How exactly does the Earth evade the Sun’s (powerful) gravity?

Tuesday, 12 January, 2010

An explanation as to why the Earth, and the other (smaller) inner planets of the solar system, have not been consumed by the Sun.

It all made sense, except for one tiny problem: this same model also suggested that a little world like Earth shouldn’t exist at all; it (or more precisely, the Moon-size proto-planets that eventually assembled into the Earth) should have spiraled into the Sun more than 4 billion years ago. A star might not gobble a Jupiter whole when it moved close enough, but it could surely swallow a canapé like the proto-Earth.

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Cross the Solar System by crossing the widest webpage online

Friday, 18 December, 2009

P H E N O M E N A L, an online scale model of the Solar System, which is said to be half a mile in width.

Unlike most models, which are compressed for viewing convenience, the planets here are also shown at their true-to-scale average distances from the Sun. That makes this page rather large – on an ordinary 72 dpi monitor it’s just over half a mile wide, making it possibly one of the largest pages on the web.

To spare some scrolling here are shortcuts to Earth, and outer most planet Pluto (yes, I still regard Pluto as an actual planet).

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The knowledge and wisdom of two deep-space voyagers

Friday, 6 November, 2009

A summary of the how the two Voyager space probes have expanded our knowledge of the solar system’s outer planets.

How then to summarise Voyager? As Stone observes “I felt that we were all in the tradition of Galileo. He was the first to see the moons of Jupiter and the first to apply an instrument to increase our ability to observe the universe. Voyager is just the latest tool which we as a civilization have managed to devise, and the tool was so powerful that we saw things that nobody had seen before and that nobody had imagined that we could see.”

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Charting the exploration of the Solar system

Wednesday, 14 October, 2009

Awesome National Geographic infographic depicting the exploration of the solar system in the last 50 years… be sure to view the larger version.

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Of course we may not need to go to Mars, it might come to us

Friday, 12 June, 2009

It seems not even the orbital stability of the solar system’s inner planets is a given. If Mercury, orbiting closest to the Sun, were to be dragged out of its current orbit by Jupiter (a situation that is somehow possible) all sorts of chaos could ensue.

Mercury is the key to catastrophe. It is especially susceptible to Jupiter’s influence because of a small celestial coincidence: Mercury’s perihelion, the point where it gets closest to the sun, slowly moves around at a rate of about 1.5 degrees every 1000 years, and Jupiter’s perihelion moves around only a little slower. One day, the two will probably fall into sync, at which time Jupiter’s incessant gravitational tugs could accumulate and pull Mercury off course.

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Flickr’s stellar collection of planets, stars, and galaxies

Friday, 27 March, 2009

Discover the solar system, galaxy, and the infinite beyond right here on Flickr.

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Is a 300 year old storm on Jupiter finally abating?

Tuesday, 24 March, 2009

There’s evidence that Jupiter’s Great Red Spot, a storm twice the size of Earth, which has been raging for the last 300 or so years, may be diminishing.

Observations of cloud cover over the past decade or so have suggested the huge, oval tempest was getting smaller as Jupiter’s climate changes. But such observations are tricky because it’s hard to find the edges of the storm compared with nearby clouds on the visible surface of a gas planet that is entirely shrouded in colorful clouds. Nearby storms can nip off parts of the giant storm, and in turn the Great Red Spot can consume nearby clouds.

300 or more years isn’t a bad innings.

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If you think the Sun is massive you ain’t seen nothing yet…

Monday, 16 March, 2009

An awesome graphic which puts the scale of the cosmos into (some sort of) perspective.

Starting with the Earth and the Moon, it eventually works up to the largest known star, the hypergiant VY Canis Majoris, the surface of which – if estimates of its size are correct – would extend to the orbit of Saturn were it to take the place of the Sun.

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Act locally, think intergalactically, Pluto is a planet in Illinois

Friday, 13 March, 2009

Today is Pluto Day, at least if you live in the US state of Illinois, where lawmakers have also decreed that Pluto is a planet, in contravention of the International Astronomical Union 2006 ruling declaring it be classified a dwarf planet, as it is “too small” to be a full-sized planet.

Clyde Tombaugh who discovered Pluto in 1930, happens to hail from Illinois, which goes someway in explaining the recent actions of the Illinois senators.

A February 26 resolution adopted by the state senate honors the Streator,Ill.-born astronomer who discovered Pluto in 1930 by declaring March 13, 2009, “Pluto Day” in the State of Illinois. The resolution states Dr. Clyde Tombaugh first noticed Pluto when he worked at the Lowell Observatory in Flagstaff, Ariz. It also says Pluto was “unfairly downgraded” when the International Astronomical Union voted to demote it.

Update: Pluto, together with Eris, are in fact classed as Plutoids not dwarf planets.

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If there is a Planet X what should we call it?

Tuesday, 10 February, 2009

Some astronomers feel there is another, as yet undiscovered, planetary member of the Solar system far out beyond the orbit of Neptune, which may be about the same size as Earth.

If we know enough to say the solar system is a filigree construction, we might reasonably assume we know where all its bits are. But lurking in the solar system’s dark recesses, rumour has it, is an unsighted world – Planet X, a frozen body perhaps as large as Mars, or even Earth.

Given Venus is considered Earth’s sister planet, as the two have approximately the same size and mass, would Planet X therefore be considered a sibling of ours? A long lost sibling perhaps?

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