Space Weather Forecasters Can Count on Jupiter

Abhishek writes "Space.com reports that forecasters who predict the Solar weather can rely on Jupiter now to help them see the part of the sun that is not visible due to Earth's rotation and revolution and sun's rotation along its own axis. Scientists observing the X-Ray emanating from the Jovian atmosphere theorised that those coming from the equator were related to solar activity but it is definitely not a perfect mirror; only one in every few thousand X-Ray photons get reflected. But even that is very useful in predicting the solar weather. 'We found that Jupiter's day-to-day disk X-rays were synchronized with the Sun's emissions,' said Anil Bhardwaj at NASA Marshall Space Flight Center, who led a new study using data from the European Space Agency's XMM-Newton telescope. Their work was detailed in Geophysical Research Letters."

Comments

Of course the information will be 1.5 hours late..

[benhocking]

Since Jupiter is about 43 light-minutes from the sun, and we're about 8 light-minutes away, the round-trip travel time (when Jupiter is on the opposite side of the sun) will be 43*2 + 8 = 94 minutes.

A lot of information we get from the sun is, naturally, only 8 minutes delayed, but I guess since solar winds travel no faster than about 750 km/s (and usually travel much slower), solar winds take more than 50 hours to reach us -- so an hour and a half delay isn't that bad.

For Half of the Time, Anyway

[CheshireCatCO]

This is only helpful for half of the time. The other half, Jupiter would be reflecting parts of the Sun that we can see because we're on the same side.

If monitoring the far side of the Sun (Don't you just *want* to say "dark side"?) really becomes important, we'd need a spacecraft in the same orbit as Earth, but on the opposite side of the Sun.

Re:For Half of the Time, Anyway

[myukew]

why the same orbit? we could build two (or four or eight...) and send them to a much closer orbit so that they can gather data of much higher quality

Re:For Half of the Time, Anyway

[CheshireCatCO]

Obviously you could do that. But you don't get a lot of improvement in data quality by getting closer to the Sun (it's pretty well-resolved from here) and it's more expensive. Which is why I suggested one in the same orbit, not because that was the only option.

Re:For Half of the Time, Anyway

[Bad D.N.A.]

We have done it, and we will do it again. A while back ESA launched the two HELIOS probes into orbits getting as close as ~ 0.3 AU. Excellent missions and a lot of very important data was obtained. There are numerous proposals in the works to launch spacecraft well within the Earth's orbit. The main post was a space-weather related issue and from that perspective 1 AU is fine. But if you really want to understand the physics going in you have to get in there and measure it.

Re:For Half of the Time, Anyway

[myukew]

ah, wait... I already replied to this but...
isn't it quite hard to get something on the same orbit as earth is but on the other side of the sun?
One would either need to slow the spacecraft down so that it ends up on the other side but that'd mean you'd need to constantly run some kind of propulsion to prevent it from crashing into the sun.
Or you could just send it to the opposite side and somehow manage to get it into a stable orbit.

IANSpaceCraftEngineer but to me both ways seem rather pricey in terms of fuel usage

We'll need to add more planets!

[benhocking]

Currently, the combination of Jupiter, Saturn, and Uranus do a pretty good job of covering the Sun from all angles. Of course, when the planets line up this won't work so well. But with the pole shifting that happens during conjunction, we'll have much bigger things to worry about anyway. (WHAT?!? There was no pole shift in 2000-2001? Well, it will happen next time.)