View Full Version : Will Earth Survive When the Sun Becomes a Red Giant?

2008-Feb-01, 12:10 AM
Billions of years in the future, when our Sun bloats up into a red giant, it will expand to consume the Earth's orbit. But wait, you say, the Earth travels the Earth's orbit… what's going to happen to our beloved planet? Will it be gobbled up like poor Mercury and Venus?

More... (http://www.universetoday.com/2008/01/31/will-earth-survive-when-the-sun-becomes-a-red-giant/)

2008-Feb-01, 01:02 AM
I'll have either moved offworld or died by then. I hope the former. ;)

Do we need new laws of physics to move Earth? Why not large-scale applications of existing concepts like gravity drag? Keep shooting solar-sailed asteroids past until we move its orbit. I mean, we are talking about a billion-plus timescale, it's not like we'll have to hurry...

2008-Feb-01, 11:17 AM
Perhaps another star or large body will come close enough to split the solar system apart, so planets end up inm other orbits or depart from the sun?
Especially if there is many dim, undetected objects (more brown dwarves, "rogue planets", perhaps even undetected TNOs. Vissible stars are perhaps to be compared to "top of the iceberg" )out there, the possibility of one of them coming close may be real?

2008-Feb-01, 03:14 PM
If the sun should expand large enough to engulf the Earth's orbit, what would be the temperature of the part in the engulfment and how long would it last in the expanded state?

Occams Ghost
2008-Feb-01, 04:28 PM
It will miss Mars... But it will certainly engulf Earth. If it doesn't, then it will certainly be left to a cinder.

2008-Feb-04, 06:34 PM
Since a red giant appears to be red, the temperature of the photosphere is likely a bit more than 500 degrees c = 932 f. If the center of the photosphere is at Venus, it will likely be hotter at Earth's moon, but the presure may be less than a nano bar, so not much immediate effect, but the watts per square meter may be more than double the present 1378 watts per square meter. I like to be optimistic that the Sun will not expand past past Venus. Neil