Space and astronomy news
UC Berkeley researchers have performed a detailed analysis on a binary pair of asteroids circling near Jupiter’s orbit, and believe they’re mostly water ice covered with a layer of dirt. These objects probably started out as small Kuiper belt objects, and then were captured at one of Jupiter’s Trojan points – a gravitational eddy in space where solar system material can collect.
Photographs taken of the surface of Mars show evidence that glaciers once scoured away at its surface. Since the Red Planet is so dry, where did they come from? Scientists think that Mars’ tilt towards the Sun changes very rapidly, and there was a time only a few million years ago when parts of the planet got much warmer during the summer. Glaciers could form on the flanks of the planet’s larger mountains, and grow to be several hundred metres thick after just a few thousand years.
A fleet of NASA and ESA spacecraft have spotted an immense jet of electrically charged particles in the solar wind between the Earth and the Sun. The jet is at least 200 times as wide as the Earth and occurs because magnetic field lines clash together in a process called “magnetic reconnection”. These jets are similar to ones which form in the Earth’s magnetic field, but at a much larger scale.
The supermassive black holes at the heart of most galaxies put out so much energy they churn the interstellar dust that surrounds them. NASA’s Chandra X-Ray Observatory recently took a series of images of 56 elliptical galaxies, and revealed that the hot gas and dust blasting out X-rays have a different distribution from the stars we can see. This gas and dust should have settled down millions of years ago, but it appears that these black holes are feeding so voraciously that they’re continuously stirring up the material.
When ESA’s Huygens probe touched down on the surface of Titan earlier this year, it hit hard, and then slumped sideways into the soft ground. After analyzing the landing in detail, ESA scientists have calculated that Huygens probably hit a surface similar to soft clay, lightly packed snow, or wet or dry sand. It penetrated about 10mm into the ground, and then settled slightly over time by a few millimetres, tilting the probe a few degrees. It’s possible that Huygens landed on a Titan beach, shortly after the hydrocarbon ocean tide went out.
Japan’s asteroid explorer, Hayabusa, successfully touched down onto the surface of asteroid Itokawa Saturday for the second time in a week, and the Japanese Agency announced that it’s clutching a sample of material. The spacecraft will now begin the long journey back to Earth, and it all goes well, its sample capsule should land in the Australian outback in June 2007. This will be the first time material from an asteroid will ever be sampled back here on the Earth.
More than half the stars in our galaxy are small, dim M-class stars. Until now, researchers looking for extraterrestrial civilizations have passed over them, since they probably don’t give off enough light to support life. But SETI researchers now think that they might be good candidates after all. A planet in orbit around an M-class star would have billions and billions of years orbiting its slow-burning star for life to evolve.
Planets in the inner Solar System suffered two devastating periods of asteroid bombardment. Scientists are fairly certain that the early period came from asteroids identical to the space rocks in the current main belt between Mars and Jupiter. The second period is a bit of a mystery, though. Scientists now think that there was a period at the end of planetary formation when the giant planets swept up leftover material and hurled much outwards, but also some towards the inner Solar System.
With Friday’s launch, NASA’s Mars Reconnaissance Orbiter is now on its way to the Red Planet. One of the instruments on board is CRISM, or the Compact Reconnaissance Imaging Spectrometer for Mars. This instrument will search for evidence of past water on the surface of the planet, by locating the residues left by minerals that formed in water. It’ll have 20 times the resolution of any previous instrument sent to Mars to do this task. With data gathered by CRISM, researchers should have a wealth of potential targets for future rovers and landers.
Astronomers from the US and France have discovered an asteroid with two small moons. The asteroid, 87 Sylvia, has been known since 1866, and known to have a single moon since 2001; the second moon was a complete surprise. The discovery was made using the European Southern Observatory’s 8.2m Very Large Telescope in Chile while astronomers were trying to pin down motions of the first moon. These moons allowed astronomers to estimate the mass of 87 Sylvia, and they found it was only 20% higher than water. It’s probably a loose pile of rubble held together by gravity, with mostly empty space.