Earth would be as bright as Venus is from the Earth at its maximum brilliance, so it should be visible when Earth and Mars are at opposition. Jupiter at opposition with Mars is about 3 magnitudes brighter than the Earth as seen from Mars, but I don't believe Jupiter will be anywhere close to opposition with Mars at that time. Jupiter at its worst would be 5.2 + 1.6 AU from Mars, which would make it about 1-2 magnitudes fainter than its opposition brightness from Mars ( about -6.0m). In either case, it would still be brighter than Venus as seen from the Earth, so again, I would predict that SPathfinder ought to be able to see both planets easily. They did spot the Sun and Diemos as you can see at the Pathfinder Astronomical Picture Gallery. The Pathfinder pointed its camera in the right direction to spot Earth as the figure above shows...but saw nothing,
This is the first image ever taken from the surface of Mars of an overcast sky. Featured are stratus clouds coming from the northeast at about 15 miles per hour (6.7 meters/second) at an approximate height of ten miles (16 kilometers) above the surface. The "you are here" notation marks where Earth was situated in the sky at the time the image was taken.
Scientists had hoped to see Earth in this image, but the cloudy conditions prevented a clear viewing. Similar images will be taken in the future with the hope of capturing a view of Earth. From Mars, Earth would appear as a tiny blue dot as a star would appear to an earthbound observer. Pathfinders' imaging system will not be able to resolve Earths' moon. The clouds consist of water ice condensed on reddish dust particles suspended in the atmosphere. Clouds on Mars are sometimes localized and can sometimes cover entire regions, but have not yet been observed to cover the entire planet.
The image was taken about an hour and forty minutes before sunrise by the Imager for Mars Pathfinder (IMP) on Sol 16 at about ten degrees up from the eastern Martian horizon.
Copyright 1997 Dr. Sten Odenwald
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