It has been an interesting year: An extremely brilliant supernova type Ia was observed in near cosmic space with an exceptionally long lightcurve. It was also revealed (via the planetary data system) that the descent profile derived for the Huygens probe did not use the altimeter, sonic or accelerometer data as planned to reconstruct the descent profile of Huygens. This is a stunning admission that the indicators designed to keep track of the probe were ignored.
We also have the close-ups of the two-faced moon Iapetus, which look for all-the-world like melting snow near the fringes and extending into the white side along the equatorial band. All of these are necessary predictions of the theory that Newtonian-derived masses for objects are not correct, and not correct by a long shot as the distance increase from a massive body like the sun.
The source of the interior forces of Enceladus remains a mystery – gravitational and radiative energy sources cannot fully explain the high temperature out-gassing. This is not a problem, if Enceladus has a much denser core than Newtonian gravity determinations allows.
There are also a few 2006 predictions that are still pending. Did New Horizon’s get a greater gravitational boost from Jupiter than expected? Did The Messenger Probe receive less gravitational braking in the Venus fly-by? Messenger’s post fly-by correction was made three weeks after the fly-by than planned. It is rare for system planners to change a scheduled burn unless the coarse of the probe is seriously deviated from expectations. On the other hand, New horizon’s coasted for more than three months before a coarse correction. In both cases, the mission navigators must know whether or not the gravitational assists netted the expected results. To the best of my knowledge, this information has not been released.
Gravity waves have still not been observed, and more possible sources of Dark Matter have been eliminated. Stardust reveal yet another comet with high terrestrial content; weighing in against the ‘dirty snowball’ model for comets once again.
So what should 2008 reveal?
First and foremost on the docket is the Phoenix Mars probe. Phoenix is the first non-airbag protected probe since Beagle and the Polar Lander failed; and fingers are crossed. According to the theory, Mars is about 14% more dense than Newtonian predictions, but this is mitigated in several ways. The true interior of Mars is more differentiated than estimated, so the surface gravity is not 14% greater-than-expected. Also the burning of propellant during the descent will net greater momentum differentials. The results will be totally confusing to mission analysts: Like the Huygens mission to Titan, the accelerometer and Doppler measurments of total force will disagree, and like Spirit, Opportunity, Pathfinder and the Viking Mars probes, there will be gaps the reconstructed descent profile.
Cassini will continue to produce amazing puzzles: Saturn’s moons are generally composed of fairly thin layers of ice on rocky cores. There have been hints that at least one of them has a magnetic core; and this will likely be true of other moons as well. The surface composition of Titan will continue to elude mission scientists, unless they include aluminum silicates and other sands and clays typically found on the Earth in the possible list of components.
The Messenger Probe will track unusual gravity anomalies on Mercury: Elevated regions will appear to be composed of much lighter materials than the average surface density. Chasma or valleys will pose striking positive anomalies – appearing much more dense than the mean surface density. Both of these observations are not real, but the result of using orbiting probes to determine the mass of the surface, but not taking into account the change in the orbital path caused by the proximity of Mercury to the sun. Conversely, Cassini will map evidence of very dense mountains and under-dense lowlands in the moons of Saturn, just as Galileo observed in the moons of Jupiter. Saturns moons will be a factor of two more curious (gravitationally speaking) than Jupiter.
Stardust will revisit Tempel 2 in the near future, revealing what Deep Impact really stirred up. If we are able to see where the probe impacted, it will not reveal the deep stadium-sized gaping penetration, but a much broader, very shallow crater. Tempel 2, like most solar objects, is a hard rock coated with icy dust.
Finally, we will continue to occasionally observe locally very long lightcurved supernovae that are more brilliant ‘Ia type’ than expected. As bigger telescopes come on line, another trend will surface: As more and more of the Ia types found at great distances are observed, it will be realized extinction factors have been grossly under estimated, meaning virtually all of the most distant supernova we observe today are much brighter than the local sample. After the lightcurves of this emerging sample of less luminous distance events are corrected for time dilation corrections, they will appear to have very short lightcurves, on average, much shorter than the local same. This is not evidence that supernova are evolving, but evidence that both the extinction estimates and the time dilation corrections are wrong.