Earth from space banner



SPACE & SCIENCE NEWS: December 2001
home > space & science news > space & science news: December 2001


Signs of an asteroid belt around Zeta Leporis Dec 31, 2001
"Alien" species of squid discovered Dec 26, 2001
The sweet taste of—meteorites? Dec 20, 2001
Astrobiology: a big joke Dec 20, 2001
Cassini's eye waters while Odyssey eyes water Dec 16, 2001
Astrobiology in San Francisco (Dec. meeting of the AGU) Dec 8, 2001
Waterworld Mars: past and future Dec 8 2001
Europa's red tinge due to bacteria? Dec 5, 2001
Evidence builds for an ocean on Callisto Dec 2, 2001


Hypothetical asteroid belt around Zeta Leporis
Signs of an asteroid belt around Zeta Leporis
(Dec. 31, 2001)


A decade ago, measurements by the Infrared Astronomy Satellite (IRAS) showed the presence of warm dust around Zeta Leporis, a star 70 light years away, twice as massive as the Sun, but only about 100 million years old (one fiftieth the Sun's age). Now, astronomers Catherine Chen and Michael Jura at UCLA report that not only may dust be present but also asteroids and possibly planets as well. Chen and Jura found that some of the dust around Zeta Lep basks at a toasty 77 °C, revealing that the dust belt's inner margin is a mere 6 astronomical units from the central star. They estimate that the entire belt has a mass comparable to that of Earth, or about 1,000 times more than the Sun's asteroid belt. The point is that the dust couldn't possibly exist unless it were being constantly replenished – it would long ago have spiralled into the star – and the only way it can be being regenerated is through the collision of larger rocky bodies. This strongly suggests the presence of asteroids. And if asteroids are present, then it may be that Zeta Leporis harbors planets as well. The next step will be to obtain an infrared spectrum of the disk to learn more about its composition.

For more, go here.

new species of squid
"Alien" species of squid discovered
(Dec. 26, 2001)


The difficulty in predicting what type of creatures might evolve on another planet, under a different set of environmental circumstances, has been underlined by the discovery of a previously unknown type of squid in the oceans here on Earth. The new cephalopod is equipped with 10 spidery, seven-meter-long arms, held in an unusual position: spread outward from the body and then bent anteriorly (i.e. at a kind of elbow). It has been spotted independently by eight different scientists in the Pacific, Atlantic, and Indian Oceans, and in the Gulf of Mexico. One sighting was made at a depth of almost five km in the western Atlantic, off the coast of Brazil. Researchers speculate that the squid may be an adult member of the recently identified family called Magnapinnidae of which only juvenile specimens had previously been seen. According to one of the scientists involved, the squid might use its long arms "like a living spider web" to catch its prey. "I think it dangles those arms until small organisms bump into them." Apparently, in a one recent encounter with a submersible, the squid seemed to have problems dislodging its arms from the vessel's hull. (NOAA).

Murchison meteorite fragment
The sweet taste of – meteorites?
(Dec. 20, 2001)


A team of NASA researchers writing in this week's Nature claim to have found a variety of extraterrestrial sugar molecules in the Murchison and Murray meteorites – two well-known carbonaceous chondrites. They believe there is little chance that these molecules are Earthly contaminants. If the claim holds up this is a key discovery because, together with amino acids, which have already been shown to arrive here from space, sugars are an important building block of life. The meteoritic sugars may predate the Solar System, having formed by the action of starlight on molecules resting on cold grains of interstellar dust. Indeed, a primitive sugar molecule has already been detected in one of the giant molecular clouds near the galactic center.

For more, go here.

Holmes and Watson
Astrobiology: a big joke
(Dec. 20, 2001)


UK psychologist Richard Wiseman has been up to some funny business – trying to find what kind of jokes make people laugh most. Having reviewed 10,000 gags with the help of 100,000 surfers from more than 70 countries, the winner was this:

Sherlock Holmes and Dr Watson are going camping. They pitch their tent under the stars and go to sleep. Some time in the middle of the night, Holmes wakes Watson up. "Watson, look up at the stars, and tell me what you deduce."
Watson says: "I see millions of stars and even if a few of those have planets, it's quite likely there are some planets like Earth; and if there are a few planets like Earth out there, there might also be life."
Holmes replies: "Watson, you idiot, somebody stole our tent!"

Cassini in Saturn orbit
Cassini's eye waters while Odyssey eyes water
(Dec. 16, 2001)


The Cassini probe en route to Saturn has developed partially blurred vision in its narrow-angle camera; specifically, it appears to have picked up some contamination which is making images from the instrument hazy around the edges. However, engineers are working to remedy the problem by turning on and off the camera's built-in heater. One cycle of warming has already brought some improvement. Another in January, it's hoped, will sharpen the camera's vision further. A similar but much worse problem with Stardust was cured in the same way.

Meanwhile, Odyssey has returned its first scientific results from Martian orbit. The spacecraft's neutron spectrometer has detected the presence of large amounts of hydrogen in soil and rock near the planet's poles. The hydrogen very likely indicates the presence of water-ice in large quantities. Scientists had been hoping for such a discovery but are surprised that it has come so early, with the probe still tightening its orbit for a mapping mission that will begin in January.

For more on this, go here.

