Earth and its neighbors aren't the first rocky planets to circle the sun, a new study suggests. Jupiter might have had a hand in flushing an earlier generation of rocky worlds into the sun to their doom, clearing the way for the current planets to form.

Reading the post on possibility of Changing Laws of Physics in distant galaxies (reference to quasar 3C 279) got me about the here and now; space ships getting past the asteroid belt. In the process came across the genesis of our planetary system. For those of us similarly interested:



https://www.sciencenews.org/article/earth-neighbors-weren%E2%80%99t-first-rocky-planets-solar-system

The belt is between Mars & Jupiter and we have already had flybys of Jupiter since 1973. It seems to have escaped general notice how NASA managed these.

Probably like driving a car at 95 mph through a 65 mph traffic.

Space crafts should launch with just enough fuel to get to filling stations near the moon and these stations would then dispense propellant derived from lunar water-ice. Such a strategy would reduce the mass of a Mars mission by 68% at launch resulting in significant cost savings. (It currently costs thousands of dollars to put 1 lb., or 0.45 kilograms, of payload into Earth orbit.)

This is completely against the established approach: 'straight-shot-to-mars-carry-everything-with-you', says MIT Professor Oliver de-Weck and suggests examining the idea of "detour into the lunar system".

Permanently shadowed craters on the lunar surface are thought to harbor large quantities of water-ice. The ice could be processed to H & O molecules a chief components of rocket fuel. The research is being led by Takuto Ishimatsu in MIT who developed a mathematical model and found the best options relies on gas stations positioned at gravitation-ally stable places to the earth-moon system called Lagrange points.

An article which could be indirectly related to 'hopping' over the belt.

'To Get to Mars, pit stop at the Moon' http://news.discovery.com/space/private-spaceflight/to-get-to-mars-pit-stop-at-the-moon-151022.htm



On the same vein it appears that the shortest path for manned flights to Jupiter could involve a detour to Mars; then use a bit of Mars gravity to 'hop' over the asteroid belt and then Jupiter's gravity to thrust beyond.

Contrary to popular imagery, the asteroid belt is mostly empty. The asteroids are spread over such a large volume that it would be improbable to reach an asteroid without aiming carefully.

Asteroids are not distributed uniformly in the asteroid belt, but could be approximated to be evenly spaced in a region from 2.2 AU (1 AU is 93 million miles, or the average distance between Earth and the Sun) to 3.2 AU from the Sun and extending 0.5 AU above and below the ecliptic (the plane of Earth's orbit, which is a convenient reference for the solar system). That yields a volume of roughly 16 cubic AU, or about 13 trillion trillion cubic miles. (Note: space is big!)