Venus Express Radar? Options

[Bubbinski]

Ah, I notice there's a bunch of new forums on this site. So I figure I might as well inaugurate at least one of them.

I see that the Europeans are going to launch a sister ship to Mars Express, only this one's going to Venus. I've checked out the ESA web site and it mentions that the probe will study the atmosphere of Venus as well as measure the surface temperatures. But the site didn't say much more, nor did I see a breakdown of what instruments the craft had. Is there going to be a radar on that spacecraft as well, to make follow up observations of targets Magellan caught? Or is there going to be a camera similar to Mars Express, only targeted toward the atmospheric clouds? And are there going to be any atmospheric or surface probes launched from the main craft, a la Beagle 2?

[Guest_BruceMoomaw_*]

Nope, no entry probe and no radar. The original design DID call for a copy of Mars Express' subsurface sounding radar on Venus Express. While there's no subsurface water to be found on Venus, this instrument could probe several km below the surface and identify lava flows and other strata, which could be extremely valuable in understanding Venus' still-puzzling geological history. But JPL would have had to provide part of the cost of this "VENSIS" instrument -- and NASA said no. So, no radar.

However, the single most important instrument on Venus Express -- the VIRTIS near-IR mapping spectrometer -- may provide a really surprising amount of information on Venus' surface geology, thanks to the existence of 6 narrow near-IR spectral windows that allow the orbiter to peer through the clouds all the way down to the surface. These will allow it to obtain really high-resolution surface temperature maps and also maps of near-surface trace gases, thus allowing a search for volcanic activity. Moreover -- although there are still uncertainties about the technical feasibility of these two moves -- it may also allow some surface compositional mapping of Venus, at least near the poles (allowing a search for four or five scientifically important minerals); and (most remarkably) an attempt to carry out Venusian seismology FROM ORBIT, since calculations indicate that modestly large quakes may produce pressure waves in Venus' very dense atmosphere big enough for VIRTIS to detect, and even allowing some geographical localization of the quake epicenters. We'll see.

VIRTIS, by the way, will definitely provide fairly high-quality images of Venus' cloud patterns in a number of different wavelengths, which in turn will allow the patchy patterns of its middle-altitude clouds below the solid upper cloud top to be observed. Indeed, that is one of its major science goals -- because, by precisely tracing the wind-driven movements of such clouds at various altitudes, it may finally provide enugh detailed information on Venus' winds to solve the still puzzling question of exactly what the mechanism is that drives its atmosphere's high-speed "superrotation". It will also look for lightning, although the evidence now points strongly against the latter. And Venus Express also carries "VMC", a little camera -- a copy of the one on Mars Express that got that last shot of the ill-fated Beagle drifiting away from the craft -- which has been modified to image the UV cloud patterns at the top of the cloud deck for comparison with VIRTIS' lower-altitude observations. Really, this could be a very interesting mission, thanks mostly to that one instrument VIRTIS.

[Mode5]

Isn't radar imaging far more accurate than that of infra-red? I don't really expect to see too much from a layman's point of view. I hope I am completely wrong. It's a great idea they have to use some of the left over equipment from the Mars Express mission. I wonder if we have a little radar sitting in a back room some where we can "loan" them. (I know it's too late for that now.)