Back to Venus with Vesper

While Venus is the same size as our Earth, its hellish surface environment makes it inhospitable to life. What went wrong with Venus? Now NASA is working on a new spacecraft called Vesper that could visit Venus, and try to get to the bottom of the question. Once launched, Vesper could begin orbiting Venus in March 2015. It would have a suite of instruments that would analyze the planet’s atmosphere over the course of two years.

Earth has a twin sister, and she’s gone bad.

The planet Venus is almost the same size as Earth, so it has been called Earth’s twin. It’s only about 30 percent closer to the sun than Earth, and at the dawn of the space age, scientists thought its cloudy atmosphere might hide a steamy jungle planet teeming with life. However, when the first American and Russian space probes visited Venus in the 1960s, it became clear that something had gone terribly wrong with the planet’s ability to support life.

The spacecraft revealed Venus as a searing desert, its waterless surface crushed under a thick atmosphere almost 100 times the pressure of Earth’s. The clouds that shroud the planet contain droplets of deadly sulfuric acid, not life-sustaining water. The surface temperature hovers around 800 degrees Fahrenheit, hot enough to melt lead. All known forms of life would be broiled alive.

Yet, both Venus and Earth may have had had similar climates shortly after they formed. “The big mystery Vesper will help answer is how these two similar worlds ended up with such different outcomes,” said Gordon Chin, Principal Investigator for the proposed mission at NASA’s Goddard Space Flight Center, Greenbelt, Md.

Vesper, the Latin name for “Evening Star” or Venus, is a proposed NASA Discovery-class mission that would increase our knowledge of what the planet’s atmosphere is made of and how it changes. Understanding the atmosphere of Venus will help scientists learn how a world that might have been a tropical Eden became instead a close approximation of Hell.



The many mysteries Vesper will investigate include:


Although the surface hardly rotates, the cloud tops swirl around the planet at over 200 miles per hour. This is called “superrotation,” and scientists want to understand what drives it.



The planet’s atmosphere is mostly carbon dioxide (CO2), which should get broken down by sunlight into carbon monoxide (CO) and oxygen. That’s not happening, at least not on a large scale, or scientists would have seen it by now. There must be some as yet unknown chemistry stabilizing the atmosphere.

Vesper will complement past and current missions to Venus like the European Space Agency’s Venus Express. That mission arrived at Venus on April 11, 2006, and will explore the planet for two Venus days, or 486 Earth days. Vesper could enter Venus orbit in March 2015. By observing the planet’s atmosphere at different times, scientists can get a more complete record of how the atmosphere is changing.


Original Source: NASA News Release