” If accepted, it “puts a completely different slant on what happened in the early solar system in […]
Sunshine Is for Health
June 20, 2002
51; The old wisdom: stay out of the sun. The new wisdom: your life could depend on getting sunshine: about 10-15 minutes of exposure three times a week. Science Daily reported that Vitamin D, produced in the skin by exposure to sunlight, provides more health to the body than previously thought. Health professionals […]