Juno: Earth Fly-by today

[Mr Shifty]

The Juno probe to Jupiter will fly by the Earth today to pick up about 7.5km/s it needs to boost its orbit out to Jupiter. It's been on a long elliptical trajectory that extends out past Mars for the last two years, and this fly-by will give it enough energy to meet up with Jupiter in 2016. It's the first solar powered spacecraft to explore the outer solar system. Wave hi as it passes by the Earth at about 1921 GMT (1221 PDT)!

http://missionjuno.swri.edu/earth-flyby

http://www.space.com/23120-jupiter-juno-spacecraft-earth-flyby-explained.html

[Meithan]

Fantastic! Two hours to closest approach!

This picture of the Moon from a distance of 206,000 km just came in:

By the way, the Juno flyby will be a chance to study the so-called flyby anomaly, which is the observation that some spacecraft have gained slightly more speed than predicted during Earth flybys. Maybe the stations tracking Juno will provide the data to finally explain it. More details at ESA's blog.

Edited October 9, 2013 by Meithan

[Meithan]

The animations don't do justice to the size of the spacecraft. Wow!

[PakledHostage]

This picture of how we look to Juno from a distance of 206,000 km just came in

That looks like the moon to me? And the caption on that photo mentions that it was taken when Juno was 206000 km from the moon.

I'm following the flyby in NASA's Eyes on the Solar System program (kind of like KSP's map view for the real world). Here's a screen shot taken at about 17:45 UT (about 8 minutes ago):

[Meithan]

That looks like the moon to me? And the caption on that photo mentions that it was taken when Juno was 206000 km from the moon.

You are quite correct, sir, that is the Moon. Apparently I got carried away by the excitement and didn't look closely. I stand corrected .

Edited October 9, 2013 by Meithan

[Pwnstarr]

Animated trajectory video!

[Meithan]

I'm following the flyby in NASA's Eyes on the Solar System program (kind of like KSP's map view for the real world).

"This visualization is currently only supported on Mac OS and Windows machines."

Aaawww

[PakledHostage]

"This visualization is currently only supported on Mac OS and Windows machines."

Aaawww

I will try to post updates.

[Mr Shifty]

"This visualization is currently only supported on Mac OS and Windows machines."

Aaawww

Yeah, that's too bad. Eyes is a very very cool piece of software; every NASA spacecraft with trajectories and info from the past into the distant future.

[PakledHostage]

Here's the view from Juno, according to Eyes on the Solar System, at 1815 UT:

[Meithan]

Thanks for the update. The Earth looks larger than in the last image.

[PakledHostage]

You can actually see the Earth growing in the field of view now if you watch the edge of the spacecraft relative to the clouds. Just checked the weather forecast in Capetown. It is clear for the next few hours. Hopefully someone will be able to catch a photo of it going by!

[Mr Shifty]

You can actually see the Earth growing in the field of view now if you watch the edge of the spacecraft relative to the clouds. Just checked the weather forecast in Capetown. It is clear for the next few hours. Hopefully someone will be able to catch a photo of it going by!

I think it will be in shadow for its closest point. Might be able to see it just before it passes the terminator, but not with the naked eye. 1900 GMT now: 11.5km distance, 44.7 km/s

[Mr Shifty]

Update 1905GMT:

[Motokid600]

I'm surprised how large the thing is. 2015 and 2016 are going to be amazing years for astronomy. The very first detailed pictures of Pluto from New Horizons then a year later we get high res low altitude pictures of Jupiter. Amazing. Hows Juno going to break into Jovian orbit? Ion propulsion? I can't imagine an areobrake.

[PakledHostage]

I think it will be in shadow for its closest point. Might be able to see it just before it passes the terminator, but not with the naked eye.

I recall seeing on the NASA mission page that it would be faintly visible to the naked eye from Cape Town, but you'd have to know where to look. I can't find the site right now though because of the US government shutdown. Even so, a long exposure with large aperture (and maybe even an elevated ISO setting for good measure) should pick it up. I've been able to capture photos of equally faint satellites with my EOS-M.

[Kryten]

Hows Juno going to break into Jovian orbit? Ion propulsion? I can't imagine an areobrake.

Chemical rocket burn. It's too far out for ion propulsion to be really practical within the kind of mass budget the mission has, the panels would have to be huge.

[Mr Shifty]

I'm surprised how large the thing is. 2015 and 2016 are going to be amazing years for astronomy. The very first detailed pictures of Pluto from New Horizons then a year later we get high res low altitude pictures of Jupiter. Amazing. Hows Juno going to break into Jovian orbit? Ion propulsion? I can't imagine an areobrake.

It's got a hydrazine/nitrogen-tetroxide British made engine. (The same one used for the MESSENGER mission to Mercury.)

http://www.bbc.co.uk/news/science-environment-19477618

[PakledHostage]

Update 1915 UT

[Mr Shifty]

And there's perigee according to Eyes: 573.4km; 53,488 km/hr; 19:21:52GMT. Hi Juno!

[PakledHostage]

Update 1945:

[Motokid600]

Hello Juno.. and goodbye. Until 2016.

[PakledHostage]

One last update for completeness (maybe we'll look back on this thread in 2016):

[PakledHostage]

I was surfing around before heading home for the day and I came across these. For your viewing pleasure...

Bill Nye Explains Juno's Earth Fly By:

Bill Nye asks "Does Jupiter Have a Core?":

Bill Nye Explains Solar Powered Spacecraft:

[rkman]

Juno Spacecraft Paper Model

http://www.jpl.nasa.gov/images/pdf/Juno_Spacecraft_Paper_Model_FC.pdf (pdf)