Having made over 3,000 orbits of Venus over the past eight years, ESA’s Venus Express has (as of May 15) completed its science mission and is now in the final few months of its operational life. With a nothing-left-to-lose attitude, the spacecraft recently made a daring and risky dive down into the upper layers of the planet’s thick atmosphere, coming within 80 miles of Venus’ broiling surface on July 12 — that’s the closest any human-made spacecraft have gotten to Venus since the Soviet Vega balloon-and-lander missions of 1985!
As dangerous as it may have been for the spacecraft, Venus Express survived the encounter and grabbed some valuable data about the planet’s atmosphere along the way. It’s now working its way up to a higher altitude orbit, but there’s no escaping the fact that its fuel reserves are nearly depleted and it will soon be back on its way down into Venus’ atmosphere on a mission-ending, one-way trip.
Although similar in size to Earth, the planet-next-door Venus is typically perceived as a hellish inferno of caustic clouds, crushing pressures and kiln-like temperatures. And while those are indeed all very much the case, Venus has recently been found to have a cooler side too… although it’s 125 km (77 miles) up in its atmosphere.
Our neighboring planet Venus really is a world of extremes; searing surface temperatures, crushing air pressure, sulfuric acid clouds…Venus pretty much pushes the envelope on every aspect of rocky-planet existence. And now here’s one more thing that made scientists do a double-take: a shape-shifting vortex swirling around Venus’ south pole!
The presence of a cyclonic storm around Venus’ poles – both north and south – has been known since Mariner 10’s pass in 1974 and then afterwards during the Pioneer Venus mission when a downwardly-spiraling formation of clouds over the planet’s north pole was imaged in infrared. It wasn’t until ESA’s Venus Express orbiter arrived in 2006 that the cyclone at the south pole was directly observed via the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument…and it proved to be much stranger than anything previously expected. Read the rest of this entry
I haven’t posted anything yet about our other neighboring planet, Venus, mostly because the currently active mission exploring it, the European Space Agency’s Venus Express orbiter, hasn’t been updating much with new images since I’ve begun this site. Still, Venus deserves some attention, so here’s a quick byte of Venus info.
Possibly the most inhospitable of planets in our solar system, the “evening star” Venus is permanently enshrouded by thick yellowish-beige clouds. In order to see any cloud structure at all, images must be made in other wavelengths of light….infrared, or ultraviolet (above). In these wavelengths invisible to our eyes, the swirling structures of Venus’ atmosphere can be made out. And what an atmosphere it is! An example of greenhouse effect to the nth degree, our neighboring Venus is a virtual oven…its scorched, rocky surface baked by 800ºF + temperatures beneath the crushing weight of its own incredibly dense atmosphere, standing “sea level” on Venus would be like being hundreds of feet underwater, just in terms of pressure per square inch. And if the heat and pressure weren’t enough, the skies are full of clouds made of corrosive sulphuric acid as well, lit by bolts of lightning and and whipped by incredible planet-wide winds clocked in the hundreds of miles per hour. All Earth-based probes that landed there (such as the Soviet Venera-13, seen below) only lasted moments on the surface before they succumbed to Venus’ destructive environment.
Venus is, quite literally, a hellish place. And, oddly enough, it is the planet that most resembles Earth, in terms of size and composition. It’s an example of how being just that much closer to the sun, without the benefit of any carbon-dioxide processing life forms like Earth has developed, drastically changes an entire planet. I may not be the most militant tree-hugger but I do realize the unmistakable effect plant life has on our world. Venus shows us what Earth could have been. Quite easily. And very well could still become. And that’s why the ESA’s Venus Express mission is so important.
More images from the Venus Express mission here.
Image credit: ESA/MPS/DLR/IDA. Venera-13 image remapped by Don P. Mitchell.