Europa and Ganymede as Seen from Earth

The two images were captured by the European Southern Observatory's Very Large Telescope based in Chile's Atacama Desert , they were taken so astronomers can analyze the light spectrum to define the makeup of the Moons for future exploration missions

Seen as blue-colored areas in the VLT image, the icy regions of Ganymede include its polar ice caps and craters where asteroid impacts have freshly exposed the ice that makes up the Galilean moon's crust. King and his colleagues also used the images to map the size of ice grains across Ganymede's surface and determine how different salts may be distributed over it.

"[The VLT] has allowed us to carry out detailed mapping of Europa and Ganymede, observing features on their surfaces smaller than 150 kilometers [90 miles] across — all at distances over 600 million kilometers [370 million miles] from the Earth," King said. "Mapping at this fine scale was previously only possible by sending spacecraft all the way to Jupiter to observe the moons up close."

This research doesn't mean that future missions to these moons are off the table, however. On the contrary, this mapping of Europa and Ganymede makes the prospect of these spacecraft missions even more enticing.
www.space.com...

Europa has a thick ice shell with a water ocean beneath and Ganymede has a rocky ice shell with an internal ocean below and water ice at the surface , it's also the largest Moon in the Solar System (larger than Mercury) and has its own magnetic field ,although weak , which means it has a liquid core and as with Europa it probably has Hydrothermal vents ... the breeding ground for life.

originally posted by: gortex
The two images were captured by the European Southern Observatory's Very Large Telescope based in Chile's Atacama Desert , they were taken so astronomers can analyze the light spectrum to define the makeup of the Moons for future exploration missions

Seen as blue-colored areas in the VLT image, the icy regions of Ganymede include its polar ice caps and craters where asteroid impacts have freshly exposed the ice that makes up the Galilean moon's crust. King and his colleagues also used the images to map the size of ice grains across Ganymede's surface and determine how different salts may be distributed over it.

"[The VLT] has allowed us to carry out detailed mapping of Europa and Ganymede, observing features on their surfaces smaller than 150 kilometers [90 miles] across — all at distances over 600 million kilometers [370 million miles] from the Earth," King said. "Mapping at this fine scale was previously only possible by sending spacecraft all the way to Jupiter to observe the moons up close."

This research doesn't mean that future missions to these moons are off the table, however. On the contrary, this mapping of Europa and Ganymede makes the prospect of these spacecraft missions even more enticing.
www.space.com...

Europa has a thick ice shell with a water ocean beneath and Ganymede has a rocky ice shell with an internal ocean below and water ice at the surface , it's also the largest Moon in the Solar System (larger than Mercury) and has its own magnetic field ,although weak , which means it has a liquid core and as with Europa it probably has Hydrothermal vents ... the breeding ground for life.

originally posted by: putnam6

originally posted by: gortex
The two images were captured by the European Southern Observatory's Very Large Telescope based in Chile's Atacama Desert , they were taken so astronomers can analyze the light spectrum to define the makeup of the Moons for future exploration missions

Seen as blue-colored areas in the VLT image, the icy regions of Ganymede include its polar ice caps and craters where asteroid impacts have freshly exposed the ice that makes up the Galilean moon's crust. King and his colleagues also used the images to map the size of ice grains across Ganymede's surface and determine how different salts may be distributed over it.

"[The VLT] has allowed us to carry out detailed mapping of Europa and Ganymede, observing features on their surfaces smaller than 150 kilometers [90 miles] across — all at distances over 600 million kilometers [370 million miles] from the Earth," King said. "Mapping at this fine scale was previously only possible by sending spacecraft all the way to Jupiter to observe the moons up close."

This research doesn't mean that future missions to these moons are off the table, however. On the contrary, this mapping of Europa and Ganymede makes the prospect of these spacecraft missions even more enticing.
www.space.com...

Europa has a thick ice shell with a water ocean beneath and Ganymede has a rocky ice shell with an internal ocean below and water ice at the surface , it's also the largest Moon in the Solar System (larger than Mercury) and has its own magnetic field ,although weak , which means it has a liquid core and as with Europa it probably has Hydrothermal vents ... the breeding ground for life.

We're gonna Screw it all up by going to Europa. We always do.

originally posted by: jarsue97
We're gonna Screw it all up by going to Europa. We always do.

It's our JOB to hurtle through the void on a ball of dirt to CHANGE things all along the way until we cannot any more.

Have a good ride.

a reply to: gortex

They are reminiscent of steel ball bearings/marbles i played with as a kid.



Great thread Gortex.

a reply to: jarsue97
care to elaborate?

There is also very recent close images from September 29, by NASA’s Juno mission , really interesting ..

This is one

Juno

That's incredible detail for Earth-observations, I guess they used the latest, most advanced adaptive optics to achieve this.

VLT can already see space stuff better than the Hubble.

a reply to: wildespace

well duh the mirrors in the Hubble is from old spy sats from the 70's

new mirrors like what is on the JWT means we can make huge mirrors even on earth

a reply to: carbonwaste

well duh the mirrors in the Hubble is from old spy sats from the 70's
new mirrors like what is on the JWT means we can make huge mirrors even on earth

Webb is not an optical telescope so it doesn't use mirrors to see , it detects light in the infrared spectrum which gives it the ability to see through dust and gas clouds.

Hubble's mirror is fine.

a reply to: gortex

i was more referring to the distributed mirror set up

they have in the works a bigger sat that uses folded mirrors like JWT's mirrors

the bigger the mirror the better the resolution

I'm sure you know how much a precision piece of glass weighs and that's what limits the space sats we could put up until JWT.


not the specta it see's in


you can only make a single mirror so big before it is to big to launch

a reply to: carbonwaste

I like the idea of of putting a telescope on the far side of the Moon , it would be relatively easy to maintain and easy to upgrade , Webb is a beautiful thing but it's just one stray rock from disaster.

a reply to: gortex

its already been hit in the lower right(?) mirror like at 5 o'clock by a small 'something' but they were able to refocus the mirrors and its just fine


but yeah something bigger than a small grain of sand would vaporize it


i have always wondered if you could use the tech for solar sail to make a HUGE mirror

originally posted by: carbonwaste
a reply to: wildespace

well duh the mirrors in the Hubble is from old spy sats from the 70's

new mirrors like what is on the JWT means we can make huge mirrors even on earth

The problem is not so much the mirror size as the atmospheric turbulence. That's why they put the Hubble up into space - to escape the atmosphere. VLT has had huge mirrors for many years, but is only now catching up to the Hubble's resolution thanks to the new adaptive optics. www.eso.org...

originally posted by: gortex
a reply to: carbonwaste

well duh the mirrors in the Hubble is from old spy sats from the 70's
new mirrors like what is on the JWT means we can make huge mirrors even on earth

Webb is not an optical telescope so it doesn't use mirrors to see

Actually, it does. Mirrors can reflect and focus infrared light just fine. webb.nasa.gov...

a reply to: wildespace

I know.
www.abovetopsecret.com...

My point was it isn't an optical telescope.