Why is the Earth moving away from the sun?

New Scientist ^ | Monday, June 1, 2009 | Kelly Beatty, Sky and Telescope

[SunkenCiv]

Skywatchers have been trying to gauge the sun-Earth distance for thousands of years. In the third century BC, Aristarchus of Samos, notable as the first to argue for a heliocentric solar system, estimated the sun to be 20 times farther away than the moon. It wasn't his best work, as the real factor is more like 400. By the late 20th century, astronomers had a much better grip on this fundamental cosmic metric -- what came to be called the astronomical unit. In fact, thanks to radar beams pinging off various solar-system bodies and to tracking of interplanetary spacecraft, the sun-Earth distance has been pegged with remarkable accuracy. The current value stands at 149,597,870.696 kilometres. Having such a precise yardstick allowed Russian dynamicists Gregoriy A. Krasinsky and Victor A. Brumberg to calculate, in 2004, that the sun and Earth are gradually moving apart. It's not much -- just 15 cm per year -- but since that's 100 times greater than the measurement error, something must really be pushing Earth outward... Takaho Miura of Hirosaki University in Japan and three colleagues... argue that the sun and Earth are literally pushing each other away due to their tidal interaction. It's the same process that's gradually driving the moon's orbit outward: Tides raised by the moon in our oceans are gradually transferring Earth's rotational energy to lunar motion. As a consequence, each year the moon's orbit expands by about 4 cm and Earth's rotation slows by 0.000017 second... the distance between the Earth and sun is growing because the sun is losing its angular momentum.

[phatus maximus]

What will the do when the galaxy collapses in on itself and goes supernova?

Die?

[SunkenCiv]

Yeah, it could be bad.

[SunkenCiv]

What a relief.

[SunkenCiv]

Those are tiny in mass in comparison with the Sun, but velocity also matters, so there’s some kind of movement of the whole works. OTOH, CMEs aren’t confined to one side, so they probably cancel out. And standing on Mercury, one couldn’t even use ‘em to make smores. ;’)

[SunkenCiv]

Loss of mass is very small, even over long periods of time.

[SunkenCiv]

“The *debate* is *over*!” — Al Gore

[SunkenCiv]

:’) Actually, I think the linkage is with Israel’s building “settlements”.

[SunkenCiv]

Thanks.

[SunkenCiv]

LOLOL!

[Red_Devil 232]

What ever, just as long as we don’t shoot out into space on a big ol’ wave of solar energy until my ‘maters are done !

[razorback-bert]

We are all going to die.

[stayathomemom]

Entropy?

[ETL]

CMEs aren’t confined to one side, so they probably cancel out.

I doubt if they would symmetrically cancel out.

BTW: CMEs can be quite large. The white circle below represents the Sun. Some 109 planet Earths could fit side by side across the white ring/Sun's diameter.

Sun Storm: A Coronal Mass Ejection
Credit: SOHO Consortium, ESA, NASA

Explanation: Late last month another erupting filament lifted off the active solar surface and blasted this enormous bubble of magnetic plasma into space. Direct light from the sun is blocked in this picture of the event with the sun's relative position and size indicated by a white half circle at bottom center. The field of view extends 2 million kilometers or more from the solar surface. While hints of these explosive events, called coronal mass ejections or CMEs, were discovered by spacecraft in the early 70s this dramatic image is part of a detailed record of this CME's development from the presently operating SOlar and Heliospheric Observatory (SOHO) spacecraft. Near the minimum of the solar activity cycle CMEs occur about once a week, but as we approach solar maximum rates of two or more per day are anticipated. Though this CME was clearly not headed for Earth, strong CMEs are seen to profoundly influence space weather, and those directed toward our planet and can have serious effects.

To enlarge image, click here:
http://antwrp.gsfc.nasa.gov/apod/ap000309.html

[Jabba the Nutt]

The End is Near! At least getting nearer at 15cm.

[poindexter]

The Moon stopped turning on its axis because it has been transferring momentum to the Earth and is a mere 1 per cent of Earth's mass.

The Moon hasn't stopped turning on its axis. The period of rotation exactly matches its orbital period, so it appears to have stopped rotating, to us here on Earth.

[ETL]

That coronal mass ejection I just posted was in March 2000.

[theymakemesick]

Solar wind blowing Earth away.... /rimshot

[a fool in paradise]

SUVs, incandescent lights, and cattle farts.

[smokingfrog]

Yes, but what about the Lense–Thirring effect?

[D Rider]

The other theory is that the speed of light is slowing down, (therefore it looks as if the earth is moving away from the sun.)Also h is increasing. It appears that hc is constant not c. It has been known for a while that the relationship between orbital time and atomic time is not constant.