Category: Stars in their eyes
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How to narrow the search for ET
The search for extraterrestrial intelligence needs all the help it can get. Depending on who you listen to, the chances of us spotting an intelligent technological society vary from an almost certainty to practically zero. The trouble is the sheer size of the search. The Milky Way contains around 10^10 sun-like stars, any one of…
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The puzzle of planet formation
“The formation of planets is one of the major unsolved problems in modern astrophysics.” That’s how Rafael Millan-Gabet at Caltech and John Monnier from the University of Michigan begin their account of how our understanding of planet formation is about to undergo a revolution. Driving this change will be a new generation of telelscopes and…
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Spotting alien Earths on the cheap
Spotting Earth-like planets orbiting other stars is all the rage these days. But unless you have access to a space-based telescope it’s kinda tricky. The problem is that the reflected light from a Jupiter-sized planet is roughly 10^4 fainter than the parent star. That’s hard to spot at any time but when this is coupled…
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First stars “powered by dark matter”
“95% of the mass in galaxies and clusters of galaxies is in the form of an unknown type of dark matter,” say Katherine Freese at the University of Michigan, Ann Arbor, and buddies. What effect might this huge amount of stuff have on star formation? The answer according to these guys is astounding. In the…
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Astronomers find hottest and fastest exoplanet
As astronomers discover greater numbers of planets orbiting other stars, they are able to revise their theorie sof planet formation accordingly. Exotic planets are particularly prized because they push the boundaries of theoretical understanding to its limits. Today, Leslie Hebb at the University of St Andrews in Scotland and colleagues announce the discovery of one…
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Why astronomical units need to be redefined
In 1983, the International Bureau of Weights and Measures defined the metre as the distance travelled by light in a vacuum in 1⁄299,792,458 of a second. That makes a metre a fixed unit of length. For astronomers, however, distance is rather more malleable. In astronomy, distance is measured in astronomical units. Astronomers think of an…
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The exoplanet photo gallery is bigger than you think
Astronomers tend to get excited by pinpricks of light. And perhaps today they have more reason than usual to celebrate the pixels that Paul Kalas at the University of California, Berkeley, and pals have found in one of the Hubble Space Telescope’s images. These pixels, they say, represent the first optical image of a planet…
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The cosmic ray revolution
Cosmic rays, the high energy protons and helium nuclei that constantly bombard the Earth, have puzzled astronomers for the best part of one hundred years. Where do they come from and how are they accelerated to energies in excess of 10^20 eV—that’s about the energy that Roger Federer gives a tennis ball during a serve?…
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Saturn’s anomalous orbit flummoxes astronomers
One of the first tests of Einstein’s theory of general relativity was to explain the precession of the perihelion of Mercury, which had long bamboozled astronomers. Newton’s law of gravity simply cannot account for it. But relativity does. Now it’s Saturn’s turn to flummox astrophysicists. The Russian astronomer Elean Pitjeva, who heads the Laboratory of…
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Martian methane and the smoking gun of life
The presence of methane in the Martian atmosphere is a puzzle. Methane is broken down rapidly by sunlight and cannot last long in any atmosphere. A few simple calculations show that the lifetime of a CH4 molecule in martian climes is around 500 years. So methane ought not to exist in the Martian atmosphere at…