Space and astronomy news
Question: How Big Can Planets Get? Answer: Here in the Solar System, we have three kinds of planets: the inner terrestrial planets, the gas giants, and the ice planets. Sadly, Pluto is no longer a planet, so we won’t deal with that here. We know how big our planets are, but how big can planets …
As you gaze up at the familiar Pleiades star cluster, here’s something new you can think about. Planets recently collided around two of the stars in the cluster, kicking up vast clouds of dust. New worlds are being formed, and destroyed, right before our very eyes. At least, if you’ve got the help from some …
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Of the many extrasolar planetary systems discovered so far, more than a third could contain Earth-like planets. This is according to a new study by scientists associated with NASA’s Center for Astrobiology. It was originally thought that Jupiter-sized planets should clear out their star systems as they form, but some new calculations show that they …
Nearly all of the extrasolar planets discovered so far have been huge, Jupiter-sized and above. The question is: could smaller, Earth-sized planets last in the same star systems? Researchers created a simulation where tiny planets were put into the same system as larger planets to see if they could gather enough material to become as …
The composition of many planets, asteroids and meteorites could be explained by the theory of “hit-and-run” collisions. Scientists originally believed that the four terrestrial planets (Mercury, Venus, Earth and Mars) were formed slowly over time as material built up by accretion. But it’s entirely possible that objects sideswiped each other, and continued on; although, with both parties pretty banged up. Large objects don’t even have to touch to do massive damage to each other through their gravitational influence.
The time frame for the formation of new planets appears to be getting shorter than previously believed. Astronomers have discovered gaps in protoplanetary disks that suggest there are gas giants forming there. One star, GM Aurigae, is a younger version of our own Sun and the gap in its disk is at about the same location as our own gas giant planets. Since GM Aurigae is only 1 million years old, these results challenge the traditional theories that planets slowly formed over many millions of years.
Astronomers from the Harvard-Smithsonian Center for Astrophysics have discovered a massive planetary zone forming around the star system TW Hydrae. By probing this vast disk of material with the National Science Foundation’s Very Large Array in the radio spectrum, they have detected that rocks and pebbles extend outward for at least 1.6 billion km (1 billion miles). These chunks of rock will slowly clump together, eventually forming larger and larger planets over millions of years. This is the first time astronomers have seen this intermediate stage, after pure dust, but before planets.
Astronomers have found the most Earthlike extrasolar planet discovered so far. This new planet is about 7.5 times the mass of the Earth, and has twice the radius of our own planet. It whips every two days around a nearby star called Gliese 876, which is only 15 light years away – this star also possesses two additional giant, Jupiter-class planets. This is the first time that a rocky (or terrestrial) planet has been discovered around another star.
Astronomers announced today that they have discovered a new class of extrasolar planets which are between 10 and 20 times the mass of the Earth – roughly the same size as Neptune. Two planets were discovered orbiting smaller stars: one around Gliese 436 and another around 55 Cancri. Both planets orbit their parent stars in about 3 days. They were discovered using the radial velocity method, which finds planets because of how they wobble their parent star. Because these planets are much smaller than Jupiter, they’re probably made of rock and ice, rather than gas.
Image credit: Harvard CfA Astronomers from the Harvard Center for Astrophysics studied Comet Kudo-Fujikawa as it swept past the Sun in early 2003, and they noticed it was emitting large amounts of carbon and water vapour. This new view of the comet matches observations of other stars that indicate there could be comets emitting similar …
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