Observations Upset Models of Stellar Evolution
December 22, 2011
Stellar evolution models go back decades. Ever since the Hertzsprung-Russell diagram came out in 1910 (graphing temperature against luminosity), showing most stars fell on a line called the “main sequence”, astrophysicists have sought to understand the life cycle of stars from birth to death. In general, the story goes, collapsing clouds of gas and dust produce main-sequence stars that burn nuclear fuel till they run out. Depending on their masses, they end up as supernovae, red giants or slowly-cooling cinders. While red dwarfs cool down slowly into the darkness, supernovae and red giants eject mass outward into space . Two new planets found close to a red giant are among new headaches for theorists.
Earth’s Twin: What Does “Potentially Habitable” Mean?
December 5, 2011
The Kepler spacecraft has found dozens of “potentially habitable” planets around other stars, but this week announced one that some news sources are calling “Earth’s twin.”
Curiosity About Mars Rising
November 22, 2011
If all goes well on November 26, the newest Mars rover, nicknamed Curiosity, will rise above Earth’s atmosphere on a rocket pushing it toward the red planet. The Mars Science Laboratory (MSL) is the largest and best-equipped rover ever built for the robotic exploration of another planetary surface.
Europa Plus Water Does Not Equal Life
November 18, 2011
NASA gave one of its high-profile press releases this week to dazzle reporters: Europa, the icy moon of Jupiter, may have large lakes of liquid water under its icy shell, closer to the surface than the deep ocean long believed to exist miles down. The curious domes rising above the ice seem to indicate heating that Would the reporters resist the temptation to speculate about life?
Space Physics and Fables
November 9, 2011
Physics is supposed to be the king of “hard science” because of its precise mathematics, predictability and falsifiability. When transferred off our planet, however, it seems speculation is the order of the day.
October 28, 2011
Members of our solar system that were little more than points of light for decades or centuries have now become familiar family members, seen up close and personal by spacecraft. Here are introductions to three worlds that are no longer mere names in a catalog. Even the names of members in this trio may be unfamiliar to some. They’re worth getting to know.
Aliens Among Us
October 26, 2011
Some SETI researchers are looking for intelligent design on Earth – by aliens! Paul Davies has written seriously about the possibility of “alien bioengineering” that could be detected in DNA. NASA’s tax-supported Astrobiology Institute gave the idea good press, apparently unaware that most SETI researchers and astrobiologists vociferously reject the theory of intelligent design.
October 22, 2011
Want the ultimate in powder snow? Ski Enceladus, a little moon of Saturn. The snow is deep and vast. Drawbacks: except for occasional craters and steep canyons, the land is flat; there are no ski lifts; there is no air; you would weigh one or two pounds, and transportation will cost you billions of dollars. Other than that, science news outlets are advertising it as a great place for snow lovers!
Comety Show: Oceans from Space
October 11, 2011
Finally, a comet has been found with a deuterium-to-hydrogen ratio that is close to that found in Earth’s oceans. That had not been true of many other comets. Astrobiologists claim this ration in Comet Hartley 2 as “proof” that our water came special delivery from water-balloon comets. But why do they believe that, what constitutes proof, and what new problems does the “proof” lead to?
Three Strikes Against Uranus
October 9, 2011
Uranus has an axial tilt of 98 degrees, giving it the appearance of a bulls-eye as it revolves around the sun. Its moons revolve comfortably around the planet’s equator. This unusual arrangement, unique in the solar system, has challenged planetary scientists since its discovery. A new model accounts for it through a series of gentle bumps from impacts as the planet was forming from dust and gas, but how would one ever test such an idea?
Mercury Messenger: Surprise!
September 30, 2011
As boring as the moon? Just a burned-out cinder? Not Mercury. True to tradition for planetary exploration, the MESSENGER spacecraft has served up a plate of surprises about the innermost planet. In orbit since March, the ship is sending theorists back to the drawing board to figure out a number of puzzling phenomena, some unique to Mercury. Commentators fall into two categories: those that are flabbergasted, and those who say all is well.
It’s Still a Rare Earth
September 25, 2011
Now that hundreds of extrasolar planets are known, how do they compare to ours? The Kepler spacecraft has found a varied assortment of all sizes and distances away from their parent stars. Only a few reside in their star’s habitable zones. But that’s only the first of many requirements for life. Two recent studies indicate that Earth remains a rare bird in the celestial aviary.
Where Do Gems and Precious Metals Come From?
September 7, 2011
Gold, diamonds, and other precious metals and gems... they are found close to the surface of the earth where humans can mine them and make jewelry. But they shouldn’t be there. Heavy elements should have sunk deep into the core of the Earth soon after it was formed. Wait till you hear some of the latest ideas about how precious metals and gems arrived near the surface. Maybe they shot up from the mantle. Maybe they came from outer space.
Science Without an Object: Astrobiology, Alien Science
September 6, 2011
Can science exist without an observable object? In recent years we have seen serious scientists ponder alternate universes and parallel universes, dark matter, dark energy and other imponderable entities. String theory has yet to rest on observable data, and physicists at CERN are getting worried about not finding the hypothetical Higgs boson. Sooner or later, these theories need to detect their subjects or lose credibility in the science club. Perhaps nowhere else has the disconnect between hype and observation reached the absurd limits of astrobiology and alien science.
8.7 Million Species Is Not a Scientific Fact
August 24, 2011
Human beings love to classify things. We pigeonhole items into bins of our own making, for whatever the reason, to give us a feeling of having things organized and understood. Do our pigeonholes reflect categories that are “out there” in nature, or are they constructs of our own minds? Science reporters are announcing in bold print that there are “8.7 million species on Earth,” but a look at the fine print shows the error bars to be so enormous, there is more error than data. What does this imply about the scientific validity of human classification schemes?