NASA has announced that its next two Discovery program missions will have the same target world: Venus. The two missions, however, will have very different approaches to studying Earth's fiery twin. The plan is to gain important insights into how Venus became such a hellish world.
Venus is roughly the size of Earth and about 25 percent closer to the Sun than us. It is also a world of incredible heat with a mean surface temperature of 464°C (867°F), crushing pressures of over 90 atmospheres, and acid rain. But it might not have always been like this. With a similar size and composition, it could have been much closer to Earth's climate and atmosphere once upon a time.
So what happened? NASA’s two new missions – the first from the space agency to visit Venus in 30 years – as well as those from other agencies could provide crucial data to help us understand this planet better and possibly answer the question.
The first selected mission is DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging), an atmospheric spherical probe that will plunge through the planet's dense atmosphere collecting detailed measurements as it goes down.
The mission will also snap the first high-resolution images of the tesserae, large surface structures on Venus that have been likened to Earth’s continents. Because its atmosphere is so thick with opaque clouds of sulfuric acid it's impossible to see through to the planet's surface. Venus might have plate tectonics like our planet. So far, Earth is the only known world that possesses such a geological feature.
More on the Venusian geology will come from the second mission, VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy). Not only will it investigate if plate tectonics did take place, or are even still currently happening, it will also help establish if there are still active volcanos on Venus.
It will also create the most detailed 3D reconstruction of the surface of Venus yet. The thick cloud cover won't allow for direct imaging of the surface so this will be achieved with a synthetic aperture radar.
“It is astounding how little we know about Venus, but the combined results of these missions will tell us about the planet from the clouds in its sky through the volcanoes on its surface all the way down to its very core,” Tom Wagner, NASA’s Discovery Program scientist, said in a statement. “It will be as if we have rediscovered the planet.”
NASA is expected to award each mission roughly $500 million for their development and the expected launch dates are estimated to be between 2028 and 2030.
After launching its last mission to Venus in 1989, the Magellan orbiter, NASA's eyes turned to Mars in the search for extraterrestrial life and potentially habitable planets for the future. Despite scientists' best efforts, Venus has been relatively ignored for the last three decades. Now, the "Venus curse" has been broken, and some of Earth's fiery twin's secrets may be revealed.
“We’re revving up our planetary science program with intense exploration of a world that NASA hasn’t visited in over 30 years,” said Thomas Zurbuchen, NASA’s associate administrator for science. “Using cutting-edge technologies that NASA has developed and refined over many years of missions and technology programs, we’re ushering in a new decade of Venus to understand how an Earth-like planet can become a hothouse. Our goals are profound. It is not just understanding the evolution of planets and habitability in our own Solar System, but extending beyond these boundaries to exoplanets, an exciting and emerging area of research for NASA.”