Was Venus habitable? A mission will investigate

NASA’s DAVINCI space mission, scheduled to launch in the early 2030s, aims to investigate whether Venus ever had continents and water oceans like Earth, as well as perhaps the other conditions necessary for existence. life.

Venus, a rocky planet like Earth and only slightly smaller in size and mass, is only slightly closer to the Sun than Earth (about 70% of the distance that separates us from the Sun). If we take the current state of the Earth as a reference, then Venus, due to its proximity to the Sun, would only be a little warmer than our world and most likely a good part of it would be habitable.

But, unfortunately, a colossal and unstoppable greenhouse effect took over this twin of the Earth, vaporized its seas and every other body of water, raised the temperature beyond what life is capable of withstanding and turned it into hell. which is today.

Now, the temperatures on its surface are so high that, for example, lead cannot exist in a solid state. The charred landscape is obscured by clouds of sulfuric acid. The thick atmosphere composed mostly of carbon dioxide has more than 90 times the pressure of Earth’s atmosphere, making its “air” near the surface behave more like a water-like fluid than a gas.

Many experts believe that before this monstrous greenhouse effect was established, Venus could have been very similar to Earth and potentially suitable for life, perhaps for more than a billion years.

DAVINCI, composed of a flyby craft and a descent probe, will focus on a mountainous region called Alpha Regio, a possible ancient continent.

Alfa Regio is one of the most striking points of Venus. Its terrain is similar in appearance to mountainous areas on Earth. DAVINCI will be the first mission to explore this terrain in detail and map its topography.

Although a few spacecraft passed through Venus’ atmosphere between 1970 and 1985, the DAVINCI probe will, if all goes well, be the first to extensively image this intriguing terrain taken from beneath Venus’s thick, opaque clouds.

The challenge is not easy. And not only because no spacecraft has crossed the atmosphere of Venus for decades and because that atmosphere tends to crush or melt its space visitors. One of the challenges is that little is known about the terrain on which the ship will land. Another is the way to get clear images in such a thick atmosphere.

To mitigate the problem of scarce data on the ground, scientists leading the DAVINCI mission began by using modern data analysis techniques to analyze data from decades-old missions to Venus. Its objective is to achieve an arrival on our neighboring planet knowing the terrain with the greatest level of detail possible. In this way, scientists will be able to make the most of the probe’s descent time to gather new information that will help answer long-standing questions about the evolutionary trajectory of Venus and why it diverged dramatically from that of Earth.

Between 1990 and 1994, NASA’s Magellan space probe, which orbited Venus, obtained radar and altimetry images of the surface, thereby mapping the topography of Alfa Regio. Recently, the DAVINCI mission team looked for more details in these maps, so scientists applied new techniques to analyze data from Magellan’s radar altimeter. They then supplemented this data with radar images taken three times from the former Arecibo Observatory in Puerto Rico, and used computer vision models to sift through the data and fill in information gaps at new scales (less than 1 kilometer). ).

As a result, scientists increased the resolution of Alfa Regio maps tenfold.

New and more detailed version of a map of the Alpha Regio region of Venus. To create the map, the DAVINCI mission science team reanalyzed, more efficiently, the radar altimeter data obtained by NASA’s Magallanes space probe in the early 1990s. It complemented this data with other radar data. collected on three occasions from the Arecibo Observatory in Puerto Rico. Finally, he used computer vision models to scrutinize graphical information and fill in information gaps. The colors on the map represent topography, with dark blues identifying low elevations and brown identifying high elevations. The red ellipse marks the area into which the DAVINCI descent probe will descend while collecting data from the environment on its way to the surface. (Image: Jim Garvin/NASA’s Goddard Space Flight Center)

The DAVINCI probe will begin photographing Alfa Regio, with the highest resolution to date, once it descends below the planet’s clouds, starting at about 40 kilometers altitude. But even there, gases in the atmosphere scatter light, just as they do at ground level, so these images will appear blurry.

DAVINCI scientists are working on a solution. Scientists recently reanalyzed old Venus image data using a new artificial intelligence technique that can sharpen the images and use them to make calculations to make three-dimensional topographic maps. Ultimately, this technique will help the mission team optimize DAVINCI images and maps of the Alpha Regio mountains. The improved images will provide scientists with the most detailed view of Venus’ surface yet achieved (just under 1 meter per pixel). And possibly this will allow us to detect ravines of fluvial origin, river beds and even rocks, for the first time in the history of the exploration of Venus. (Fountain: NCYT by Amazings)