قالب وردپرس درنا توس
Home / Science / Planet Venus: Hope for a new mission in the hothouse world

Planet Venus: Hope for a new mission in the hothouse world



  Venus

Image copyright
NASA

The longstanding idea that Venus is geologically dead is a "myth," say scientists.

And new research is about to end this perception forever.

Continuing volcanic and tectonic activity (activity in the outer shell of the planet) suggests that the planet is very different from Earth, but very much alive.

Now scientists are building new narratives to explain the planet's landscape.

This includes an idea that suggests the existence of "toffee planets". This theory involves knowledge gained through the study of exoplanets.

The new ideas were discussed here at the 50th Lunar and Planet Science Conference (LPSC) in The Woodlands, Texas.

Astronomy Missions

Focusing on Mars The past few decades have changed our view of the geology of this planet.

In the meantime, researchers exploring the surface of Venus have relied heavily on data from Magellan ̵

1; a NASA mission that ended in 1994. A European mission, Venus Express, and a Japanese spacecraft, Akatsuki, have been involved since then, but both focus on atmospheric research.

After years of not feeling like a new mission, there is a sense that the turnaround could eventually turn.

The European Space Agency (Esa) is evaluating a Venus mission EnVision alongside two proposals for astronomy – Theseus and Spica. NASA is also proposed other concepts.

Early junior scientists are now choosing to be back in numbers. And scientists from other disciplines provide their know-how and bring new ideas.

Picture certificate
NASA

Caption

The Venus is covered by a thick carbon dioxide atmosphere

Venus is a hothouse world with a surface temperature of 500 ° C – hot enough to melt lead. But it is not just the heat that makes it inhospitable: The dense atmosphere of the planet has increased the surface pressure to 90 bar. That's the equivalent of what you would experience 900 meters under the sea.

But Venus and Earth were much more alike. "They probably started as twins, but they split up," Dr. Richard Ghail of Royal Holloway from the University of London, lead investigator at EnVision.

"The Earth has gained oxygen and life during this time, and has essentially a rather cold climate, while Venus has been getting hotter and drier over a long period of time."

Lost water

Like Mars, Venus also had In the past, you may have the right conditions for life. However, Ghail says that while the Red Planet could have hosted large surface waters for about 100 million years, Venus has been able to harbor oceans for more than a billion years in its early history.

How and when did she lose this? Water is just one of the puzzles scientists want to use to illuminate new missions. Fate could even represent an extreme future path for Earth.

The history of Venus exploration with robotic probes goes back more than 50 years. If the US is synonymous with exploring Mars, it was the Soviets who left their mark on our next neighbor in the 1960s, 70s and 80s.

Image copyright
NASA

Caption

Artwork: Early Venus has had oceans on its surface for more than a billion years

They launched nearly 30 probes on the planet, with multiple failures. However, the successful missions sent back important data, including images of the surface. One probe detected what a lightning bolt might be, while others analyzed rock samples that were basalts – similar to the general types found on Earth.

Part of the resurgent interest in Venus is focused on the nature of the geological character, activity continues, and what it can tell us about rocky planets in general.

Tectonic Activity

It is believed that Venus lacks plate tectonics, the process responsible for recycling the earth's crust. The notion that Venus has essentially been "dead" since the eruption of volcanism hundreds of millions of years ago is, however, mistaken for a growing number of researchers.

Many signs of tectonic activity on Earth, such as comb networks and faults, can be found on Venus.

Image copyright
NASA

Caption

The Soviet Venera 13 probe returned images from the surface

Dr. Ghail has found signs that Venus' crust is crumbling into blocks of 500-1,000 km in diameter, which move in much the same way that ice floats on an ocean, bumps and rubs against each other. The process is driven by convection (the process of heat transfer that pushes hotter material up and cooler, denser material down) in the cladding region below the crust.

"They move into the block next to them, and that moves Block next door, and so on, you can connect those things together and see that everything is moving towards Ishtar in the Northern Hemisphere," said the Royal Holloway Researchers to BBC News.

Ishtar Terra is one of the most important highland regions of Venus, sometimes referred to as the "continent".

"I think you take enough pack ice, you squeeze it in one place, thicken it and make a big plateau," Dr. Ghail.

Toffee Planet

Dr. Carolina K Byrne from the North Carolina State University says this idea fits well with a theory he developed about the relationship between the thickness of the lithosphere, the rigid outer shell of a planet, and its gravity.

"The basic thinking is that if you have a thicker layer on a lower gravity world, then we thought you had higher gravity – like a super-earth (a class of medium-sized planets around others Stars, but not seen in the solar system) – then this brittle layer would be proportionately thinner. "

He calculates that certain combinations of planetary mass, air pressure, and composition, and the distance of a planet to its star, can produce something that can be used as toffee. Planet is called where the lithosphere stands is very thin.

"For example, one of the ways lava might appear is that magma rises to a certain depth and finds its way through cracks or dikes, but if you do not have a thick layer … it will not It could be a larger mass, but it will not be concentrated, so you would not expect to find volcanic chains, "Dr. Byrne. 19659005 I think it might be quite thick, but in some parts of Venus, in the lowlands, the brittle layer might be quite thin. "

Under this scenario, the notion that crustal blocks move like pack ice is plausible, Dr. Byrne said, if selected, EnVision will wear a synthetic aperture radar to test some of these ideas.

" I think so That happens, other people believe that nothing happens. The other possibility is that it is really earth-like and really active. The only way to distinguish between them is with the radar. We do it routinely on Earth, so we take a Venus with an earth observation radar.

Follow Paul on Twitter.


Source link