Titan
Astrobiology in San Francisco (Dec. meeting of the AGU
(Dec. 8, 2001)


The American Geophysical Union's 2001 Fall Meeting takes place Dec. 10-14 in San Francisco and includes numerous presentations and sessions related to the search for life and water in the solar system. Just to mention two of the items, Jonathan Lunine, professor of Planetary Science and Physics at the University of Arizona, will be talking on Monday about "Oceans on Titan Past, Present and Future". His abstract reads:

Titan is Saturn's largest moon, and the second largest natural satellite in the solar system. Composed of half rock by mass, the satellite probably contains enough radiogenic material so that, when combined with accretional heating, differentiation into a rocky deep mantle and icy upper mantle is likely. Unlike its near twins in size and density, Jupiter's Ganymede and Callisto, Titan is endowed with a dense atmosphere, mostly nitrogen but with an admixture of methane. The methane is photolyzed in the upper atmosphere to make, with the participation of nitrogen, a complex mixture of hydrocarbons and nitriles. This in turn forms aerosols which descend to the surface, and have accumulated over time as solids and liquids. If photochemistry has occurred in a steady state fashion over Titan's history, perhaps hundreds of meters of liquid hydrocarbons (expressed as equivalent depth of the layer) reside in the upper crust and on the surface. The Cassini-Huygens mission will search for such liquids and assess the extent of photochemistry through time. Titan's overall history with respect to surface liquids may be complex. In the distant past accretional heating could have sustained a deep layer of mixed water-ammonia liquid as a kind of cryogenic magma ocean. Liquid hydrocarbons have come and gone on the surface through time to the present. In the distant future, when the Sun becomes a red giant star, Titan could once again possess a water-ammonia surface ocean.

Dirk Schulze-Makuch and Louis Irwin of the University of Texas at El Paso will talk on "Gravitational Flexing and the Potential for Life on the Outer Icy Satellites." Their abstract reads:

Though water is abundant on many satellites of the solar system, the potential sources of energy for dynamic geophysical activity and possible biological processes are less well known. Gravitational flexing and the presence of a liquid medium could have provided biologically favorable conditions early in the history of the solar system when many of the satellites most likely held a water vapor atmosphere. Gravitational attraction between numerous satellites and their parent planets exceeds that between the Earth and the Moon (G(Earth x Moon)). They include (for G(Earth × Moon =1) Io (× 321), Ganymede (× 86), Europa (× 68), Callisto (× 19), Titan (× 17), and Triton (× 6). Perhaps more relevant is the flexing to which a satellite is exposed between maximum and minimum gravitational interactions among its sibling moons. Flexing is greatest by far on Io (13.7%), but appreciable on Oberon (0.071%), Europa (0.058%), Callisto (0.054%), Titania (0.046%), Ganymede (0.042%), Rhea (0.018%), Dione (0.010%), Tethys (0.007%), and Enceladus (0.005%). Tidal flats on Earth typically have high biological productivity, and may have provided an environment for the origin of life. Similar conditions followed by subsequent cooling in the outer solar system could have replaced the atmosphere of distant satellites with an ice shield, leaving liquid water with living organisms beneath the frozen crust. Such ecosystems conceivably could still be supported by kinetic energy due to tidal flexing within the liquid subsurface.

Mars
Waterworld Mars: past and future
(Dec. 8, 2001)


Long-term changes, possibly related to a global shift in climate, have been detected on the surface of Mars. High-resolution images of Mars' south pole by Mars Global Surveyor show dramatic erosion in its year-round frosty upper layers. Scientists have also identified a reservoir of carbon dioxide that, if released, could alter the planet completely. The size of the reservoir, still unknown, could also influence the presence of liquid water on the Martian surface through a combination of increased atmospheric pressure and greenhouse warming. For more on this, go here (space.com).

Meanwhile, results from NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) suggest that, although covered by frozen deserts today, Mars may have been born with more water in proportion to its mass than the Earth. The new measurements suggest that if this early Martian water had been spread evenly across the planet, it could have created a global ocean at least 1.25 km deep. For more on this, go here (Spaceflight Now).

Europa
Europa's red tinge due to bacteria?
(Dec. 5, 2001)


Europa's unusual spectrum matches some of the features of the spectra of bacteria, according to astrogeologist Brad Dalton. One of the bacterial specimens he matched to the Jovian moon's light characteristics was Deinoccus radiodurans (literally "strange berry that withstands radiation"). This microbial oddball, which smells of rotten cabbage, also happens to be pinky-red in color – similar to the hue of parts of Europa's surface. Although the idea seems far-fetched – and reminiscent of Hoyle and Wickramasinghe's claims that the spectrum of interstellar dust grains matches those of bacteria – it certainly isn't out of the question. If the putative sub-ice ocean on Europa does harbor primitive life, the frozen remains of those microorganisms may well have found their way to the surface through cracks and fissures. An interesting possibility at least.

For more, go here (New Scientist).

Callisto
Evidence builds for an ocean on Callisto
(Dec. 2, 2001)


Suspicions are growing that the outermost of Jupiter's four big moons, Callisto, may have a sub-ice ocean of the type believed to exist on Europa. The latest clue to the presence of subterranean liquid is the absence of any major feature on Callisto on the opposite side to the great Valhalla impact basin. Such antipodean features have been noted on the Moon and Mercury but the fact that the impact which created Valhalla failed to generate some structure at the opposition point suggests the shock waves were absorbed by a subsurface fluid layer. Magnetometer data from Galileo had already hinted at underground oceans on Europa, Callisto, and the biggest of the Galilean moons – Ganymede.

For more, go here.

BACK TO TOP



You are here:

Home
> Space & Science news
> December 2001


Other news sections

Latest science news
Archeo news
Eco news
Health news
Living world news
Paleo news
Strange news
Tech news


Also on this site:

Encyclopedia of Science

Encyclopedia of Alternative Energy and Sustainable Living

News archive
Bookshop
Contact